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Hall M, Lanphear B, Chevrier J, Hornung R, Green R, Goodman C, Ayotte P, Martinez-Mier EA, Zoeller RT, Till C. Letter to the editor regarding Hall et al. (2023): Fluoride exposure and hypothyroidism in a Canadian pregnancy cohort. Sci Total Environ 2024:173121. [PMID: 38734092 DOI: 10.1016/j.scitotenv.2024.173121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/06/2024] [Accepted: 05/08/2024] [Indexed: 05/13/2024]
Affiliation(s)
- Meaghan Hall
- Psychology Department, York University, Toronto, ON, Canada.
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada.
| | - Jonathan Chevrier
- Department of Epidemiology, Biostatistics and Occupational Health, Faculty of Medicine and Health Sciences, School of Population and Global Health, McGill University, Montreal, QC, Canada.
| | - Rick Hornung
- Psychology Department, York University, Toronto, ON, Canada
| | - Rivka Green
- Psychology Department, York University, Toronto, ON, Canada
| | - Carly Goodman
- Psychology Department, York University, Toronto, ON, Canada.
| | - Pierre Ayotte
- Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec City, QC, Canada.
| | | | - R Thomas Zoeller
- Biology Department, The University of Massachusetts Amherst, Amherst, MA, United States.
| | - Christine Till
- Psychology Department, York University, Toronto, ON, Canada.
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Krzeczkowski JE, Hall M, McGuckin T, Lanphear B, Bertinato J, Ayotte P, Chevrier J, Goodman C, Green R, Till C. Erratum to Iodine status in a large Canadian pregnancy cohort. American Journal of Obstetrics & Gynecology MFM. Volume 5, Issue 1, January 2023, 100784. Am J Obstet Gynecol MFM 2024:101208. [PMID: 38604925 DOI: 10.1016/j.ajogmf.2023.101208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Affiliation(s)
- John E Krzeczkowski
- Department of Psychology, York University, 4700 Keele St., Toronto M3J 1P3, Canada (Krzeczkowski, Hall, McGuckin).
| | - Meaghan Hall
- Department of Psychology, York University, 4700 Keele St., Toronto M3J 1P3, Canada (Krzeczkowski, Hall, McGuckin)
| | - Taylor McGuckin
- Department of Psychology, York University, 4700 Keele St., Toronto M3J 1P3, Canada (Krzeczkowski, Hall, McGuckin)
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada (Lanphear)
| | - Jesse Bertinato
- Nutrition Research Division, Bureau of Nutritional Sciences, Health Products and Food Branch, Health Canada, Ottawa, Canada (Bertinato); Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada (Bertinato)
| | - Pierre Ayotte
- Faculty of Medicine, Department of Social and Preventive Medicine, Université Laval, Québec City, Canada (Ayotte)
| | - Jonathan Chevrier
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Canada (Chevrier)
| | - Carly Goodman
- Department of Psychology, York University, Toronto, Canada (Goodman, Green, Till)
| | - Rivka Green
- Department of Psychology, York University, Toronto, Canada (Goodman, Green, Till)
| | - Christine Till
- Department of Psychology, York University, Toronto, Canada (Goodman, Green, Till)
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Grandjean P, Meddis A, Nielsen F, Beck IH, Bilenberg N, Goodman CV, Hu H, Till C, Budtz-Jørgensen E. Dose dependence of prenatal fluoride exposure associations with cognitive performance at school age in three prospective studies. Eur J Public Health 2024; 34:143-149. [PMID: 37798092 PMCID: PMC10843960 DOI: 10.1093/eurpub/ckad170] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/07/2023] Open
Abstract
BACKGROUND Fluoride may be a developmental neurotoxicant at elevated exposures. We merged new data from a prospective Odense Child Cohort (OCC) with results from two previous birth cohort studies from Mexico and Canada to characterize the dose-effect relationship in greater detail. METHODS The OCC contributed 837 mother-child pairs to the total of >1500. We measured creatinine-adjusted urine-fluoride concentrations in maternal urine samples obtained during late pregnancy. Child IQ was determined at age 7 years using an abbreviated version of the Wechsler Intelligence Scales for Children. Findings from the three cohorts were used to calculate the joint benchmark concentration (BMC) and the lower confidence limit (BMCL) after adjustment for covariables. RESULTS In the OCC, urine-fluoride concentrations varied between 0.08 and 3.04 mg/l (median 0.52 mg/l) but were not significantly associated with full-scale IQ at age 7 years (β = 0.08; 95% confidence interval -1.14 to 1.30 for a doubling in exposure). No difference was apparent between boys and girls. In the OCC, the BMC was 0.92 mg/l, with a BMCL of 0.30 mg/l. The joint analysis of all three cohorts showed a statistically significant association between urine-fluoride and IQ, with a BMC of 0.45 mg/l (BMCL, 0.28 mg/l), slightly higher than the BMC previously reported for the two North American cohorts alone. CONCLUSIONS As the BMCL reflects an approximate threshold for developmental neurotoxicity, the results suggest that pregnant women and children may need protection against fluoride toxicity.
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Affiliation(s)
- Philippe Grandjean
- Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | | | - Flemming Nielsen
- Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark
| | - Iben H Beck
- Department of Environmental Medicine, University of Southern Denmark, Odense, Denmark
| | - Niels Bilenberg
- Department of Child and Adolescent Psychiatry, Odense University Hospital, Odense, Denmark
| | - Carly V Goodman
- Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada
| | - Howard Hu
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Christine Till
- Department of Psychology, Faculty of Health, York University, Toronto, ON, Canada
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Hall M, Hornung R, Chevrier J, Ayotte P, Lanphear B, Till C. Fluoride exposure and thyroid hormone levels in pregnancy: The MIREC cohort. Environ Int 2024; 184:108442. [PMID: 38237505 PMCID: PMC10973885 DOI: 10.1016/j.envint.2024.108442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 01/03/2024] [Accepted: 01/10/2024] [Indexed: 02/23/2024]
Abstract
BACKGROUND Fluoride exposure may increase the risk of hypothyroidism, but results from previous studies are inconsistent at low-level fluoride exposure (i.e., ≤0.7 mg/L). Human studies of fluoride and thyroid hormone levels in pregnancy are scarce. OBJECTIVES We examined associations between fluoride exposure and maternal thyroid hormone levels in a Canadian pregnancy cohort, with consideration for fetal sex-specific effects. METHODS We measured fluoride concentrations in drinking water and spot urine samples collected during each trimester from 1876 pregnant women enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) study. We also measured maternal thyroid stimulating hormone (TSH), free thyroxine (FT4), and total thyroxine (TT4) levels during the first trimester of pregnancy. We used linear and non-linear regression models to estimate associations between fluoride exposure and levels of TSH, FT4, and TT4. We explored effect modification by fetal sex and considered maternal iodine status as a potential confounder. RESULTS A 1 mg/L increase in urinary fluoride was associated with a 0.30 (95 %CI: 0.08, 0.51) logarithmic unit (i.e., 35.0 %) increase in TSH among women pregnant with females, but not males (B = 0.02; 95 %CI: -0.16, 0.19). Relative to women with urinary fluoride concentrations in the first quartile (0.05-0.32 mg/L), those with levels in the third quartile (0.49-0.75 mg/L) had higher FT4 and TT4 (i.e., inverted J-shaped associations), but the association was not statistically significant after adjustment for covariates (p = 0.06). Water fluoride concentration showed a U-shaped association with maternal FT4, whereby women with water fluoride concentrations in the second (0.13-0.52 mg/L) and third (0.52-0.62 mg/L) quartiles had significantly lower FT4 compared to those with levels in the first quartile (0.04-0.13 mg/L). Adjustment for maternal iodine status did not change the results. DISCUSSION Fluoride exposure was associated with alterations in maternal thyroid hormone levels, the magnitude of which appeared to vary by fetal sex. Given the importance of maternal thyroid hormones for fetal neurodevelopment, replication of findings is warranted.
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Affiliation(s)
- Meaghan Hall
- Psychology Department, York University, Toronto, ON, Canada.
| | - Rick Hornung
- Retired, Consultant to Psychology Department, York University, Toronto, ON, Canada.
| | - Jonathan Chevrier
- School of Population and Global Health, McGill University, Montreal, QC, Canada.
| | - Pierre Ayotte
- Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec City, QC, Canada.
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada.
| | - Christine Till
- Psychology Department, York University, Toronto, ON, Canada.
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Krzeczkowski JE, Hall M, Saint-Amour D, Oulhote Y, McGuckin T, Goodman CV, Green R, Muckle G, Lanphear B, Till C. Prenatal fluoride exposure, offspring visual acuity and autonomic nervous system function in 6-month-old infants. Environ Int 2024; 183:108336. [PMID: 38064923 PMCID: PMC10981044 DOI: 10.1016/j.envint.2023.108336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 11/10/2023] [Accepted: 11/17/2023] [Indexed: 01/25/2024]
Abstract
BACKGROUND Prenatal fluoride exposure can have adverse effects on children's development; however, associations with visual and cardiac autonomic nervous system functioning are unknown. We examined associations between prenatal fluoride exposure and visual acuity and heart rate variability (HRV) in 6-month-old infants. METHODS We used data from Canadian mother-infant pairs participating in the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort. We estimated prenatal fluoride exposure using: i) fluoride concentration in drinking water (mg/L), ii) maternal urinary fluoride adjusted for specific gravity (MUFSG; mg/L) and averaged across pregnancy, and iii) maternal fluoride intake (µg/kg/day) from consumption of water, tea, and coffee, adjusted for maternal body weight (kg). We used multivariable linear regression to examine associations between each measure of fluoride exposure and Teller Acuity Card visual acuity scores (n = 435) and assessed HRV (n = 400) using two measures: root mean square of successive differences (RMSSD) and the standard deviation of N-N intervals (SDNN) measured at 6-months of age. RESULTS Median (IQR) values for water fluoride, MUFSG, and daily fluoride intake were 0.20 (IQR: 0.13-0.56) mg/L; 0.44 (0.28-0.70) mg/L and 4.82 (2.58-10.83) µg/kg/day, respectively. After adjustment for confounding variables, water fluoride concentration was associated with poorer infant visual acuity (B = -1.51; 95 % CI: -2.14,-0.88) and HRV as indicated by lower RMSSD (B = -1.60; 95 % CI: -2.74,-0.46) but not SDNN. Maternal fluoride intake was also associated with poorer visual acuity (B = -0.82; 95 % CI: -1.35,-0.29) and lower RMSSD (B = -1.22; 95 % CI: -2.15,-0.30). No significant associations were observed between MUFSG and visual acuity or HRV. CONCLUSION Fluoride in drinking water was associated with reduced visual acuity and alterations in cardiac autonomic function in infancy, adding to the growing body of evidence suggesting fluoride's developmental neurotoxicity.
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Affiliation(s)
- John E Krzeczkowski
- Department of Health Sciences, Brock University, St. Catharines, Ontario, Canada.
| | - Meaghan Hall
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Dave Saint-Amour
- Faculté de médecine - Département d'ophtalmologie, Université de Montréal, Montréal, Québec, Canada
| | - Youssef Oulhote
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sina, New York, NY, USA
| | - Taylor McGuckin
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Carly V Goodman
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Rivka Green
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Gina Muckle
- Centre de recherche du CHU de Québec-Université Laval, Québec, Canada; École de Psychologie, Université Laval, Québec, Québec, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
| | - Christine Till
- Department of Psychology, York University, Toronto, Ontario, Canada
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Goodman CV, Green R, DaCosta A, Flora D, Lanphear B, Till C. Sex difference of pre- and post-natal exposure to six developmental neurotoxicants on intellectual abilities: a systematic review and meta-analysis of human studies. Environ Health 2023; 22:80. [PMID: 37978510 PMCID: PMC10655280 DOI: 10.1186/s12940-023-01029-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 10/26/2023] [Indexed: 11/19/2023]
Abstract
BACKGROUND Early life exposure to lead, mercury, polychlorinated biphenyls (PCBs), polybromide diphenyl ethers (PBDEs), organophosphate pesticides (OPPs), and phthalates have been associated with lowered IQ in children. In some studies, these neurotoxicants impact males and females differently. We aimed to examine the sex-specific effects of exposure to developmental neurotoxicants on intelligence (IQ) in a systematic review and meta-analysis. METHOD We screened abstracts published in PsychINFO and PubMed before December 31st, 2021, for empirical studies of six neurotoxicants (lead, mercury, PCBs, PBDEs, OPPs, and phthalates) that (1) used an individualized biomarker; (2) measured exposure during the prenatal period or before age six; and (3) provided effect estimates on general, nonverbal, and/or verbal IQ by sex. We assessed each study for risk of bias and evaluated the certainty of the evidence using Navigation Guide. We performed separate random effect meta-analyses by sex and timing of exposure with subgroup analyses by neurotoxicant. RESULTS Fifty-one studies were included in the systematic review and 20 in the meta-analysis. Prenatal exposure to developmental neurotoxicants was associated with decreased general and nonverbal IQ in males, especially for lead. No significant effects were found for verbal IQ, or postnatal lead exposure and general IQ. Due to the limited number of studies, we were unable to analyze postnatal effects of any of the other neurotoxicants. CONCLUSION During fetal development, males may be more vulnerable than females to general and nonverbal intellectual deficits from neurotoxic exposures, especially from lead. More research is needed to examine the nuanced sex-specific effects found for postnatal exposure to toxic chemicals.
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Affiliation(s)
- Carly V Goodman
- Faculty of Health, York University, Toronto, M3J 1P3, ON, Canada.
| | - Rivka Green
- Faculty of Health, York University, Toronto, M3J 1P3, ON, Canada
| | - Allya DaCosta
- Faculty of Health, York University, Toronto, M3J 1P3, ON, Canada
| | - David Flora
- Faculty of Health, York University, Toronto, M3J 1P3, ON, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, BC, Canada
| | - Christine Till
- Faculty of Health, York University, Toronto, M3J 1P3, ON, Canada
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Goodman CV, Till C, Green R, El-Sabbagh J, Arbuckle TE, Hornung R, Lanphear B, Seguin JR, Booij L, Fisher M, Muckle G, Bouchard MF, Ashley-Martin J. Prenatal exposure to legacy PFAS and neurodevelopment in preschool-aged Canadian children: The MIREC cohort. Neurotoxicol Teratol 2023; 98:107181. [PMID: 37178772 PMCID: PMC10979774 DOI: 10.1016/j.ntt.2023.107181] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 04/04/2023] [Accepted: 05/09/2023] [Indexed: 05/15/2023]
Abstract
BACKGROUND Exposure to perfluoroalkyl substances (PFAS) has been shown to be neurotoxic in experimental studies, but epidemiological evidence linking prenatal PFAS exposure to child neurodevelopment is equivocal and scarce. OBJECTIVE To quantify associations between prenatal exposure to legacy PFAS and children's intelligence (IQ) and executive functioning (EF) in a Canadian pregnancy and birth cohort and to determine if these associations differ by child sex. METHODS We measured first-trimester plasma concentrations of perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and perfluorohexanesulfonic acid (PFHxS) in the Maternal-Infant Research on Environmental Chemicals (MIREC) study and assessed children's full-scale (n = 522), performance (n = 517), and verbal (n = 519) IQ using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III). Children's working memory (n = 513) and ability to plan and organize (n = 514) were assessed using a parent-reported questionnaire, the Behavior Rating Inventory of Executive Function - Preschool Version (BRIEF-P). We quantified associations between individual log2-transformed PFAS exposure and children's IQ and EF using multiple linear regression analyses and evaluated effect modification by child sex. We also used Repeated Holdout Weighted Quantile Sum (WQS) regression models with effect modification by child sex to quantify the effect of combined exposure to all three PFAS chemicals on IQ and EF. All models were adjusted for key sociodemographic characteristics. RESULTS Geometric mean plasma concentrations (IQR) for PFOA, PFOS and PFHxS were 1.68 (1.10-2.50), 4.97 (3.20-6.20) and 1.09 (0.67-1.60) μg/L respectively. We found evidence of effect modification by child sex in all models examining performance IQ (p < .01). Specifically, every doubling of PFOA, PFOS, and or PFHxS was inversely associated with performance IQ, but only in males (PFOA: B = -2.80, 95% CI: -4.92, -0.68; PFOS: B = -2.64, 95% CI: -4.77, -0.52; PFHxS: B = -2.92, 95% CI: -4.72, -1.12). Similarly, every quartile increase in the WQS index was associated with poorer performance IQ in males (B = -3.16, 95% CI: -4.90, -1.43), with PFHxS contributing the largest weight to the index. In contrast, no significant association was found for females (B = 0.63, 95% CI: -0.99, 2.26). No significant associations were found for EF in either males or females. CONCLUSIONS Higher prenatal PFAS exposure was associated with lower performance IQ in males, suggesting that this association may be sex- and domain-specific.
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Affiliation(s)
- Carly V Goodman
- Department of Psychology, York University, Toronto, ON, Canada
| | - Christine Till
- Department of Psychology, York University, Toronto, ON, Canada.
| | - Rivka Green
- Department of Psychology, York University, Toronto, ON, Canada
| | - Jana El-Sabbagh
- Department of Psychology, York University, Toronto, ON, Canada
| | - Tye E Arbuckle
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children's Hospital Medical Center (retired), United States
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Jean R Seguin
- CHU Sainte-Justine Research Centre and Department of Psychiatry, School of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Linda Booij
- CHU Sainte-Justine Research Centre and Department of Psychiatry, School of Medicine, Université de Montréal, Montreal, QC, Canada; Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montreal, QC, Canada
| | - Mandy Fisher
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Gina Muckle
- École de psychologie, Université Laval, Centre de recherche du CHU de Québec-Université Laval, Montreal, QC, Canada
| | - Maryse F Bouchard
- CHU Sainte-Justine Research Centre and Department of Environmental and Occupational Health, School of Public Health, Université de Montréal, Montreal, QC, Canada; Institut national de la recherche scientifique, Université du Quebec, Quebec City, QC, Canada
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Hall M, Lanphear B, Chevrier J, Hornung R, Green R, Goodman C, Ayotte P, Martinez-Mier EA, Zoeller RT, Till C. Fluoride exposure and hypothyroidism in a Canadian pregnancy cohort. Sci Total Environ 2023; 869:161149. [PMID: 36764861 PMCID: PMC9992168 DOI: 10.1016/j.scitotenv.2022.161149] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 12/19/2022] [Accepted: 12/19/2022] [Indexed: 06/18/2023]
Abstract
BACKGROUND While fluoride can have thyroid-disrupting effects, associations between low-level fluoride exposure and thyroid conditions remain unclear, especially during pregnancy when insufficient thyroid hormones can adversely impact offspring development. OBJECTIVES We evaluated associations between fluoride exposure and hypothyroidism in a Canadian pregnancy cohort. METHODS We measured fluoride concentrations in drinking water and three dilution-corrected urine samples and estimated fluoride intake based on self-reported beverage consumption. We classified women enrolled in the Maternal-Infant Research on Environmental Chemicals Study as euthyroid (n = 1301), subclinical hypothyroid (n = 100) or primary hypothyroid (n = 107) based on their thyroid hormone levels in trimester one. We used multinomial logistic regression to estimate the association between fluoride exposure and classification of either subclinical or primary hypothyroidism and considered maternal thyroid peroxidase antibody (TPOAb) status, a marker of autoimmune hypothyroidism, as an effect modifier. In a subsample of 466 mother-child pairs, we used linear regression to explore the association between maternal hypothyroidism and child Full-Scale IQ (FSIQ) at ages 3-to-4 years and tested for effect modification by child sex. RESULTS A 0.5 mg/L increase in drinking water fluoride concentration was associated with a 1.65 (95 % confidence interval [CI]: 1.04, 2.60) increased odds of primary hypothyroidism. In contrast, we did not find a significant association between urinary fluoride (adjusted odds ratio [aOR]: 1.00; 95%CI: 0.73, 1.39) or fluoride intake (aOR: 1.25; 95%CI: 0.99, 1.57) and hypothyroidism. Among women with normal TPOAb levels, the risk of primary hypothyroidism increased with both increasing water fluoride and fluoride intake (aOR water fluoride concentration: 2.85; 95%CI: 1.25, 6.50; aOR fluoride intake: 1.75; 95%CI: 1.27, 2.41). Children born to women with primary hypothyroidism had lower FSIQ scores compared to children of euthyroid women, especially among boys (B coefficient: -8.42; 95 % CI: -15.33, -1.50). DISCUSSION Fluoride in drinking water was associated with increased risk of hypothyroidism in pregnant women. Thyroid disruption may contribute to developmental neurotoxicity of fluoride.
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Affiliation(s)
- Meaghan Hall
- Psychology Department, York University, Toronto, ON, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Jonathan Chevrier
- School of Population and Global Health, McGill University, Montreal, QC, Canada
| | - Rick Hornung
- Retired; Consultant to Psychology Department, York University, Toronto, ON, Canada
| | - Rivka Green
- Psychology Department, York University, Toronto, ON, Canada
| | - Carly Goodman
- Psychology Department, York University, Toronto, ON, Canada
| | - Pierre Ayotte
- Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec City, QC, Canada
| | | | - R Thomas Zoeller
- Biology Department, The University of Massachusetts Amherst, Amherst, MA, United States
| | - Christine Till
- Psychology Department, York University, Toronto, ON, Canada.
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Farmus L, Till C, Green R, Hornung R, Martinez-Mier EA, Ayotte P, Muckle G, Lanphear B, Flora D. Critical windows of fluoride neurotoxicity in Canadian children by Farmus and colleagues - In reply to Guichon et al. (2022). Environ Res 2023:115201. [PMID: 36709871 DOI: 10.1016/j.envres.2022.115201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 12/30/2022] [Indexed: 06/18/2023]
Affiliation(s)
- Linda Farmus
- Department of Psychology, York University, Toronto, Canada
| | - Christine Till
- Department of Psychology, York University, Toronto, Canada
| | - Rivka Green
- Department of Psychology, York University, Toronto, Canada
| | - Richard Hornung
- Consultant to Psychology Department, York University, Toronto, ON, Canada
| | | | - Pierre Ayotte
- Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec City, QC, Canada
| | - Gina Muckle
- Centre de Recherche Du CHU de Québec, Université Laval, School of Psychology, Université Laval, Québec, QC, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada
| | - David Flora
- Department of Psychology, York University, Toronto, Canada
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Farmus L, Till C, Green R, Hornung R, Martinez-Mier EA, Ayotte P, Muckle G, Lanphear B, Flora D. Critical windows of fluoride neurotoxicity in Canadian children by Farmus and colleagues - In reply to Wood et al. (2023). Environ Res 2023:115299. [PMID: 36709876 DOI: 10.1016/j.envres.2023.115299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 01/11/2023] [Indexed: 06/18/2023]
Affiliation(s)
- Linda Farmus
- Department of Psychology, York University, Toronto, Canada
| | - Christine Till
- Department of Psychology, York University, Toronto, Canada
| | - Rivka Green
- Department of Psychology, York University, Toronto, Canada
| | - Richard Hornung
- Consultant to Psychology Department, York University, Toronto, ON, Canada
| | | | - Pierre Ayotte
- Department of Social and Preventive Medicine, Faculty of Medicine, Université Laval, Québec City, QC, Canada
| | - Gina Muckle
- Centre de Recherche Du CHU de Québec, Université Laval, Québec City, QC, Canada; School of Psychology, Université Laval, Québec, QC, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada
| | - David Flora
- Department of Psychology, York University, Toronto, Canada
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Krzeczkowski JE, Hall M, McGuckin T, Lanphear B, Bertinato J, Ayotte P, Chevrier J, Goodman C, Green R, Till C. Iodine status in a large Canadian pregnancy cohort. Am J Obstet Gynecol MFM 2023; 5:100784. [PMID: 36280147 PMCID: PMC9972225 DOI: 10.1016/j.ajogmf.2022.100784] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 10/18/2022] [Indexed: 11/09/2022]
Affiliation(s)
- John E Krzeczkowski
- Department of Psychology, York University, 4700 Keele St., Toronto M3J 1P3, Canada.
| | - Meaghan Hall
- Department of Psychology, York University, 4700 Keele St., Toronto M3J 1P3, Canada
| | - Taylor McGuckin
- Department of Psychology, York University, 4700 Keele St., Toronto M3J 1P3, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, Canada
| | - Jesse Bertinato
- Nutrition Research Division, Bureau of Nutritional Sciences, Health Products and Food Branch, Health Canada, Ottawa, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Canada
| | - Pierre Ayotte
- Faculty of Medicine, Department of Social and Preventive Medicine, Université Laval, Québec City, Canada
| | - Jonathan Chevrier
- Department of Epidemiology, Biostatistics and Occupational Health, McGill University, Montréal, Canada
| | - Carly Goodman
- Department of Psychology, York University, Toronto, Canada
| | - Rivka Green
- Department of Psychology, York University, Toronto, Canada
| | - Christine Till
- Department of Psychology, York University, Toronto, Canada
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Farmus L, Till C, Green R, Hornung R, Martinez Mier EA, Ayotte P, Muckle G, Lanphear BP, Flora DB. ADDENDUM: Critical windows of fluoride neurotoxicity in Canadian Children. Environ Res 2022; 215:114468. [PMID: 37310286 DOI: 10.1016/j.envres.2022.114468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Affiliation(s)
- Linda Farmus
- Faculty of Health, York University, Ontario, Canada
| | | | - Rivka Green
- Faculty of Health, York University, Ontario, Canada
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - E Angeles Martinez Mier
- Department of Cardiology, Operative Dentistry and Dental Public Health, Indiana University School of Dentistry, Indiana, USA
| | - Pierre Ayotte
- Centre de Recherche Du CHU de Qúebec, Université Laval, Quebec, Canada
- Department of Social and Preventive Medicine, Laval University, Quebec, Canada
| | - Gina Muckle
- Centre de Recherche Du CHU de Qúebec, Université Laval, Quebec, Canada
- School of Psychology, Laval University, Quebec, Canada
| | - Bruce P Lanphear
- Faculty of Health Sciences, Simon Fraser University, British Columbia, Canada
- Child & Family Research Institute, BC Children's Hospital, University of British Columbia, British Columbia, Canada
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13
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Shaffer RM, Forsyth JE, Ferraro G, Till C, Carlson LM, Hester K, Haddock A, Strawbridge J, Lanfear CC, Hu H, Kirrane E. Lead exposure and antisocial behavior: A systematic review protocol. Environ Int 2022; 168:107438. [PMID: 35994796 DOI: 10.1016/j.envint.2022.107438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 07/19/2022] [Accepted: 07/25/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Lead exposure remains highly prevalent worldwide despite decades of research highlighting its link to numerous adverse health outcomes. In addition to well-documented effects on cognition, there is growing evidence of an association with antisocial behavior, including aggression, conduct problems, and crime. An updated systematic review on this topic, incorporating study evaluation and a developmental perspective on the outcome, can advance the state of the science on lead and inform global policy interventions to reduce exposure. OBJECTIVES We aim to evaluate the link between lead exposure and antisocial behavior. This association will be investigated via a systematic review of human epidemiological and experimental nonhuman mammalian studies. METHODS The systematic review protocol presented in this publication is informed by recommendations for the conduct of systematic reviews in toxicology and environmental health research (COSTER) and follows the study evaluation approach put forth by the U.S. EPA Integrated Risk Information System (IRIS) program. DATA SOURCES We will search the following electronic databases for relevant literature: PubMed, BIOSIS and Web of Science. Search results will be stored in EPA's Health and Environmental Research Online (HERO) database. STUDY ELIGIBILITY AND CRITERIA Eligible human epidemiological studies will include those evaluating any population exposed to lead at any lifestage via ingestion or inhalation exposure and considering an outcome of antisocial behavior based on any of the following criteria: psychiatric diagnoses (e.g., oppositional defiant disorder (ODD), conduct disorder (CD), disruptive behavior disorders (DBD)); violation of social norms (e.g., delinquency, criminality); and aggression. Eligible experimental animal studies will include those evaluating nonhuman mammalian studies exposed to lead via ingestion, inhalation, or injection exposure during any lifestage. The following outcomes will be considered relevant: aggression; antisocial behavior; and altered fear, anxiety, and stress response. STUDY APPRAISAL AND SYNTHESIS METHODS Screening will be conducted with assistance from an artificial intelligence application. Two independent reviewers for each data stream (human, animal) will screen studies with highest predicted relevance against pre-specified inclusion criteria at the title/abstract and full-text level. Study evaluation will be conducted using methods adapted from the U.S. EPA IRIS program. After data extraction, we will conduct a narrative review and quantitative meta-analysis on the human epidemiological studies as well as a narrative review of the experimental animal studies. We will evaluate the strength of each evidence stream separately and then will develop a summary evidence integration statement based on inference across evidence streams.
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Affiliation(s)
- Rachel M Shaffer
- US Environmental Protection Agency, Center for Public Health and Environmental Assessment, Washington, DC, and Research Triangle Park, NC, United States
| | - Jenna E Forsyth
- Stanford University, Woods Institute for the Environment, Stanford, CA, United States
| | - Greg Ferraro
- North Carolina State University, Raleigh, NC, United States
| | | | - Laura M Carlson
- US Environmental Protection Agency, Center for Public Health and Environmental Assessment, Washington, DC, and Research Triangle Park, NC, United States
| | - Kirstin Hester
- US Environmental Protection Agency, Center for Public Health and Environmental Assessment, Washington, DC, and Research Triangle Park, NC, United States
| | - Amanda Haddock
- US Environmental Protection Agency, Center for Public Health and Environmental Assessment, Washington, DC, and Research Triangle Park, NC, United States
| | - Jenna Strawbridge
- Oak Ridge Associated Universities, US Environmental Protection Agency, Center for Public Health and Environmental Assessment, Research Triangle Park, NC, United States
| | - Charles C Lanfear
- Nuffield College, University of Oxford, Oxford, England, United Kingdom
| | - Howard Hu
- Department of Population and Public Health Sciences, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Ellen Kirrane
- US Environmental Protection Agency, Center for Public Health and Environmental Assessment, Washington, DC, and Research Triangle Park, NC, United States.
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14
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Goodman CV, Bashash M, Green R, Song P, Peterson KE, Schnaas L, Mercado-García A, Martínez-Medina S, Hernández-Avila M, Martinez-Mier A, Téllez-Rojo MM, Hu H, Till C. Domain-specific effects of prenatal fluoride exposure on child IQ at 4, 5, and 6-12 years in the ELEMENT cohort. Environ Res 2022; 211:112993. [PMID: 35276192 PMCID: PMC9890727 DOI: 10.1016/j.envres.2022.112993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 02/13/2022] [Accepted: 02/19/2022] [Indexed: 05/17/2023]
Abstract
OBJECTIVE Prenatal exposure to fluoride has been associated with adverse neurodevelopmental outcomes. However, the neuropsychological profile of fluoride's developmental neurotoxicity at low levels and the stability of this relationship across childhood has not been characterized. We investigated the longitudinal and domain specific effect of prenatal fluoride exposure on IQ among children ages 4, 5, and 6-12 years in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort. METHODS We measured the average of maternal urinary fluoride at each trimester of pregnancy adjusted for creatinine (MUFCRE). Children were administered the McCarthy Scales of Children's Abilities at ages 4 (N = 386) and 5 (N = 308), and the Wechsler Abbreviated Scale of Intelligence at age 6-12 (N = 278). We used generalized estimating equation (GEE) models to estimate the population averaged effect of MUFCRE concentration on longitudinal General Cognitive Index (GCI)/Full-Scale IQ (FSIQ), Verbal IQ (VIQ), and Performance IQ (PIQ) scores (N = 348). We tested for possible interactions between MUFCRE and child sex as well as for MUFCRE and time point on children's IQ. All models controlled for relevant available covariates. RESULTS The mean/median MUFCRE concentration was 0.90/0.83 mg/L (SD = 0.39; IQR, 0.64-1.11 mg/L). A 0.5 mg/L increase in MUFCRE predicted an average 2.12-point decrease in GCI/FSIQ (95% CI: -3.49, -0.75) and 2.63-point decrease in PIQ (95% CI: -3.87, -1.40). MUFCRE was marginally associated with VIQ across time (B = -1.29, 95% CI: -2.60, 0.01). No interactions between MUFCRE and child sex or MUFCRE and time were observed. CONCLUSION The negative association between prenatal fluoride exposure and longitudinal IQ was driven by decrements in non-verbal intelligence (i.e. PIQ), suggesting that visual-spatial and perceptual reasoning abilities may be more impacted by prenatal fluoride exposure as compared to verbal abilities.
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Affiliation(s)
- Carly V Goodman
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Morteza Bashash
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Rivka Green
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Peter Song
- School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Karen E Peterson
- School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | | | | | | | | | | | | | - Howard Hu
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Christine Till
- Faculty of Health, York University, Toronto, Ontario, Canada
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15
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Goodman CV, Hall M, Green R, Chevrier J, Ayotte P, Martinez-Mier EA, McGuckin T, Krzeczkowski J, Flora D, Hornung R, Lanphear B, Till C. Iodine Status Modifies the Association between Fluoride Exposure in Pregnancy and Preschool Boys' Intelligence. Nutrients 2022; 14:2920. [PMID: 35889877 PMCID: PMC9319869 DOI: 10.3390/nu14142920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 12/07/2022] Open
Abstract
In animal studies, the combination of in utero fluoride exposure and low iodine has greater negative effects on offspring learning and memory than either alone, but this has not been studied in children. We evaluated whether the maternal urinary iodine concentration (MUIC) modifies the association between maternal urinary fluoride (MUF) and boys' and girls' intelligence. We used data from 366 mother-child dyads in the Maternal-Infant Research on Environmental Chemicals Study. We corrected trimester-specific MUF and MUIC for creatinine, and averaged them to yield our exposure variables (MUFCRE, mg/g; MUICCRE, µg/g). We assessed children's full-scale intelligence (FSIQ) at 3 to 4 years. Using multiple linear regression, we estimated a three-way interaction between MUFCRE, MUICCRE, and child sex on FSIQ, controlling for covariates. The MUICCRE by MUFCRE interaction was significant for boys (p = 0.042), but not girls (p = 0.190). For boys whose mothers had low iodine, a 0.5 mg/g increase in MUFCRE was associated with a 4.65-point lower FSIQ score (95% CI: -7.67, -1.62). For boys whose mothers had adequate iodine, a 0.5 mg/g increase in MUFCRE was associated with a 2.95-point lower FSIQ score (95% CI: -4.77, -1.13). These results suggest adequate iodine intake during pregnancy may minimize fluoride's neurotoxicity in boys.
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Affiliation(s)
- Carly V. Goodman
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - Meaghan Hall
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - Rivka Green
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - Jonathan Chevrier
- Department of Epidemiology, Biostatistics, and Occupational Health, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC H3A 1G1, Canada;
| | - Pierre Ayotte
- Département de Médecine Sociale et Préventive, Faculté de Médecine, Université Laval, Québec, QC G1V 0A6, Canada;
| | - Esperanza Angeles Martinez-Mier
- Cariology, Operative Dentistry and Dental Public Health, Indiana University School of Dentistry, Indianapolis, IN 46202, USA;
| | - Taylor McGuckin
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - John Krzeczkowski
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - David Flora
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA;
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, BC V5A 1S6, Canada;
| | - Christine Till
- Department of Psychology, York University, Toronto, ONT M3J 1P3, Canada; (C.V.G.); (M.H.); (R.G.); (T.M.); (J.K.); (D.F.)
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16
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Green R, Lanphear B, Phipps E, Goodman C, Joy J, Rihani S, Flora D, Till C. Development and Validation of the Prevention of Toxic Chemicals in the Environment for Children Tool: A Questionnaire for Examining the Community's Knowledge of and Preferences Toward Toxic Chemicals and Children's Brain Development. Front Public Health 2022; 10:863071. [PMID: 35646798 PMCID: PMC9130721 DOI: 10.3389/fpubh.2022.863071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/14/2022] [Indexed: 11/13/2022] Open
Abstract
Early-life exposures to toxic chemicals can adversely impact brain development. Understanding people's knowledge of the impact of toxic chemicals on brain development is critical to reduce widespread exposure to chemicals. Yet it is unknown what people know about risks of toxic chemicals and how to reduce exposures. We developed and validated the questionnaire, PRevention of Toxic chemicals in the Environment for Children Tool (PRoTECT), to examine people's knowledge and attitudes about the influence of toxic chemicals on child development. We used best practices for developing and validating scales. First, we drafted items to assess knowledge of the impact of toxic chemicals on brain development, levels of concern regarding exposures, and preferences for prevention of neurodevelopmental disorders. Second, we received feedback on item clarity from five focus groups consisting of 46 community participants. In addition, 17 experts completed a content validity scale for each item and provided qualitative feedback. We administered the revised 18-item questionnaire to 190 participants of child-bearing age for scale development, and using exploratory factor analysis, we found evidence for a four-factor model of PRoTECT, RMSR = 0.05, of which 16 of the 18 items had adequate content validity with loadings >0.40 on a derived factor. We discuss future directions and applications of PRoTECT.
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Affiliation(s)
- Rivka Green
- Department of Psychology, York University, Toronto, ON, Canada
| | - Bruce Lanphear
- Faculty of Health, Simon Fraser University, Burnaby, BC, Canada
| | - Erica Phipps
- Prenatal Environmental Health Education (PEHE) Collaboration, University of Ottawa, Ottawa, ON, Canada
| | - Carly Goodman
- Department of Psychology, York University, Toronto, ON, Canada
| | - Jasmine Joy
- Department of Psychology, York University, Toronto, ON, Canada
| | - Samer Rihani
- Faculty of Health, Simon Fraser University, Burnaby, BC, Canada
| | - David Flora
- Department of Psychology, York University, Toronto, ON, Canada
| | - Christine Till
- Department of Psychology, York University, Toronto, ON, Canada
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17
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Goodman C, Hall M, Green R, Hornung R, Martinez-Mier EA, Lanphear B, Till C. Maternal fluoride exposure, fertility and birth outcomes: The MIREC cohort. Environ Adv 2022; 7:100135. [PMID: 36644332 PMCID: PMC9837859 DOI: 10.1016/j.envadv.2021.100135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
OBJECTIVE Fluoride exposure >1.5 mg/L from water has been associated with adverse pregnancy and birth outcomes. Little is known, however, about the effect of fluoride at levels consistent with water fluoridation (i.e., 0.7 mg/L) on pregnancy and birth outcomes. We examined the relationship between maternal fluoride exposure, fertility, and birth outcomes in a Canadian pregnancy cohort living in areas where municipal drinking water fluoride concentrations ranged from 0.04 to 0.87 mg/L. METHODS Using data from the Maternal-Infant Research on Environmental Chemicals (MIREC) study, we estimated fluoride exposure during pregnancy using three different metrics: (1) maternal urinary fluoride concentrations standardized for specific gravity (MUFSG) and averaged across all three trimesters (N = 1566), (2) water fluoride concentration (N = 1370), and (3) fluoride intake based on self-reported consumption of water, coffee, and tea, adjusted for body weight (N = 1192). Data on fertility, birth weight, gestational age, preterm birth, and small-for-gestational age (SGA) were assessed. We used multiple linear regression to examine associations between fluoride exposure, birth weight and gestational age, and logistic regression to examine associations with fertility, preterm birth, and SGA, adjusted for relevant covariates. RESULTS Median (IQR) MUFSG was 0.50 (0.33-0.76) mg/L, median water fluoride was 0.52 (0.17-0.64) mg/L, and median fluoride intake was 0.008 (0.003-0.013) mg/kg/day. MUFSG, water fluoride concentrations, and fluoride intake were not significantly associated with fertility, birth weight, gestational age, preterm birth, or SGA. Fetal sex did not modify any of the associations. CONCLUSION Fluoride exposure during pregnancy was not associated with fertility or birth outcomes in this Canadian cohort.
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Affiliation(s)
- Carly Goodman
- Department of Psychology, Faculty of Health, York University, 4700 Keele St, Toronto, Ontario M3J 1P3, Canada
| | - Meaghan Hall
- Department of Psychology, Faculty of Health, York University, 4700 Keele St, Toronto, Ontario M3J 1P3, Canada
| | - Rivka Green
- Department of Psychology, Faculty of Health, York University, 4700 Keele St, Toronto, Ontario M3J 1P3, Canada
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | | | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Christine Till
- Department of Psychology, Faculty of Health, York University, 4700 Keele St, Toronto, Ontario M3J 1P3, Canada
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18
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Riddell JK, Malin AJ, Flora D, McCague H, Till C. Corrigendum to Association of water fluoride and urinary fluoride concentrations with attention deficit hyperactivity disorder in Canadian youth. Environ Int 2022; 161:107091. [PMID: 35085934 DOI: 10.1016/j.envint.2022.107091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Affiliation(s)
| | - Ashley J Malin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - David Flora
- Faculty of Health, York University, Ontario, Canada
| | - Hugh McCague
- Institute for Social Research, York University, Ontario, Canada
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19
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Grandjean P, Hu H, Till C, Green R, Bashash M, Flora D, Tellez-Rojo MM, Song PX, Lanphear B, Budtz-Jørgensen E. A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children. Risk Anal 2022; 42:439-449. [PMID: 34101876 PMCID: PMC9831700 DOI: 10.1111/risa.13767] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 04/30/2021] [Accepted: 05/22/2021] [Indexed: 05/11/2023]
Abstract
As a guide to establishing a safe exposure level for fluoride exposure in pregnancy, we applied benchmark dose modeling to data from two prospective birth cohort studies. We included mother-child pairs from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort in Mexico and the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort in Canada. Maternal urinary fluoride concentrations (U-F, in mg/L, creatinine-adjusted) were measured in urine samples obtained during pregnancy. Children were assessed for intelligence quotient (IQ) at age 4 (n = 211) and between six and 12 years (n = 287) in the ELEMENT cohort, and three to four years (n = 407) in the MIREC cohort. We calculated covariate-adjusted regression coefficients and their standard errors to assess the association of maternal U-F concentrations with children's IQ measures. Assuming a benchmark response of 1 IQ point, we derived benchmark concentrations (BMCs) and benchmark concentration levels (BMCLs). No deviation from linearity was detected in the dose-response relationships, but boys showed lower BMC values than girls. Using a linear slope for the joint cohort data, the BMC for maternal U-F associated with a 1-point decrease in IQ scores was 0.31 mg/L (BMCL, 0.19 mg/L) for the youngest boys and girls in the two cohorts, and 0.33 mg/L (BMCL, 0.20 mg/L) for the MIREC cohort and the older ELEMENT children. Thus, the joint data show a BMCL in terms of the adjusted U-F concentrations in the pregnant women of approximately 0.2 mg/L. These results can be used to guide decisions on preventing excess fluoride exposure in pregnant women.
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Affiliation(s)
- Philippe Grandjean
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USA
- Department of Public Health, University of Southern Denmark, Odense, Denmark
- Address correspondence to Philippe Grandjean, Environmental Medicine, University of Southern Denmark, J.B. Winslows vej 17A, 5000 Odense C, Denmark; tel: +45 6550 3769; fax: +45 6591 1458;
| | - Howard Hu
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - Rivka Green
- Faculty of Health, York University, Ontario, Canada
| | - Morteza Bashash
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - David Flora
- Faculty of Health, York University, Ontario, Canada
| | - Martha Maria Tellez-Rojo
- Centro de Investigacion en Salud Poblacional, Instituto Nacional de Salud Publica, Cuernavaca, Morelos, Mexico
| | - Peter X.K. Song
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, British Columbia, Canada
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20
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Fabri TL, O'Mahony J, Fadda G, Gur RE, Gur RC, Ann Yeh E, Banwell BL, Till C. Cognitive function in pediatric-onset relapsing myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Mult Scler Relat Disord 2022; 59:103689. [DOI: 10.1016/j.msard.2022.103689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 01/27/2022] [Accepted: 02/12/2022] [Indexed: 12/29/2022]
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21
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De Somma E, O'Mahony J, Brown RA, Brooks BL, Yeh EA, Cardenas de La Parra A, Arnold D, Collins DL, Maranzano J, Narayanan S, Marrie RA, Bar-Or A, Banwell B, Till C. Disrupted cognitive development following pediatric acquired demyelinating syndromes: a longitudinal study. Child Neuropsychol 2021; 28:649-670. [PMID: 34872458 DOI: 10.1080/09297049.2021.2002289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Long-term cognitive deficits have been observed in some children who experience an acquired demyelinating syndrome (ADS). We examined changes in cognitive functioning over the first two years following incident ADS andtested whether normalized brain and thalamic volume accounted for decline over time. Twenty-five youth (mean age 12.8 years) with ADS, 9 of whom were diagnosed with multiple sclerosis (MS) and 16 of whom experienced monophasic ADS (monoADS), underwent two neuropsychological evaluationsand MRI scans at approximately6- and 24-months post ADS-onset. We examined changes in cognitive outcomes over time and between patient groups. Generalized linear mixed-effect regression models were used to examine the association of normalized brain and thalamic volumesbetween the two timepointswith cognitive z-scores. Cognitive performance was within the age-expected range for both groups and remained stable over time on 15 measures. In the combined sample of monoADS and MS patients, declines (p < .05) were noted on the Symbol Digit Modalities Test (SDMT), the Auditory Working Memory (AWM), and the WJ-III Visual Matching (VisMat)tests, but did not survive FDR correction. Clinically significant declines, as measured by the Reliable Change Index, were observed on the SDMT,AWM, and VisMattests by 19, 42, and 32%, respectively. Lower normalized brain volume at 6-months predicted a negative change in SDMT (B = 0.45, 95%CI: 0.07,0.83) and AWM (B = 0.30, 95%CI: 0.13, 0.47). Chronicity of demyelination is not required for cognitive decline nor for reduced brain volume, suggesting that even a single demyelinating event may negatively impact cognitive potential in children.
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Affiliation(s)
| | - Julia O'Mahony
- Neurosciences and Mental Health, Hospital for Sick Children, Canada Hospital for Sick Children, Toronto, Canada
| | | | - Brian L Brooks
- Neurosciences Program, Alberta Children's Hospital, Calgary, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Canada.,Departments of Pediatrics, Clinical Neurosciences, and Psychology, University of Calgary, Calgary, Canada
| | - E Ann Yeh
- Neurosciences and Mental Health, Hospital for Sick Children, Canada Hospital for Sick Children, Toronto, Canada.,Department of Neurology, Hospital for Sick Children, Toronto, Canada
| | | | - Douglas Arnold
- McConnell Brain Imaging Centre, McGill University, Montreal, Canada
| | - D Louis Collins
- McConnell Brain Imaging Centre, McGill University, Montreal, Canada
| | | | - Sridar Narayanan
- McConnell Brain Imaging Centre, McGill University, Montreal, Canada
| | - Ruth Ann Marrie
- Departments of Internal Medicine and Community Health Sciences, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Amit Bar-Or
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Brenda Banwell
- Children's Hospital of Philadelphia, Departments of Neurology and Pediatrics Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Christine Till
- Department of Psychology, York University, Toronto, Canada.,Neurosciences and Mental Health, Hospital for Sick Children, Canada Hospital for Sick Children, Toronto, Canada
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Till C, Green R. Controversy: The evolving science of fluoride: when new evidence doesn't conform with existing beliefs. Pediatr Res 2021; 90:1093-1095. [PMID: 32443137 PMCID: PMC9922476 DOI: 10.1038/s41390-020-0973-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 03/11/2020] [Indexed: 02/02/2023]
Abstract
Over the past 75 years, health authorities have declared that community water fluoridation-a practice that reaches over 400 million worldwide-is safe. Yet, studies conducted in North America examining the safety of fluoride exposure in pregnancy were nonexistent. When a Canadian study reported that higher fluoride exposure in pregnant women was associated with lower IQ scores in young children, critics attacked the methodology of the study and discounted the significance of the results. Health authorities continued to conclude that fluoride is unequivocally safe, despite four well-conducted studies over the last 3 years consistently linking fluoride exposure in pregnancy with adverse neurodevelopmental effects in offspring. We describe the challenges of conducting fluoride research and the overt cognitive biases we have witnessed in the polarized fluoride debate. The tendency to ignore new evidence that does not conform to widespread beliefs impedes the response to early warnings about fluoride as a potential developmental neurotoxin. Evolving evidence should inspire scientists and health authorities to re-evaluate claims about the safety of fluoride, especially for the fetus and infant for whom there is no benefit.
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Affiliation(s)
- Christine Till
- Department of Psychology, York University, 4700 Keele St., Toronto, ON, Canada.
| | - Rivka Green
- Department of Psychology, York University, 4700 Keele St., Toronto, ON, Canada
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23
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Farmus L, Till C, Green R, Hornung R, Martinez Mier EA, Ayotte P, Muckle G, Lanphear BP, Flora DB. Critical windows of fluoride neurotoxicity in Canadian children. Environ Res 2021; 200:111315. [PMID: 34051202 PMCID: PMC9884092 DOI: 10.1016/j.envres.2021.111315] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/28/2021] [Accepted: 05/07/2021] [Indexed: 05/08/2023]
Abstract
BACKGROUND Fluoride has been associated with IQ deficits during early brain development, but the period in which children are most sensitive is unknown. OBJECTIVE We assessed effects of fluoride on IQ scores across prenatal and postnatal exposure windows. METHODS We used repeated exposures from 596 mother-child pairs in the Maternal-Infant Research on Environmental Chemicals pregnancy and birth cohort. Fluoride was measured in urine (mg/L) collected from women during pregnancy and in their children between 1.9 and 4.4 years; urinary fluoride was adjusted for specific gravity. We estimated infant fluoride exposure (mg/day) using water fluoride concentration and duration of formula-feeding over the first year of life. Intelligence was assessed at 3-4 years using the Wechsler Preschool and Primary Scale of Intelligence-III. We used generalized estimating equations to examine the associations between fluoride exposures and IQ, adjusting for covariates. We report results based on standardized exposures given their varying units of measurement. RESULTS The association between fluoride and performance IQ (PIQ) significantly differed across prenatal, infancy, and childhood exposure windows collapsing across child sex (p = .001). The strongest association between fluoride and PIQ was during the prenatal window, B = -2.36, 95% CI: -3.63, -1.08; the association was also significant during infancy, B = -2.11, 95% CI: -3.45, -0.76, but weaker in childhood, B = -1.51, 95% CI: -2.90, -0.12. Within sex, the association between fluoride and PIQ significantly differed across the three exposure windows (boys: p = .01; girls: p = .01); among boys, the strongest association was during the prenatal window, B = -3.01, 95% CI: -4.60, -1.42, whereas among girls, the strongest association was during infancy, B = -2.71, 95% CI: -4.59, -0.83. Full-scale IQ estimates were weaker than PIQ estimates for every window. Fluoride was not significantly associated with Verbal IQ across any exposure window. CONCLUSION Associations between fluoride exposure and PIQ differed based on timing of exposure. The prenatal window may be critical for boys, whereas infancy may be a critical window for girls.
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Affiliation(s)
- Linda Farmus
- Faculty of Health, York University, Ontario, Canada
| | | | - Rivka Green
- Faculty of Health, York University, Ontario, Canada
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - E Angeles Martinez Mier
- Department of Cardiology, Operative Dentistry and Dental Public Health, Indiana University School of Dentistry, Indiana, USA
| | - Pierre Ayotte
- Centre de Recherche Du CHU de Québec, Université Laval, Québec, Canada; Department of Social and Preventive Medicine, Laval University, Quebec, Canada
| | - Gina Muckle
- Centre de Recherche Du CHU de Québec, Université Laval, Québec, Canada; School of Psychology, Laval University, Quebec, Canada
| | - Bruce P Lanphear
- Faculty of Health Sciences, Simon Fraser University, British Columbia, Canada; Child & Family Research Institute, BC Children's Hospital, University of British Columbia, British Columbia, Canada
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24
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Fabri TL, Datta R, O'Mahony J, Barlow-Krelina E, De Somma E, Longoni G, Gur RE, Gur RC, Bacchus M, Ann Yeh E, Banwell BL, Till C. Memory, processing of emotional stimuli, and volume of limbic structures in pediatric-onset multiple sclerosis. Neuroimage Clin 2021; 31:102753. [PMID: 34273791 PMCID: PMC8319518 DOI: 10.1016/j.nicl.2021.102753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/22/2021] [Accepted: 06/29/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE The limbic system is involved in memory and in processing of emotional stimuli. We measured volume of the hippocampus, amygdala, and thalamus, and assessed their relative contribution to episodic memory and emotion identification in POMS. METHOD Sixty-five POMS participants (Mage = 18.3 ± 3.9 years; 48 female (73.8%)), average disease duration = 3.8 ± 3.8 years) and 76 age- and sex-matched controls (Mage = 18.1 ± 4.6 years; 49 female (64.5%)) completed the Penn Computerized Neurocognitive Battery (PCNB); 59 of 65 POMS participants and 69 out of 76 controls underwent 3 T MRI scanning. We derived age-adjusted Z-scores on accuracy and response time (RT) measures of episodic memory and emotion identification of the PCNB. Magnetic resonance imaging (MRI) volumetrics were normalized using the scaling factor computed by SIENAx. On PCNB tests that differed between groups, we used multiple linear regression to assess relationships between regional brain volumes and either episodic memory or emotion identification outcomes controlling for age, sex, accuracy/RT, and parental education. RESULTS POMS participants were slower and less accurate than controls on the episodic memory domain but did not differ from controls on emotion outcomes. At the subtest level, POMS participants showed reduced accuracy on Word Memory (p = .002) and slower performance on Face Memory (p = .04) subtests. POMS participants had smaller total and regional brain volumes of the hippocampus, amygdala, and thalamus (p values ≤ 0.01). Collapsing across groups, both hippocampal and thalamic volume were significant predictors of Word Memory accuracy; hippocampal volume (B = 0.24, SE = 0.10, p = .02) was more strongly associated with Word Memory performance than thalamic volume (B = 0.16, SE = 0.05, p = .003), though the estimate with was less precise. CONCLUSIONS POMS participants showed reduced episodic memory performance compared to controls. Aspects of episodic memory performance were associated with hippocampal and thalamic volume. Emotion identification was intact, despite volume loss in the amygdala.
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Affiliation(s)
| | - Ritobrato Datta
- Division of Neurology, Children's Hospital of Philadelphia, United States
| | - Julia O'Mahony
- Departments of Internal Medicine, University of Manitoba, Winnipeg, MB, Canada
| | | | | | - Giulia Longoni
- Department of Paediatrics, Division of Neurology, The Hospital for Sick Children, University of Toronto, Canada
| | - Raquel E Gur
- Penn-CHOP Lifespan Brain Institute, Departments of Psychiatry, Neurology, and Radiology, University of Pennsylvania School of Medicine, United States
| | - Ruben C Gur
- Penn-CHOP Lifespan Brain Institute, Departments of Psychiatry, Neurology, and Radiology, University of Pennsylvania School of Medicine, United States
| | - Micky Bacchus
- Division of Neurology, Children's Hospital of Philadelphia, United States
| | - E Ann Yeh
- Department of Paediatrics, Division of Neurology, The Hospital for Sick Children, University of Toronto, Canada
| | - Brenda L Banwell
- Division of Neurology, Children's Hospital of Philadelphia, United States; Perelman School of Medicine, University of Pennsylvania, United States
| | - Christine Till
- Department of Psychology, York University, Canada; Department of Paediatrics, Division of Neurology, The Hospital for Sick Children, University of Toronto, Canada.
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25
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Barlow-Krelina E, Fabri TL, O'Mahony J, Gur RC, Gur RE, De Somma E, Bolongaita L, Dunn CL, Bacchus M, Yeh EA, Marrie RA, Bar-Or A, Banwell BL, Till C. Examining cognitive speed and accuracy dysfunction in youth and young adults with pediatric-onset multiple sclerosis using a computerized neurocognitive battery. Neuropsychology 2021; 35:388-398. [PMID: 34043389 DOI: 10.1037/neu0000729] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE We evaluated performance on the Penn Computerized Neurocognitive Battery (PCNB), a tool assessing accuracy and response time across four cognitive domains, alongside the Symbol Digit Modalities Test (SDMT), a measure of processing speed commonly used in MS. We determined whether performance decrements are more likely to be detected on measures of accuracy versus response time in pediatric-onset multiple sclerosis (POMS). METHODS Performance on the SDMT, accuracy on PCNB tests belonging to four domains (executive function, episodic memory, complex cognition, social cognition), and response time on the PCNB were compared for 65 POMS patients (age range: 8-29 years) and 76 healthy controls (HCs) by ANCOVA. Associations between the Overall PCNB score and SDMT were examined for both groups, and their agreement in classifying impairment was assessed using Cohen's kappa. RESULTS POMS patients (age at testing = 18.3 ± 4.0 years; age at POMS onset = 14.9 ± 2.3 years) demonstrated reduced accuracy relative to HCs on tests of working memory, attention/inhibition, verbal memory, and visuospatial processing, after adjusting for response time (p ≤ .002). Patients demonstrated slower overall response time on the PCNB (p = .003), while group differences on the SDMT did not meet significance (p = .03). Performance on the PCNB and SDMT were correlated (MS: r = 0.43, HC: r = 0.50, both p < .001), however, the degree of agreement for impairment was minimal (k = 0.22, p = .14). CONCLUSION Specific cognitive deficits exist independently of slowed information processing speed in POMS, and may represent more significant areas of dysfunction. Delineation of accuracy and response time in neuropsychological assessment is important to identify areas of cognitive deficit in POMS. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
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Affiliation(s)
| | | | - Julia O'Mahony
- Neurosciences and Mental Health Program, The Hospital for Sick Children
| | - Ruben C Gur
- Penn-CHOP Lifespan Brain Institute, University of Pennsylvania Perelman School of Medicine
| | - Raquel E Gur
- Penn-CHOP Lifespan Brain Institute, University of Pennsylvania Perelman School of Medicine
| | | | - Lady Bolongaita
- Neurosciences and Mental Health Program, The Hospital for Sick Children
| | - Candice L Dunn
- Division of Neurology, Children's Hospital of Philadelphia
| | - Micky Bacchus
- Division of Neurology, Children's Hospital of Philadelphia
| | - E Ann Yeh
- Neurosciences and Mental Health Program, The Hospital for Sick Children
| | - Ruth Ann Marrie
- Department of Internal Medicine, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba
| | - Amit Bar-Or
- Division of Neurology, Children's Hospital of Philadelphia
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26
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Riddell JK, Malin AJ, McCague H, Flora DB, Till C. Urinary Fluoride Levels among Canadians with and without Community Water Fluoridation. Int J Environ Res Public Health 2021; 18:6203. [PMID: 34201160 PMCID: PMC8226595 DOI: 10.3390/ijerph18126203] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/04/2021] [Accepted: 06/06/2021] [Indexed: 11/17/2022]
Abstract
Drinking water is a major source of dietary fluoride intake in communities with water fluoridation. We examined the association between urinary fluoride adjusted for specific gravity (UFSG) and tap water fluoride levels, by age and sex, among individuals living in Canada. Participants included 1629 individuals aged 3 to 79 years from Cycle 3 (2012-2013) of the Canadian Health Measures Survey. We used multiple linear regression to estimate unique associations of tap water fluoride levels, age, sex, ethnicity, body mass index (BMI), use of fluoride-containing dental products, smoking in the home, and tea consumption with UFSG. UFSG concentration was significantly higher among participants who received fluoridated drinking water (mean = 1.06 mg/L, standard deviation = 0.83) than among those who did not (M = 0.58 mg/L, SD = 0.47), p < 0.01. UFSG increased over adulthood (ages 19 to 79). Higher UFSG concentration was associated with being female, tea drinking, and smoking in the home. In conclusion, community water fluoridation is a major source of contemporary fluoride exposure for Canadians. Lifestyle factors including tea consumption, as well as demographic variables such as age and sex, also predict urinary fluoride level, and are therefore important factors when interpreting population-based fluoride biomonitoring data.
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Affiliation(s)
- Julia K. Riddell
- Department of Clinical Health Psychology, University of Manitoba, Winnipeg, MB N3E 3N4, Canada
| | - Ashley J. Malin
- Department of Preventive Medicine, Keck School of Medicine of USC, Los Angeles, CA 90032, USA;
| | - Hugh McCague
- Institute for Social Research, York University, Toronto, ON M3J 1P3, Canada; (H.M.); (D.B.F.)
| | - David B. Flora
- Institute for Social Research, York University, Toronto, ON M3J 1P3, Canada; (H.M.); (D.B.F.)
- Faculty of Health, York University, Toronto, ON M3J 1P3, Canada;
| | - Christine Till
- Faculty of Health, York University, Toronto, ON M3J 1P3, Canada;
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27
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Cunningham JEA, McCague H, Malin AJ, Flora D, Till C. Fluoride exposure and duration and quality of sleep in a Canadian population-based sample. Environ Health 2021; 20:16. [PMID: 33602214 PMCID: PMC7893939 DOI: 10.1186/s12940-021-00700-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 02/03/2021] [Indexed: 05/31/2023]
Abstract
BACKGROUND Fluoride from dietary and environmental sources may concentrate in calcium-containing regions of the body such as the pineal gland. The pineal gland synthesizes melatonin, a hormone that regulates the sleep-wake cycle. We examined associations between fluoride exposure and sleep outcomes among older adolescents and adults in Canada. METHODS We used population-based data from Cycle 3 (2012-2013) of the Canadian Health Measures Survey. Participants were aged 16 to 79 years and 32% lived in communities supplied with fluoridated municipal water. Urinary fluoride concentrations were measured in spot samples and adjusted for specific gravity (UFSG; n = 1303) and water fluoride concentrations were measured in tap water samples among those who reported drinking tap water (n = 1016). We used multinomial and ordered logistic regression analyses (using both unweighted and survey-weighted data) to examine associations of fluoride exposure with self-reported sleep outcomes, including sleep duration, frequency of sleep problems, and daytime sleepiness. Covariates included age, sex, ethnicity, body mass index, chronic health conditions, and household income. RESULTS Median (IQR) UFSG concentration was 0.67 (0.63) mg/L. Median (IQR) water fluoride concentration was 0.58 (0.27) mg/L among participants living in communities supplied with fluoridated municipal water and 0.01 (0.06) mg/L among those living in non-fluoridated communities. A 0.5 mg/L higher water fluoride level was associated with 34% higher relative risk of reporting sleeping less than the recommended duration for age [unweighted: RRR = 1.34, 95% CI: 1.03, 1.73; p = .026]; the relative risk was higher, though less precise, using survey-weighted data [RRR = 1.96, 95% CI: 0.99, 3.87; p = .05]. UFSG was not significantly associated with sleep duration. Water fluoride and UFSG concentration were not significantly associated with frequency of sleep problems or daytime sleepiness. CONCLUSIONS Fluoride exposure may contribute to sleeping less than the recommended duration among older adolescents and adults in Canada.
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Affiliation(s)
| | - Hugh McCague
- Institute for Social Research, York University, Toronto, Ontario Canada
| | - Ashley J. Malin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY USA
| | - David Flora
- Faculty of Health, York University, Toronto, Ontario Canada
| | - Christine Till
- Faculty of Health, York University, Toronto, Ontario Canada
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28
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Green R, Rubenstein J, Popoli R, Capulong R, Till C. Sex-specific neurotoxic effects of early-life exposure to fluoride: A review of the epidemiologic and animal literature. CURR EPIDEMIOL REP 2020; 7:263-273. [PMID: 33816056 PMCID: PMC8011433 DOI: 10.1007/s40471-020-00246-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/21/2020] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW A growing body of evidence suggests adverse neurodevelopmental effects of early-life exposure to fluoride that may differ depending on timing of exposure and sex of the exposed. We conducted a literature search to identify the animal and human epidemiologic studies that examined sex-specific neurodevelopmental differences in response to prenatal and postnatal exposure to fluoride. RECENT FINDINGS Six of 138 animal studies and 15 of 106 human epidemiologic studies tested for sex-specific effects. Prenatal exposure to fluoride was associated with a male susceptibility to adverse behavioural effects in four of six animal studies and lower IQ in one of three prospective cohort studies. The body of evidence examining sex-effects associated with postnatal fluoride exposure was scarce, and many animal and cross-sectional human studies were considered to have a high risk of bias. SUMMARY Compared to females, male offspring appear to be more sensitive to prenatal, but not postnatal, exposure to fluoride. We discuss several sex-specific mechanisms and emphasize the need for future research.
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Affiliation(s)
- R. Green
- York University, Department of Psychology, 4700 Keele St
| | - J. Rubenstein
- York University, Department of Psychology, 4700 Keele St
| | - R. Popoli
- York University, Department of Psychology, 4700 Keele St
| | - R. Capulong
- York University, Department of Psychology, 4700 Keele St
| | - C. Till
- York University, Department of Psychology, 4700 Keele St
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29
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Green R, Till C, Cantoral A, Lanphear B, Martinez-Mier EA, Ayotte P, Wright RO, Tellez-Rojo MM, Malin AJ. Associations between Urinary, Dietary, and Water Fluoride Concentrations among Children in Mexico and Canada. Toxics 2020; 8:E110. [PMID: 33233802 PMCID: PMC7711675 DOI: 10.3390/toxics8040110] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 10/29/2020] [Accepted: 10/30/2020] [Indexed: 01/09/2023]
Abstract
Fluoride, which may be toxic to the developing brain, is added to salt in Mexico and drinking water in Canada to prevent dental caries. We compared childhood urinary fluoride (CUF) concentrations in Mexico City and Canada to characterize patterns of fluoride exposure in these two populations. We also examined associations of CUF with dietary and water fluoride levels in Mexico City and Canada respectively. We included 561 children (ages 4–6; mean age 4.8 years) from the Programming Research in Obesity, Growth, Environment, and Social Stress (PROGRESS) cohort in Mexico City, and 645 children (ages 2–6; mean age 3.7 years) from the Maternal–Infant Research on Environmental Chemicals (MIREC) cohort in Canada. We applied Spearman correlations, T-tests, ANOVA or covariate-adjusted linear regression to examine associations of CUF (mg/L; adjusted for specific gravity) with demographics and dietary or water fluoride concentrations. We used Welch equivalence testing to compare means across cohorts. Mean (SD) CUF was equivalent (t = 4.26, p < 0.001) in PROGRESS: 0.74 (0.42) and fluoridated Canadian communities: 0.66 (0.47), but lower in non-fluoridated Canadian communities: 0.42 (0.31) (t = −6.37, p < 0.001). Water fluoride concentrations were significantly associated with CUF after covariate adjustment for age and sex in MIREC (B = 0.44, 95% CI: 0.30, 0.59, p < 0.001). In contrast, daily food and beverage fluoride intake was not associated with CUF in PROGRESS (p = 0.82). We found that CUF levels are comparable among children in Mexico City and fluoridated Canadian communities, despite distinct sources of exposure. Community water fluoridation is a major source of fluoride exposure for Canadian children.
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Affiliation(s)
- Rivka Green
- Department of Psychology, York University, Toronto, ON M3J 1P3, Canada; (R.G.); (C.T.)
| | - Christine Till
- Department of Psychology, York University, Toronto, ON M3J 1P3, Canada; (R.G.); (C.T.)
| | - Alejandra Cantoral
- Departamento de Salud, Universidad Iberoamericana, Ciudad de México 01219, Mexico
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, BC V5A 1S6, Canada;
| | | | - Pierre Ayotte
- Department of Social and Preventive Medicine, Laval University, Quebec City, QC G1V 0A6, Canada;
| | - Robert O. Wright
- Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (R.O.W.); (A.J.M.)
| | - Martha M. Tellez-Rojo
- School of Public Health, Instituto Nacional de Salud Pública, Cuernavaca 62100, Mexico;
| | - Ashley J. Malin
- Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; (R.O.W.); (A.J.M.)
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30
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Grandjean P, Hu H, Till C, Green R, Bashash M, Flora D, Tellez-Rojo MM, Song P, Lanphear B, Budtz-Jørgensen E. A Benchmark Dose Analysis for Maternal Pregnancy Urine-Fluoride and IQ in Children. medRxiv 2020:2020.10.31.20221374. [PMID: 33173917 PMCID: PMC7654913 DOI: 10.1101/2020.10.31.20221374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
As a safe exposure level for fluoride in pregnancy has not been established, we used data from two prospective studies for benchmark dose modeling. We included mother-child pairs from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort in Mexico and the Maternal-Infant Research on Environmental Chemicals (MIREC) cohort in Canada. Children were assessed for IQ at age 4 (n=211) and between 6 and 12 years (n=287) in the ELEMENT cohort and between ages 3 and 4 years (n=512) in the MIREC cohort. We calculated covariate-adjusted regression coefficients and their standard errors to explore the concentration-effect function for maternal urinary fluoride with children's IQ, including possible sex-dependence. Assuming a benchmark response of 1 IQ point, we derived benchmark concentrations (BMCs) of maternal urinary fluoride and benchmark concentration levels (BMCLs). No deviation from linearity was detected from the results of the two studies. Using a linear slope, the BMC for maternal urinary fluoride associated with a 1-point decrease in IQ scores of preschool-aged boys and girls was 0.29 mg/L (BMCL, 0.18 mg/L). The BMC was 0.30 mg/L (BMCL, 0.19 mg/L) when pooling the IQ scores from the older ELEMENT children and the MIREC cohort. Boys showed slightly lower BMC values compared with girls. Relying on two prospective studies, maternal urine-fluoride exposure at levels commonly occurring in the general population, the joint data showed BMCL results about 0.2 mg/L. These results can be used to guide decisions on preventing excess fluoride exposure in vulnerable populations.
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Affiliation(s)
- Philippe Grandjean
- Harvard T.H. Chan School of Public Health, Department of Environmental Health, Boston, MA 02115, USA
- Department of Public Health, University of Southern Denmark, Odense, Denmark
| | - Howard Hu
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | | | - Rivka Green
- Faculty of Health, York University, Ontario, Canada
| | - Morteza Bashash
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - David Flora
- Faculty of Health, York University, Ontario, Canada
| | - Martha Maria Tellez-Rojo
- Centro de Investigacion en Salud Poblacional, Instituto Nacional de Salud Publica, Cuernavaca, Morelos, Mexico
| | - Peter Song
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, MI, USA
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, British Columbia, Canada
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31
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Barlow-Krelina E, Chen Y, Yasui Y, Till C, Gibson TM, Ness KK, Leisenring WM, Howell RM, Nathan PC, Oeffinger KC, Robison LL, Armstrong GT, Krull KR, Edelstein K. Consistent Physical Activity and Future Neurocognitive Problems in Adult Survivors of Childhood Cancers: A Report From the Childhood Cancer Survivor Study. J Clin Oncol 2020; 38:2041-2052. [PMID: 32330104 DOI: 10.1200/jco.19.02677] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE To investigate longitudinal associations between physical activity (PA) and neurocognitive problems in adult survivors of childhood cancer. METHODS A total of 12,123 5-year survivors diagnosed between 1970 and 1999 (median [range] age at diagnosis, 7 [0-21] years, time since diagnosis at baseline, 16 [6-30] years) and 720 siblings self-reported PA and neurocognitive problems. PA was collected at baseline, and PA and neurocognitive data were obtained 7 (1-12) years and 12 (9-14) years later. PA consistency was defined as any combination of ≥ 75 minutes of vigorous or 150 minutes of moderate activity per week on all surveys. Multiple linear regressions, conducted separately for CNS and non-CNS survivors, identified associations between PA consistency and neurocognitive outcomes (expected mean, 50; standard deviation [SD], 10). Mediating effects of body mass index (BMI) and chronic health conditions (CHCs) were evaluated. RESULTS Survivors were less likely than siblings to report consistent PA (28.1% v 33.6%) and more likely to report problems in Task Efficiency (T-scores mean ± SD: siblings, 50.0 ± 0.4; CNS, 61.4 ± 0.4; non-CNS, 53.3 ± 0.3), Emotion Regulation (siblings, 51.4 ± 0.4; CNS, 54.5 ± 0.3; non-CNS 53.4 ± 0.2), and Memory (siblings, 50.8 ± 0.4; CNS, 58.9 ± 0.4; non-CNS, 53.5 ± 0.2; all P < .001). Survivors of CNS cancers (52.8 ± 0.3) also reported poorer Organization than siblings (49.9 ± 0.4; P < .001). After adjusting for age at diagnosis, age at questionnaire, emotional distress, and cancer treatment exposures, consistent PA was associated with fewer neurocognitive problems compared with consistent inactivity for both CNS and non-CNS groups (T-score differences ranging from -7.9 to -2.2) and larger neurocognitive improvements over time (-6.0 to -2.5), all P ≤ .01. BMI and severe CHCs partially mediated the PA-neurocognitive associations, but the mediation effects were small (change in β ≤ 0.4). CONCLUSION Adult survivors of childhood cancer who report more consistent PA have fewer neurocognitive problems and larger improvements in these concerns many years after treatment.
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Affiliation(s)
| | - Yan Chen
- University of Alberta, Edmonton, Alberta, Canada
| | - Yutaka Yasui
- University of Alberta, Edmonton, Alberta, Canada.,St Jude Children's Research Hospital, Memphis, TN
| | - Christine Till
- York University, Toronto, Ontario, Canada.,Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | | - Paul C Nathan
- Hospital for Sick Children, Toronto, Ontario, Canada
| | | | | | | | | | - Kim Edelstein
- Princess Margaret Cancer Centre, Toronto, Ontario, Canada
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Affiliation(s)
- Christine Till
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Rivka Green
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver,
British Columbia, Canada
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Till C, Green R, Flora D, Hornung R, Martinez-Mier EA, Blazer M, Farmus L, Ayotte P, Muckle G, Lanphear B. Fluoride exposure from infant formula and child IQ in a Canadian birth cohort. Environ Int 2020; 134:105315. [PMID: 31743803 PMCID: PMC6913880 DOI: 10.1016/j.envint.2019.105315] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Revised: 09/24/2019] [Accepted: 11/05/2019] [Indexed: 05/23/2023]
Abstract
BACKGROUND Infant consumption of formula reconstituted with fluoridated water can lead to excessive fluoride intake. We examined the association between fluoride exposure in infancy and intellectual ability in children who lived in fluoridated or non-fluoridated cities in Canada. METHODS We examined 398 mother-child dyads in the Maternal-Infant Research on Environmental Chemicals cohort who reported drinking tap water. We estimated water fluoride concentration using municipal water reports. We used linear regression to analyze the association between fluoride exposure and IQ scores, measured by the Wechsler Primary and Preschool Scale of Intelligence-III at 3-4 years. We examined whether feeding status (breast-fed versus formula-fed) modified the impact of water fluoride and if fluoride exposure during fetal development attenuated this effect. A second model estimated the association between fluoride intake from formula and child IQ. RESULTS Thirty-eight percent of mother-child dyads lived in fluoridated communities. An increase of 0.5 mg/L in water fluoride concentration (approximately equaling the difference between fluoridated and non-fluoridated regions) corresponded to a 9.3- and 6.2-point decrement in Performance IQ among formula-fed (95% CI: -13.77, -4.76) and breast-fed children (95% CI: -10.45, -1.94). The association between water fluoride concentration and Performance IQ remained significant after controlling for fetal fluoride exposure among formula-fed (B = -7.93, 95% CI: -12.84, -3.01) and breastfed children (B = -6.30, 95% CI: -10.92, -1.68). A 0.5 mg increase in fluoride intake from infant formula corresponded to an 8.8-point decrement in Performance IQ (95% CI: -14.18, -3.34) and this association remained significant after controlling for fetal fluoride exposure (B = -7.62, 95% CI: -13.64, -1.60). CONCLUSIONS Exposure to increasing levels of fluoride in tap water was associated with diminished non-verbal intellectual abilities; the effect was more pronounced among formula-fed children.
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Affiliation(s)
| | - Rivka Green
- Faculty of Health, York University, Ontario, Canada
| | - David Flora
- Faculty of Health, York University, Ontario, Canada
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children's Hospital Medical Center, OH, USA
| | | | - Maddy Blazer
- Faculty of Health, York University, Ontario, Canada
| | - Linda Farmus
- Faculty of Health, York University, Ontario, Canada
| | - Pierre Ayotte
- Centre de Recherche du CHU de Québec, Université Laval, Québec, Canada; Department of Social and Preventive Medicine, Laval University, Quebec, Canada
| | - Gina Muckle
- Centre de Recherche du CHU de Québec, Université Laval, Québec, Canada; School of Psychology, Laval University, Quebec, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, British Columbia, Canada; Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Canada
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Riddell JK, Malin AJ, Flora D, McCague H, Till C. Association of water fluoride and urinary fluoride concentrations with attention deficit hyperactivity disorder in Canadian youth. Environ Int 2019; 133:105190. [PMID: 31654913 PMCID: PMC8118663 DOI: 10.1016/j.envint.2019.105190] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 09/11/2019] [Accepted: 09/13/2019] [Indexed: 05/05/2023]
Abstract
BACKGROUND Exposure to fluoride has been linked with increased prevalence of attention deficit hyperactivity disorder (ADHD) in the United States and symptoms of inattention in Mexican children. We examined the association between fluoride exposure and attention outcomes among youth living in Canada. METHOD We used cross-sectional data collected from youth 6 to 17 years of age from the Canadian Health Measures Survey (Cycles 2 and 3). Urinary fluoride concentration adjusted for specific gravity (UFSG) was available for 1877 participants. Water fluoride concentration measured in tap water samples was available for 980 participants. Community water fluoridation (CWF) status was determined by viewing reports on each city's website or contacting the water treatment plant. We used logistic regression to test the association between the three measures of fluoride exposure and ADHD diagnosis. Linear regression was used to examine the relationship between the three measures of fluoride exposure and the hyperactivity/inattention score on the Strengths and Difficulties Questionnaire (SDQ). RESULTS UFSG did not significantly predict ADHD diagnosis or hyperactive/inattentive symptoms. A 1 mg/L increase in tap water fluoride level was associated with a 6.1 times higher odds of an ADHD diagnosis (95% CI = 1.60, 22.8). A significant interaction between age and tap water fluoride level (p = .03) indicated a stronger association between tap water fluoride and hyperactivity/inattention symptoms among older youth. A 1 mg/L increase in water fluoride level was associated with a 1.5 SDQ score increase (95% CI: 0.23, 2.68, p = .02) for youth at the 75th percentile of age (14 years old). Similarly, there was a significant interaction between age and CWF. At the 75th percentile of age (14 years old), those living in a fluoridated region had a 0.7-point higher SDQ score (95% CI = 0.34, 1.06, p < .01) and the predicted odds of an ADHD diagnosis was 2.8 times greater compared with youth in a non-fluoridated region (aOR = 2.84, 95% CI: 1.40, 5.76, p < .01). DISCUSSION Exposure to higher levels of fluoride in tap water is associated with an increased risk of ADHD symptoms and diagnosis of ADHD among Canadian youth, particularly among adolescents. Prospective studies are needed to confirm these results.
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Affiliation(s)
| | - Ashley J Malin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - David Flora
- Faculty of Health, York University, Ontario, Canada
| | - Hugh McCague
- Institute for Social Research, York University, Ontario, Canada
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Marrie RA, O'Mahony J, Maxwell C, Ling V, Till C, Barlow-Krelina E, Yeh EA, Arnold DL, Bar-Or A, Banwell B. Factors associated with health care utilization in pediatric multiple sclerosis. Mult Scler Relat Disord 2019; 38:101511. [PMID: 31722282 DOI: 10.1016/j.msard.2019.101511] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 11/02/2019] [Accepted: 11/05/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND We assessed whether clinical characteristics and health-related quality of life (HRQOL) are independently associated with subsequent hospitalizations and physician visits among children with multiple sclerosis (MS); and whether differences in HRQOL account for differences in physician visits between children with MS, monophasic acquired demyelinating syndromes (ADS) and healthy children. METHODS We used linked administrative (health) data from Ontario, Canada and data from a prospective cohort study including HRQOL (measured using the PedsQL), age, sex, cognitive function (accuracy and response time as assessed by Penn Neurocognitive Battery), number of relapses, and neurologic abnormalities on examination. We used generalized linear models with generalized estimating equations to examine factors associated with hospitalizations and ambulatory physician visit rates following each HRQOL assessment, adjusting for age, sex, and socioeconomic status. RESULTS We included 36 children with MS, 43 with monophasic ADS and 43 healthy controls. Among children with MS, more relapses were associated with increased odds of hospitalization (odds ratio 1.59; 1.18-2.14); better cognitive accuracy scores were associated with fewer physician visits (rate ratio [RR] 0.68; 0.47-0.98). Children with MS had higher rates of physician visits than healthy children (RR 1.44; 1.00-2.08), unlike children with a monophasic ADS, but HRQOL scores did not account for these differences. CONCLUSION Within the MS population, more relapses are associated with increased odds of hospitalization while better cognitive performance is associated with reduced rates of physician visits. Differences in HRQOL do not account for differences in physician visits by children with MS as compared to healthy children.
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Affiliation(s)
- Ruth Ann Marrie
- Departments of Medicine and Community Health Sciences, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
| | - Julia O'Mahony
- Institute of Health Policy, Management and Evaluation, University of Toronto, The Hospital for Sick Children, Toronto, Ontario, Canada.
| | - Colleen Maxwell
- Schools of Pharmacy and Public Health and Health Systems, University of Waterloo, Waterloo, Ontario, Canada; ICES, Toronto, Ontario, Canada.
| | | | - Christine Till
- Department of Psychology, York University, Toronto, Ontario, Canada.
| | | | - E Ann Yeh
- Department of Pediatrics, University of Toronto; Division of Neurology, The Hospital for Sick Children, Neurosciences and Mental Health, SickKids Research Institute, Toronto, Ontario, Canada.
| | - Douglas L Arnold
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
| | - Amit Bar-Or
- Center for Neuroinflammation and Experimental Therapeutics and Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
| | - Brenda Banwell
- Division of Child Neurology, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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Green R, Lanphear B, Hornung R, Flora D, Martinez-Mier EA, Neufeld R, Ayotte P, Muckle G, Till C. Association Between Maternal Fluoride Exposure During Pregnancy and IQ Scores in Offspring in Canada. JAMA Pediatr 2019; 173:940-948. [PMID: 31424532 PMCID: PMC6704756 DOI: 10.1001/jamapediatrics.2019.1729] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/04/2019] [Indexed: 01/10/2023]
Abstract
IMPORTANCE The potential neurotoxicity associated with exposure to fluoride, which has generated controversy about community water fluoridation, remains unclear. OBJECTIVE To examine the association between fluoride exposure during pregnancy and IQ scores in a prospective birth cohort. DESIGN, SETTING, AND PARTICIPANTS This prospective, multicenter birth cohort study used information from the Maternal-Infant Research on Environmental Chemicals cohort. Children were born between 2008 and 2012; 41% lived in communities supplied with fluoridated municipal water. The study sample included 601 mother-child pairs recruited from 6 major cities in Canada; children were between ages 3 and 4 years at testing. Data were analyzed between March 2017 and January 2019. EXPOSURES Maternal urinary fluoride (MUFSG), adjusted for specific gravity and averaged across 3 trimesters available for 512 pregnant women, as well as self-reported maternal daily fluoride intake from water and beverage consumption available for 400 pregnant women. MAIN OUTCOMES AND MEASURES Children's IQ was assessed at ages 3 to 4 years using the Wechsler Primary and Preschool Scale of Intelligence-III. Multiple linear regression analyses were used to examine covariate-adjusted associations between each fluoride exposure measure and IQ score. RESULTS Of 512 mother-child pairs, the mean (SD) age for enrollment for mothers was 32.3 (5.1) years, 463 (90%) were white, and 264 children (52%) were female. Data on MUFSG concentrations, IQ scores, and complete covariates were available for 512 mother-child pairs; data on maternal fluoride intake and children's IQ were available for 400 of 601 mother-child pairs. Women living in areas with fluoridated tap water (n = 141) compared with nonfluoridated water (n = 228) had significantly higher mean (SD) MUFSG concentrations (0.69 [0.42] mg/L vs 0.40 [0.27] mg/L; P = .001; to convert to millimoles per liter, multiply by 0.05263) and fluoride intake levels (0.93 [0.43] vs 0.30 [0.26] mg of fluoride per day; P = .001). Children had mean (SD) Full Scale IQ scores of 107.16 (13.26), range 52-143, with girls showing significantly higher mean (SD) scores than boys: 109.56 (11.96) vs 104.61 (14.09); P = .001. There was a significant interaction (P = .02) between child sex and MUFSG (6.89; 95% CI, 0.96-12.82) indicating a differential association between boys and girls. A 1-mg/L increase in MUFSG was associated with a 4.49-point lower IQ score (95% CI, -8.38 to -0.60) in boys, but there was no statistically significant association with IQ scores in girls (B = 2.40; 95% CI, -2.53 to 7.33). A 1-mg higher daily intake of fluoride among pregnant women was associated with a 3.66 lower IQ score (95% CI, -7.16 to -0.14) in boys and girls. CONCLUSIONS AND RELEVANCE In this study, maternal exposure to higher levels of fluoride during pregnancy was associated with lower IQ scores in children aged 3 to 4 years. These findings indicate the possible need to reduce fluoride intake during pregnancy.
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Affiliation(s)
- Rivka Green
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
- Child and Family Research Institute, British Columbia Children’s Hospital, University of British Columbia, Vancouver, British Columbia, Canada
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio
| | - David Flora
- Faculty of Health, York University, Toronto, Ontario, Canada
| | | | - Raichel Neufeld
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Pierre Ayotte
- Department of Social and Preventive Medicine, Laval University, Québec City, Québec, Canada
- Centre de Recherche du CHU de Québec, Université Laval, Québec City, Québec, Canada
| | - Gina Muckle
- Centre de Recherche du CHU de Québec, Université Laval, Québec City, Québec, Canada
- School of Psychology, Laval University, Québec City, Québec, Canada
| | - Christine Till
- Faculty of Health, York University, Toronto, Ontario, Canada
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Henry NL, Unger JM, Till C, Schott AF, Crew KD, Lew DL, Fisch MJ, Moinpour CM, Wade JL, Hershman DL. Abstract P1-11-04: Association between body mass index (BMI) and response to duloxetine for aromatase inhibitor (AI)-associated musculoskeletal symptoms (AIMSS). Cancer Res 2019. [DOI: 10.1158/1538-7445.sabcs18-p1-11-04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: AIMSS occurs often in women treated with AI therapy for early stage breast cancer and can negatively impact adherence and persistence with therapy. Duloxetine is a serotonin norepinephrine reuptake inhibitor used to treat mood disorders and chronic pain. In SWOG S1202, patients with AIMSS treated with duloxetine reported statistically significant improvement in pain by 12 weeks compared to placebo. Obesity is a predictor of increased likelihood of developing AIMSS, and a prior study of omega 3 fatty acid versus placebo for AIMSS showed a potential differential response to therapy by BMI. In this exploratory analysis of S1202, we investigated the association between baseline BMI and response to therapy.
Methods: In S1202, 299 postmenopausal women with stage I-III hormone receptor-positive breast cancer on AI therapy who developed new or worsening average pain of 4-10 on a numerical rating scale were enrolled, randomized 1:1 to duloxetine or placebo with randomization stratified by baseline pain (4-6 vs. 7-10) and prior taxane therapy (yes vs. no). Patients were treated for 12 weeks. Patient-reported outcomes including Brief Pain Inventory (BPI) were obtained at baseline and weeks 2, 6, 12, and 24. Patients were categorized into BMI<30 kg/m2 (non-obese) or BMI≥30 kg/m2 (obese). The pre-specified aim of this secondary analysis was to examine whether the effect of intervention on BPI average pain at 12 weeks differed between obese and non-obese patients. Multiple linear regression was used, adjusting for the stratification factors and the baseline score. We tested whether the interaction of BMI status and intervention effect was statistically significant at α=.05.
Results: 289 patients were eligible for the analysis, 54% of whom were obese. The cohorts were well balanced other than by race. The difference by intervention arm in the 12-week mean BPI scores between baseline and follow-up scores was substantially different for the obese versus non-obese cohorts. In the patients with BMI<30, the reduction in observed mean average pain score was similar in the duloxetine- and placebo-treated patients (-2.46 points vs. -2.34 points, p=.75). In contrast, in the patients with BMI≥30 the reduction in pain score was statistically significantly greater for the duloxetine-treated compared to the placebo-treated patients (-2.73 points vs. -1.64 points, p=.003; interaction p-value=.02). Differences in intervention effects between obese and non-obese groups were even stronger at 2-weeks (interaction p-value=.001) and 6-weeks (interaction p-value<.0001). Similar findings were evident for other pain-related patient-reported outcomes.
Conclusions: In the placebo-controlled S1202 trial, obese patients with AIMSS obtained more analgesic benefit from duloxetine. Additional studies are warranted to determine the biologic basis for these findings, such as a different mechanism underlying development of AIMSS or pain expression in patients with obesity, or other confounding variables related to analgesic response to duloxetine relative to placebo.
Support: NIH/NCI grants CA189974, CA189821, CA180820; and in part by Damon Runyon-Lilly Clinical Investigator Award #CI-53-10 [to NLH], and in part by Lilly USA, LLC.
Citation Format: Henry NL, Unger JM, Till C, Schott AF, Crew KD, Lew DL, Fisch MJ, Moinpour CM, Wade JL, Hershman DL. Association between body mass index (BMI) and response to duloxetine for aromatase inhibitor (AI)-associated musculoskeletal symptoms (AIMSS) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-11-04.
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Affiliation(s)
- NL Henry
- University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Michigan, Ann Arbor, MI; AIM Specialty Health, Chicago, IL; Columbia University, New York, NY; Heartland NCORP, Decatur, IL
| | - JM Unger
- University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Michigan, Ann Arbor, MI; AIM Specialty Health, Chicago, IL; Columbia University, New York, NY; Heartland NCORP, Decatur, IL
| | - C Till
- University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Michigan, Ann Arbor, MI; AIM Specialty Health, Chicago, IL; Columbia University, New York, NY; Heartland NCORP, Decatur, IL
| | - AF Schott
- University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Michigan, Ann Arbor, MI; AIM Specialty Health, Chicago, IL; Columbia University, New York, NY; Heartland NCORP, Decatur, IL
| | - KD Crew
- University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Michigan, Ann Arbor, MI; AIM Specialty Health, Chicago, IL; Columbia University, New York, NY; Heartland NCORP, Decatur, IL
| | - DL Lew
- University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Michigan, Ann Arbor, MI; AIM Specialty Health, Chicago, IL; Columbia University, New York, NY; Heartland NCORP, Decatur, IL
| | - MJ Fisch
- University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Michigan, Ann Arbor, MI; AIM Specialty Health, Chicago, IL; Columbia University, New York, NY; Heartland NCORP, Decatur, IL
| | - CM Moinpour
- University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Michigan, Ann Arbor, MI; AIM Specialty Health, Chicago, IL; Columbia University, New York, NY; Heartland NCORP, Decatur, IL
| | - JL Wade
- University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Michigan, Ann Arbor, MI; AIM Specialty Health, Chicago, IL; Columbia University, New York, NY; Heartland NCORP, Decatur, IL
| | - DL Hershman
- University of Utah, Salt Lake City, UT; Fred Hutchinson Cancer Research Center, Seattle, WA; University of Michigan, Ann Arbor, MI; AIM Specialty Health, Chicago, IL; Columbia University, New York, NY; Heartland NCORP, Decatur, IL
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Bashash M, Marchand M, Hu H, Till C, Martinez-Mier EA, Sanchez BN, Basu N, Peterson KE, Green R, Schnaas L, Mercado-García A, Hernández-Avila M, Téllez-Rojo MM. Prenatal fluoride exposure and attention deficit hyperactivity disorder (ADHD) symptoms in children at 6-12 years of age in Mexico City. Environ Int 2018; 121:658-666. [PMID: 30316181 DOI: 10.1016/j.envint.2018.09.017] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/20/2018] [Accepted: 09/08/2018] [Indexed: 05/23/2023]
Abstract
BACKGROUND Epidemiologic and animal-based studies have raised concern over the potential impact of fluoride exposure on neurobehavioral development as manifested by lower IQ and deficits in attention. To date, no prospective epidemiologic studies have examined the effects of prenatal fluoride exposure on behavioral outcomes using fluoride biomarkers and sensitive measures of attention. OBJECTIVE We aimed to examine the association between prenatal fluoride exposure and symptoms associated with attention-deficit/hyperactivity disorder (ADHD). METHOD 213 Mexican mother-children pairs of the Early Life Exposures to Environmental Toxicants (ELEMENT) birth cohort study had available maternal urinary samples during pregnancy and child assessments of ADHD-like behaviors at age 6-12. We measured urinary fluoride levels adjusted for creatinine (MUFcr) in spot urine samples collected during pregnancy. The Conners' Rating Scales-Revised (CRS-R) was completed by mothers, and the Conners' Continuous Performance Test (CPT-II) was administered to the children. RESULTS Mean MUFcr was 0.85 mg/L (SD = 0.33) and the Interquartile Range (IQR) was 0.46 mg/L. In multivariable adjusted models using gamma regression, a 0.5 mg/L higher MUFcr (approximately one IQR higher) corresponded with significantly higher scores on the CRS-R for DSM-IV Inattention (2.84 points, 95% CI: 0.84, 4.84) and DSM-IV ADHD Total Index (2.38 points, 95% CI: 0.42, 4.34), as well as the following symptom scales: Cognitive Problems and Inattention (2.54 points, 95% CI: 0.44, 4.63) and ADHD Index (2.47 points; 95% CI: 0.43, 4.50). The shape of the associations suggested a possible celling effect of the exposure. No significant associations were found with outcomes on the CPT-II or on symptom scales assessing hyperactivity. CONCLUSION Higher levels of fluoride exposure during pregnancy were associated with global measures of ADHD and more symptoms of inattention as measured by the CRS-R in the offspring.
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Affiliation(s)
- Morteza Bashash
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
| | - Maelle Marchand
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Howard Hu
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.
| | - Christine Till
- Faculty of Health - Department of Psychology, York University, ON, Canada
| | | | - Brisa N Sanchez
- University of Michigan School of Public Health, Ann Arbor, MI, United States of America
| | - Niladri Basu
- Faculty of Agricultural and Environmental Sciences, McGill University, Montreal, QC, Canada
| | - Karen E Peterson
- University of Michigan School of Public Health, Ann Arbor, MI, United States of America; Center for Human Growth and Development, University of Michigan, Ann Arbor, MI, United States of America; Harvard W.T. Chan School of Public Health, Boston, MA, United States of America
| | - Rivka Green
- Faculty of Health - Department of Psychology, York University, ON, Canada
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Malin AJ, Riddell J, McCague H, Till C. Fluoride exposure and thyroid function among adults living in Canada: Effect modification by iodine status. Environ Int 2018; 121:667-674. [PMID: 30316182 DOI: 10.1016/j.envint.2018.09.026] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 09/14/2018] [Accepted: 09/14/2018] [Indexed: 05/23/2023]
Abstract
BACKGROUND Fluoride exposure has the potential to disrupt thyroid functioning, though adequate iodine intake may mitigate this effect. This is the first population-based study to examine the impact of chronic low-level fluoride exposure on thyroid function, while considering iodine status. The objective of this study was to determine whether urinary iodine status modifies the effect of fluoride exposure on thyroid stimulating hormone (TSH) levels. METHODS This cross-sectional study utilized weighted population-based data from Cycle 3 (2012-2013) of the Canadian Health Measures Survey (CHMS). Information was collected via a home interview and a visit to a mobile examination centre. The weighted sample represented 6,914,124 adults in Canada aged 18-79 who were not taking any thyroid-related medication. Urinary fluoride concentrations were measured in spot samples using an ion selective electrode and adjusted for specific gravity (UFSG). Serum TSH levels provided a measure of thyroid function. Multivariable regression analyses examined the relationship between UFSG and TSH, controlling for covariates. RESULTS Approximately 17.8% of participants fell in the moderately-to-severely iodine deficient range. The mean (SD) age of the sample was 46.5 (15.6) years and the median UFSG concentration was 0.74 mg/L. Among iodine deficient adults, a 1 mg/L increase in UFSG was associated with a 0.35 mIU/L increase in TSH [95% CI: 0.06, 0.64; p = 0.01, one-tailed]. CONCLUSIONS Adults living in Canada who have moderate-to-severe iodine deficiencies and higher levels of urinary fluoride may be at an increased risk for underactive thyroid gland activity.
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Affiliation(s)
- Ashley J Malin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1057, New York 10029, NY, USA; Psychology Department, Faculty of Health, York University, 4700 Keele St, Toronto M3J 1P3, ON, Canada.
| | - Julia Riddell
- Psychology Department, Faculty of Health, York University, 4700 Keele St, Toronto M3J 1P3, ON, Canada.
| | - Hugh McCague
- Institute for Social Research, York University, 242A-4700 Keele St, Toronto, ON, Canada, M3J 1P3.
| | - Christine Till
- Psychology Department, Faculty of Health, York University, 4700 Keele St, Toronto M3J 1P3, ON, Canada.
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Green R, Till C, Al-Hakeem H, Cribbie R, Téllez-Rojo MM, Osorio E, Hu H, Schnaas L. Assessment of neuropsychological performance in Mexico City youth using the Cambridge Neuropsychological Test Automated Battery (CANTAB). J Clin Exp Neuropsychol 2018; 41:246-256. [PMID: 30336715 DOI: 10.1080/13803395.2018.1529229] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
BACKGROUND The Cambridge Neuropsychological Test Automated Battery (CANTAB) is a computerized tool used to measure cognitive function in diverse populations and is sensitive for assessing developmental changes in children. Although CANTAB has been used in several countries, its applicability in a Mexican child population is unknown. This study examined developmental trends on CANTAB in a large sample of urban Mexico City youth and tested the hypothesis that their performance would be similar to a large US normative sample. METHOD As part of a birth cohort, Early Life Exposures in Mexico to Environmental Toxicants, 826 children, ages 5-15 years, completed CANTAB. Subtests measured planning (Stockings of Cambridge; SOC), short-term memory (Delayed Matching to Sample; DMS), sustained attention (Rapid Visual Information Processing; RVP), ability to match visual stimuli (Match to Sample Visual Search; MTS), flexibility (Intra-extra Dimensional Set Shift; IED), and response inhibition (Stop Signal Task; SST). Determinants of performance on the CANTAB, including age, maternal/child IQ, and sex, were analyzed using Spearman correlation and Welch t tests. Equivalence testing compared performance with existing norms. RESULTS Performance improved with age on all measures. Child IQ was mildly associated with measures of memory and attention but not executive functioning, consistent with US norms. Maternal IQ was not associated with any outcomes, and males performed better on IED. Mexican norms were comparable to US norms on almost all outcomes, with the exception of a short-term visual recognition memory task (DMS). CONCLUSIONS This study provides the largest normative data for CANTAB performance in a community sample of Mexican youth. Findings demonstrate the expected maturational effects of executive function, specifically in cognitive shifting and inhibition. Levels of executive function performance demonstrated by a Mexican sample were consistent with normative values reported in US youth. These findings, as well as expected associations with child IQ, indicate high applicability of CANTAB for Mexican youth in neurobehavioral studies.
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Affiliation(s)
- Rivka Green
- a Department of Psychology , York University , Toronto , ON , Canada
| | - Christine Till
- a Department of Psychology , York University , Toronto , ON , Canada
| | - Hiba Al-Hakeem
- a Department of Psychology , York University , Toronto , ON , Canada
| | - Rob Cribbie
- a Department of Psychology , York University , Toronto , ON , Canada
| | - Martha M Téllez-Rojo
- b Centro de Investigación en Nutrición y Salud , Instituto Nacional de Salud Pública , Mexico City , Mexico
| | - Erika Osorio
- c Subdirección de Investigación en Intervenciones Comunitarias , Instituto Nacional de Perinatología , Mexico City , Mexico
| | - Howard Hu
- d Dalla Lana School of Public Health , University of Toronto , Toronto , ON , Canada.,e School of Public Health , University of Washington , Seattle, WA , USA
| | - Lourdes Schnaas
- c Subdirección de Investigación en Intervenciones Comunitarias , Instituto Nacional de Perinatología , Mexico City , Mexico
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Till C, Green R, Grundy JG, Hornung R, Neufeld R, Martinez-Mier EA, Ayotte P, Muckle G, Lanphear B. Community Water Fluoridation and Urinary Fluoride Concentrations in a National Sample of Pregnant Women in Canada. Environ Health Perspect 2018; 126:107001. [PMID: 30392399 PMCID: PMC6371693 DOI: 10.1289/ehp3546] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
BACKGROUND Fluoride exposures have not been established for pregnant women who live in regions with and without community water fluoridation. OBJECTIVE Our aim was to measure urinary fluoride levels during pregnancy. We also assessed the contribution of drinking-water and tea consumption habits to maternal urinary fluoride (MUF) concentrations and evaluated the impact of various dilution correction standards, including adjustment for urinary creatinine and specific gravity (SG). METHODS We measured MUF concentrations in spot samples collected in each trimester of pregnancy from 1,566 pregnant women in the Maternal-Infant Research on Environmental Chemicals cohort. We calculated intraclass correlation coefficients (ICCs) to assess variability in MUF concentrations across pregnancy. We used regression analyses to estimate associations between MUF levels, tea consumption, and water fluoride concentrations as measured by water treatment plants. RESULTS Creatinine-adjusted MUF values ([Formula: see text]; milligrams per liter) were almost two times higher for pregnant women living in fluoridated regions ([Formula: see text]) compared with nonfluoridated regions ([Formula: see text]; [Formula: see text]). MUF values tended to increase over the course of pregnancy using both unadjusted values and adjusted values. Reproducibility of the unadjusted and adjusted MUF values was modest ([Formula: see text]). The municipal water fluoride level was positively associated with creatinine-adjusted MUF ([Formula: see text], 95% CI: 0.46, 0.57), accounting for 24% of the variance after controlling for covariates. Higher MUF concentrations correlated with numbers of cups of black ([Formula: see text] but not green tea ([Formula: see text]). Urinary creatinine and SG correction methods were highly correlated ([Formula: see text]) and were interchangeable in models examining predictors of MUF. CONCLUSION Community water fluoridation is a major source of fluoride exposure for pregnant women living in Canada. Urinary dilution correction with creatinine and SG were shown to be interchangeable for our sample of pregnant women. https://doi.org/10.1289/EHP3546.
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Affiliation(s)
- Christine Till
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Rivka Green
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - John G Grundy
- Faculty of Health, York University, Toronto, Ontario, Canada
| | - Richard Hornung
- Pediatrics and Environmental Health, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - Raichel Neufeld
- Faculty of Health, York University, Toronto, Ontario, Canada
| | | | - Pierre Ayotte
- Department of Social and Preventive Medicine, Laval University, Quebec, Quebec, Canada
- Centre de Recherche du CHU de Québec, Université Laval, Quebec, Quebec, Canada
| | - Gina Muckle
- Centre de Recherche du CHU de Québec, Université Laval, Quebec, Quebec, Canada
- School of Psychology, Laval University, Quebec, Quebec, Canada
| | - Bruce Lanphear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
- Child & Family Research Institute, BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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Green R, Adler A, Banwell BL, Fabri TL, Yeh EA, Collins DL, Sled JG, Narayanan S, Till C. Involvement of the Amygdala in Memory and Psychosocial Functioning in Pediatric-Onset Multiple Sclerosis. Dev Neuropsychol 2018; 43:524-534. [PMID: 29911891 DOI: 10.1080/87565641.2018.1485679] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Youth with multiple sclerosis (MS) often experience cognitive impairment and psychosocial disturbances. We describe the relationship between memory function, psychosocial skills, and brain volume in 32 patients with pediatric-onset MS and 30 controls. Amygdala volume was significantly lower in patients compared with controls. In general, poorer memory was associated with reduced functional communication skills and reduced amygdala volume. Greater amygdala volume in patients correlated with parent-reported functional communication and social skills. Adjusting for whole-brain volume, right amygdala volume was positively associated with visual memory; left amygdala volume was a stronger predictor of parent-reported social skills.
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Affiliation(s)
- Rivka Green
- a Department of Psychology , York University , Toronto , Canada
| | - Ayala Adler
- a Department of Psychology , York University , Toronto , Canada
| | - Brenda L Banwell
- b Children's Hospital of Philadelphia, Perelman School of Medicine , University of Pennsylvania , Philadelphia , PA , USA.,c Neurosciences and Mental Health Program , The Hospital for Sick Children , Toronto , Canada
| | - Tracy L Fabri
- a Department of Psychology , York University , Toronto , Canada
| | - E Ann Yeh
- c Neurosciences and Mental Health Program , The Hospital for Sick Children , Toronto , Canada.,d Division of Neurology, Department of Paediatrics , University of Toronto , Toronto , Ontario , Canada
| | - D Louis Collins
- e McConnell Brain Imaging Centre, Montreal Neurological Institute , McGill University , Montreal , Canada
| | - John G Sled
- f Translational Medicine Program , The Hospital for Sick Children , Toronto , Canada
| | - Sridar Narayanan
- e McConnell Brain Imaging Centre, Montreal Neurological Institute , McGill University , Montreal , Canada
| | - Christine Till
- a Department of Psychology , York University , Toronto , Canada.,d Division of Neurology, Department of Paediatrics , University of Toronto , Toronto , Ontario , Canada
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Maranzano J, Till C, Assemlal HE, Fonov V, Brown R, Araujo D, O’Mahony J, Yeh EA, Bar-Or A, Marrie RA, Collins L, Banwell B, Arnold DL, Narayanan S. Detection and clinical correlation of leukocortical lesions in pediatric-onset multiple sclerosis on multi-contrast MRI. Mult Scler 2018; 25:980-986. [DOI: 10.1177/1352458518779952] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Objective: To determine the frequency of cortical lesions (CLs) in patients with pediatric-onset multiple sclerosis (POMS) using multi-contrast magnetic resonance imaging (MRI), and the relationship between frontal CL load and upper limb dexterity assessed with the Nine-Hole Peg Test (9-HPT). Methods: Participants completed the 9-HPT and were imaged on a 3T MRI scanner to collect T1-weighted three-dimensional (3D) magnetization prepared rapid gradient echo (MPRAGE), proton density–weighted, T2-weighted and fluid-attenuated inversion recovery (FLAIR) images. CLs were manually segmented using all MRI contrasts. Results: We enrolled 24 participants with POMS (mean (standard deviation) age at first symptom: 13.3 (±2.7) years; mean age at scan: 18.8 (±3) years; mean disease duration of 5 (±3.2) years). A total of 391 CLs (mean, 16.3 ± 27.2; median, 7) were identified in 19 of 24 POMS patients (79%). The total number of CLs was positively associated with white matter lesion volume ( p = 0.04) but not with thalamic volume, age at the time of the scan, or disease duration. The number of frontal CLs was associated with slower performance on the 9-HPT ( p = 0.05). Conclusion: Multi-contrast 3T MRI led to a high rate of CL detection, demonstrating that cortical pathology occurs even in pediatric-onset disease. Frontal lobe CL count was associated with reduced manual dexterity, indicating that these CLs are clinically relevant.
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Affiliation(s)
- Josefina Maranzano
- Departments of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Christine Till
- Department of Psychology, York University, Toronto, ON, Canada Division of Neurology, Department of Pediatrics, The Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - Haz-Edine Assemlal
- Departments of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Vladimir Fonov
- Image Processing Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Robert Brown
- Departments of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - David Araujo
- Departments of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Julia O’Mahony
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - E Ann Yeh
- Division of Neurology, Department of Pediatrics, The Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - Amit Bar-Or
- Children’s Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ruth Ann Marrie
- Departments of Internal Medicine and Community Health Sciences, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Louis Collins
- Image Processing Laboratory, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada
| | - Brenda Banwell
- Children’s Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA Division of Neurology, Department of Pediatrics, The Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON, Canada
| | - Douglas L Arnold
- Departments of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
| | - Sridar Narayanan
- Departments of Neurology and Neurosurgery, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada
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Hershman DL, Till C, Wright JD, Ramsey SD, Barlow WE, Unger JM. Abstract P6-12-09: Association between cardiovascular risk factors and cardiac events among breast cancer patients enrolled in SWOG clinical trials. Cancer Res 2018. [DOI: 10.1158/1538-7445.sabcs17-p6-12-09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Background: Due to early detection and improved treatments, women with breast cancer are living longer. Breast cancer shares risk factors with cardiovascular disease (CVD), and its treatments have adverse cardiovascular effects. Less is known about the association between cardiac risk factors and long-term cardiac events among the patients enrolled in breast cancer trials, as most trials fail to collect this information.
Methods: We examined the SWOG database to identify phase II/III breast cancer trials from 1999-2011. Among patients over 65 years, we linked the SWOG clinical records to Medicare claims data according to social security number and date of birth. This analysis included patients with 6+ months of Medicare coverage prior to baseline and 12+ months of Medicare coverage at any point after baseline. The comorbidities investigated at baseline were diabetes, hypertension, hypercholesterolemia, coronary artery/ischemic heart disease and obesity. A cardiac event was defined as an acute ischemic event or acute heart failure. Cox regression was used to calculate time-to-event, stratified by study ID and adjusted for baseline age, race, and prognostic risk score. Cox regression was performed separately for each CVD risk factor, and an additional analysis was performed to assess the impact of having multiple concurrent risk factors. Secondary analyses were performed separately by study type (Adjuvant, Advanced).
Results: Among patients linked to Medicare included in this cohort (N=742), the median age was 70, and median follow-up was 6 years. The majority of patients were non-Hispanic white. The most prevalent conditions were hypercholesterolemia (58%) and hypertension (73%). Only 13% had no baseline risk CVD factors. In a Cox regression, all baseline risk factors except hypercholesterolemia and obesity were statistically significantly or borderline statistically significantly associated with an increased risk of eventual cardiac event, and for ischemic heart disease the increased risk was more than two-fold (HR=2.27, 95% CI=1.46-3.54, p=0.0003) and for baseline diabetes nearly two-fold (HR=1.75, 95% CI=1.13-2.71, p=0.01). In addition, there was evidence of a linear association of number of concurrent risk factors and cardiac events (HR per additional risk factor = 1.35 (1.09-1.66), p=0.005). In the stratified analysis, the associations were statistically significant only for participants on adjuvant studies. No association between baseline cardiac risk factors and cardiovascular outcomes were seen among patients with advanced cancer.
Conclusions:In summary, we found that even among healthy breast cancer patients selected for clinical trials, baseline CVD risk factors are associated with an increased risk of cardiac events, however this association was not observed for patients with advanced disease, who are more likely to die from breast cancer before experiencing a cardiovascular event.
Citation Format: Hershman DL, Till C, Wright JD, Ramsey SD, Barlow WE, Unger JM. Association between cardiovascular risk factors and cardiac events among breast cancer patients enrolled in SWOG clinical trials [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-09.
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Affiliation(s)
- DL Hershman
- Columbia University Medical Center, New York, New York, NY; Fred Hutchinson Cancer Research Center, Seattle, WA; SWOG Statistical Center, Seattle, WA
| | - C Till
- Columbia University Medical Center, New York, New York, NY; Fred Hutchinson Cancer Research Center, Seattle, WA; SWOG Statistical Center, Seattle, WA
| | - JD Wright
- Columbia University Medical Center, New York, New York, NY; Fred Hutchinson Cancer Research Center, Seattle, WA; SWOG Statistical Center, Seattle, WA
| | - SD Ramsey
- Columbia University Medical Center, New York, New York, NY; Fred Hutchinson Cancer Research Center, Seattle, WA; SWOG Statistical Center, Seattle, WA
| | - WE Barlow
- Columbia University Medical Center, New York, New York, NY; Fred Hutchinson Cancer Research Center, Seattle, WA; SWOG Statistical Center, Seattle, WA
| | - JM Unger
- Columbia University Medical Center, New York, New York, NY; Fred Hutchinson Cancer Research Center, Seattle, WA; SWOG Statistical Center, Seattle, WA
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Till C, Kuni B, De Somma E, Yeh EA, Banwell B. A feasibility study of working memory training for individuals with paediatric-onset multiple sclerosis. Neuropsychol Rehabil 2017; 29:1177-1192. [PMID: 28920511 DOI: 10.1080/09602011.2017.1372786] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Objective: To investigate the feasibility and experiences of paediatric-onset multiple sclerosis (MS) patients completing a working memory training programme. Methods: Nine paediatric-onset MS patients (mean age 19.3 ± 4.1 years) identified as having attention and/or working memory difficulties underwent a five-week (five days/week) internet-based working memory training programme (Cogmed™); weekly coaching was provided. Measures of adherence and tolerance were used to establish the feasibility of implementing computerised cognitive training. Qualitative experiences reported by the patients were analysed and factors that may modulate the effects of training were explored. Results: Six of the nine enrolled patients completed the programme within the recommended time, and all individuals, with the exception of one, were considered to tolerate the training well. Eight of the nine participants acknowledged that training was helpful in one or more ways. All but one participant reported improvements in working memory, although evidence for improvement on objective neuropsychological testing was limited. Lower normalised brain volume emerged as a potentially important variable in predicting extent of improvement on the training programme. Conclusion: Selected paediatric-onset MS patients can tolerate and complete an intensive cognitive rehabilitation programme. Future investigation of moderators of training effects and the stability of the findings over time is needed.
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Affiliation(s)
- Christine Till
- a Department of Psychology , York University , Toronto , Canada.,b Neurosciences and Mental Health Program, Research Institute , The Hospital for Sick Children , Toronto , Canada
| | - Bravina Kuni
- a Department of Psychology , York University , Toronto , Canada
| | - Elisea De Somma
- a Department of Psychology , York University , Toronto , Canada
| | - E Ann Yeh
- b Neurosciences and Mental Health Program, Research Institute , The Hospital for Sick Children , Toronto , Canada.,c Department of Neurology , The Hospital for Sick Children , Toronto , Canada
| | - Brenda Banwell
- b Neurosciences and Mental Health Program, Research Institute , The Hospital for Sick Children , Toronto , Canada.,d Division of Child Neurology, Children's Hospital of Philadelphia, Department of Neurology, Perelman School of Medicine , University of Pennsylvania , Philadelphia , USA
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Akbar N, Signori A, Amato MP, Sormani MP, Portaccio E, Niccolai C, Goretti B, Till C, Banwell B. Maturational Trajectory of Processing Speed Performance in Pediatric Multiple Sclerosis. Dev Neuropsychol 2017; 42:299-308. [DOI: 10.1080/87565641.2017.1351974] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Nadine Akbar
- School of Rehabilitation Therapy, Queen’s University, Kingston, Ontario, Canada
| | - Alessio Signori
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
| | - Maria Pia Amato
- Neurologic Unit, Department NEUROFARBA, Section Neurosciences, University of Florence, Florence, Italy
| | - Maria Pia Sormani
- Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
| | | | - Claudia Niccolai
- Neurologic Unit, Department NEUROFARBA, Section Neurosciences, University of Florence, Florence, Italy
| | - Benedetta Goretti
- Neurologic Unit, Department NEUROFARBA, Section Neurosciences, University of Florence, Florence, Italy
| | - Christine Till
- Department of Psychology, York University, Toronto, Ontario, Canada
| | - Brenda Banwell
- Department of Neurology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania
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Gibbons CA, Sadeghi M, Barlow-Krelina E, Shaikh KT, Alan Fung WL, Meschino WS, Till C. M15 Computerised cognitive training for individuals with early stage huntington’s disease. J Neurol Psychiatry 2016. [DOI: 10.1136/jnnp-2016-314597.300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Amato MP, Krupp LB, Charvet LE, Penner I, Till C. Pediatric multiple sclerosis. Neurology 2016; 87:S82-7. [DOI: 10.1212/wnl.0000000000002883] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 03/01/2016] [Indexed: 11/15/2022] Open
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Akbar N, Banwell B, Sled JG, Binns MA, Doesburg SM, Rypma B, Lysenko M, Till C. Brain activation patterns and cognitive processing speed in patients with pediatric-onset multiple sclerosis. J Clin Exp Neuropsychol 2015; 38:393-403. [DOI: 10.1080/13803395.2015.1119255] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Akbar N, Till C, Sled JG, Binns MA, Doesburg SM, Aubert-Broche B, Collins DL, Araujo D, Narayanan S, Arnold DL, Lysenko M, Banwell B. Altered resting-state functional connectivity in cognitively preserved pediatric-onset MS patients and relationship to structural damage and cognitive performance. Mult Scler 2015; 22:792-800. [PMID: 26362891 DOI: 10.1177/1352458515602336] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 07/30/2015] [Indexed: 01/18/2023]
Abstract
OBJECTIVE To evaluate resting-state functional connectivity (FC) and relationship to brain volumes and cognition in a sample of cognitively preserved pediatric-onset multiple sclerosis (MS) patients. METHODS Sixteen cognitively intact pediatric-onset MS patients and 15 healthy age- and sex-matched controls underwent cognitive testing and 3T anatomical and functional MRI. Resting-state FC patterns were examined using region-of-interest-based timeseries correlations. RESULTS Compared to controls, pediatric-onset MS patients demonstrated higher FC of the precuneus, particularly with the anterior cingulate cortex (z=4.21, p<.001), frontal medial cortex (z=3.48, p<.001), and cerebellum (z=3.72, p<.001). Greater T2 lesion volume and lower normalized thalamic volume were associated with reduced FC of the thalamus, especially for FC with the right superior occipital region (t=-2.87, p=.0123 and t=2.27, p=.04 respectively). FC of the left frontal medial cortex was negatively correlated with composite cognitive z-score in the pediatric-onset MS group (p<.05). CONCLUSIONS Greater resting-state FC between posterior and anterior brain regions is present in pediatric-onset MS. With greater disease-related structural pathology, there is a disruption of thalamo-cortical FC. In the absence of actual cognitive impairment, heightened FC of the frontal medial cortex was associated with lower cognitive performance, suggesting that greater functional resources are recruited during resting-state in patients with reduced cognitive efficiency.
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Affiliation(s)
- Nadine Akbar
- Neurosciences and Mental Health Program, Research Institute, The Hospital for Sick Children, Canada/Institute of Medical Science, University of Toronto, Canada
| | | | - John G Sled
- Physiology and Experimental Medicine, Research Institute, The Hospital for Sick Children, Canada/Department of Medical Biophysics, University of Toronto, Canada
| | - Malcolm A Binns
- Rotman Research Institute at Baycrest Centre, Canada/Dalla Lana School of Public Health, University of Toronto, Canada
| | - Sam M Doesburg
- Neurosciences and Mental Health Program, Research Institute, The Hospital for Sick Children, Canada/Institute of Medical Science, University of Toronto, Canada
| | | | - Donald Louis Collins
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Canada
| | - David Araujo
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Canada
| | - Sridar Narayanan
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Canada
| | - Douglas L Arnold
- McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Canada
| | | | - Brenda Banwell
- Department of Neurology, Children's Hospital of Philadelphia, USA
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