Early-life exposure to perfluoroalkyl substances and serum antibody concentrations towards common childhood vaccines in 18-month-old children in the Odense Child Cohort

Exposure to per- and polyfluoroalkyl substances (PFAS) has been associated with reduced antibody response to childhood vaccinations. Previous studies have mostly focused on antibodies against diphtheria or tetanus, while fewer studies have assessed antibodies toward attenuated viruses, such as measles, mumps or rubella (MMR). Therefore, we set out to determine associations between prenatal and early postnatal PFAS exposure and vaccine-specific Immunoglobulin G (IgG) in the background-exposed Odense Child Cohort. Blood samples were drawn in pregnancy at gestation weeks 8-16 and from the offspring at age 18 months. In the maternal serum samples we quantified perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA). In the offspring serum samples we quantified the same five PFAS compounds and IgG towards diphtheria, tetanus and MMR. A total of 880 and 841 children were included in the analyses of diphtheria and tetanus or MMR, respectively. Multiple linear regression models were used for estimation of difference in virus-specific IgG per doubling of PFAS concentrations. Maternal PFAS concentrations were non-significantly inversely associated with most vaccine-specific antibody concentrations. Likewise, child PFAS concentrations were associated with non-significant reductions of antibodies towards tetanus and MMR. A significant reduction in the percent difference in mumps antibody concentration per doubling of child PFNA (-9.2% (95% confidence interval: -17.4;-0.2)), PFHxS (-8.3% (-15.0;-1.0) and PFOS (-7.9% (-14.8;-0.4) was found. These findings are of public health concern, as inadequate response towards childhood vaccines may represent a more general immune dysfunction.

Prenatal and early postnatal exposure to perfluoroalkyl substances and bone mineral content and density in the Odense Child Cohort

INTRODUCTION

Exposure to perfluoroalkyl substances (PFAS) has been associated with lower bone mineral density (BMD) in animal and human studies, but prospective data from children are limited.

OBJECTIVES

To determine associations between prenatal and early postnatal PFAS exposure and BMD at age 7 years.

METHODS

In the Odense Child Cohort, Denmark, pregnant women were recruited in 2010-2012, and their children were invited for subsequent health examinations. At 12 weeks of gestation the pregnant women delivered a serum sample, and at age 18 months serum was obtained from the child to measure perfluorooctane sulfonic acid(PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) by LC-MS/MS. At age 7 years DXA scans were performed to measure bone mineral content (BMC) and BMD Z-score. PFAS in pregnancy (n = 881) and/or at age 18 months (n = 668) were regressed against DXA measurements, adjusted for maternal education, child height Z-score, sex (for BMC) and for postnatal exposure, additionally duration of total breastfeeding. We additionally performed structural equation models determining combined effects of pre-and postnatal PFAS exposures.

RESULTS

Higher prenatal and early postnatal serum concentrations of all measured PFAS were associated with lower BMC and BMD Z-scores at age 7 years, all estimates were negative although not all significant. For each doubling of 18-month exposure to PFNA or PFOS, BMD Z-scores were lowered by -0.10 (95 % CI -0.19;-0.00) and -0.08 (-0.17;-0.00), respectively after adjustment. Pre- and postnatal PFAS were correlated, but structural equation models suggested that associations with BMD were stronger for 18-month than prenatal PFAS exposure.

DISCUSSION

Bone density is established in childhood, and a reduction in BMD during early childhood may have long-term implication for peak bone mass and lifelong bone health. Future studies of the impact of PFAS exposure on fracture incidence will help elucidate the clinical relevance.

Association Between Prenatal and Early Postnatal Exposure to Perfluoroalkyl Substances and IQ Score in 7-Year-Old Children From the Odense Child Cohort

Perfluoroalkyl substances (PFAS) are persistent chemicals capable of crossing the placenta and passing into breast milk. Evidence suggests that PFAS exposure may affect brain development. We investigated whether prenatal or early postnatal PFAS exposure was associated with intelligence quotient (IQ) scores in schoolchildren from the Odense Child Cohort (Denmark, 2010-2020). We assessed concentrations of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) in maternal serum collected during the first trimester of pregnancy and in child serum at age 18 months. At 7 years of age, children completed an abbreviated version of the Wechsler Intelligence Scale for Children, Fifth Edition, from which Full Scale Intelligence Quotient (FSIQ) and Verbal Comprehension Index scores were estimated. In multiple linear regression analyses conducted among 967 mother-child pairs, a doubling in maternal PFOS and PFNA concentrations was associated with a lower FSIQ score, while no significant associations were observed for PFOA, PFHxS, or PFDA. PFAS concentrations at age 18 months and duration of breastfeeding were strongly correlated, and even in structural equation models it was not possible to differentiate between the opposite effects of PFAS exposure and duration of breastfeeding on FSIQ. PFAS exposure is ubiquitous; therefore, an association with even a small reduction in IQ is of public health concern.

Prenatal and early postnatal exposure to perfluoroalkyl substances and bone mineral content and density in the Odense child cohort

INTRODUCTION

Exposure to perfluoroalkyl substances (PFAS) has been associated with lower bone mineral density (BMD) in animal and human studies, but prospective data from children are limited.

OBJECTIVES

To determine associations between prenatal and early postnatal PFAS exposure and BMD at age 7 years.

METHODS

In the Odense Child Cohort, Denmark, pregnant women were recruited in 2010-2012, and their children were invited for subsequent health examinations. At 12 weeks of gestation the pregnant women delivered a serum sample, and at age 18 months serum was obtained from the child to measure perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) by LC-MS/MS. At age 7 years DXA scans were performed to measure bone mineral content (BMC) and BMD Z-score. PFAS in pregnancy (n = 924) and/or at age 18 months (n = 511) were regressed against DXA measurements, adjusted for maternal education, child height Z-score, sex (for BMC) and for postnatal exposure, additionally duration of total breastfeeding. We additionally performed structural equation models determining combined effects of pre-and postnatal PFAS exposures.

RESULTS

Higher prenatal and early postnatal serum concentrations of all measured PFAS were associated with lower BMC and BMD Z-scores at age 7 years, all estimates were negative although not all significant. For each doubling of prenatal or 18-month exposure to PFDA, BMD Z-scores were lowered by -0.07 (95 % CI -0.10; -0.03) and -0.14 (-0.25; -0.03), respectively after adjustment. Pre- and postnatal PFAS were correlated, but structural equation models suggested that associations with BMD were stronger for 18-month than prenatal PFAS exposure.

DISCUSSION

Bone density is established in childhood, and a reduction in BMD during early childhood may have long-term implication for peak bone mass and lifelong bone health. Future studies of the impact of PFAS exposure on fracture incidence will help elucidate the clinical relevance.

Prenatal Exposure to Butyl Paraben Is Associated With Fat Percentage in 7-Year-Old Boys

CONTEXT

Parabens are used as preservatives in consumer products but are suspected of having endocrine-disrupting properties. A recent study reported an association between in utero exposure to butyl paraben and overweight in childhood, with a stronger trend in girls.

OBJECTIVE

We therefore studied the association between parabens in maternal urine in third trimester and fat percentage in children aged 7 years.

DESIGN, SETTING, AND PARTICIPANTS

We used data from the Odense Child Cohort, a mother-child cohort with enrollment from 2010 to 2012, in which the children are followed. Paraben concentration was assessed in maternal urine at median gestational week 28.7 and body composition measured as total, gynoid, and android fat percentages assessed by dual X-ray absorptiometry in their children at age 7 years.

MAIN OUTCOME MEASUREMENTS

Total, gynoid, and android fat percentages and z-score for body mass index.

INTERVENTIONS

None.

RESULTS

Paraben exposure was low. In multivariate linear regressions, detection of butylparaben in maternal urine was associated with an increase of 17% [95% confidence intervals (CI) 3.0%, 32%] in total body fat percentage and an increase of 23% (95% CI 5.1%, 43%) in android fat percentage in boys, compared to boys whose mother had no detectable butylparaben in urine. No significant associations between in utero exposure to methyl-, ethyl- or propyl parabens and body composition were found, and no significant associations were seen in girls.

CONCLUSION

Our findings suggest that parabens, which are believed to have low toxicity, may affect obesity development at vulnerable time periods during development.

Implant positioning (IMPO) in undisplaced femoral neck fractures: Association to reoperation and development of an IMPO scoring system

INTRODUCTION

This study aims to investigate whether implant positioning is associated to risk of reoperation following internal fixation of undisplaced femoral neck fractures (FNF) with a posterior tilt < 20° in patients > 65 years.

METHOD

Patients were retrieved from the Danish Multidisciplinary Hip Fracture Register in the period 2009-2013. The patients' health records and x-rays were reviewed for age, sex, implant, Charlson Comorbidity Index, mortality, reoperation, fracture classification and implant positioning. X-rays were measured for implant positioning using a pre-existing scoring system (the Schep score) as well as some additional measurements. Primary outcome was reoperation within 2 years. The study included 406 patients, 75% females and the median (range) age was 82 (65-99) years. Odds ratios (OR) are shown with 95% confidence interval.

RESULTS

There were 45 (11%) reoperations. Six measurements were individually associated to risk of reoperation: 1) Distance to inferior calcar < 1 or ≥ 6 mm, OR 2 (1.1-4), 2) Distance to superior cortex 10 mm, OR 2(1.1-5), 3) Tip-head distance < 3 or ≥ 20 mm, OR 2 (1.1-4), 4) Placement in the superior or inferior 15 mm, OR 2 (1.1-5), 5) Placement in the anterior 25 %, OR 6 (1.8-20), 6) Inter-implant angle ≥ 5°, OR 3 (1.4-8). The Schep score had no associated to reoperation, and therefore a new implant positioning (IMPO) score was developed. The IMPO score consists of 6 items; 1 point given for each acceptable implant placement. An IMPO score less than 5 had an increased risk of reoperation; 0-2 points OR 22 (7-71) and OR 5 (2-11) for 3-4 points, compared to a score of 5-6. Among the 207 patients with a score of 5-6, the reoperation frequency was 4%.

CONCLUSIONS

This study identified implant positioning as a predictor to an increased risk of reoperation in undisplaced FNF. The newly developed IMPO score seems promising for identifying risk of reoperation.

Fracture-induced changes in biomarkers CTX, PINP, OC, and BAP-a systematic review

To assess the time from fracture until bone turnover markers (BTM), which are biochemical markers reflecting in vivo bone formation and resorptive activity, have returned to a stable level since BTM have been shown to be at least as good as bone mineral density in monitoring the effect of anti-resorptive treatment in osteoporosis. This study searched for articles in PUBMED, CINAHL, Medline, EM-BASE, and Cochrane, and identified 3486 unique articles. These articles were screened based on predefined inclusion and exclusion criteria. Seven articles addressing time to normalization of either CTX, PINP, osteocalcin, or bone-specific alkaline phosphatase after a recent fracture were identified and these were analyzed qualitatively. CTX appeared to return to baseline within 6 months. PINP appeared to return to baseline within 6 months and interestingly dip below baseline after a year. Osteocalcin was elevated throughout the first year after a fracture, with most changes in the first 6 months. Bone-specific alkaline phosphatase (BAP) was increased for up to a year, however with a discrepancy between used assays. Seven studies were identified, showing CTX and PINP to return to baseline within 6 months. OC was elevated for 12 months. BAP was increased for up to a year. However, none of these studies had fasting patients and a long follow-up period with regular measurements. The studies could indicate that the BTM CTX and PINP have returned to baseline within 6 months; however, further studies are needed assessing pre-analytical factors while having a long follow-up. Bone turnover markers appear as good as or better than bone mineral density in monitoring the effect of anti-resorptive medication in osteoporosis. This study tries to identify the time from fracture until BTM are back at baseline. Most studies did not however take pre-analytical variation into consideration. Further research is therefore needed.