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Alsaeedi EE, Rose P, Welham SJM. Salivary iodide status as a measure of whole body iodine homoeostasis? Br J Nutr 2024; 131:1740-1753. [PMID: 38287697 PMCID: PMC11063662 DOI: 10.1017/s000711452400031x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 01/09/2024] [Accepted: 01/23/2024] [Indexed: 01/31/2024]
Abstract
Iodine is a trace element required to produce the thyroid hormones, which are critical for development, growth and metabolism. To ensure appropriate population iodine nutrition, convenient and accurate methods of monitoring are necessary. Current methods for determining iodine status either involve a significant participant burden or are subject to considerable intra-individual variation. The continuous secretion of iodide in saliva potentially permits its use as a convenient, non-invasive assessment of status in populations. To assess its likely effectiveness, we reviewed studies analysing the association between salivary iodide concentration (SIC) and dietary iodine intake, urinary iodide concentration (UIC) and/or 24-h urinary iodide excretion (UIE). Eight studies conducted in different countries met the inclusion criteria, including data for 921 subjects: 702 healthy participants and 219 with health conditions. SIC correlated positively with UIC and/or UIE in four studies, with the strength of relationship ranging from r = 0·19 to r = 0·90 depending on sampling protocol, age, and if salivary values were corrected for protein concentration. Additionally, SIC positively correlated with dietary intake, being strongest when saliva was collected after dinner. SIC varied with external factors, including thyroid function, use of some medications, smoking and overall health status. Evidence provided here supports the use of SIC as a viable, low-burden method for determining iodine status in populations. However, small sample sizes and high variability indicates the need for more extensive analyses across age groups, ethnicities, disease states and dietary groups to clarify the relative accuracy and reliability in each case and standardise procedure.
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Affiliation(s)
- Eatedal Eenizan Alsaeedi
- University of Nottingham, School of Biosciences, Division of Food, Nutrition & Dietetics, Loughborough, LeicestershireLE12 5RD, UK
- University of Hafr Al Batin, College of Applied Medical Sciences, Division of Clinical Nutrition, Hafr Al Batin, Saudi Arabia
| | - Peter Rose
- University of Nottingham, School of Biosciences, Division of Food, Nutrition & Dietetics, Loughborough, LeicestershireLE12 5RD, UK
| | - Simon J. M. Welham
- University of Nottingham, School of Biosciences, Division of Food, Nutrition & Dietetics, Loughborough, LeicestershireLE12 5RD, UK
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2
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Eriksson J, Barregard L, Sallsten G, Berlinger B, Weinbruch S, Manousou S, Ellingsen DG, Nyström HF. Urinary iodine excretion and optimal time point for sampling when estimating 24-h urinary iodine. Br J Nutr 2023; 130:1289-1297. [PMID: 36744548 PMCID: PMC10511680 DOI: 10.1017/s0007114523000326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 01/10/2023] [Accepted: 01/30/2023] [Indexed: 02/07/2023]
Abstract
Iodine deficiency may cause thyroid dysfunction. The iodine intake in a population is measured by urinary iodine concentration (UIC) in spot samples or 24-h urinary iodine excretion (24UIE). 24UIE is considered the gold standard and may be estimated using an equation including UIC, urinary creatinine concentration, sex and age (e24UIE). The aims of this study were to evaluate the preferable timing of UIC when using this equation and assess the variability of UIE. Sixty healthy non-smoking women (n 31) and men (n 29) were included in Gothenburg, Sweden. Twelve urine samples were collected at six fixed times on two separate days. Variability was calculated for UIC, 24UIE, e24UIE, iodine excretion per hour (iHr) and UIC adjusted for creatinine and specific gravity. Median 24UIE was 156 µg/24 h and the median UIC (all spot samples) was 104 µg/l. UIC (P < 0·001), 24UIE (P = 0·001) and e24UIE (P < 0·001) were significantly higher in men. e24UIE was relatively similar to 24UIE. However, when e24UIE was calculated from UIC in the first void, it was about 15 % lower than 24UIE (P < 0·001). iHr was lowest in the morning and highest in the afternoon. Median iHr was higher in men (7·4 v. 5·3 µg/h, P < 0·001). The variability of UIE was higher within individuals than between individuals. This study suggests that most time points for estimation of individual 24UIE are appropriate, but they should preferably not be collected in the first void.
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Affiliation(s)
- Janna Eriksson
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Praktikertjänst AB, Skövde, 54130, Sweden
| | - Lars Barregard
- Occupational and Environmental Medicine, Department of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Gerd Sallsten
- Occupational and Environmental Medicine, Department of Public Health and Community Medicine, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden
| | - Balazs Berlinger
- National Institute of Occupational Health, Oslo, Norway
- Department of Animal Hygiene, Herd Health and Mobile Clinic, University of Veterinary Medicine, Budapest, Hungary
| | - Stephan Weinbruch
- National Institute of Occupational Health, Oslo, Norway
- Institute of Applied Geosciences, Darmstadt Technical University, Darmstadt, Germany
| | - Sofia Manousou
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Frölunda Specialist Hospital, Västra Frölunda, Sweden
| | | | - Helena Filipsson Nyström
- Department of Internal Medicine and Clinical Nutrition, Institute of Medicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Department of Endocrinology, Institute of Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
- Wallenberg’s Centre for Molecular and Translational Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
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3
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Nikanorova AA, Barashkov NA, Pshennikova VG, Teryutin FM, Nakhodkin SS, Solovyev AV, Romanov GP, Burtseva TE, Fedorova SA. A Systematic Review and Meta-Analysis of Free Triiodothyronine (FT3) Levels in Humans Depending on Seasonal Air Temperature Changes: Is the Variation in FT3 Levels Related to Nonshivering Thermogenesis? Int J Mol Sci 2023; 24:14052. [PMID: 37762355 PMCID: PMC10531421 DOI: 10.3390/ijms241814052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
Thyroid hormones play a crucial role in regulating normal development, growth, and metabolic function. However, the controversy surrounding seasonal changes in free triiodothyronine (FT3) levels remains unresolved. Therefore, the aim of this study was to conduct a systematic review and meta-analysis of variations in FT3 levels in relation to seasonal air temperatures in the context of current knowledge about its role in nonshivering thermogenesis. Ten eligible articles with a total of 336,755 participants were included in the meta-analysis. The studies were categorized into two groups based on the air temperature: "Cold winter", where the winter temperature fell below 0 °C, and "Warm winter", where the winter temperature was above 0 °C. The analysis revealed that in cold regions, FT3 levels decreased in winter compared to summer (I2 = 57%, p < 0.001), whereas in warm regions, FT3 levels increased during winter (I2 = 28%, p < 0.001). These findings suggest that seasonal variations in FT3 levels are likely to be influenced by the winter temperature. Considering the important role of the FT3 in the nonshivering thermogenesis process, we assume that this observed pattern is probably related to the differences in use of thyroid hormones in the brown adipose tissue during adaptive thermogenesis, which may depend on intensity of cold exposure.
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Affiliation(s)
- Alena A. Nikanorova
- Yakut Science Centre of Complex Medical Problems, Yaroslavskogo 6/3, 677000 Yakutsk, Russia; (A.A.N.); (V.G.P.); (F.M.T.); (T.E.B.); (S.A.F.)
| | - Nikolay A. Barashkov
- Yakut Science Centre of Complex Medical Problems, Yaroslavskogo 6/3, 677000 Yakutsk, Russia; (A.A.N.); (V.G.P.); (F.M.T.); (T.E.B.); (S.A.F.)
| | - Vera G. Pshennikova
- Yakut Science Centre of Complex Medical Problems, Yaroslavskogo 6/3, 677000 Yakutsk, Russia; (A.A.N.); (V.G.P.); (F.M.T.); (T.E.B.); (S.A.F.)
| | - Fedor M. Teryutin
- Yakut Science Centre of Complex Medical Problems, Yaroslavskogo 6/3, 677000 Yakutsk, Russia; (A.A.N.); (V.G.P.); (F.M.T.); (T.E.B.); (S.A.F.)
| | - Sergey S. Nakhodkin
- M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677013 Yakutsk, Russia; (S.S.N.); (A.V.S.); (G.P.R.)
| | - Aisen V. Solovyev
- M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677013 Yakutsk, Russia; (S.S.N.); (A.V.S.); (G.P.R.)
| | - Georgii P. Romanov
- M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677013 Yakutsk, Russia; (S.S.N.); (A.V.S.); (G.P.R.)
| | - Tatiana E. Burtseva
- Yakut Science Centre of Complex Medical Problems, Yaroslavskogo 6/3, 677000 Yakutsk, Russia; (A.A.N.); (V.G.P.); (F.M.T.); (T.E.B.); (S.A.F.)
- M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677013 Yakutsk, Russia; (S.S.N.); (A.V.S.); (G.P.R.)
| | - Sardana A. Fedorova
- Yakut Science Centre of Complex Medical Problems, Yaroslavskogo 6/3, 677000 Yakutsk, Russia; (A.A.N.); (V.G.P.); (F.M.T.); (T.E.B.); (S.A.F.)
- M.K. Ammosov North-Eastern Federal University, Kulakovskogo 46, 677013 Yakutsk, Russia; (S.S.N.); (A.V.S.); (G.P.R.)
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Fuse Y, Ito Y, Tsukada N, Shishiba Y, Irie M. Iodine intake in healthy Japanese aged from 6 to 70 years residing in the same district. Endocr J 2022; 69:253-262. [PMID: 34602518 DOI: 10.1507/endocrj.ej21-0479] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Iodine is an essential component of thyroid hormones and a dietary micronutrient for humans, and adequate iodine intake is necessary to maintain thyroid function. A population's iodine intake and nutritional status are assessed based on urinary iodine excretion. There are few studies on iodine nutritional status for all age groups residing in the same area in Japan. Between 2010 and 2017, a total of 769 healthy subjects aged 6.4-73 years in three sites in Yokohama City, were enrolled in the survey. The urinary iodine concentration (UIC), iodine to creatinine (Cr) ratio (UI/Cr) and estimated 24-h urinary iodine excretion (UIE) in single spot urine samples were measured, and habitual dietary iodine intake was assessed by food frequency questionnaires. The estimated 24-h UIE was calculated using individual predicted 24-h creatinine excretion by the validated equations developed for healthy Japanese children and adults which vary by age, gender and anthropometry. The median UIC for all participants was 219 μg/L, suggesting adequate iodine intake for this population. There was an increasing trend in median UI/Cr and estimated 24-h UIE by age. A significant correlation between UIC and UI/Cr (r = 0.6378), UIC and estimated 24-h UIE (r = 0.6804), and UI/Cr and estimated 24-h UIE (r = 0.5756) were observed. These estimates can be feasible, convenient and alternative methods to 24-h urine collection in order to assess iodine status in some populations such as ethnically or racially homogeneous and well-nourished people. Additional studies are required to validate these findings.
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Affiliation(s)
- Yozen Fuse
- Research Committee on Iodine Related Health Problems, Foundation for Growth Science, Tokyo 113-0033, Japan
| | - Yoshiya Ito
- Division of Clinical Medicine, Japanese Red Cross Hokkaido College of Nursing, Kitami 090-0011, Japan
| | - Nobu Tsukada
- Kagawa Nutrition University, Institute of Nutrition Sciences, Sakado 350-0288, Japan
| | - Yoshimasa Shishiba
- Research Committee on Iodine Related Health Problems, Foundation for Growth Science, Tokyo 113-0033, Japan
| | - Minoru Irie
- Research Committee on Iodine Related Health Problems, Foundation for Growth Science, Tokyo 113-0033, Japan
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Arns-Glaser L, Zandberg L, Assey VD, Baumgartner J, Abdallah F, Galetti V, Dary O, Zimmermann MB, Andersson M. Seasonal effects on urinary iodine concentrations in women of reproductive age: An observational study in Tanzania and South Africa. Am J Clin Nutr 2022; 115:298-309. [PMID: 34601579 DOI: 10.1093/ajcn/nqab327] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 09/24/2021] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Iodine intake in populations is usually assessed by measuring urinary iodine concentrations (UICs) in spot samples. Hot climate conditions may reduce urine volume, thus leading to overestimations of UIC and thereby masking inadequate iodine intake. OBJECTIVES We investigated the effects of season on UICs in 2 populations exposed to high-temperature climates. METHODS In this observational study, we examined women (18-49 years) in Tanzania (ncold = 206; nhot = 179) and South Africa (ncold = 157; nhot = 126) during cold and hot seasons. From each woman in both seasons, we obtained two 24-hour urine collections and 2 spot urine samples, as well as salt, water, and cow's milk samples. We measured the urine volume, UIC, and urinary creatinine concentration (UCC). The 24-hour urinary iodine excretion (UIE) was calculated and used to estimate the iodine intake. We used linear mixed-effects models to test for differences between seasons. RESULTS In Tanzanian women, we observed no seasonal effect on the urine volume, 24-hour UIE, 24-hour UIC, spot UIC, spot UIC:UCC ratio, or salt iodine concentration. In South African women, the median 24-hour urine volume was 1.40 L (IQR, 0.96-2.05 L) in the winter and 15% lower in the summer (P < 0.001). The median 24-hour UIE was 184 µg/day (IQR, 109-267 µg/day) in the winter and 34% lower in the summer (P < 0.001), indicating a lower iodine intake. As a result, UICs did not significantly differ between seasons in 24-hour collections and spot samples, whereas the spot UIC:UCC ratio differed by 21% (P < 0.001) and reflected the lower iodine intake. In both study populations, the within- and between-person variabilities in urine volume, 24-hour UICs, and spot UICs were higher than the variability between seasons. CONCLUSIONS Spot UIC may slightly overestimate the iodine intake in hot temperatures due to concentrated urine, and methods to correct for urine volume may be considered. Local seasonal differences in iodine intakes may also occur in some populations. This trial was registered at http://www.clinicaltrials.gov as NCT03215680.
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Affiliation(s)
- Leonie Arns-Glaser
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Lizelle Zandberg
- Centre of Excellence for Nutrition, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Vincent D Assey
- Nutrition Services Section Ministry of Health, Community Development, Gender, Elderly and Children, Dar es Salaam, Tanzania.,Iodine Global Network, Ottawa, Canada
| | - Jeannine Baumgartner
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland.,Centre of Excellence for Nutrition, Faculty of Health Sciences, North-West University, Potchefstroom, South Africa
| | - Fatma Abdallah
- Iodine Global Network, Ottawa, Canada.,Tanzania Food and Nutrition Centre, Dar es Salaam, Tanzania
| | - Valeria Galetti
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland
| | - Omar Dary
- Division of Nutrition and Environmental Health, Office of Maternal and Child Health and Nutrition, Bureau for Global Health, United States Agency for International Development, Washington, DC, USA
| | - Michael B Zimmermann
- Human Nutrition Laboratory, Institute of Food, Nutrition and Health, ETH Zurich, Zurich, Switzerland.,Iodine Global Network, Ottawa, Canada
| | - Maria Andersson
- Iodine Global Network, Ottawa, Canada.,Nutrition Research Unit, Children's Research Centre, University Children's Hospital Zurich, Zürich, Switzerland
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Hlucny K, Alexander BM, Gerow K, Larson-Meyer DE. Reflection of Dietary Iodine in the 24 h Urinary Iodine Concentration, Serum Iodine and Thyroglobulin as Biomarkers of Iodine Status: A Pilot Study. Nutrients 2021; 13:2520. [PMID: 34444680 PMCID: PMC8398459 DOI: 10.3390/nu13082520] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/18/2021] [Accepted: 07/18/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND The iodine status of the US population is considered adequate, but subpopulations remain at risk for iodine deficiency and a biomarker of individual iodine status has yet to be determined. The purpose of this study was to determine whether a 3 day titration diet, providing known quantities of iodized salt, is reflected in 24 h urinary iodine concentration (UIC), serum iodine, and thyroglobulin (Tg). METHODS A total of 10 participants (31.3 ± 4.0 years, 76.1 ± 6.3 kg) completed three, 3 day iodine titration diets (minimal iodine, US RDA, (United States Recommended Daily Allowance), and 3× RDA). The 24 h UIC, serum iodine, and Tg were measured following each diet. The 24 h UIC and an iodine-specific food frequency questionnaire (FFQ) were completed at baseline. RESULTS UIC increased an average of 19.3 μg/L for every gram of iodized salt consumed and was different from minimal to RDA (p = 0.001) and RDA to 3× RDA diets (p = 0.04). Serum iodine was different from RDA to 3× RDA (p = 0.006) whereas Tg was not responsive to diet. Baseline UIC was associated with iodine intake from milk (r = 0.688, p = 0.028) and fish/seafood (r = 0.646, p = 0.043). CONCLUSION These results suggest that 24 h UIC and serum iodine may be reflective of individual iodine status and may serve as biomarkers of iodine status.
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Affiliation(s)
- Katelyn Hlucny
- Department of Family and Consumer Sciences, University of Wyoming, Laramie, WY 82071, USA;
| | - Brenda M. Alexander
- Department of Animal Science, University of Wyoming, Laramie, WY 82071, USA;
| | - Ken Gerow
- Department of Mathematics and Statistics, University of Wyoming, Laramie, WY 82071, USA;
| | - D. Enette Larson-Meyer
- Department of Human Nutrition, Foods and Exercise, Virginia Tech, Blacksburg, VA 24061, USA
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7
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Mairesse A, Wauthier L, Courcelles L, Luyten U, Burlacu MC, Maisin D, Favresse J, van Dievoet MA, Gruson D. Biological variation and analytical goals of four thyroid function biomarkers in healthy European volunteers. Clin Endocrinol (Oxf) 2021; 94:845-850. [PMID: 33107075 DOI: 10.1111/cen.14356] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/30/2020] [Accepted: 10/05/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Interpretation of thyroid function tests by means of biological variation (BV) data is essential to identify significant changes between serial measurements at an individual level. Data on thyroid parameters in adults are limited. OBJECTIVES We aimed at determining the BV of four thyroid function test (thyroid-stimulating hormone (TSH), free thyroxin (FT4), free triiodothyronine (FT3) and thyroglobulin (Tg)) by applying recent recommendations to acquire BV data on a latest generation of immunoassay. METHODS Nineteen healthy volunteers (8 males and 11 females) were drawn every week during 5 consecutive weeks. Samples were analysed in duplicate on the Cobas 602 analyzer (Roche Diagnostics). After normality assessment, outlier exclusion and homogeneity of variance analysis, analytical variation (CVA ), within-subject biological variation (CVI ) and between-subject biological variation (CVG ) were determined using nested ANOVA. RESULTS CVA , CVI and CVG were 0.9%, 19.7% and 37.6% for TSH; 3.6%, 4.6% and 10.8% for FT4; 2.2%, 6.0% and 8.6% for FT3; and 0.9%, 15.4% and 84.9% for Tg. Index of individuality (II) for all parameters was between 0.2 and 0.7. The percentage above which the change between two measures is truly significant (reference change value) was 54.7% for TSH, 16.2% for FT4, 17.7% for FT3 and 42.8% for Tg. CONCLUSION Based on recent international recommendations, our study provides updated BV data for four thyroid function tests in European healthy volunteers. Reliable BV characteristics, and especially RCV, can facilitate the interpretation of consecutive thyroid function tests in an individual and therefore have the potential to efficiently support clinical decisions regarding thyroid diseases.
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Affiliation(s)
- Antoine Mairesse
- Clinical Biology Department, Cliniques Universitaires St Luc, Université catholique de Louvain, Brussels, Belgium
| | - Loris Wauthier
- Clinical Biology Department, Cliniques Universitaires St Luc, Université catholique de Louvain, Brussels, Belgium
| | - Louisiane Courcelles
- Clinical Biology Department, Cliniques Universitaires St Luc, Université catholique de Louvain, Brussels, Belgium
| | - Urszula Luyten
- Clinical Biology Department, Cliniques Universitaires St Luc, Université catholique de Louvain, Brussels, Belgium
| | - Maria-Cristina Burlacu
- Department of Endocrinology and Nutrition, Cliniques Universitaires St-Luc, Universite Catholique de Louvain, Brussels, Belgium
| | - Diane Maisin
- Clinical Biology Department, Cliniques Universitaires St Luc, Université catholique de Louvain, Brussels, Belgium
| | - Julien Favresse
- Department of Laboratory Medicine, Clinique St-Luc Bouge, Namur, Belgium
- Department of Pharmacy, Namur Research Institute for Life Sciences, University of Namur, Belgium
| | - Marie-Astrid van Dievoet
- Clinical Biology Department, Cliniques Universitaires St Luc, Université catholique de Louvain, Brussels, Belgium
| | - Damien Gruson
- Clinical Biology Department, Cliniques Universitaires St Luc, Université catholique de Louvain, Brussels, Belgium
- Pôle de recherche en Endocrinologie, Diabète et Nutrition, Institut de Recherche Expérimentale et Clinique, Cliniques Universitaires St-Luc and Université Catholique de Louvain, Brussels, Belgium
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Guo W, Pan Z, Zhang Y, Jin Y, Dong S, Wu W, Chen W, Zhang W. Saliva Iodine Concentration in Children and Its Association with Iodine Status and Thyroid Function. J Clin Endocrinol Metab 2020; 105:5873876. [PMID: 32687189 DOI: 10.1210/clinem/dgaa471] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 07/17/2020] [Indexed: 02/12/2023]
Abstract
CONTEXT The effectiveness of saliva iodine concentration (SIC) in evaluating iodine status in children is not clear. OBJECTIVE We aimed to explore associations between SIC and assessed indicators of iodine status and thyroid function. DESIGN Cross-sectional study. SETTING Primary schools in Shandong, China. PARTICIPANTS Local children aged 8 to 13 years with no known thyroid disease were recruited to this study. MAIN OUTCOME MEASURES Blood, saliva, and urine samples were collected to evaluate thyroid function and iodine status. RESULTS SIC positively correlated with spot urinary iodine concentration (r = 0.29, P < 0.0001), 24-hour urinary iodine concentration (r = 0.35, P < 0.0001), and 24-hour urinary iodine excretion (r = 0.40, P < 0.0001). The prevalence of thyroid nodules (TN) and goiter showed an upward trend with SIC quantiles (P for trend < 0.05). Children with SIC <105 μg/L had a higher risk of insufficient iodine status (OR = 4.18; 95% CI, 2.67-6.56) compared with those with higher SIC. Those having SIC >273 μg/L were associated with greater risks of TN (OR = 2.70; 95% CI, 1.38-5.26) and excessive iodine status (OR = 18.56; 95% CI, 5.66-60.91) than those with lower SIC values. CONCLUSIONS There is a good correlation between SIC and urinary iodine concentrations. It is of significant reference value for the diagnosis of iodine deficiency with SIC of less than 105 μg/L and for the diagnosis of iodine excess and TN with SIC of more than 273 μg/L. Given the sanitary nature and convenience of saliva iodine collection, SIC is highly recommended as a good biomarker of recent iodine status in school-aged children.
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Affiliation(s)
- Wenxing Guo
- The Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Ziyun Pan
- The Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Ying Zhang
- The Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Ya Jin
- The Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Shuyao Dong
- The Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Wen Wu
- The Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Wen Chen
- The Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
| | - Wanqi Zhang
- The Department of Nutrition and Food Hygiene, School of Public Health, Tianjin Medical University, Tianjin, China
- Key Laboratory of Environment, Nutrition and Population Health of Tianjin, Tianjin, China
- Key Laboratory of Hormones and Development (Ministry of Health), Tianjin, China
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9
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Dietary Relationship with 24 h Urinary Iodine Concentrations of Young Adults in the Mountain West Region of the United States. Nutrients 2020; 12:nu12010121. [PMID: 31906335 PMCID: PMC7019367 DOI: 10.3390/nu12010121] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 12/08/2019] [Accepted: 12/19/2019] [Indexed: 01/05/2023] Open
Abstract
Background: Iodine deficiency is not seen as a public health concern in the US. However certain subpopulations may be vulnerable due to inadequate dietary sources. The purpose of the present study was to determine the dietary habits that influence iodine status in young adult men and women, and to evaluate the relationship between iodine status and thyroid function. Methods: 111 participants (31.6 ± 0.8 years, 173.2 ± 1.0 cm, 74.9 ± 1.7 kg) provided 24 h urine samples and completed an iodine-specific Food Frequency Questionnaire (FFQ) for assessment of urinary iodine content (UIC) as a marker of iodine status and habitual iodine intake, respectively. Serum Thyroid Stimulating Hormone (TSH) concentration was evaluated as a marker of thyroid function. Spearman correlational and regression analysis were performed to analyze the associations between iodine intake and iodine status, and iodine status and thyroid function. Results: 50.4% of participants had a 24 h UIC < 100 µg/L). Dairy (r = 0.391, p < 0.000) and egg intake (r = 0.192, p = 0.044) were the best predictors of UIC, accounting for 19.7% of the variance (p ≤ 0.0001). There was a significant correlation between UIC and serum TSH (r = 0.194, p < 0.05) but TSH did not vary by iodine status category (F = 1.087, p = 0.372). Discussion: Total dairy and egg intake were the primary predictors of estimated iodine intake, as well as UIC. Iodized salt use was not a significant predictor, raising questions about the reliability of iodized salt recall. These data will be useful in directing public health and clinical assessment efforts in the US and other countries.
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Skalny AV, Mona W, Kao R, Skalnaya MG, Huang PT, Wu CC, Ajsuvakova OP, Skalnaya OA, Tinkov AA. Hair Trace Element Levels in Han and Indigenous Hualien Inhabitants in Taiwan. Biol Trace Elem Res 2019; 191:1-9. [PMID: 30465167 DOI: 10.1007/s12011-018-1581-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 11/13/2018] [Indexed: 10/27/2022]
Abstract
The objective of the present study was to assess the impact of ethnicity on hair trace element content in Han and aboriginal inhabitants of Hualien in Taiwan. Fifty Han (female/male = 35/15) and 50 aboriginal (female/male = 40/10) Hualien inhabitants aged 40-60 years were involved in the present study. Anthropometric data and dietary patterns were recorded. Hair mineral, essential, and toxic trace element levels were assessed using inductively coupled plasma mass spectrometry at NexION 300D (PerkinElmer Inc., USA) equipped with ESI SC-2 DX4 autosampler (Elemental Scientific Inc., USA). No group difference in gender, age, body weight, height, or physical activity was observed. Fish intake was more frequent in Han inhabitants, whereas aborigines consumed significantly more nuts. Indigenous people were characterized by higher hair Al (45%), Ca (threefold), Co (71%), Fe (twofold), I (74%), K (60%), Mg (2.5-fold), Na (62%), P (6%), Sn (78%), and V (46%) content. In turn, Han Hualien inhabitants had higher hair Be (twofold), Li, Se, Si levels as compared to indigenous counterparts. Multiple regression analysis demonstrated that ethnicity was significantly associated with hair Ca (β = 0.302), Mn (β = 0.284), P (β = 0.387), and Se (β = - 0.310) levels after adjustment for other confounders. At the same time, the overall models were significant for Ca, Mn, Se, and As. The obtained data may provide a background for monitoring and correction of trace element status in patients of different ethnic groups. However, further detailed studies are required to highlight the mechanisms underlying the observed associations.
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Affiliation(s)
- Anatoly V Skalny
- Yaroslavl State University, Sovetskaya St., 14, Yaroslavl, 150000, Russia
- Peoples' Friendship University of Russia (RUDN University), Moscow, Russia
- IM Sechenov First Moscow State Medical University, Moscow, Russia
| | - Watan Mona
- Jian Township Health Center, Hualien, Taiwan
| | - Ryan Kao
- Upper School, Taipei American School, Taipei, Taiwan
| | - Margarita G Skalnaya
- Peoples' Friendship University of Russia (RUDN University), Moscow, Russia
- IM Sechenov First Moscow State Medical University, Moscow, Russia
| | | | - Cheng-Chi Wu
- Neomedi clinic, Shijian road, New Taipei, Taiwan
| | - Olga P Ajsuvakova
- Yaroslavl State University, Sovetskaya St., 14, Yaroslavl, 150000, Russia
- Peoples' Friendship University of Russia (RUDN University), Moscow, Russia
- IM Sechenov First Moscow State Medical University, Moscow, Russia
| | | | - Alexey A Tinkov
- Yaroslavl State University, Sovetskaya St., 14, Yaroslavl, 150000, Russia.
- Peoples' Friendship University of Russia (RUDN University), Moscow, Russia.
- IM Sechenov First Moscow State Medical University, Moscow, Russia.
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11
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Santi D, Spaggiari G, Brigante G, Setti M, Tagliavini S, Trenti T, Simoni M. Semi-annual seasonal pattern of serum thyrotropin in adults. Sci Rep 2019; 9:10786. [PMID: 31346248 PMCID: PMC6658473 DOI: 10.1038/s41598-019-47349-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 07/16/2019] [Indexed: 12/19/2022] Open
Abstract
Circannual rhythmicity in thyroid-stimulating hormone (TSH) secretion is proposed, whereas evidences on seasonal peripheral thyroid hormones’ fluctuation are contradictory. This study was designed to evaluate hypothalamic-pituitary-thyroid (HPT) seasonal secretion pattern using a big data approach. An observational, retrospective, big data trial was carried out, including all TSH measurements performed in a single laboratory between January 2010 and December 2017. A large dataset was created matching TSH data with patients’ age, gender, environmental temperature exposure, and free triiodothyronine (fT3) and free thyroxine (fT4) when available. The trend and seasonal distributions were analysed using autoregressive integrated moving average models. A total of 1,506,495 data were included in the final database with patients mean age of 59.00 ± 18.44 years. The mean TSH serum levels were 2.08 ± 1.57 microIU/mL, showing a seasonal distribution with higher levels in summer and winter seasons, independently from age, gender and environmental temperatures. Neither fT3 nor fT4 showed a seasonal trend. TSH seasonal changes occurred independently from peripheral thyroid hormone variations, gender, age and environmental temperatures. Although seasonal TSH fluctuation could represent a residual ancestral mechanism to maintain HPT homeostasis, the underlying physiological mechanism remains unclear and specific studies are needed to clarify its impacting role in humans.
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Affiliation(s)
- Daniele Santi
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy. .,Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria of Modena, OCSAE, Modena, Italy.
| | - Giorgia Spaggiari
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.,Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria of Modena, OCSAE, Modena, Italy
| | - Giulia Brigante
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.,Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria of Modena, OCSAE, Modena, Italy
| | - Monica Setti
- Service of Clinical Engineering, Azienda Ospedaliero-Universitaria of Modena, Modena, Italy
| | - Simonetta Tagliavini
- Department of Laboratory Medicine and Anatomy Pathology, Azienda USL of Modena, Modena, Italy
| | - Tommaso Trenti
- Department of Laboratory Medicine and Anatomy Pathology, Azienda USL of Modena, Modena, Italy
| | - Manuela Simoni
- Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, Italy.,Unit of Endocrinology, Department of Medical Specialties, Azienda Ospedaliero-Universitaria of Modena, OCSAE, Modena, Italy
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12
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Cui T, Wang W, Chen W, Pan Z, Gao S, Tan L, Pearce EN, Zimmermann MB, Shen J, Zhang W. Serum Iodine Is Correlated with Iodine Intake and Thyroid Function in School-Age Children from a Sufficient-to-Excessive Iodine Intake Area. J Nutr 2019; 149:1012-1018. [PMID: 31070733 DOI: 10.1093/jn/nxy325] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 11/29/2018] [Accepted: 12/26/2018] [Indexed: 01/18/2023] Open
Abstract
BACKGROUND An alternative feasible and convenient method of assessing iodine intake is needed. OBJECTIVE The aim of this study was to examine the utility of serum iodine for assessing iodine intake in children. METHODS One blood sample and 2 repeated 24-h urine samples (1-mo interval) were collected from school-age children in Shandong, China. Serum free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), thyroglobulin (Tg), total iodine (StI), and non-protein-bound iodine (SnbI) concentrations and urine iodine (UIC) and creatinine (UCr) concentrations were measured. Iodine intake was estimated based on two 24-h urine iodine excretions (24-h UIE). Associations between serum iodine and other factors were analyzed using the Spearman rank correlation test. Receiver operating characteristic (ROC) curves were used to illustrate diagnostic ability of StI and SnbI. RESULTS In total, 1686 children aged 7-14 y were enrolled. The median 24-h UIC for the 2 collections was 385 and 399 μg/L, respectively. The median iodine intake was estimated to be 299 μg/d and was significantly higher in boys than in girls (316 μg/d compared with 283 μg/d; P < 0.001). StI and SnbI were both positively correlated with FT4 (ρ = 0.30, P < 0.001; and ρ = 0.21, P < 0.001), Tg (ρ = 0.21, P < 0.001; and ρ = 0.19, P < 0.001), 24-h UIC (ρ = 0.56, P < 0.001; and ρ = 0.47, P < 0.001), 24-h UIE (ρ = 0.46, P < 0.001; and ρ = 0.49, P < 0.001), urine iodine-to-creatinine ratio (ρ = 0.58, P < 0.001; and ρ = 0.62, P < 0.001), and iodine intake (ρ = 0.49, P < 0.001; and ρ = 0.53, P < 0.001). The areas under the ROC curves for StI and SnbI for the diagnosis of excessive iodine intake in children were 0.76 and 0.77, respectively. The optimal StI and SnbI threshold values for defining iodine excess in children were 101 and 56.2 μg/L, respectively. CONCLUSIONS Serum iodine was positively correlated with iodine intake and the serum FT4 concentration in children. It is a potential biomarker for diagnosing excessive iodine intake in children. This trial was registered at clinicaltrials.gov as NCT02915536.
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Affiliation(s)
- Tingkai Cui
- School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China.,Tianjin Center for International Collaborative Research in Environment, Nutrition and Public Health, Tianjin, China
| | - Wei Wang
- School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China.,Tianjin Center for International Collaborative Research in Environment, Nutrition and Public Health, Tianjin, China
| | - Wen Chen
- School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China.,Tianjin Center for International Collaborative Research in Environment, Nutrition and Public Health, Tianjin, China
| | - Ziyun Pan
- School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China.,Tianjin Center for International Collaborative Research in Environment, Nutrition and Public Health, Tianjin, China
| | - Shu Gao
- School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China.,Tianjin Center for International Collaborative Research in Environment, Nutrition and Public Health, Tianjin, China
| | - Long Tan
- School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China.,Tianjin Center for International Collaborative Research in Environment, Nutrition and Public Health, Tianjin, China
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, Boston, MA
| | - Michael B Zimmermann
- The Human Nutrition Laboratory, Swiss Federal Institute of Technology, Zürich, Switzerland
| | - Jun Shen
- School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China.,Tianjin Center for International Collaborative Research in Environment, Nutrition and Public Health, Tianjin, China
| | - Wanqi Zhang
- School of Public Health, Tianjin Medical University, Tianjin, China.,Tianjin Key Laboratory of Environment, Nutrition and Public Health, Tianjin, China.,Tianjin Center for International Collaborative Research in Environment, Nutrition and Public Health, Tianjin, China.,Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
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13
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Wainwright P, Cook P. The assessment of iodine status - populations, individuals and limitations. Ann Clin Biochem 2018; 56:7-14. [PMID: 29703103 DOI: 10.1177/0004563218774816] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Iodine deficiency is a significant global health concern, and the single greatest cause of preventable cognitive impairment. It is also a growing public health concern in the UK particularly among pregnant women. Biomarkers such as urinary iodine concentration have clear utility in epidemiological studies to investigate population-level iodine status, but determination of iodine status in individuals is much more problematic with current assays. This article reviews the available biomarkers of iodine status and their relative utility at the level of both populations and individuals for the investigation of iodine deficiency and iodine excess.
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Affiliation(s)
- Patrick Wainwright
- 1 Chemical Pathology and Metabolic Medicine, Department of Laboratory Medicine, University Hospital Southampton, Southampton, UK.,2 Current affiliation: Department of Blood Sciences, Glan Clwyd Hospital, Bodelwyddan, UK
| | - Paul Cook
- 1 Chemical Pathology and Metabolic Medicine, Department of Laboratory Medicine, University Hospital Southampton, Southampton, UK
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14
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Are nappers unhealthy? Menopause 2016; 23:938-41. [DOI: 10.1097/gme.0000000000000717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Moreno-Reyes R, Kyrilli A, Lytrivi M, Bourmorck C, Chami R, Corvilain B. Is there still a role for thyroid scintigraphy in the workup of a thyroid nodule in the era of fine needle aspiration cytology and molecular testing? F1000Res 2016; 5. [PMID: 27158470 PMCID: PMC4850874 DOI: 10.12688/f1000research.7880.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/20/2016] [Indexed: 01/01/2023] Open
Abstract
Thyroid scintigraphy is now rarely used in the work-up of a thyroid nodule except in the presence of a low TSH value. Therefore, autonomously functioning thyroid nodules (AFTNs) with a normal TSH value are diagnosed only in the rare medical centers that continue to use thyroid scan systematically in the presence of a thyroid nodule. In this review, we discuss the prevalence of AFTN with a normal TSH level and the possible consequences of performing fine needle aspiration cytology (FNAC) in an undiagnosed AFTN. We also discuss the risk of malignant AFTN which may be higher than previously stated.
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Affiliation(s)
- Rodrigo Moreno-Reyes
- Department of Nuclear Medicine, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Aglaia Kyrilli
- Department of Endocrinology, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Maria Lytrivi
- Department of Endocrinology, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Carole Bourmorck
- Department of Endocrinology, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Rayan Chami
- Department of Endocrinology, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
| | - Bernard Corvilain
- Department of Endocrinology, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium
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16
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Ji X, Liu P, Sun Z, Su X, Wang W, Gao Y, Sun D. Intra-individual variation in urinary iodine concentration: effect of statistical correction on population distribution using seasonal three-consecutive-day spot urine in children. BMJ Open 2016; 6:e010217. [PMID: 26920442 PMCID: PMC4769391 DOI: 10.1136/bmjopen-2015-010217] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 02/01/2016] [Accepted: 02/02/2016] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE To determine the effect of statistical correction for intra-individual variation on estimated urinary iodine concentration (UIC) by sampling on 3 consecutive days in four seasons in children. SETTING School-aged children from urban and rural primary schools in Harbin, Heilongjiang, China. PARTICIPANTS 748 and 640 children aged 8-11 years were recruited from urban and rural schools, respectively, in Harbin. PRIMARY AND SECONDARY OUTCOME MEASURES The spot urine samples were collected once a day for 3 consecutive days in each season over 1 year. The UIC of the first day was corrected by two statistical correction methods: the average correction method (average of days 1, 2; average of days 1, 2 and 3) and the variance correction method (UIC of day 1 corrected by two replicates and by three replicates). The variance correction method determined the SD between subjects (Sb) and within subjects (Sw), and calculated the correction coefficient (Fi), Fi=Sb/(Sb+Sw/di), where di was the number of observations. The UIC of day 1 was then corrected using the following equation:[Formula: see text] RESULTS The variance correction methods showed the overall Fi was 0.742 for 2 days' correction and 0.829 for 3 days' correction; the values for the seasons spring, summer, autumn and winter were 0.730, 0.684, 0.706 and 0.703 for 2 days' correction and 0.809, 0.742, 0.796 and 0.804 for 3 days' correction, respectively. After removal of the individual effect, the correlation coefficient between consecutive days was 0.224, and between non-consecutive days 0.050. CONCLUSIONS The variance correction method is effective for correcting intra-individual variation in estimated UIC following sampling on 3 consecutive days in four seasons in children. The method varies little between ages, sexes and urban or rural setting, but does vary between seasons.
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Affiliation(s)
- Xiaohong Ji
- Key Laboratory of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, People's Republic of China
| | - Peng Liu
- Key Laboratory of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, People's Republic of China
| | - Zhenqi Sun
- Key Laboratory of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, People's Republic of China
| | - Xiaohui Su
- Key Laboratory of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, People's Republic of China
| | - Wei Wang
- Key Laboratory of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, People's Republic of China
| | - Yanhui Gao
- Key Laboratory of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, People's Republic of China
| | - Dianjun Sun
- Key Laboratory of Etiology and Epidemiology, Education Bureau of Heilongjiang Province and Ministry of Health, Center for Endemic Disease Control, Chinese Center for Disease Control and Prevention, Harbin Medical University, Harbin, People's Republic of China
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17
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Chen W, Wu Y, Lin L, Tan L, Shen J, Pearce EN, Guo X, Wang W, Bian J, Jiang W, Zhang W. 24-Hour Urine Samples Are More Reproducible Than Spot Urine Samples for Evaluation of Iodine Status in School-Age Children. J Nutr 2016; 146:142-6. [PMID: 26609173 DOI: 10.3945/jn.115.215806] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 10/28/2015] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Variation in different urinary measurements for evaluation of iodine status is of concern to clinicians and researchers. OBJECTIVE This study evaluated variations between urine iodine concentration (UIC), spot and 24-h urine sample creatinine concentrations, and 24-h urine iodine excretion (24-h UIE) in repeated samples from school-age children. METHODS Urine samples (24 h and morning spot) were collected on 2 occasions from 981 children in Ningjin and Lingxian counties, China. Samples from Ningjin were collected in October and November 2013, and samples from Lingxian were collected in April and May 2014. Morning spot urine iodine concentration (MUIC), morning spot urine creatinine, 24-h UIC, and 24-h urine creatinine were measured in all samples. The 24-h UIE was calculated by multiplying the 24-h UIC by the 24-h urine volume. RESULTS In Ningjin County, the 24-h UIC and 24-h UIE did not differ between repeated collections [192 and 172 μg/L, respectively, for 24-h UIC (P = 0.08); 123 and 120 μg/L, respectively, for 24-h UIE (P = 0.56)], whereas the MUIC was lower in November 2013 than in October 2013 (170 and 190 μg/L, respectively; P = 0.034). In Lingxian County, no significant differences were observed in 24-h UIC between the repeated collections (230 and 218 μg/L, respectively; P = 0.79), whereas the 24-h UIE and MUIC were higher in the samples collected in May 2014 than in April 2014 [161 and 155 μg/L, respectively, for 24-h UIE (P = 0.002); 244 and 203 μg/L, respectively, for MUIC (P < 0.001)]. When data from both counties were combined, no difference was observed between repeated 24-h UIC (214 compared with 196 μg/L; P = 0.17) and 24-h UIE (143 compared with 143 μg/d; P = 0.06), but MUICs were lower in the first collection than in the second collection (199 and 207 μg/L, respectively; P = 0.002). The κ values were >0.4 for 24-h UIC and mean UIE, whereas relatively low κ values were observed for MUIC and mean UIE. CONCLUSION The 24-h UIC was more accurate and reproducible than the MUIC in evaluating iodine status in a large-scale population study of school-age children.
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Affiliation(s)
- Wen Chen
- The Department of Nutrition and Food Hygiene, School of Public Health
| | - Yalan Wu
- The Department of Nutrition and Food Hygiene, School of Public Health
| | - Laixiang Lin
- Tianjin Institution of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Long Tan
- The Department of Nutrition and Food Hygiene, School of Public Health
| | - Jun Shen
- The Department of Nutrition and Food Hygiene, School of Public Health
| | - Elizabeth N Pearce
- Section of Endocrinology, Diabetes, and Nutrition, Boston University School of Medicine, Boston, MA; and
| | - Xiaohui Guo
- The Department of Nutrition and Food Hygiene, School of Public Health
| | - Wei Wang
- The Department of Nutrition and Food Hygiene, School of Public Health
| | - Jianchao Bian
- The Shandong Institute for Endemic Disease Control and Research, Shangdong Province, China
| | - Wen Jiang
- The Shandong Institute for Endemic Disease Control and Research, Shangdong Province, China
| | - Wanqi Zhang
- The Department of Nutrition and Food Hygiene, School of Public Health,
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18
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Trumpff C, Vandevijvere S, Moreno-Reyes R, Vanderpas J, Tafforeau J, Van Oyen H, De Schepper J. Neonatal thyroid-stimulating hormone level is influenced by neonatal, maternal, and pregnancy factors. Nutr Res 2015; 35:975-81. [DOI: 10.1016/j.nutres.2015.09.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 08/28/2015] [Accepted: 09/01/2015] [Indexed: 01/03/2023]
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19
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Ehrenkranz J, Bach PR, Snow GL, Schneider A, Lee JL, Ilstrup S, Bennett ST, Benvenga S. Circadian and Circannual Rhythms in Thyroid Hormones: Determining the TSH and Free T4 Reference Intervals Based Upon Time of Day, Age, and Sex. Thyroid 2015; 25:954-61. [PMID: 26061389 DOI: 10.1089/thy.2014.0589] [Citation(s) in RCA: 124] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND Establishing the reference interval for thyrotropin (TSH) and free thyroxine (T4) is clinically important because a number of disease states have been linked to alterations in TSH and free T4 concentrations that are within the 95% confidence interval for normal thyroid hormone values. Age, sex, time of day, and ethnicity are known to affect circulating levels of TSH and free T4 but have not been used to establish reference intervals. The purpose of this study was to define the reference interval for TSH and free T4 taking into account age, sex, ethnicity, and circadian and circannual variability. METHODS We performed a retrospective analysis of 465,593 TSH and 112,994 free T4 measurements from subjects ages 1-104 years with no thyroid disease using a single TSH and free T4 immunoassay method. Boundaries for the central 95% of patient values, taking into account hour of day, day of year, sex, and age were calculated. RESULTS Females had significantly higher TSH and free T4 levels than males; the magnitude of these differences did not exceed 0.1 mIU/L or 0.1 ng/dL respectively. Although the 2.5% TSH reference interval remains constant through the day, date, and age ranges, the upper limit (97.5%) of the TSH reference interval increases from 6.45 to 7.55 mIU/L with age, due primarily to a progressive increase in the amplitude of the nocturnal TSH surge. Additionally, significant ethnic differences in TSH circadian periodicity occur between African American, Pacific Island, and Caucasian populations. CONCLUSIONS The reference interval for TSH varies significantly by age, sex, hour of day, and ethnicity. Time of year does not affect the TSH reference interval, and age, sex, hour of day and time of year do not affect the free T4 reference interval.
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Affiliation(s)
- Joel Ehrenkranz
- 1 Department of Medicine, Intermountain Central Laboratory , Murray, Utah
| | - Phillip R Bach
- 2 Central Laboratory, Intermountain Healthcare , Murray, Utah
| | - Gregory L Snow
- 3 Statistical Data Center, Intermountain Healthcare Research , Salt Lake City, Utah
| | | | - Jo Lynn Lee
- 5 Intermountain Healthcare , Salt Lake City, Utah
| | - Sarah Ilstrup
- 2 Central Laboratory, Intermountain Healthcare , Murray, Utah
| | | | - Salvatore Benvenga
- 6 Department of Clinical and Experimental Medicine, Policlinico Universitario di Messina , Messina, Italy
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20
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Abstract
AbstractObjectiveLow iodine intake during pregnancy may cause thyroid dysfunction, which results in inadequate fetal brain development. In the absence of a universal salt iodization programme, we conducted a nationwide survey of iodine deficiency in pregnant women in Latvia.DesignA countrywide twenty-cluster survey, with at least twenty women per cluster. Participants completed a questionnaire on dietary habits concerning iodine intake (n 739). Thyroid function (thyroid-stimulating hormone, free thyroxine and thyroperoxidase antibodies) was measured (n 550). Urinary iodine was measured using the ammonium persulfate method (n 696).SettingThe survey was performed in all regions of Latvia during the spring and autumn seasons in 2013.SubjectsPregnant women (n 829).ResultsThe median creatinine (Cr)-standardized urinary iodine concentration (UIC) was 80·8 (interquartile range (IQR) 46·1–130·6) µg/g Cr or 69·4 (IQR 53·9–92·6) µg/l during pregnancy, and 81 % of pregnant women had UIC levels below the WHO recommended range of 150–250 µg/g Cr. The UIC was lowest during the first trimester of pregnancy, 56·0 (IQR 36·4–100·6) µg/g Cr, reaching higher concentrations of 87·5 (IQR 46·4–141·7) µg/g Cr and 86·9 (IQR 53·8–140·6) µg/g Cr in the second and third trimesters, respectively. Women taking supplements containing ≥150 µg iodine (6·8 % of respondents) had non-significantly higher UIC than did women without supplementation (96·2 v. 80·3 µg/g Cr, respectively, P=NS). Thyroperoxidase antibody concentration did not correlate significantly with UIC: Spearman’s ρ=−0·012, P=0·78.ConclusionsThe median UIC indicates iodine deficiency in pregnant women in Latvia. Iodine supplementation (150 µg daily) and regular UIC monitoring should be suggested to overcome iodine deficiency and to reach the recommended levels without inducing autoimmune processes.
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21
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The iodized salt programme in Bangalore, India provides adequate iodine intakes in pregnant women and more-than-adequate iodine intakes in their children. Public Health Nutr 2014; 18:403-13. [DOI: 10.1017/s136898001400055x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractObjectiveTo compare the iodine status of pregnant women and their children who were sharing all meals in Bangalore, India.DesignA cross-sectional study evaluating demographic characteristics, household salt iodine concentration and salt usage patterns, urinary iodine concentrations (UIC) in women and children, and maternal thyroid volume (ultrasound).SettingAntenatal clinic of an urban tertiary-care hospital, which serves a low-income population.SubjectsHealthy pregnant women in all trimesters, aged 18–35 years, who had healthy children aged 3–15 years.ResultsMedian (range) iodine concentrations of household powdered and crystal salt were 55·9 (17·2–65·9) ppm and 18·9 (2·2–68·2) ppm, respectively. The contribution of iodine-containing supplements and multi-micronutrient powders to iodine intake in the families was negligible. Adequately iodized salt, together with small amounts of iodine in local foods, were providing adequate iodine during pregnancy: (i) the overall median (range) UIC in women was 172 (5–1024) µg/l; (ii) the median UIC was >150 µg/l in all trimesters; and (iii) thyroid size was not significantly different across trimesters. At the same time, the median (range) UIC in children was 220 (10–782) µg/l, indicating more-than-adequate iodine intake at this age. Median UIC was significantly higher in children than in their mothers (P=0·008).ConclusionsIn this selected urban population of southern India, the iodized salt programme provides adequate iodine to women throughout pregnancy, at the expense of higher iodine intake in their children. Thus we suggest that the current cut-off for median UIC in children indicating more-than-adequate intake, recommended by the WHO/UNICEF/International Council for the Control of Iodine Deficiency Disorders may, need to be reconsidered.
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Chami R, Moreno-Reyes R, Corvilain B. TSH measurement is not an appropriate screening test for autonomous functioning thyroid nodules: a retrospective study of 368 patients. Eur J Endocrinol 2014; 170:593-9. [PMID: 24451082 DOI: 10.1530/eje-13-1003] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
OBJECTIVE Based on the assumption that normal TSH concentration rules out the presence of autonomous functioning thyroid nodules (AFTNs), clinical guidelines on the management of thyroid nodules only recommend a thyroid scan if TSH concentration is subnormal. However, the proportion of AFTN presenting with a normal TSH is unknown. Our objective is therefore to determine the proportion of AFTNs with a normal TSH level to ascertain whether a normal TSH really rules out an AFTN. DESIGN Retrospective study on 368 patients with an AFTN. METHODS Thyroid scans with a diagnosis of AFTN were reviewed retrospectively by one of us (R Moreno-Reyes), blinded to the clinical data. The diagnosis of solitary AFTN was confirmed in 368 patients. Among them, we selected 217 patients based on the absence of another thyroid nodule >10 mm, the absence of medical conditions able to interfere with thyroid function, and the completeness of the data. RESULTS The proportion of AFTNs with normal TSH was 49%. This proportion increased to 71% in patients for whom thyroid scan was performed in the workup of a thyroid nodule. CONCLUSIONS Our data suggest that serum TSH is not an effective screening tool to diagnose AFTNs. Using 'TSH-only' screening, as recommended by the majority of guidelines, the diagnosis of AFTN would have been missed in 71% of our patients in the workup of a thyroid nodule. Thyroid scan remains the gold standard for detecting AFTN and should be considered before performing fine-needle aspiration cytology (FNAC), as the reliability of FNAC in an unsuspected AFTN remains unclear.
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Roef G, Taes Y, Toye K, Goemaere S, Fiers T, Verstraete A, Kaufman JM. Heredity and lifestyle in the determination of between-subject variation in thyroid hormone levels in euthyroid men. Eur J Endocrinol 2013; 169:835-44. [PMID: 24086088 DOI: 10.1530/eje-13-0265] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Variation in thyroid hormone (TH) concentrations between subjects is greater than in a single subject over a prolonged period of time, suggesting an individual set point for thyroid function. We have previously shown that TH levels within normal range are associated with clinical indices such as bone mass, BMI, and heart rate. The aim of this study on young men was therefore to gain insight into the determinants of variation in TH levels among healthy subjects. METHODS Healthy male siblings (n=941, 25-45 years) were recruited in a cross-sectional, population-based study; a history or treatment of thyroid disease and thyroid auto-immunity were exclusion criteria. A complete assessment of TH status was performed (TSH, free thyroxine (FT4), free triiodothyronine (FT3), thyroperoxidase, and thyroglobulin antibodies, reverse T3 (rT3), thyroid-binding globulin (TBG), and urinary iodine levels). Genotyping was performed by TaqMan and KASP (KBiosciences) genotyping assays. RESULTS (F)T4, rT3, and TBG had heritability estimates between 80 and 90%. Estimates were lower for (F)T3 (60%) and lowest for TSH (49%). Significant associations were observed between different single-nucleotide polymorphisms (SNPs) in the thyroid pathway and TSH, FT4, ratio FT3:FT4, and rT3. Nevertheless, these SNPs only explain a limited part of the heredity. As to age and lifestyle-related factors, (F)T3 was negatively related to age and education level, positively to smoking and BMI (all P<0.0001) but not substantially to urinary iodine concentrations. Smoking was also negatively related to TSH and positively to FT4. CONCLUSION Both genetic and lifestyle-related factors play a role in determining between-subject variation in TH levels in euthyroid young men, although genetic factors seem most important.
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Affiliation(s)
- Greet Roef
- Departments of Endocrinology and Metabolic Bone Diseases
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Bowers J, Terrien J, Clerget-Froidevaux MS, Gothié JD, Rozing MP, Westendorp RGJ, van Heemst D, Demeneix BA. Thyroid hormone signaling and homeostasis during aging. Endocr Rev 2013; 34:556-89. [PMID: 23696256 DOI: 10.1210/er.2012-1056] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Studies in humans and in animal models show negative correlations between thyroid hormone (TH) levels and longevity. TH signaling is implicated in maintaining and integrating metabolic homeostasis at multiple levels, notably centrally in the hypothalamus but also in peripheral tissues. The question is thus raised of how TH signaling is modulated during aging in different tissues. Classically, TH actions on mitochondria and heat production are obvious candidates to link negative effects of TH to aging. Mitochondrial effects of excess TH include reactive oxygen species and DNA damage, 2 factors often considered as aging accelerators. Inversely, caloric restriction, which can retard aging from nematodes to primates, causes a rapid reduction of circulating TH, reducing metabolism in birds and mammals. However, many other factors could link TH to aging, and it is these potentially subtler and less explored areas that are highlighted here. For example, effects of TH on membrane composition, inflammatory responses, stem cell renewal and synchronization of physiological responses to light could each contribute to TH regulation of maintenance of homeostasis during aging. We propose the hypothesis that constraints on TH signaling at certain life stages, notably during maturity, are advantageous for optimal aging.
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Affiliation(s)
- J Bowers
- Muséum national d'Histoire Naturelle, Laboratoire de Physiologie Générale et Comparée, Unité Mixte de Recherche, Centre National de la Recherche Scientifique 7221, 75231 Paris cedex 5, France
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Iodine deficiency among Belgian pregnant women not fully corrected by iodine-containing multivitamins: a national cross-sectional survey. Br J Nutr 2012; 109:2276-84. [DOI: 10.1017/s0007114512004473] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Low iodine intake during pregnancy may cause thyroid dysfunction in pregnant women and their newborn. In the present study, iodine status among a nation-wide representative sample of Belgian pregnant women in the first and third trimester of pregnancy was determined, and determinants of iodine status were assessed 1 year after the introduction of bread fortified with iodised salt. The women were selected according to a multistage proportionate-to-size sampling design. Urine samples were collected and a general questionnaire was completed face to face with the study nurse. The median urinary iodine concentration (UIC) among pregnant women (n1311) was 124·1 μg/l and 122·6 μg/g creatinine when corrected for urinary creatinine. The median UIC in the first trimester (118·3 μg/l) was significantly lower than that in the third trimester (131·0 μg/l) but significantly higher than among non-pregnant women (84·8 μg/l). Iodine-containing supplement intake was reported by 60·8 % of the women and 57·4 % of the women took this supplement daily. The risk of iodine deficiency was significantly higher in younger women, in women not taking iodine-containing supplements, with low consumption of milk and dairy drinks and during autumn. Women with a higher BMI had a higher risk of iodine deficiency but the risk was lower in women who reported alcohol consumption. The median UIC during pregnancy indicates iodine deficiency in Belgium and some women are at a higher risk of deficiency. The current low iodine intake in women of childbearing age precludes the correction of iodine deficiency in pregnant women supplemented with multivitamins containing 150 μg iodine as recommended.
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Konrade I, Dambrova M, Makrecka M, Neimane L, Strele I, Liepinsh E, Lejnieks A, Vevere P, Gruntmanis U, Pirags V. Seasonal iodine deficiency in Latvian school children. Thyroid 2012; 22:1088-9. [PMID: 22947352 DOI: 10.1089/thy.2011.0506] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Vandevijvere S, Mourri AB, Amsalkhir S, Avni F, Van Oyen H, Moreno-Reyes R. Fortification of bread with iodized salt corrected iodine deficiency in school-aged children, but not in their mothers: a national cross-sectional survey in Belgium. Thyroid 2012; 22:1046-53. [PMID: 22947351 DOI: 10.1089/thy.2012.0016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND In the years 1985-1998, it was noted that mild iodine deficiency (MID) was a public health problem in Belgium. Therefore, an agreement was signed in 2009 between the bakery sector and the Ministry of Health, to fortify bread with iodized salt. We tested the hypothesis that the iodine status of Belgian children improved after the introduction of bread fortified with iodized salt. Since the dietary habits of children and adults may differ, we also investigated whether the median urinary iodine concentration (UIC) among the children in this study reflected the iodine status of their mothers. METHODS The study was cross-sectional. In a van, equipped with an ultrasound device, the thyroid volumes (Tvol) of children were measured and household salt samples and urine samples were collected from the children and their mothers. From across Belgium, 60 schools were selected and 1541 children participated in the study. RESULTS The median UIC in children was 113.1 and 84.4 μg/L among their mothers. The median UIC among children was substantially greater compared to more than 10 years ago (80 μg/L; p<0.001). The median UIC in school-aged children was lower in Wallonia than in Flanders (p<0.001) and was higher in boys than in girls (p<0.001). The percentage of children with goiter was 7.2%. Of the 904 salt samples received, 63.2% did not contain iodine. CONCLUSIONS Fortification of bread with iodized salt corrected iodine deficiency in Belgian children, but not in their mothers. To provide these women with an adequate iodine intake, the use of both iodized salt in bread and iodized instead of noniodized household salt needs to increase. Our findings suggest that the median UIC in children may not be an adequate surrogate of adults' iodine status. Therefore, monitoring iodine status should not be limited to children, but should be extended to women of child-bearing age.
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Affiliation(s)
- Stefanie Vandevijvere
- Department of Public Health and Surveillance, Scientific Institute of Public Health, Brussels, Belgium.
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Vandevijvere S. Sodium reduction and the correction of iodine intake in Belgium: Policy options. ACTA ACUST UNITED AC 2012; 70:10. [PMID: 22958752 PMCID: PMC3461451 DOI: 10.1186/0778-7367-70-10] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Accepted: 05/30/2012] [Indexed: 11/10/2022]
Abstract
Many studies suggest that high salt intakes are related to high blood pressure and consequently cardiovascular diseases. In addition salt intake was found to be related with obesity, renal stones, osteoporosis and stomach cancer. Belgium, such as other European countries, is suffering from both salt intakes that are twice as high as the recommended intakes and mild iodine deficiency. No comprehensive strategy encompassing both public health problems has been developed. While specific salt reduction targets for processed foods are still under discussion using a consensus approach with industry, an agreement was signed between the bakery sector and the Ministry of Health in April 2009, to encourage and increase the use of iodised salt in the production of bread. Based on results of recent surveys on population iodine status it is advised not to currently revise iodine concentrations in salt in bread but to advocate for a higher percentage of bakers using iodised salt and to install a good monitoring system to control the percentage of bakers effectively using adequately iodised salt. With regard to salt reduction, it is of utmost importance that all companies contribute and harmonise the salt content of their products according to the lowest possible thresholds in a first step. In order to achieve this goal, it will be necessary, in addition to the consensus approach, to come up with at least some legislative tools such as a salt tax or mandatory labelling of foods exceeding a specific sodium concentration. Once salt reduction targets have been clearly defined in Belgium over the longer term, a legal framework should be set in place where iodine concentration in salt for the production of bread and household salt is strictly regulated by law, to avoid a large variability in the iodine content of salt brands consumed. In conclusion, it is possible to tackle salt reduction and iodine deficiency at the same time on the condition that the approach is coordinated and well monitored. All the interventions and measures taken should clearly include education and communication directed towards consumers, food producers, public health professionals, pharmacists, healthcare workers, and media representatives.
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Affiliation(s)
- Stefanie Vandevijvere
- Scientific Institute of Public Health, Department of Public Health and Surveillance, J,Wytsmanstraat 14, Brussels, 1050, Belgium.
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Abstract
The aim of the present study was to calculate the distribution of total iodine intake among Flemish preschoolers and to identify the major sources contributing to iodine intake. A simulation model using a combination of deterministic and probabilistic techniques was utilised. Scenario analyses were performed to assess iodine intake via dairy products, industrially added iodised salt in bread and discretionarily added iodised household salt. Relevant data from 3-d estimated dietary records of 696 preschoolers 2·5–6·5 years old were used. Usual iodine intakes were calculated using the Iowa State University method. With a more generalised utilisation of iodised salt in bread (44 % of the bakers in 2011 instead of 12 % in 2002), mean iodine intake increased from 159 to 164 μg/d using the McCance and Widdowson's food composition table and from 104 to 109 μg/d using the German food composition table. The percentage of preschoolers with an iodine intake below the estimated average requirement (65 μg/d) decreased from 5–12 to 4–9 %, while the percentage of preschoolers with an iodine intake above the tolerable upper intake level (300 μg/d) remained constant (0·3–4 %). Mean iodine intake via food supplements was 4·2 μg/d (total population) and 16·9 μg/d (consumers only). Both in 2002 and 2011, sugared dairy products, milk and iodised salt (21·4, 13·1, and 8·7 %, respectively in 2011) were the main contributors to total iodine intake. In conclusion, dietary iodine intake could still be improved in Flemish preschoolers. The use of adequately iodised household salt and the more generalised use of iodised salt by bakers should be further encouraged.
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König F, Andersson M, Hotz K, Aeberli I, Zimmermann MB. Ten repeat collections for urinary iodine from spot samples or 24-hour samples are needed to reliably estimate individual iodine status in women. J Nutr 2011; 141:2049-54. [PMID: 21918061 DOI: 10.3945/jn.111.144071] [Citation(s) in RCA: 246] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although the median urinary iodine concentration (UIC) is a good indicator of iodine status in populations, there is no established biomarker for individual iodine status. If the UIC were to be used to assess individuals, it is unclear how many repeat urine collections would be needed and if the collections should be spot samples or 24-h samples. In a prospective, longitudinal, 15-mo study, healthy Swiss women (n = 22) aged 52-77 y collected repeated 24-h urine samples (total n = 341) and corresponding fasting, second-void, morning spot urine samples (n = 177). From the UIC in spot samples, 24-h urinary iodine excretion (UIE) was extrapolated based on the age- and sex-adjusted iodine:creatinine ratio. Measured UIE in 24-h samples, estimated 24-h UIE, and UIC in spot samples were (geometric mean ± SD) 103 ± 28 μg/24 h, 86 ± 33 μg/24 h, and 68 ± 28 μg/L, respectively, with no seasonal differences. Intra-individual variation (mean CV) was comparable for measured UIE (32%) and estimated UIE (33%). The CV tended to be higher for the spot UIC (38%) than for the estimated 24-h UIE (33%) (P = 0.12). In this population, 10 spot urine samples or 24-h urine samples were needed to assess individual iodine status with 20% precision. Spot samples would likely be preferable because of their ease of collection. However, the large number of repeated urine samples needed to estimate individual iodine status is a major limitation and emphasizes the need for further investigation of more practical biomarkers of individual iodine status.
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Affiliation(s)
- Franziska König
- Human Nutrition Laboratory, Institute of Food, Nutrition, and Health, ETH Zurich, Zurich, Switzerland
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