Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Filtros adicionais











País/Região como assunto
Intervalo de ano
1.
Thyroid ; 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31524090

RESUMO

BACKGROUND: Severe maternal iodine deficiency can impact fetal brain development through effects on maternal and/or fetal thyroid hormone availability. The effects of mild-to-moderate iodine deficiency on thyroid function are less clear. The aim was to investigate the association of maternal urinary iodine concentration corrected for creatinine (UI/Creat) with thyroid function and auto-antibodies in a mild-to-moderate iodine deficient pregnant population. METHODS: This study was embedded within the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy (SELMA) study. Clinical reference ranges were determined by the 2.5th and 97.5th population-based percentile cut-offs. The associations of UI/Creat with thyrotropin (TSH), free T4 (FT4), free triiodothyronine (FT3), total T4 (TT4), total triiodothyronine (TT3) were studied using multivariable linear regression in TPOAb negative women. The association of UI/Creat with TPOAb and TgAb positivity was analyzed using multivariable logistic regression. RESULTS: Urinary iodine and thyroid function were measured at a median (95% range) gestational age of 10 (6-14) weeks in 2009 women. The median (95% range) UI/Creat was 85 µg/g (36-386) and the UI/Creat was below 150 µg/g in 80.1% of women. Reference ranges did not differ substantially by UI/Creat. A lower UI/Creat was associated with a lower TSH (P=0.027), a higher TT4 (P=0.032), and with a corresponding trend towards slightly higher FT4 (P=0.081), FT3 (P=0.079), and TT3 (P=0.10). UI/Creat was not associated with the FT4/FT3 (P=0.94) or TT4/TT3 ratios (P=0.63). Women with a UI/Creat of 150-249 µg/g had the lowest prevalence of TPOAb positivity (6.1%), while women with a UI/Creat of <150 µg/g had a higher prevalence [11.0%, OR (95%CI) 1.84 (1.07-3.20), P=0.029]. Women with a UI/Creat ≥500 µg/g showed the highest prevalence and a higher risk of TPOAb positivity, however only a small proportion of women had such a UI/Creat [12.5%, OR (95%CI) 2.36 (0.54-10.43), P=0.26]. CONCLUSIONS: We could not identify any meaningful differences in thyroid function reference ranges. Lower iodine availability was associated with a slightly lower TSH and a higher TT4. Women with adequate iodine intake had the lowest risk of TPOAb positivity.

2.
Thyroid ; 29(9): 1316-1326, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31426724

RESUMO

Background: Thyroid hormone is essential for optimal fetal brain development. Evidence suggests that both low and high maternal thyroid hormone availability may have adverse effects on child neurodevelopmental outcomes, but the effect on behavioral problems remains unclear. We studied the association of maternal thyrotropin (TSH) and free thyroxine (fT4) concentrations during the first 18 weeks of pregnancy with child attention-deficit hyperactivity disorder (ADHD). Methods: A total of 7669 mother-child pairs with data on maternal thyroid function and child ADHD were selected from three prospective population-based birth cohorts: INfancia y Medio Ambiente (INMA; N = 1073, Spain), Generation R (N = 3812, The Netherlands), and Avon Longitudinal Study of Parents and Children (ALSPAC; N = 2784, United Kingdom). Exclusion criteria were multiple pregnancy, fertility treatment, usage of medication affecting the thyroid, and pre-existing thyroid disease. We used logistic regression models to study the association of maternal thyroid function with the primary outcome, ADHD, assessed via the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) criteria by parents and/or teachers at a median child age of 4.5 to 7.6 years, and with the secondary outcome, an ADHD symptom score above the 90th percentile. Effect modification by gestational age and sex was tested with interaction terms and stratified analyses. Results: Overall, 233 (3%) children met the criteria for ADHD. When analyzed continuously, neither fT4 nor TSH was associated with a higher risk of ADHD (odds ratio [OR] 1.1, 95% confidence interval [CI 1.0-1.3], p = 0.060 and OR 0.9 [CI 0.9-1.1], p = 0.385, respectively) or with high symptom scores. When investigating effect modification by gestational age, a higher fT4 was associated with symptoms above the 90th percentile but only in the first trimester (for fT4 per 1 SD: OR 1.2 [CI 1.0-1.4], p = 0.027). However, these differential effects by gestational age were not consistent. No significant effect modification by sex was observed. Conclusions: We found no clear evidence of an association between maternal thyroid function and child ADHD.

3.
Artigo em Inglês | MEDLINE | ID: mdl-30920622

RESUMO

CONTEXT: While the consequences of severe iodine deficiency are beyond doubt, the effects of mild-to-moderate iodine deficiency in pregnancy on child neurodevelopment are less well established. OBJECTIVE: To study the association between maternal iodine status during pregnancy and child IQ and to identify vulnerable time-windows of exposure to suboptimal iodine availability. DESIGN: Meta-analysis of individual-participant data from three prospective population-based birth cohorts: Generation R (The Netherlands), INMA (Spain), and ALSPAC (United Kingdom); pregnant women were enrolled between 2002-2006, 2003-2008, and 1990-1992, respectively. SETTING: General community. PARTICIPANTS: 6180 mother-child pairs with measures of urinary iodine and creatinine concentrations in pregnancy and child IQ. Exclusion criteria were multiple pregnancy, fertility treatment, medication affecting the thyroid, and pre-existing thyroid disease. INTERVENTION(S): None. MAIN OUTCOME MEASURE: Child non-verbal and verbal IQ assessed at 1.5-8 years of age. RESULTS: There was a positive curvilinear association of the urinary iodine-to-creatinine ratio (UI/Creat) with mean verbal IQ only. UI/Creat < 150 µg/g was not associated with lower non-verbal IQ [-0.6 points, 95% CI -1.7 to 0.4, P=0.246] or lower verbal IQ [-0.6, 95% CI -1.3 to 0.1, P=0.082]. Stratified analyses showed that the association of UI/Creat with verbal IQ was only present up to 14 weeks of gestation. CONCLUSIONS: Fetal brain development is vulnerable to mild-to-moderate iodine deficiency, particularly in the first trimester. Our results show that any potential randomized, controlled trial investigating the effect of iodine supplementation in mild-to-moderate iodine deficient women on child neurodevelopment, should start with supplementation not later than the first trimester.

4.
Eur J Nutr ; 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30734058

RESUMO

PURPOSE: As a component of thyroid hormones, adequate iodine intake is essential during pregnancy for fetal neurodevelopment. Across Europe, iodine deficiency is common in pregnancy, but data are lacking on the predictors of iodine status at this life stage. We, therefore, aimed to explore determinants of iodine status during pregnancy in three European populations of differing iodine status. METHODS: Data were from 6566 pregnant women from three prospective population-based birth cohorts from the United Kingdom (ALSPAC, n = 2852), Spain (INMA, n = 1460), and The Netherlands (Generation R, n = 2254). Urinary iodine-to-creatinine ratio (UI/Creat, µg/g) was measured in spot-urine samples in pregnancy (≤ 18-weeks gestation). Maternal dietary intake, categorised by food groups (g/day), was estimated from food-frequency questionnaires (FFQs). Multivariable regression models used dietary variables (energy-adjusted) and maternal characteristics as predictors of iodine status. RESULTS: Median UI/Creat in pregnant women of ALSPAC, INMA, and Generation R was 121, 151, and 210 µg/g, respectively. Maternal age was positively associated with UI/Creat in all cohorts (P < 0.001), while UI/Creat varied by ethnicity only in Generation R (P < 0.05). Of the dietary predictors, intake of milk and dairy products (per 100 g/day) was positively associated with UI/Creat in all cohorts [ALSPAC (B = 3.73, P < 0.0001); INMA (B = 6.92, P = 0.002); Generation R (B = 2.34, P = 0.001)]. Cohort-specific dietary determinants positively associated with UI/Creat included fish and shellfish in ALSPAC and INMA, and eggs and cereal/cereal products in Generation R. CONCLUSIONS: The cohort-specific dietary determinants probably reflect not only dietary habits but iodine-fortification policies; hence, public-health interventions to improve iodine intake in pregnancy need to be country-specific.

5.
J Clin Endocrinol Metab ; 103(10): 3729-3736, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30020468

RESUMO

Context: Thyroperoxidase antibody (TPOAb) positivity is a major risk factor for gestational thyroid dysfunction. During the first 18 to 20 weeks of pregnancy, high concentrations of human chorionic gonadotropin (hCG) stimulate the thyroid to ensure adequate thyroid hormone availability for the developing fetus. However, TPOAb-positive women have an impaired thyroidal response to hCG stimulation. Objective: To study the association of maternal TPOAb positivity during pregnancy with child IQ. Design, Setting, and Participants: This study was embedded in two prospective birth cohorts: Generation R (Rotterdam, the Netherlands) and Avon Longitudinal Study of Parents and Children (ALSPAC; United Kingdom). Mother-child pairs with available data on early pregnancy TPOAb (≤18 weeks of gestation) and offspring IQ were included (n = 3637 for Generation R and n = 2396 for ALSPAC). Main Outcome Measures: Child IQ at 5 to 10 years of age. Results: In Generation R, TPOAb positivity was associated with a 2.0 ± 0.9-point lower mean child IQ (P = 0.03). Sensitivity analyses showed negative effect estimates already from TPOAb concentrations considerably lower than currently used manufacturer cutoffs. In ALSPAC, neither TPOAb positivity nor TPOAb concentrations below manufacturer cutoffs were associated with child IQ (TPOAb positivity: 0.7 ± 1.0; P = 0.45). Adjustment for maternal TSH or free T4 concentrations or urinary iodine/creatinine ratio did not change the results. Conclusion: TPOAb positivity during pregnancy was associated with lower child IQ in Generation R but not in ALSPAC. Further studies are needed to elucidate whether differences between the study populations, such as maternal iodine status, could be the underlying cause for these differences.

6.
J Clin Endocrinol Metab ; 103(8): 2967-2979, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29757392

RESUMO

Context: Low maternal free T4 (FT4) has been associated with poor child neurodevelopment in some single-center studies. Evidence remains scarce for the potential adverse effects of high FT4 and whether associations differ in countries with different iodine status. Objective: To assess the association of maternal thyroid function in early pregnancy with child neurodevelopment in countries with a different iodine status. Design, Setting, and Participants: Meta-analysis of individual participant data from 9036 mother-child pairs from three prospective population-based birth cohorts: INMA [Infancia y Medio Ambiente (Environment and Childhood project) (Spain)], Generation R (Netherlands), and ALSPAC (Avon Longitudinal Study of Parents and Children, United Kingdom). The exclusion criteria were multiple pregnancies, fertility treatments, thyroid-interfering medication usage, and known thyroid disease. Main Outcomes: Child nonverbal IQ at 5 to 8 years of age, verbal IQ at 1.5 to 8 years of age, and autistic traits within the clinical range at 5 to 8 years of age. Results: FT4 <2.5th percentile was associated with a 3.9-point (95% CI, -5.7 to -2.2) lower nonverbal IQ and a 2.1-point (95% CI, -4.0 to -0.1) lower verbal IQ. A suggestive association of hypothyroxinemia with a greater risk of autistic traits was observed. FT4 >97.5th percentile was associated with a 1.9-fold (95% CI, 1.0 to 3.4) greater risk of autistic traits. No independent associations were found with TSH. Conclusions: Low maternal FT4 was consistently associated with a lower IQ across the cohorts. Further studies are needed to replicate the findings of autistic traits and investigate the potential modifying role of maternal iodine status. FT4 seems a reliable marker of fetal thyroid state in early pregnancy, regardless of the type of immunoassay.

7.
J Allergy Clin Immunol ; 132(6): 1303-10, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23987795

RESUMO

BACKGROUND: The Prevention and Incidence of Asthma and Mite Allergy (PIAMA) risk score predicts the probability of having asthma at school age among preschool children with suggestive symptoms. OBJECTIVE: We sought to externally validate the PIAMA risk score at different ages and in ethnic and socioeconomic subgroups of children in addition to updating it. METHODS: We studied 2877 children with preschool asthma-like symptoms participating in the multiethnic, prospective, population-based cohort study Generation R. The PIAMA risk score was assessed at preschool age, and asthma was predicted at age 6 years. Discrimination (concordance index [C-index]) and calibration were calculated. The PIAMA risk score was updated, and its performance was similarly analyzed. RESULTS: At age 6 years, 6% (168/2877) of the children had asthma. The discriminative ability of the original PIAMA risk score to predict asthma in Generation R was similar compared with that in the PIAMA cohort (C-index = 0.74 vs 0.71). The predicted risks by using the original PIAMA risk score for having asthma at the age of 6 years tended to be slightly higher than the observed risks (8% vs 6%). No differences in discriminative ability were found at different ages or in ethnic and socioeconomic subgroups (P > .05). The updated PIAMA risk score had a C-index of 0.75. CONCLUSIONS: The PIAMA risk score showed good external validity. The discriminative ability was similar at different ages and in ethnic and socioeconomic subgroups of preschool children, which suggests good generalizability. Further studies are needed to reproduce the predictive performance of the updated PIAMA risk score in other populations and settings and to assess its clinical relevance.


Assuntos
Asma/diagnóstico , Asma/epidemiologia , Grupos Étnicos , Fatores Socioeconômicos , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Masculino , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Fatores de Risco , Inquéritos e Questionários
8.
Int Dent J ; 61(5): 247-51, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21995371

RESUMO

AIM: To determine the frequency of intake and patterns in consumption of potentially erosive beverages in school children in the Netherlands. METHODS: A cross-sectional, single centre study was performed among 502 school children in Rotterdam, in age varying between 12 and 19 years. Data on consumption of soft drinks, energy drinks, sports drinks and alcopops were obtained through a self-reported questionnaire. Gender- and age-related differences in consumption were analysed with Chi-square, Kruskal-Wallis and Mann-Whitney tests. Associations between variables were investigated with Chi-square tests and Spearman's rank order correlation analysis. RESULTS: Boys consumed soft drinks, energy drinks and sports drinks more frequently than girls, and on average also consumed higher amounts of these drinks. No gender-related differences were observed in alcopop consumption. Consumption of all drinks was most frequent at 14- or 15-year of age, with the exception of alcopops which was most frequent by 16-year-old school children. Significant positive associations were observed between the consumption of soft drinks, energy drinks and/or sports drinks. Alcopop consumption was only associated with consumption of energy drinks. CONCLUSION: Consumption of soft drinks, energy drinks, sports drinks and alcopops by school children is related to age and gender. The significant positive associations between the consumption of these drinks suggest that a subgroup of school children exists with a high cumulative intake of these potentially erosive drinks.


Assuntos
Bebidas/efeitos adversos , Adolescente , Fatores Etários , Bebidas/estatística & dados numéricos , Distribuição de Qui-Quadrado , Criança , Estudos Transversais , Comportamento Alimentar , Feminino , Humanos , Masculino , Países Baixos , Fatores Sexuais , Estatísticas não Paramétricas , Inquéritos e Questionários , Erosão Dentária/etiologia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA