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1.
JAMA ; : 1-11, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31664429

RESUMO

Importance: It is unclear whether levothyroxine treatment provides clinically important benefits in adults aged 80 years and older with subclinical hypothyroidism. Objective: To determine the association of levothyroxine treatment for subclinical hypothyroidism with thyroid-related quality of life in adults aged 80 years and older. Design, Setting, and Participants: Prospectively planned combined analysis of data involving community-dwelling adults aged 80 years and older with subclinical hypothyroidism. Data from a randomized clinical trial were combined with a subgroup of participants aged 80 years and older from a second clinical trial. The trials were conducted between April 2013 and May 2018. Final follow-up was May 4, 2018. Exposures: Participants were randomly assigned to receive levothyroxine (n = 112; 52 participants from the first trial and 60 from the second trial) or placebo (n = 139; 53 participants from the first trial and 86 from the second trial). Main Outcomes and Measures: Co-primary outcomes were Thyroid-Related Quality of Life Patient-Reported Outcome (ThyPRO) questionnaire scores for the domains of hypothyroid symptoms and tiredness at 1 year (range, 0-100; higher scores indicate worse quality of life; minimal clinically important difference, 9). Results: Of 251 participants (mean age, 85 years; 118 [47%] women), 105 were included from the first clinical trial and 146 were included from the second clinical trial. A total of 212 participants (84%) completed the study. The hypothyroid symptoms score decreased from 21.7 at baseline to 19.3 at 12 months in the levothyroxine group vs from 19.8 at baseline to 17.4 at 12 months in the placebo group (adjusted between-group difference, 1.3 [95% CI, -2.7 to 5.2]; P = .53). The tiredness score increased from 25.5 at baseline to 28.2 at 12 months in the levothyroxine group vs from 25.1 at baseline to 28.7 at 12 months in the placebo group (adjusted between-group difference, -0.1 [95% CI, -4.5 to 4.3]; P = .96). At least 1 adverse event occurred in 33 participants (29.5%) in the levothyroxine group (the most common adverse event was cerebrovascular accident, which occurred in 3 participants [2.2%]) and 40 participants (28.8%) in the placebo group (the most common adverse event was pneumonia, which occurred in 4 [3.6%] participants). Conclusions and Relevance: In this prospectively planned analysis of data from 2 clinical trials involving adults aged 80 years and older with subclinical hypothyroidism, treatment with levothyroxine, compared with placebo, was not significantly associated with improvement in hypothyroid symptoms or fatigue. These findings do not support routine use of levothyroxine for treatment of subclinical hypothyroidism in adults aged 80 years and older. Trial Registration: ClinicalTrials.gov Identifier: NCT01660126; Netherlands Trial Register: NTR3851.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31665318

RESUMO

CONTEXT: Current ATA Guidelines for differentiated thyroid cancer (DTC) stratify patients to decide on additional radioiodine (RAI) therapy after surgery, and to predict recurring/persisting disease. However, studies evaluating the detection of distant metastases and how these Guidelines perform in patients with distant metastases are scarce. OBJECTIVE: To evaluate the 2015 ATA Guidelines in DTC patients with respect to 1) the detection of distant metastases, and 2) the accuracy of its Risk Stratification System in patients with distant metastases. PATIENTS AND MAIN OUTCOME MEASURES: We retrospectively included 83 DTC patients who were diagnosed with distant metastases around initial therapy, and a control population of 472 patients (312 Low,160 Intermediate Risk) who did not have a certain indication for RAI therapy. We used the control group to assess the percentage of distant metastases that would have been missed if no RAI therapy was given. RESULTS: Two hundred-forty-six patients had no routine indication for RAI therapy of which four (1.6%) had distant metastases. Further, of the 83 patients with distant metastases, 14 patients (17%) had excellent response, while 55 (67%) had structural disease after a median follow-up of 62 months. None of the 14 patients that achieved an excellent response had a recurrence. CONCLUSIONS: In patients without a routine indication for RAI therapy according to the 2015 ATA Guidelines, distant metastases would initially have been missed in 1.6% of the patients. Further, in patients with distant metastases upon diagnosis, the 2015 ATA Guidelines are an excellent predictor of both persistent disease and recurrence.

3.
PLoS Med ; 16(10): e1002957, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31652264

RESUMO

BACKGROUND: Variations in thyroid function within reference ranges are associated with increased risk of diseases and death. However, the impact of thyroid function on life expectancy (LE) with and without noncommunicable diseases (NCDs) remains unknown. We therefore aimed to investigate the association of thyroid function with total LE and LE with and without NCD among euthyroid individuals. METHODS AND FINDINGS: The study was embedded in the Rotterdam Study, a prospective population-based study carried out in the Netherlands. In total, 7,644 participants without known thyroid disease and with thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels within reference ranges were eligible. NCDs were defined as presence of cardiovascular disease, diabetes mellitus type 2, or cancer. We used the demographic tool of multistate life tables to calculate LE estimates at the age of 50 years, using prevalence, incidence rates, and hazard ratios for three transitions (healthy to NCD, healthy to death, and NCD to death). The total LE and LE with and without NCD among TSH and FT4 tertiles were calculated separately in men and women. Analyses were adjusted for sociodemographic and cardiovascular risk factors. The mean (standard deviation) age of the participants was 64.5 (9.7) years, and 52.3% were women. Over a median follow-up of 8 years (interquartile range 2.7-9.9 years), 1,396 incident NCD events and 1,422 deaths occurred. Compared with those in the lowest TSH tertile, men and women in the highest TSH tertile were expected to live 1.5 years (95% confidence interval [CI] 0.8-2.3, p < 0.001) and 1.5 years (CI 0.8-2.2, p < 0.001) longer, respectively, of which 1.4 years (CI 0.5-2.3, p = 0.002) and 1.3 years (CI 0.3-2.1, p = 0.004) with NCD. Compared with those in the lowest FT4 tertile, the difference in LE for men and women in the highest FT4 tertile was -3.7 years (CI -5.1 to -2.2, p < 0.001) and -3.3 years (CI -4.7 to -1.9, p < 0.001), respectively, of which -1.8 years (CI -3.1 to -0.7, p = 0.003) and -2.0 years (CI -3.4 to -0.7, p = 0.003) without NCD. A limitation of the study is the observational design. Thus, the possibility of residual confounding cannot be entirely ruled out. CONCLUSIONS: In this study, we found that people with low-normal thyroid function (i.e., highest tertile of TSH and lowest tertile of FT4 reference ranges) are expected to live more years with and without NCD than those with high-normal thyroid function (i.e., lowest tertile of TSH and highest tertile of FT4 reference ranges). These findings provide support for a re-evaluation of the current reference ranges of thyroid function.

4.
Eur J Endocrinol ; 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31639771

RESUMO

Objective Earlier cross-sectional studies showed that patients with differentiated thyroid cancer (DTC) have a significant reduction of Quality of Life (QoL) compared to controls. However, recent longitudinal studies showed mixed results, and had relative short follow-up or lacked knowledge about QoL before initial surgery. Therefore, we initiated a longitudinal study to assess changes of QoL in patients undergoing treatment for DTC. Methods We prospectively included patients, aged 18 to 80 years, who were treated for DTC at a Dutch university hospital. Using questionnaires, QoL was assessed before surgery, just before radioiodine (RAI) therapy, and regularly during follow-up. Repeated measurement analysis was used to assess changes of QoL over time, and we explored the influence of different characteristics on QoL. Results Longitudinal QoL assessments were available in 185 patients (mean age 47 years; 71% women). All patients were treated according to the Dutch guidelines with total thyroidectomy followed by RAI (83% after thyroid hormone withdrawal). Median time between baseline and final questionnaire was 31 months, and patients completed a median of three questionnaires. QoL at baseline was lower than in the general population, developed non-linear over time, was lowest around RAI therapy, and recovered over time. Females, younger patients, and patients with persistent hypoparathyroidism had lower QoL scores. Conclusions In a population of DTC patients, QoL before initial therapy is already lower than in the general population. Thereafter, QoL develops non-linear over time in general, with lowest QoL around RAI therapy while two to three years later it approximates baseline values.

5.
JAMA Netw Open ; 2(10): e1912902, 2019 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-31617922

RESUMO

Importance: Air pollutants interact with estrogen nuclear receptors, but their effect on thyroid signaling is less clear. Thyroid function is of particular importance for pregnant women because of the thyroid's role in fetal brain development. Objective: To determine the short-term association of exposure to air pollution in the first trimester with thyroid function throughout pregnancy. Design, Setting, and Participants: In this cohort study, 9931 pregnant women from 4 European cohorts (the Amsterdam Born Children and Their Development Study, the Generation R Study, Infancia y Medio Ambiente, and Rhea) and 1 US cohort (Project Viva) with data on air pollution exposure and thyroid function during pregnancy were included. The recruitment period for the Amsterdam Born Children and Their Development Study was January 2003 to March 2004; for Generation R, April 2002 to January 2006; for Infancia y Medio Ambiente, November 2003 to January 2008; for Rhea, February 2007 to February 2008; and for Project Viva, April 1999 to November 2002. Statistical analyses were conducted from January 2018 to April 2019. Main Outcomes and Measures: Residential air pollution concentrations (ie, nitrogen oxide and particulate matter [PM]) during the first trimester of pregnancy were estimated using land-use regression and satellite-derived aerosol optical depth models. Free thyroxine, thyrotropin, and thyroid peroxidase antibody levels were measured across gestation. Hypothyroxinemia was defined as free thyroxine below the fifth percentile of the cohort distribution with normal thyrotropin levels, following the American Thyroid Association guidelines. Results: Among 9931 participants, the mean (SD) age was 31.2 (4.8) years, 4853 (48.9%) had more than secondary educational levels, 5616 (56.6%) were nulliparous, 404 (4.2%) had hypothyroxinemia, and 506 (6.7%) tested positive for thyroid peroxidase antibodies. Concentrations of nitrogen dioxide and PM with an aerodynamic diameter of 2.5 µm or less (PM2.5) were lower and had less variation in women in the US cohort than those in European cohorts. No associations of nitrogen oxide with thyroid function were found. Higher exposures to PM2.5 were associated with higher odds of hypothyroxinemia in pregnant women (odds ratio per 5-µg/m3 change, 1.21; 95% CI, 1.00-1.47). Although exposure to PM with an aerodynamic diameter of 10 µm or less was not significantly associated with hypothyroxinemia, the coefficient was similar to that for the association of PM2.5 with hypothyroxinemia (odds ratio per 10-µg/m3 change, 1.18; 95% CI, 0.93-1.48). Absorbances of PM2.5 and PM with aerodynamic diameter from 2.5 to 10 µg and were not associated with hypothyroxinemia. There was substantial heterogeneity among cohorts with respect to thyroid peroxidase antibodies (P for heterogeneity, <.001), showing associations of nitrogen oxide and PM with thyroid autoimmunity only in the women in the Generation R Study. Conclusions and Relevance: The findings of this study suggest that first-trimester exposures to PM2.5 were associated with mild thyroid dysfunction throughout pregnancy. The association of PM2.5 exposure with thyroid function during pregnancy is of global health importance because air pollution exposure is widespread and hypothyroxinemia may adversely influence the brain development of offspring.

7.
Thyroid ; 2019 Oct 10.
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 autoantibodies 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 cutoffs. The associations of UI/Creat with thyrotropin (TSH), free thyroxine (fT4), free triiodothyronine (fT3), total T4 (TT4), and total T3 (TT3) were studied using multivariable linear regression in thyroid peroxidase antibody (TPOAb)-negative women. The association of UI/Creat with TPOAb and thyroglobulin antibody (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 toward 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%, odds ratio [OR] confidence interval [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.

8.
Environ Int ; 132: 105124, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31479957

RESUMO

BACKGROUND: Animal studies suggest that organophosphate (OP) pesticides exposure affects thyroid function, but evidence in humans remains sparse and inconclusive. Gestational exposure is of particular interest, since thyroid hormone is essential for fetal brain development. OP pesticides are able to cross the placental and blood-brain barrier and may interfere with fetal development processes regulated by thyroid hormone. OBJECTIVE: To investigate the association of gestational OP pesticides exposure during pregnancy with maternal and cord blood thyroid hormone concentrations. METHODS: This study was embedded within Generation R (Rotterdam, the Netherlands), a prospective population-based birth cohort. Mother-child pairs with OP pesticides assessment and maternal (N = 715) or cord blood (N = 482) thyroid hormone measurements were included. OP pesticides exposure was assessed at <18, 18-25, and >25 weeks gestation by measuring six urinary dialkylphosphate (DAP) metabolites. Thyroid stimulating hormone (TSH) and free thyroxine (FT4) were measured in maternal and cord blood. Maternal measures also included total thyroxine (TT4) and TPO antibodies (TPOAbs). To study the association of creatinine-adjusted DAP metabolite concentrations with thyroid function and TPO antibodies, multivariable linear regression models including relevant confounders were used. RESULTS: There was no association of DAP metabolites with maternal TSH, FT4, TT4 or TPOAb concentrations during pregnancy. Similarly, there was no association of DAP metabolites with cord blood TSH or FT4. Results did not change when DAP concentrations were analyzed at individual time points or as mean gestational exposure. CONCLUSION: Gestational OP pesticides exposure, as assessed by repeatedly measured urinary DAP metabolite concentrations in an urban population, was not associated with maternal or cord blood thyroid hormone concentrations. These findings do not support a mediating role for serum thyroid hormone availability in the relation of early life exposure to low levels of OP pesticides with child neurodevelopment. However, disruption of the thyroid system at tissue level cannot be excluded. In addition, this is one of the first studies on this subject and measurement error in DAP metabolites might have resulted in imprecise estimates. Future studies should use more urine samples to increase precision and should investigate specific OP pesticide metabolites.

9.
Environ Int ; 133(Pt A): 105123, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31521814

RESUMO

BACKGROUND: Bisphenols and triclosan are considered as potential thyroid disruptors. While mild alterations in maternal thyroid function can result in adverse pregnancy and child developmental outcomes, there is still uncertainty whether bisphenols or triclosan can interfere with thyroid function during pregnancy. OBJECTIVES: We aimed to investigate the association of urinary bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF) and triclosan with early pregnancy thyroid function. METHODS: This study was embedded in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy study (SELMA), a population-based prospective pregnancy cohort. In total, 1996 participants were included in the current study. Maternal urinary concentrations of three bisphenols and triclosan, collected at median (95% range) 10 (6-14) weeks of pregnancy as well as serum concentrations of thyroid stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), total thyroxine (TT4), and total triiodothyronine (TT3) were measured. RESULTS: Higher BPA levels were associated with lower TT4 concentrations (non-monotonic, P = 0.03), a lower FT4/FT3 ratio (ß [SE] -0.02 [0.01], P = 0.03) and a lower TT4/TT3 ratio (ß [SE] -0.73 [0.27], P = 0.008). Higher BPF levels were associated with a higher FT3 (ß [SE] 0.01 [0.007], P = 0.04). There were no associations between other bisphenols or triclosan and absolute TSH, (F)T4 or (F)T3 concentrations. The association of BPA with thyroid function differed with gestational age. The negative association of BPA with FT4/FT3 and TT4/TT3 ratios was only apparent in early but not late gestation (P for interaction: 0.003, 0.008, respectively). CONCLUSION: These human data during pregnancy substantiate experimental findings suggesting that BPA could potentially affect thyroid function and deiodinase activities in early gestation.

10.
Thyroid ; 29(10): 1499-1510, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31436139

RESUMO

Background: Mutations in the thyroid hormone (TH) transporter monocarboxylate transporter 8 (MCT8) cause MCT8 deficiency, characterized by severe intellectual and motor disability and abnormal serum thyroid function tests. Various Mct8 knock-out mouse models as well as mct8 knock-out and knockdown zebrafish models are used as a disease model for MCT8 deficiency. Although important for model eligibility, little is known about the functional characteristics of the MCT8 orthologues in these species. Therefore, we here compared the functional characteristics of mouse (mm) MCT8 and zebrafish (dr) Mct8 to human (hs) MCT8. Methods: We performed extensive transport studies in COS-1 and JEG-3 cells transiently transfected with hsMCT8, drMct8, and mmMCT8. Protein expression levels and subcellular localization were assessed by immunoblotting, surface biotinylation, and immunocytochemistry. Sequence alignment and structural modeling were used to interpret functional differences between the orthologues. Results: hsMCT8, drMct8, and mmMCT8 all facilitated the uptake and efflux of 3,3'-diiodothyronine (3,3'-T2), rT3, triiodothyronine (T3), and thyroxine (T4), although the initial uptake rates of drMct8 were 1.5-4.0-fold higher than for hsMCT8 and mmMCT8. drMct8 exhibited 3-50-fold lower apparent IC50 values than hsMCT8 and mmMCT8 for all tested substrates, and substrate preference of drMct8 (3,3'-T2, T3 > T4 > rT3) differed from hsMCT8 and mmMCT8 (T3 > T4 > rT3, 3,3'-T2). Compared with hsMCT8 and mmMCT8, cis-inhibition studies showed that T3 uptake by drMct8 was inhibited at a lower concentration and by a broader spectrum of TH metabolites. Total and cell surface expression levels of drMct8 and hsMCT8 were equal and both significantly exceeded those of mmMCT8. Structural modeling located most non-conserved residues outside the substrate pore, except for H192 in hsMCT8, which is replaced by a glutamine in drMct8. However, a H192Q substituent of hsMCT8 did not alter its transporter characteristics. Conclusion: Our studies substantiate the eligibility of mice and zebrafish models for human MCT8 deficiency. However, differences in the intrinsic transporter properties of MCT8 orthologues may exist, which should be realized when comparing MCT8 deficiency in different in vivo models. Moreover, our findings may indicate that the protein domains outside the substrate channel may play a role in substrate selection and protein stability.

11.
Lancet Diabetes Endocrinol ; 7(9): 695-706, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31377265

RESUMO

BACKGROUND: Deficiency of the thyroid hormone transporter monocarboxylate transporter 8 (MCT8) causes severe intellectual and motor disability and high serum tri-iodothyronine (T3) concentrations (Allan-Herndon-Dudley syndrome). This chronic thyrotoxicosis leads to progressive deterioration in bodyweight, tachycardia, and muscle wasting, predisposing affected individuals to substantial morbidity and mortality. Treatment that safely alleviates peripheral thyrotoxicosis and reverses cerebral hypothyroidism is not yet available. We aimed to investigate the effects of treatment with the T3 analogue Triac (3,3',5-tri-iodothyroacetic acid, or tiratricol), in patients with MCT8 deficiency. METHODS: In this investigator-initiated, multicentre, open-label, single-arm, phase 2, pragmatic trial, we investigated the effectiveness and safety of oral Triac in male paediatric and adult patients with MCT8 deficiency in eight countries in Europe and one site in South Africa. Triac was administered in a predefined escalating dose schedule-after the initial dose of once-daily 350 µg Triac, the daily dose was increased progressively in 350 µg increments, with the goal of attaining serum total T3 concentrations within the target range of 1·4-2·5 nmol/L. We assessed changes in several clinical and biochemical signs of hyperthyroidism between baseline and 12 months of treatment. The prespecified primary endpoint was the change in serum T3 concentrations from baseline to month 12. The co-primary endpoints were changes in concentrations of serum thyroid-stimulating hormone (TSH), free and total thyroxine (T4), and total reverse T3 from baseline to month 12. These analyses were done in patients who received at least one dose of Triac and had at least one post-baseline evaluation of serum throid function. This trial is registered with ClinicalTrials.gov, number NCT02060474. FINDINGS: Between Oct 15, 2014, and June 1, 2017, we screened 50 patients, all of whom were eligible. Of these patients, four (8%) patients decided not to participate because of travel commitments. 46 (92%) patients were therefore enrolled in the trial to receive Triac (median age 7·1 years [range 0·8-66·8]). 45 (98%) participants received Triac and had at least one follow-up measurement of thyroid function and thus were included in the analyses of the primary endpoints. Of these 45 patients, five did not complete the trial (two patients withdrew [travel burden, severe pre-existing comorbidity], one was lost to follow-up, one developed of Graves disease, and one died of sepsis). Patients required a mean dose of 38.3 µg/kg of bodyweight (range 6·4-84·3) to attain T3 concentrations within the target range. Serum T3 concentration decreased from 4·97 nmol/L (SD 1·55) at baseline to 1·82 nmol/L (0·69) at month 12 (mean decrease 3·15 nmol/L, 95% CI 2·68-3·62; p<0·0001), while serum TSH concentrations decreased from 2·91 mU/L (SD 1·68) to 1·02 mU/L (1·14; mean decrease 1·89 mU/L, 1·39-2·39; p<0·0001) and serum free T4 concentrations decreased from 9·5 pmol/L (SD 2·5) to 3·4 (1·6; mean decrease 6·1 pmol/L (5·4-6·8; p<0·0001). Additionally, serum total T4 concentrations decreased by 31·6 nmol/L (28·0-35·2; p<0·0001) and reverse T3 by 0·08 nmol/L (0·05-0·10; p<0·0001). Seven treatment-related adverse events (transiently increased perspiration or irritability) occurred in six (13%) patients. 26 serious adverse events that were considered unrelated to treatment occurred in 18 (39%) patients (mostly hospital admissions because of infections). One patient died from pulmonary sepsis leading to multi-organ failure, which was unrelated to Triac treatment. INTERPRETATION: Key features of peripheral thyrotoxicosis were alleviated in paediatric and adult patients with MCT8 deficiency who were treated with Triac. Triac seems a reasonable treatment strategy to ameliorate the consequences of untreated peripheral thyrotoxicosis in patients with MCT8 deficiency. FUNDING: Dutch Scientific Organization, Sherman Foundation, NeMO Foundation, Wellcome Trust, UK National Institute for Health Research Cambridge Biomedical Centre, Toulouse University Hospital, and Una Vita Rara ONLUS.

12.
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.

13.
JAMA ; 322(7): 632-641, 2019 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-31429897

RESUMO

Importance: Maternal hypothyroidism and hyperthyroidism are risk factors for preterm birth. Milder thyroid function test abnormalities and thyroid autoimmunity are more prevalent, but it remains controversial if these are associated with preterm birth. Objective: To study if maternal thyroid function test abnormalities and thyroid autoimmunity are risk factors for preterm birth. Data Sources and Study Selection: Studies were identified through a search of the Ovid MEDLINE, EMBASE, Web of Science, the Cochrane Central Register of Controlled Trials, and Google Scholar databases from inception to March 18, 2018, and by publishing open invitations in relevant journals. Data sets from published and unpublished prospective cohort studies with data on thyroid function tests (thyrotropin [often referred to as thyroid-stimulating hormone or TSH] and free thyroxine [FT4] concentrations) or thyroid peroxidase (TPO) antibody measurements and gestational age at birth were screened for eligibility by 2 independent reviewers. Studies in which participants received treatment based on abnormal thyroid function tests were excluded. Data Extraction and Synthesis: The primary authors provided individual participant data that were analyzed using mixed-effects models. Main Outcomes and Measures: The primary outcome was preterm birth (<37 weeks' gestational age). Results: From 2526 published reports, 35 cohorts were invited to participate. After the addition of 5 unpublished data sets, a total of 19 cohorts were included. The study population included 47 045 pregnant women (mean age, 29 years; median gestational age at blood sampling, 12.9 weeks), of whom 1234 (3.1%) had subclinical hypothyroidism (increased thyrotropin concentration with normal FT4 concentration), 904 (2.2%) had isolated hypothyroxinemia (decreased FT4 concentration with normal thyrotropin concentration), and 3043 (7.5%) were TPO antibody positive; 2357 (5.0%) had a preterm birth. The risk of preterm birth was higher for women with subclinical hypothyroidism than euthyroid women (6.1% vs 5.0%, respectively; absolute risk difference, 1.4% [95% CI, 0%-3.2%]; odds ratio [OR], 1.29 [95% CI, 1.01-1.64]). Among women with isolated hypothyroxinemia, the risk of preterm birth was 7.1% vs 5.0% in euthyroid women (absolute risk difference, 2.3% [95% CI, 0.6%-4.5%]; OR, 1.46 [95% CI, 1.12-1.90]). In continuous analyses, each 1-SD higher maternal thyrotropin concentration was associated with a higher risk of preterm birth (absolute risk difference, 0.2% [95% CI, 0%-0.4%] per 1 SD; OR, 1.04 [95% CI, 1.00-1.09] per 1 SD). Thyroid peroxidase antibody-positive women had a higher risk of preterm birth vs TPO antibody-negative women (6.6% vs 4.9%, respectively; absolute risk difference, 1.6% [95% CI, 0.7%-2.8%]; OR, 1.33 [95% CI, 1.15-1.56]). Conclusions and Relevance: Among pregnant women without overt thyroid disease, subclinical hypothyroidism, isolated hypothyroxinemia, and TPO antibody positivity were significantly associated with higher risk of preterm birth. These results provide insights toward optimizing clinical decision-making strategies that should consider the potential harms and benefits of screening programs and levothyroxine treatment during pregnancy.


Assuntos
Doenças Autoimunes/diagnóstico , Iodeto Peroxidase/imunologia , Complicações na Gravidez/diagnóstico , Nascimento Prematuro/etiologia , Doenças da Glândula Tireoide/diagnóstico , Testes de Função Tireóidea , Adulto , Autoanticorpos/sangue , Doenças Autoimunes/sangue , Doenças Autoimunes/complicações , Feminino , Idade Gestacional , Humanos , Hipotireoidismo/complicações , Hipotireoidismo/diagnóstico , Recém-Nascido , Gravidez , Complicações na Gravidez/sangue , Doenças da Glândula Tireoide/sangue , Doenças da Glândula Tireoide/complicações , Tireotropina/sangue , Tiroxina/sangue
14.
Thyroid ; 29(10): 1475-1484, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31347461

RESUMO

Background: Subclinical thyroid disease occurs in approximately 5-8% of all pregnancies and is associated with a higher risk of adverse outcomes such as miscarriage, preterm birth, and suboptimal child neurodevelopment. It is generally assumed that subclinical thyroid disease that persists from early to late pregnancy is associated with a higher risk of adverse outcomes than transient disease. However, it is unknown as to what percentage of women with subclinical disease during early pregnancy have persistent disease in the third trimester. Methods: This study comprised 42,492 mothers for whom early and late pregnancy thyrotropin (TSH), free thyroxine (fT4), triiodothyronine (T3), or TPOAbs were available and who did not receive thyroid treatment before or during pregnancy. We adjusted for potential confounders, including maternal age, parity, anthropometrics, and ß-hCG concentrations. Results: Subclinical hypothyroidism and hypothyroxinemia persisted in 24.8% and 17.7% of cases. Overt hyperthyroidism persisted in 8.4% of cases while subclinical hyperthyroidism persisted in 20.9% of cases. Low T3 persisted in 43.4% of cases while elevated T3 persisted in 15.7% of cases. TPOAb positivity persisted in 84.0% of cases. In women with subclinical hypothyroidism, a TSH below ∼5 mU/L at the time of diagnosis was associated with an up to 50% lower risk of persistency. The fT4 concentration at diagnosis predicted hyperthyroidism persistency and TPOAb positivity predicted persistency of all disease entities. Conclusions: Early pregnancy thyroid disease only persists until the third trimester in 8.4-24.8% of cases when left untreated. The main predictor for persistency is TPOAb positivity, with TPOAb-positive women having a lower risk that subclinical hypothyroidism or hypothyroxinemia persists, but a higher risk that (subclinical) hyperthyroidism persists.

15.
Lancet Diabetes Endocrinol ; 7(8): 629-637, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31262704

RESUMO

BACKGROUND: Adequate thyroid hormone availability during pregnancy is necessary for optimal fetal brain development. During the first 18-20 weeks of gestation, fetal thyroid hormone availability largely depends on the placental transfer of maternal thyroxine. Although various studies have shown that maternal thyroid dysfunction is associated with suboptimal child neurodevelopmental outcomes, the most vulnerable time window remains to be identified. The aim of this study is to examine the association of maternal thyroid function with child brain morphology and to study whether any association depends on the timing of thyroid assessment. METHODS: This prospective cohort study was part of the Generation R Study in Rotterdam, Netherlands, with a prospective population-based birth cohort. Pregnant women living in Rotterdam with an expected delivery date between April 1, 2002, and Jan 1, 2006, were eligible. Other inclusion criteria were maternal serum thyroid-stimulating hormone (TSH) and free thyroxine (FT4) measurement in early or mid-pregnancy (≤18 weeks) and available brain MRI data for child at age 10 years. Exclusion criteria were pre-existing thyroid disorder, thyroid disorder treatment, twin pregnancy, in-vitro fertilisation-induced pregnancy, and suboptimal-quality MRI data or major incidental finding on MRI. The main outcome was the association between maternal TSH and FT4 concentrations with brain MRI outcomes of children. Regression analyses accounted for gestational age at blood sampling, maternal age, ethnicity, education level, smoking, thyroid peroxidase antibody positivity, child sex, age at MRI, and total intracranial volume. Effect modification by gestational age at blood sampling was also investigated. FINDINGS: Between Dec 1, 2001, and June 30, 2005, 7069 women were enrolled during early or mid-pregnancy (≤18 weeks of gestation), of whom 5088 were not included because they did not have available data on maternal serum TSH or FT4 concentrations (n=1175), their child did not have brain MRI done (n=3377), or they met exclusion criteria (n=536). Thus, 1981 mother-child pairs were included in the study, with TSH and FT4 concentrations measured during pregnancy at a median of 13·1 weeks of gestation (IQR 12·1-14·5) and offspring brain morphology assessed by MRI at a median age of 9·9 years (9·7-10·2). Maternal TSH had an inverted U-shaped association with offspring total grey matter volume (p=0·007) and with cortical grey matter volume (p=0·022). The association of maternal TSH with child total grey matter volume (pinteraction=0·053) and cortical volume (pinteraction=0·086) differed by the duration of gestation. Analyses stratified for gestational age at blood sampling showed an inverted U-shaped association of maternal TSH with child total grey matter volume and cortical grey matter volume, which was most evident at 8 weeks gestation. After about 14 weeks of gestation, TSH was no longer associated with child brain morphology. Maternal FT4 concentrations were not associated with child total grey matter volume after adjusting for total intracranial volume (p=0·75). INTERPRETATION: Here, we show that both low and high maternal thyroid function are associated with smaller child total grey matter and cortical volume. To the best of our knowledge, this study is the first to show that an association with a neurodevelopmental outcome is most evident when maternal thyroid function is measured early in pregnancy. These novel findings suggest that embryonic brain development is particularly vulnerable to altered maternal thyroid function. FUNDING: Netherlands Organisation for Health Research and Development and the Sophia Children's Hospital Foundation.

16.
BMJ Open ; 9(7): e029716, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31350252

RESUMO

INTRODUCTION: Prospective cohort studies on the association between subclinical thyroid dysfunction and depressive symptoms have yielded conflicting findings, possibly because of differences in age, sex, thyroid-stimulating hormone cut-off levels or degree of baseline depressive symptoms. Analysis of individual participant data (IPD) may help clarify this association. METHODS AND ANALYSIS: We will conduct a systematic review and IPD meta-analysis of prospective studies on the association between subclinical thyroid dysfunction and depressive symptoms. We will identify studies through a systematic search of the literature in the Ovid Medline, Ovid Embase, Cochrane Central Register of Controlled Trials (CENTRAL) and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases from inception to April 2019 and from the Thyroid Studies Collaboration. We will ask corresponding authors of studies that meet our inclusion criteria to collaborate by providing IPD. Our primary outcome will be depressive symptoms at the first available individual follow-up, measured on a validated scale. We will convert all the scores to the Beck Depression Inventory scale. For each cohort, we will estimate the mean difference of depressive symptoms between participants with subclinical hypothyroidism or hyperthyroidism and control adjusted for depressive symptoms at baseline. Furthermore, we will adjust our multivariable linear regression analyses for age, sex, education and income. We will pool the effect estimates of all studies in a random-effects meta-analysis. Heterogeneity will be assessed by I2. Our secondary outcomes will be depressive symptoms at a specific follow-up time, at the last available individual follow-up and incidence of depression at the first, last and at a specific follow-up time. For the binary outcome of incident depression, we will use a logistic regression model. ETHICS AND DISSEMINATION: Formal ethical approval is not required as primary data will not be collected. Our findings will have considerable implications for patient care. We will seek to publish this systematic review and IPD meta-analysis in a high-impact clinical journal. PROSPERO REGISTRATION NUMBER: CRD42018091627.

17.
J Clin Endocrinol Metab ; 104(12): 5853-5863, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31216012

RESUMO

CONTEXT: Previous studies suggest that maternal thyroid function affects fetal growth, but the association between combined thyroid hormones from early to late pregnancy and newborn birth weight remains unknown. OBJECTIVE: To explore the association of maternal thyroid function during early and late pregnancy with birth weight. DESIGN: A large prospective cohort study of a Chinese population. SETTING: This study recruited pregnant women who underwent first-trimester prenatal screenings at the International Peace Maternity and Child Health Hospital between January 2013 and December 2016. PARTICIPANTS: This study enrolled 46,186 mothers in whom TSH, free thyroxine (FT4), T3, and thyroid peroxidase antibody concentrations were measured in the first and third trimesters and in whom data on birth weight were available. MAIN OUTCOME MEASURES: Birth weight, small for gestational age, large for gestational age (LGA). RESULTS: A higher TSH or FT4 concentration, or a lower T3 concentration, during the first or third trimester was associated with a lower birth weight. The lowest percentiles of maternal FT4 (FT4 < 2.5th percentile) in both trimesters were associated with a 0.34-SD higher birth weight. The effect estimates were greater in those in the first trimester (0.23 SD) or in the third trimester (0.17 SD). The association of maternal TSH and FT4 with birth weight differed according to fetal sex. CONCLUSIONS: Persistently low FT4 concentrations throughout pregnancy were associated with higher birth weight and an increased risk of LGA. Based on these findings, we recommend monitoring mildly altered concentrations of thyroid hormone throughout pregnancy.

19.
Thyroid ; 29(8): 1073-1079, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31140385

RESUMO

Background: The 2015 American Thyroid Association (ATA) Risk Stratification System for differentiated thyroid cancer (DTC) is designed to predict recurring/persisting disease but not survival. Earlier studies evaluating this system evaluated the 2009 edition, comprised a low number of patients with ATA high-risk, had low numbers of patients with follicular thyroid cancer (FTC), or did not distinguish between papillary and FTC. Therefore, we evaluated the prognostic value of the 2015 ATA Risk Stratification System in a large population of high-risk thyroid cancer patients, which included a substantial proportion of FTC patients. Methods: We retrospectively studied adult patients with DTC who were diagnosed and/or treated at a Dutch university hospital between January 2002 and December 2015. All patients fulfilled the 2015 ATA high-risk criteria. Overall survival and disease-specific survival (DSS) were analyzed using the Kaplan-Meier method. Logistic regression and Cox proportional hazards models were used to estimate the effects of DTC subtype and ATA high-risk criteria on response to therapy, recurrence, as well as survival. Results: We included 236 patients with high-risk DTC (32% FTC) with a mean age of 56 years. Median follow-up was 6 years. At final follow-up, 69 patients (29%) had excellent response, while 120 (51%) had structural disease. All high-risk criteria, except large pathologic lymph nodes, were inversely related to excellent response and positively related to structural disease at final follow-up. During follow-up, 14% of the 79 patients who achieved excellent response developed a recurrence. Finally, 10-year DSS was much higher in the initial excellent response than in the initial structural disease group (100% vs. 61%, respectively). Conclusions: In a population of high-risk DTC patients harboring a large subset of FTC patients, the 2015 ATA Risk Stratification System is not only an excellent predictor of persisting disease but also of survival. As much as 14% of the high-risk patients who had an excellent response upon dynamic risk stratification experienced a recurrence during follow-up. Clinicians should thus be aware of the relatively high recurrence risk in these patients, even after an excellent response to therapy.

20.
Sci Rep ; 9(1): 5396, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30932012

RESUMO

Sufficient thyroid iodine uptake is needed to ensure effective radioactive iodine (RAI) treatment, which is mediated by the sodium-iodide symporter (NIS). Activation of AMP-activated-protein-kinase (AMPK), leads to decreased NIS expression and thyroid iodine uptake in in vitro and animal models. Clinically relevant conditions that lead to AMPK activation include metformin use and hypocaloric conditions. Here, we aim to assess the effects of metformin and hypocaloric diet on thyroid iodine uptake in healthy volunteers. Healthy male volunteers were included and randomized. Group 1 (n = 8) received metformin, group 2 (n = 7) followed a hypocaloric diet (1500 kcal/day), superposed on a moderate iodine restriction diet; Baseline measurements included thyroid iodine-123 (I-123) uptake and TSH, fT4, T3 and rT3 levels. After two weeks, thyroid function and I-123 uptake measurements were repeated. Baseline characteristics were similar between groups. Levels of TSH and fT4 were similar after each intervention. T3 decreased after hypocaloric diet and metformin (-0.2 ± 0.19 nmol/L, p = 0.0327; respectively -0.13 ± 0.13 nmol/L, p = 0.0282), resulting in decreased T3/rT3 ratios. There was no significant difference in thyroid I-123 uptake after each intervention. In conclusion, metformin treatment and hypocaloric diet resulted in a significant decrease in T3 levels and T3/rT3 ratios in healthy volunteers, without significant effects on thyroid iodine uptake. We found no indications that metformin or hypocaloric diet will have clinically relevant effects on RAI uptake.

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