| 1. |
- Nassan, Feiby L., et al.
(författare)
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Dibutyl-phthalate exposure from mesalamine medications and serum thyroid hormones in men
- 2019
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Ingår i: International journal of hygiene and environmental health (Print). - : Urban & Fischer. - 1438-4639 .- 1618-131X. ; 222:1, s. 101-110
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Dibutyl phthalate (DBP) is an endocrine disruptor and used in some medication coatings, such as mesalamine for treatment inflammatory bowel disease (IBD).OBJECTIVES: To determine whether high-DBP from some mesalamine medications alters thyroid function.METHODS: Seventy men with IBD, without thyroid disease or any radiation history participated in a crossover-crossback prospective study and provided up to 6 serum samples (2:baseline, 2:crossover, 2:crossback). Men on non-DBP mesalamine (background exposure) at baseline crossed-over to DBP-mesalamine (high exposure) then crossed-back to non-DBP mesalamine (B1HB2-arm) and vice versa for men on DBP-mesalamine at baseline (H1BH2-arm). Serum concentrations of total triiodothyronine (T3), total thyroxine (T4), free triiodothyronine (FT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH) and thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb).RESULTS: After crossover in B1HB2-arm (26 men, 134 samples), T3 decreased 10% (95% confidence interval (CI): 14%,-5%), T3/T4 ratio decreased 8% (CI: 12%,-3%), TPOAb, and TgAb concentrations decreased, 11% (-20%, -2%) and 15% (-23%, -5%), respectively; after crossback, they increased. When men in the H1BH2-arm (44 men, 193 samples) crossed-over, T3 decreased 7% (CI: -11%, -2%) and T3/T4 ratio decreased 6% (CI: -9%, -2%). After crossback, only TgAb increased and FT4 decreased.CONCLUSIONS: High-DBP novel exposure or removal from chronic high-DBP exposure could alter elements of the thyroid system, and most probably alters the peripheral T4 conversion to T3 and thyroid autoimmunity, consistent with thyroid disruption. After exposure removal, these trends were mostly reversed.
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| 2. |
- Derakhshan, Arash, et al.
(författare)
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Reference ranges and determinants of thyroid function during early pregnancy : the SELMA study
- 2018
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : Oxford University Press. - 0021-972X .- 1945-7197. ; 103:9, s. 3548-3556
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Tidskriftsartikel (refereegranskat)abstract
- Context: Establishing reference ranges as well as identifying and quantifying the determinants of thyroid function during pregnancy is important for proper clinical interpretation and optimizing research efforts. However, such data are sparse, specifically for (F)T3 measurements and most studies do not take into account thyroid antibodies or hCG.Objective: To determine reference ranges and to identify/quantify determinants of TSH, FT4, FT3, TT4 and TT3.Design, Setting and Participants: This study included 2,314 participants of the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy study, a population-based prospective pregnancy cohort of mother-child pairs. Reference ranges were calculated by 2.5-97.5th percentiles after excluding TPOAb and/or TgAb positive women.Intervention: None.Main Outcome Measures: TSH, FT4, FT3, TT4 and TT3 in prenatal serum.Results: After exclusion of TPOAb positive women, reference range were: TSH: 0.11-3.48 mU/L, FT4: 11.6-19.4 pmol/L, FT3: 3.72-5.92 pg/mL, TT4: 82.4-166.2 pmol/L and TT3: 1.28-2.92 nmol/L. Additional exclusion of TgAb positive women did not change the reference ranges substantially. Exposure to tobacco smoke, as assessed by questionnaires and serum cotinine, was associated with lower TSH and higher FT3 and TT3. BMI and gestational age were the main determinants of TSH (only for BMI), FT4, FT3, TT4 and TT3.Conclusions: We show that the exclusion of TgAb positive women on top of excluding TPOAb positive women hardly affects clinical reference ranges. We identified various relevant clinical determinants of TSH, FT4, FT3, TT4 and TT3 which could reflect endocrine disrupting effects and/or effects on thyroid hormone transport or deiodination.
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| 3. |
- Levie, Deborah, et al.
(författare)
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The Association of Maternal Iodine Status in Early Pregnancy with Thyroid Function in the Swedish Environmental Longitudinal, Mother and Child, Asthma and Allergy Study
- 2019
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Ingår i: Thyroid. - : Mary Ann Liebert. - 1050-7256 .- 1557-9077. ; 29:11, s. 1660-1668
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Tidskriftsartikel (refereegranskat)abstract
- 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 mu g/g (36-386) and the UI/Creat was below 150 mu g/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 mu g/g had the lowest prevalence of TPOAb positivity (6.1%), while women with a UI/Creat of <150 mu g/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 mu g/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.
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