Top

Published in:

Open Access 01-12-2017 | Research article

Urinary iodine in early pregnancy is associated with subclinical hypothyroidism in Tianjin, China: an observational study

Authors: Kunling Wang, Jie Zhang, Fengao Li, Wanqi Zhang, Hao Wang, Li Ding, Yaxin Liu, Laixiang Lin, Shuang Zhang, Mei Zhu

Published in: BMC Endocrine Disorders | Issue 1/2017

Abstract

Background

Subclinical hypothyroidism (SH) is associated with adverse obstetric outcomes and neurodevelopment disorders. Both iodine deficiency and excess are associated with SH; however, few data regarding iodine nutrition status of pregnant women with SH are available. This study aimed to clarify whether iodine deficiency or excess is associated with SH, especially, when test results for anti-thyroid autoantibodies are negative.

Methods

A total of 115 women with SH and 104 women with euthyroidism (EH) in early pregnancy in Tianjin, China were investigated, and their serum thyroid-stimulating hormone, free thyroxine, free triiodothyronine, anti-thyroid peroxidase antibody (TPOAb), anti-thyroid globulin antibody (TGAb), urinary iodine (UIC), and urinary creatinine (UCr) concentrations were measured. Thyroid ultrasonography was performed to determine thyroid echogenicity and volume. The UIC, UIC/UCr ratio, prevalence of TPOAb and TGAb positivity, and thyroid gland volume were compared between the EH and SH groups. UIC and ultrasonographic features were analysed in subjects in the SH group who were negative for TPOAb and TGAb.

Results

Median UIC of SH (154.0 μg/L) and EH (150.1 μg/L) met the World Health Organization criterion for iodine sufficiency in pregnant women. Neither UIC nor the UIC/UCr ratio differed significantly between groups. The prevalence of TPOAb and TGAb positivity in the SH group was significantly higher than that in the EH group (P < 0.01). The percentage of subjects with UIC ≥ 250 μg/L in the SH group was significantly higher than that in the EH group (p = 0.004). The percentage of subjects negative for autoantibodies and UIC ≥ 250 μg/L in the SH group tended to be higher than that in subjects in the EH group negative for autoantibodies, but the difference was not statistically significant (p = 0.025, adjusted test level α = 0.0167). Eight of 18 subjects in the SH group with negative results for TPOAb and TGAb were diagnosed with Hashimoto thyroiditis by means of thyroid ultrasonography.

Conclusions

Women in early pregnancy with SH in Tianjin were iodine sufficient, but still at risk of iodine deficiency as pregnancy progressed. UIC ≥ 250 μg/L was associated with increased risk of SH. Serological negative autoimmune thyroiditis and UIC ≥ 250 μg/L may play a role in pathogenesis of SH cases with negative results for autoantibodies.

Ashoor G, Maiz N, Rotas M, Jawdat F, Nicolaides KH. Maternal thyroid function at 11 to 13 weeks of gestation and subsequent fetal death. Thyroid. 2010;20:989–93.CrossRefPubMed

Liu H, Shan Z, Li C, Mao J, Xie X, Wang W, Fan C, Wang H, Zhang H, Han C, Wang X, Liu U, Fan Y, Bao S, Teng W. Maternal subclinical hypothyroidism, thyroid autoimmunity, and the risk of miscarriage: a prospective cohort study. Thyroid. 2014;24:1642–9.CrossRefPubMedPubMedCentral

Negro R, Schwartz A, Gismondi R, Tinelli A, Mangieri T, Stagnaro-Green A. Increased pregnancy loss rate in thyroid antibody negative women with TSH levels between 2.5 and 5.0 in the first trimester of pregnancy. J Clin Endocrinol Metab. 2010;95:E44-8.CrossRefPubMed

Karakosta P, Alegakis D, Georgiou V, Roumeliotaki T, Fthenou E, Vassilaki M, Boumpas D, Castanas E, Kogevinas M, Chatzi L. Thyroid dysfunction and autoantibodies in early pregnancy are associated with increased risk of gestational diabetes and adverse birth outcomes. J Clin Endocrinol Metab. 2012;97:4464–72.CrossRefPubMed

Lazarus JH. Thyroid function in pregnancy. Br Med Bull. 2011;97:137–48.CrossRefPubMed

Su PY, Huang K, Hao JH, Xu YQ, Yan SQ, Li T, Xu YH, Tao FB. Maternal thyroid function in the first twenty weeks of pregnancy and subsequent fetal and infant development: a prospective population-based cohort study in China. J Clin Endocrinol Metab. 2011;96:3234–41.CrossRefPubMed

Lazarus J, Brown RS, Daumerie C, Hubalewska-Dydejczyk A, Negro R, Vaidya B. 2014 European thyroid association guidelines for the management of subclinical hypothyroidism in pregnancy and in children. Eur Thyroid J. 2014;3:76–94.CrossRefPubMedPubMedCentral

Shi X, Han C, Li C, Mao J, Wang W, Xie X, Li C, Xu B, Meng T, Du J, et al. Optimal and safe upper limits of iodine intake for early pregnancy in iodine-sufficient regions: a cross-sectional study of 7190 pregnant women in China. J Clin Endocrinol Metab. 2015;100:1630–8.CrossRefPubMed

Teng W, Shan Z, Teng X, Guan H, Li Y, Teng D, Jin Y, Yu X, Fan C, Chong W, et al. Effect of iodine intake on thyroid diseases in China. N Engl J Med. 2006;354:2783–93.CrossRefPubMed

10.

Yan YQ, Chen ZP, Yang XM, Liu H, Zhang JX, Zhong W, Yao W, Zhao JK, Zhang ZZ, Hua JL, et al. Attention to the hiding iodine deficiency in pregnant and lactating women after universal salt iodization: A multi-community study in China. J Endocrinol Invest. 2005;28:547–53.CrossRefPubMed

11.

Mao G, Ding G, Lou X, Zhang R, Zheng P, Mo Z, Wang X, Zhu W, Zhou J, Gu F. Survey of iodine nutritional status in 2011, Zhejiang, China. Asia Pac J Clin Nutr. 2015;24:234–44.PubMed

12.

Su X, Liu S, Shen H, Zhang S, Wei H, Yu J, Ye Y, Li Y, Liu Y, Zhang Z. National iodine deficiency disorder surveillance: a sum up of data in 2005 and an analysis. Chin J Endem. 2007;26:67–9.

13.

Teng W, Duan T, Ning G. Guidelines for the diagnosis and management of thyroid diseases during pregnancy and postpartum. Chin J Endocrinol Metab. 2012;28:356.

14.

Organization WH. Assessment of iodine deficiency disorders and monitoring their elimination: a guide for programme managers. 2007.

15.

Brunn J, Block U, Ruf G, Bos I, Kunze WP, Scriba PC. Volumetric analysis of thyroid lobes by real-time ultrasound (author’s transl). Dtsch Med Wochenschr. 1981;106:1338–40. in German.CrossRefPubMed

16.

Stagnaro-Green A, Abalovich M, Alexander E, Azizi F, Mestman J, Negro R, Nixon A, Pearce EN, Soldin OP, Sullivan S, et al. Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid. 2011;21:1081–125.CrossRefPubMedPubMedCentral

17.

Glinoer D. The importance of iodine nutrition during pregnancy. Public Health Nutr. 2007;10:1542–6.CrossRefPubMed

18.

Zimmermann MB, Boelaert K. Iodine deficiency and thyroid disorders. Lancet Diabetes Endocrinol. 2015;3:286–95.CrossRefPubMed

19.

Trumpff C, De Schepper J, Tafforeau J, Van Oyen H, Vanderfaeillie J, Vandevijvere S. Mild iodine deficiency in pregnancy in Europe and its consequences for cognitive and psychomotor development of children: a review. J Trace Elem Med Biol. 2013;27:174–83.CrossRefPubMed

20.

Zimmermann MB. The role of iodine in human growth and development. Semin Cell Dev Biol. 2011;22:645–52.CrossRefPubMed

21.

Sang Z, Wei W, Zhao N, Zhang G, Chen W, Liu H, Shen J, Liu J, Yan Y, Zhang W. Thyroid dysfunction during late gestation is associated with excessive iodine intake in pregnant women. J Clin Endocrinol Metab. 2012;97:E1363–9.CrossRefPubMed

22.

Zimmermann MB, Andersson M. Assessment of iodine nutrition in populations: past, present, and future. Nutr Rev. 2012;70:553–70.CrossRefPubMed

23.

Yang J, Zheng H, Li X, Zhu L, Hao Z, Chen G, Liu Y, Wang Y. Assessment of iodine status and associated factors in vulnerable populations in Henan Province, China, in 2012. Asia Pac J Clin Nutr. 2014;23:626–33.PubMed

24.

Zhang H, Lv S, Mu Z, Li W, Zhang X, Wang Y, Rutherford S. Iodised salt contribution to iodine nutrition status of pregnant and lactating women. Br J Nutr. 2015;114:126–33.CrossRefPubMed

25.

Chen W, Hou C, Zhu Y, Li D, Gu J, Liu Z, Chen Z. An evaluation of the effectiveness of implementation of national food safety standard for “Iodine Concentratin in Edible Salt”(GB 26878–2011). Chin J Endemiol. 2014;33:407–10.

26.

Wolff J, Chaikoff I, Goldberg R, Meier J. The Temporary Nature of The Inhibitory Action of Excess Iodide on Organic Iodine Synthesis in the Normal Thyroid 1. Endocrinology. 1949;45:504–13.CrossRefPubMed

27.

Leung AM, Braverman LE. Consequences of excess iodine. Nat Rev Endocrinol. 2014;10:136–42.CrossRefPubMed

28.

Premawardhana L, Parkes A, John R, Harris B, Lazarus J. Thyroid peroxidase antibodies in early pregnancy: utility for prediction of postpartum thyroid dysfunction and implications for screening. Thyroid. 2004;14:610–5.CrossRefPubMed

29.

Rago T, Chiovato L, Grasso L, Pinchera A, Vitti P. Thyroid ultrasonography as a tool for detecting thyroid autoimmune diseases and predicting thyroid dysfunction in apparently healthy subjects. J Endocrinol Investig. 2001;24:763–9.CrossRef

30.

Wasniewska M, Salerno M, Cassio A, Corrias A, Aversa T, Zirilli G, Capalbo D, Bal M, Mussa A, De Luca F. Prospective evaluation of the natural course of idiopathic subclinical hypothyroidism in childhood and adolescence. Eur J Endocrinol. 2009;160:417–21.CrossRefPubMed

31.

Cerbone M, Agretti P, De Marco G, Improda N, Pignata C, Santamaria F, Tonacchera M, Salerno M. Non-autoimmune subclinical hypothyroidism due to a mutation in TSH receptor: report on two brothers. Ital J Pediatr. 2013;39:5.CrossRefPubMedPubMedCentral

32.

Laurberg P, Knudsen N, Andersen S, Carle A, Pedersen IB, Karmisholt J. Thyroid function and obesity. Eur Thyroid J. 2012;1:159–67.CrossRefPubMedPubMedCentral

Title: Urinary iodine in early pregnancy is associated with subclinical hypothyroidism in Tianjin, China: an observational study
Authors: Kunling Wang
Jie Zhang
Fengao Li
Wanqi Zhang
Hao Wang
Li Ding
Yaxin Liu
Laixiang Lin
Shuang Zhang
Mei Zhu
Publication date: 01-12-2017
Publisher: BioMed Central
Published in: BMC Endocrine Disorders / Issue 1/2017
Electronic ISSN: 1472-6823
DOI: https://doi.org/10.1186/s12902-017-0162-x

ACC 2024 Congress Coverage

Heart Failure Video

Keynote webinar | Spotlight on sleep in brain health

Springer Medicine

Urinary iodine in early pregnancy is associated with subclinical hypothyroidism in Tianjin, China: an observational study

Abstract

Background

Methods

Results

Conclusions

ACC 2024 Congress Coverage

Year in Review: Heart failure and cardiomyopathies

Semaglutide benefits people with type 2 diabetes and obesity-related heart failure

Incentivised to exercise

New intervention for STEMI-related cardiogenic shock

» View more highlights on the ACC 2024 congress hub page

Keynote webinar | Spotlight on sleep in brain health

Springer Medicine

Abstract

Background

Methods

Results

Conclusions

Please log in to get access to this content

Other articles of this Issue 1/2017

Frequency and determinants of thyroid autoimmunity in Ghanaian type 2 diabetes patients: a case-control study

Prolonged preoperative treatment of acromegaly with Somatostatin analogs may improve surgical outcome in patients with invasive pituitary macroadenoma (Knosp grades 1–3): a retrospective cohort study conducted at a single center

Hyperuricemia and metabolic syndrome in type 2 diabetes mellitus patients at Hawassa university comprehensive specialized hospital, South West Ethiopia

Multihormonal pituitary adenoma concomitant with Pit-1 and Tpit lineage cells causing acromegaly associated with subclinical Cushing’s disease: a case report

Study protocol; Thyroid hormone Replacement for Untreated older adults with Subclinical hypothyroidism - a randomised placebo controlled Trial (TRUST)

Screening for celiac disease in poorly controlled type 2 diabetes mellitus: worth it or not?

ACC 2024 Congress Coverage

Year in Review: Heart failure and cardiomyopathies

Semaglutide benefits people with type 2 diabetes and obesity-related heart failure

Incentivised to exercise

New intervention for STEMI-related cardiogenic shock

» View more highlights on the ACC 2024 congress hub page