Horm Metab Res 2017; 49(03): 192-200
DOI: 10.1055/s-0042-117279
Endocrine Care
© Georg Thieme Verlag KG Stuttgart · New York

Thyroid Function and Metabolic Syndrome: A Population-Based Thyroid Study

Ladan Mehran
1   Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran
,
Atieh Amouzegar
1   Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran
,
Parnian Kheirkhah Rahimabad
1   Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran
,
Maryam Tohidi
2   Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran
,
Zhale Tahmasebinejad
1   Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran
,
Fereidoun Azizi
1   Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran
› Author Affiliations
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Publication History

Publication Date:
28 March 2017 (online)

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Abstract

The impact of thyroid dysfunction in subclinical ranges on metabolic syndrome (MetS) is not well known. The aim of the present study is to evaluate the association of thyroid dysfunction with MetS and its components. In the cross-sectional population-based Tehran Thyroid Study, out of 5 786 randomly selected participants, aged≥20 years, subjects with thyroid nodules and cancer or any severe systemic disease, those who were pregnant and those using thyroid medication were excluded, leaving 5 422 subjects to be investigated. Body weight, waist circumference, and blood pressure were measured. Fasting blood glucose and concentrations of lipids and lipoproteins, free T4, and TSH were assayed. Mean age of the participants was 40.3±14.4 of whom 101 (2%) had overt hypothyroidism, 294 (5%) subclinical hypothyroidism, 82 (2%) overt hyperthyroidism, and 178 (3%) had subclinical hyperthyroidism; 1 704 (32%) had MetS. Clinically hypothyroid subjects had the highest prevalence of MetS (41.6%), abdominal obesity (45%), and hypertriglyceridemia (58%) compared to other groups (p<0.05). Significant odds ratio for prevalent MetS was observed only in clinically hypothyroid men [OR: 2.9, 95% CI: 1.04, 8.4, p=0.04]. In women, the association between overt hypothyroidism and MetS was marginally significant only in the crude model [OR: 0.068, 95% CI (0.97–2.42), p=0.06]. There was higher risk of Mets in subclinically hypothyroid subjects, aged>50. Overt and subclinical hyperthyroidism had significantly higher odds of hyperglycemia in men and women after full adjustment for age, smoking, and BMI. Overt hypothyroidism and subclinical hypothyroidism especially in the elderly could be associated with MetS. Hyperthyroidism may induce hyperglycemia.

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