Endocrine Abstracts

Introduction: Recent reports suggest that thyroid hormones are independently associated with components of metabolic syndrome. We studied the association between thyroid hormones, insulin resistance and components of metabolic syndrome in euthyroid overweight or obese individuals.

Methods: A total of 45 overweight or obese women with no past history of thyroid disease or diabetes mellitus were studied. Body fat was estimated by bio-impedance method and waist circumference was taken as an indirect measure of central fat accumulation. Fasting blood sample was analyzed for total triiodothyronine (T₃), total thyroxine (T₄), thyroid-stimulating hormone (TSH), free triiodothyronine (FT₃), lipid profile, insulin and glucose. Metabolic syndrome was defined as per ATP III guidelines and insulin resistance was calculated by homeostasis model assessment (HOMA-IR).

Results: The mean age of the participants was 32.6 (18–56) years and the mean body mass index (BMI) was 29.9 (25.7–44.3) kg/m². Evidence of insulin resistance (HOMA-IR >3) was seen in 34/45 (75%) and metabolic syndrome in 29/45 (64%) participants. T3 showed positive correlation with triglycerides, LDL-cholesterol (LDL-C), total cholesterol, insulin, HOMA-IR and negatively with body fat. TSH correlated positively with BMI, insulin, HOMA-IR, LDL-C and negatively with HDL-cholesterol (P<0.05). FT₃ correlated positively with waist circumference and T₄ did not show correlation with metabolic syndrome parameters.

Conclusion: Our preliminary data showed an association between thyroid hormones and metabolic syndrome in euthyroid range. T₃ and TSH were associated with more variables of metabolic syndrome than FT₃ and T₄. Further large scale population data is necessary to confirm these findings.