Relationship between Thyroid Hormones and Body Mass Index in Healthy Indian Adults

Abstract

Introduction: Prior studies have reported that thyroid dysfunction such as overt hypothyroidism and hyperthyroidism are associated with weight gain and loss. In Indian normal healthy adults, relationship between thyroid hormones and Body Mass Index (BMI) has previously been studied but not explained very well. Aim: The present study aims to investigate the relationship between thyroid hormones and obesity measured by BMI in normal healthy adults who further classified in three categories as per the BMI in normal, overweight and obese. Materials and Methods: This observational cross-sectional study was conducted between 1st May 2019 and 30th June 2019. Consecutively, adults who attended Out-Patient Department (OPD) of Department of Medicine at Hamidia Hospital as attendant of patients and healthy hospital’s staff were selected for the study. Thyroid-Stimulating Hormone (TSH), total Thyroxine (T4), total Triiodothyronine (T3), total cholesterol, Low-Density Lipoprotein Cholesterol (LDL-C), High-Density Lipoprotein Cholesterol (HDL-C), triglyceride and glucose levels were measured in all study subjects. Height, weight, Waist Circumference (WC) and Hip Circumference (HC) were measured and BMI and Waist to Hip Ratio (WHR) were calculated by formula. According to Asian guidelines for BMI, all subjects were divided into three groups as healthy normal (18.5-22.9 Kg/m2), Overweight (23-24.9 Kg/m2) and Obese (≥25 Kg/m2). Results: Out of 100 study subjects, 58% were females and 42% were males. According to BMI, 33 (33%) participants were found in normal weight, 36 (36%) were in overweight and 31 (31%) were in obese group. Atherogenic lipid levels such as total cholesterol, LDL-C and triglyceride and blood glucose were found increased and HDL-C levels were found decreased in overweight and obese group. The TSH levels were found significantly increased in overweight and obese subjects as compared to normal subjects, also a statistically significant difference was found for TSH between overweight and obese subjects. Out of 100 subjects, 88% were shown euthyroidism, 10% were shown hypothyroidism and 2% were shown hyperthyroidism. Pearson’s correlation between BMI and TSH was not found significant in normal, overweight and obese groups, while a significant difference was noted between T3, T4 and BMI in overweight group. Conclusion: In the present study, total 12% thyroid dysfunction was observed. In view of the relationship between BMI and thyroid hormones, any significant relationship was not found in Indian normal as well as obese adults groups.

Keywords

• lipid profile
• obesity
• thyroid function