Abstract

Background: It is believed that overt hyperthyroidism is associated with weight loss and hypothyroidism is associated with weight gain. Studies have shown that there is inter individual variations of thyroid function in persons with thyroid hormone levels within the normal physiological range. A clear epidemiological relation between thyroid hormone status and weight gain and obesity has not been established.

Objectives: The study was conducted to determine any correlation between thyroid hormone function indicated by thyroid stimulating factor (TSH) and body mass index (BMI).

Methods: This is cross-sectional study of 316 individuals (26 male and 292 female) out of which 22 individuals had subclinical hypothyroidism (SCH), 208 individuals had hypothyroidism and 88 individuals were euthyroid. TSH was estimated by Chemilluminence immune assay. Anthropometric parameters were measured for all participants and comparisons were done according to gender and thyroid hormone status.

Results: median TSH level was 5.1mIU for total population, 11.29mIU in hypothyroid group, 6.86mIU in subclinical hypothyroid group and 2.60mIu in euthyroid group. Median BMI was 25.6kg/m2 for total population, 25.5kg/m2 for hypothyroid group, 26.2kg/m2 for subclinical hypothyroid group and 25.6kg/m2 for euthyroid group. Median waist circumference was 88.5cm for total population, 88.7cm for hypothyroid group, 88cm for subclinical hypothyroid group and 88cm for euthyroid group. R2 for TSH and BMI for hypothyroid group was 0.0003, for subclinical hypothyroid group was 0.010 and for euthyroid group was 0.006 with p value being 0.80, 0.65 and 0.45 respectively. R2 for TSH and waist circumference for hypothyroid group was 0.0051, for subclinical hypothyroid was 0.0002 and for euthyroid was 0.052 with p value being 0.30, 0.93 and 0.03 respectively.

Conclusion: There is no correlation between TSH and BMI. Further studies involving large number of subjects are needed to confirm the findings.

Keywords

body mass index, thyroid, hormone, TSH, BMI, hyperthyroidism, epidemiological, obesity