Alterations in Lipid Metabolism in Patients of Thyroid Hyperfunction

The thyroid disorders are found to be prevalent in Himalayan and sub Himalayan regions and the studies focusing on the association between thyroid function markers and lipid metabolism are sparse. The present study was aimed to study the impact of thyroid hyperfunction on lipoprotein metabolism and hepatic lipase activity. Two ninety subjects (255 females, 35 males) aged 2555 years with a clinical diagnosis of thyroid hyperfunction were included in the study. The serum TSH, T3, T4, total cholesterol (TC), HDL and triglycerides (TG) levels were measured using standardized assays. The distribution of subclinical and overt hyperthyroidism was 38% and 62.06%, respectively. Levels of HDL and LDL were significantly (P<0.05) low and TC, VLDL and TG were not altered in patients with subclinical hyperthyrodism compared with euthyroid subjects. Serum lipids were significantly (p<0.001) less in overt hyperthyroid patients compared to euthyroid controls. The activity of hepatic lipase (P<0.001) was elevated in overt cases. Pearson’s bivariate correlation analysis revealed that there was a positive relationship between serum TSH and TC (r = 0.68404), LDL (r = 0.76232), VLDL (r = 0.89975) and TG (r = 0.62905) in hyperthyroid patients. Hepatic lipase activity was not affected by low levels of TSH (r= 0.29). It was noteworthy in this study that even a slight alteration in thyroid hormones showed a significant decrease in serum lipids. The lipid metabolism in overt thyroid hyperfunction was found to be influenced by hepatic lipase activity.