Lipoproteins and Lipid Peroxidation in Thyroid disorders

Abstract

Alteration in thyroid function results in changes in composition and transport of lipoproteins. Abnormalities of lipid metabolism associated with hypothyroidism may predispose to the development of atherosclerotic coronary artery disease. The aim of our study is to evaluate lipids and the oxidative stress due to thyroid dysfunction. Serum T3, T4, TSH, total cholesterol, low density lipoprotein, high density lipoprotein and triglycerides were measured using standardized assays. In a total of 80 patients with thyroid dysfunction, 53 patients are hypothyroid and 27 patients are hyperthyroid as compared with 40 healthy controls. In hypothyroid cases, T3 (2.741 ng/dl), T4 (7.3 µg/dl) are significantly decreased where as TSH (10.16 µ IU/ml) levels were elevated. In hyperthyroid patients T3 (6.071 ng/dl) and T4 (7.36 µg/dl) were increased but TSH values are low (2.042 µ IU/ml) but statistically not significant compared to controls. In hypothyroid cases total cholesterol (5.87mg/dl), triglycerides (3.233mg/dl), LDL (5.48mg/dl), VLDL (3.142mg/dl) were significantly increased, but there was no significant change in HDL cholesterol. In hyperthyroid cases, total cholesterol (2.51mg/dl), HDL (3.066mg/dl) significantly high, whereas triglycerides (0.633mg/dl), LDL (2.149mg/dl) and VLDL (0.532mg/dl) are within normal. MDA is higher in both hypothyroid (7.88mg/dl) and hyperthyroid (6.829mg/dl) cases. In conclusion, thyroid disorders are related to oxidative damage in tissues.