Effect of altered levels of micronutrients on lipid parameters in thyroid dysfunction.

ABSTRACT

Trace elements are extremely important for normal metabolism. Copper is one of the trace metals which has important physiological function in maintaining thyroid activity. Copper is known to effect lipid metabolism. Increase in serum copper level is associated with decrease in concentration of total cholesterol (TC). Thyroid hormone binding transcription factors, which are essential for modulation of gene expression, contain zinc bound to cysteine residues and also thyroid hormones influence zinc metabolism by affecting zinc absorption and excretion. Zinc is required for enzymes involved in lipid synthesis and lipoprotein excretion. The purpose of this study was to determine the effect of various levels of serum copper and zinc on total cholesterol, plasma triglyceride and low density lipoprotein cholesterol in subjects with thyroid dysfunction. 61 subjects were divided into three groups of 13 hypothyroid, 23 hyperthyroid and 25 euthyroid based on thyroid stimulating hormone levels. The correlation between serum copper and low density lipoprotein (p <0.01) (r = -0.842), serum zinc correlated strongly negative and significantly with total cholesterol (r= -0.564) , low density lipoprotein cholesterol (r= -0.666) in hyperthyroid group. But the correlation in hypothyroid and euthyroid group differed and was not significant. Elevated levels of total cholesterol and low density lipoprotein cholesterol may be proatherogenic and increase the risk of cardio vascular diseases hence measures must be taken in correcting and maintaining levels of micronutrients in thyroid dysfunction.