Association of thyroid stimulating hormone and coronary lipid risk factors with lipid peroxidation in hypothyroidism

Abstract

Hypothyroidism is the second most prevalent disorder in India and most cases require lifelong treatment. Disordered myocardial function is one of the complications of overt hypothyroidism. Dyslipidemia and lipid peroxidation are two biochemical derangements of hypothyroidism and both have been found to be associated. Still uncertainty remains regarding the origin of lipid peroxidation in this clinical condition. Besides, thyroid stimulating hormone or thyrotropin at a higher concentration can induce secretion of inflammatory cytokines and decrease the antioxidant status. Hence, we analyzed the association of lipid risk factors and thyrotropin in hypothyroidism with the extent of lipid peroxidation. A total of 42 primary hypothyroid patients volunteered to give fasting blood samples prior to therapy for the analysis of oxidative stress, thyroid and lipid profiles. Oxidative stress was confirmed by the increased levels of malondialdehyde and protein carbonylation and decreased levels of reduced glutathione. Simple correlation analyses revealed the association of lipid peroxidation with both thyrotropin and lipid risk factors. Partial correlation analyses showed that thyrotropin and lipid risk factors mutually influence their association with the higher malondialdehyde levels in these patients. Hyperthyrotropinemia may be considered not only as an index of the severity of hypothyroidism but also of the extent of the associated lipid peroxidation.