Protein carbonylation in freshly diagnosed hypothyroidism is independent of thyrotropin levels

Abstract

AbstractBackgroundHypothyroidism is a common endocrine disorder with female preponderance. Protein carbonyls (cP) and malondialdehyde (MDA) are generated due to protein and lipid peroxidation, respectively. Oxidative stress (OS) in freshly diagnosed hypothyroidism met with conflicting data in the research. And, a clear relationship between OS and early hypothyroidism is very limited and obscure. Therefore, we aimed to investigate the association between levels of MDA vs. thyrotropin (TSH) and cP vs. TSH among freshly diagnosed hypothyroid subjects.MethodsWe collected blood samples of 80 hypothyroid subjects prior to initiation of thyroxine therapy to know the association between OS and freshly diagnosed hypothyroidism. Serum MDA, cP along with total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and triacylglycerols (TG) were quantified in patients as well as 80 age- and sex-matched control subjects.ResultsLevels of MDA and cP were significantly elevated among hypothyroid subjects as compared to control. The rise in MDA levels positively correlated with TSH values among the patients. In addition, cP levels were substantially elevated as compared to MDA values; however, it does not correlate with TSH among hypothyroid subjects.ConclusionsOur study found no relationship between cP and TSH in freshly diagnosed hypothyroidism. Though it may be due to differential degradation of protein peroxidation products, the mechanism needs further elucidation in future studies.