Serum Adipokines and Metabolic Parameters With Hormone Replacement in Newly Diagnosed Hypothyroidism

Overview

Primary hypothyroidism is associated with significant metabolic disturbances, including dyslipidemia, insulin resistance, adipose tissue dysfunction, and altered adipokine secretion. Although levothyroxine replacement therapy effectively restores thyroid hormone levels, the extent to which biochemical recovery reflects metabolic improvement remains unclear. This prospective observational study aims to evaluate changes in serum adipokine levels, including asprosin, adipolin, omentin-1, and visfatin, together with metabolic parameters in newly diagnosed primary hypothyroid patients before and after 8 weeks of levothyroxine replacement therapy. In addition to conventional biochemical markers, multiple cardiometabolic indices related to insulin resistance, lipid metabolism, and hepatic metabolic burden will be analyzed. The study is designed to investigate whether normalization of thyroid function is accompanied by parallel metabolic recovery and to explore the potential role of adipokine dynamics in adipose-metabolic remodeling during early levothyroxine treatment.

Hypothyroidism is associated with multiple cardiometabolic abnormalities, including dyslipidemia, insulin resistance, adipose tissue dysfunction, altered energy homeostasis, and chronic low-grade inflammation. Although levothyroxine replacement therapy is effective in restoring thyroid hormone levels, metabolic recovery may not occur simultaneously with biochemical normalization of thyroid function. Adipokines are biologically active molecules secreted by adipose tissue and play important roles in glucose metabolism, lipid regulation, inflammation, and cardiometabolic risk. Among these adipokines, asprosin, adipolin, omentin-1, and visfatin have been associated with insulin resistance, obesity-related metabolic dysfunction, hepatic metabolism, and inflammatory pathways. However, data regarding the dynamic changes of these adipokines after levothyroxine replacement in newly diagnosed primary hypothyroidism remain limited and inconsistent. This prospective observational study was designed to evaluate changes in serum adipokine levels and metabolic parameters before and after levothyroxine replacement therapy in newly diagnosed primary hypothyroid patients. Serum samples and metabolic measurements will be obtained before treatment initiation and after 8 weeks of levothyroxine therapy. In addition to conventional thyroid function tests, multiple metabolic indices associated with insulin resistance, lipid metabolism, hepatosteatosis, and cardiometabolic risk will be analyzed, including HOMA-IR, TyG index, METS-IR, AIP, HSI, and Castelli risk indices. The primary objective of the study is to evaluate changes in adipokine levels following levothyroxine replacement therapy. Secondary objectives include assessing the relationship between adipokine dynamics and metabolic remodeling, insulin resistance, lipid metabolism, obesity phenotype, and hepatic metabolic burden during early biochemical recovery.