Impact of Adipocytokines-Leptin and Adiponectin on Thyroid Stimulating Hormone among Hypothyroid Patients

Abstract

Background: Adipocytokines, secreted from the adipose tissues have profound effect on complex metabolic and endocrine functions. Among them, leptin and adiponectin are the most recognized molecules which influence body homeostasis and metabolism. Moreover, patients with thyroid disease usually exhibit disturbances of these metabolic activities. Thus adipocytokines and thyroid hormones may influence similar aspects of metabolic functions. Objective:The main objective of current study was to evaluate the association and impact of leptin and adiponectin on thyroid stimulating hormone (TSH) among hypothyroid patients. Materials and Methods: For the present study a total 350 individuals were enlisted, out of which 200 were hypothyroid patients and 150 age and sex matched healthy controls aged ≥ 12 years. The serum TSH, leptin and adiponectin concentration were measured by CLIA method and results were computed by statistical methods such as mean, standard deviation, standard error and correlation using MS-Excel 2007. Result: Our data showed that hypothyroidism was more prevalent in the age group 30-50(62%) and an elevated TSH level was observed with advancing age among the patients as compared to controls. The inverse relation of leptin and adiponectin has been seen among the patients. When patients were compared with controls, they were with normal values which were in the range of standardized lab values leptin (3.7-13ng/dl) and adiponectin (5-10µg/ml). Conclusion: In conclusion, our data interpreted variations in the level of leptin and adiponectin among the hypothyroid individuals with high TSH level. As abnormal levels of these adipocytokines indicates the risk for other metabolic diseases like cardiovascular disease, obesity etc. Leptin is a protein hormone encoded by the obesity gene (ob) acts as neurotransmitters to brain to maintain body weight. It is majorly produced from white adipose tissue, but can also be produced by other tissues like placenta, ovary, mammary epithelial cells, hypophysis, stomach, and liver. The normal level of leptin in female is 7-13ng/dl and in male is 1-5ng/dl. Its concentration increases in obesity, Type 2 diabetes mellitus, hypertension and metabolic syndrome.2 Whereas adiponectin is a unique adipokine secreted by adipocytes has anti-atherogenic, anti-inflammatory and insulin sensitizing properties. Clinically normal range of plasma adiponectin is 5-10µg/ml. Its concentration is decreased with obesity, non-insulin dependent diabetes mellitus insulin resistance and dyslipidaemia. 3Thyroid hormones are also crucial for the regulation of total energy consumption and body composition besides their roles in normal growth, development, and reproduction. The normal levels of these hormones i.e. T 3 , T 4 and TSH are in the range of 0.87-2nmol/L, 6.09-12.23nmol/L and 0.34-5.6µIU/L respectively. Hypothyroidism and hyperthyroidism are associated with thyroid dysfunction. Clinical presentations are most commonly for hypothyroid and goiters and infrequently for hyperthyroidism.