Modulation of the serum leptin by thyroid hormones: Observations in newly diagnosed thyrotoxic patients

Abstract

Background: Leptin and thyroid hormones both are involved in regulation of energy metabolism. Many studies were conducted for studying the relationship and the interaction between the thyrostat and the lipostat which till present is incompletely understood. The aim of this work was to study serum leptin levels in patients suffering from thyrotoxicosis who are newly diagnosed treatment naive patients, thus the association between leptin and thyroid hormones can be purified as much as possible. Methods: a case control study conducted at Port-Said General hospital endocrine out-patient clinic. The study included 15 patients with thyrotoxicosis and 30 control euthyroid subjects (15 lean, 15 obese). All of the included patients are analyzed for thyroid profile and serum leptin. Results: The results revealed a statistically significant difference regarding serum leptin between the Thyrotoxic group and control obese. No correlation was found between serum leptin and either BMI, TSH, Free T3 or Free T4 in each of the studied group, but a significant negative correlation was found between leptin and either free T3 and free T4 in the combined groups. Conclusion: Serum leptin level is lower in treatment naive thyrotoxic patients when compared to euthyroid control. The serum leptin showed no correlation with either BMI or TSH, also no correlation was found between serum leptin and free T3 or free T4 in each of the studied group suggesting presence of other factors that indirectly affect and interconnect these two major endocrinal systems involving energy metabolism.