Exercise training and spexin ameliorate thyroid changes in obese type 2 diabetic rats: the possible interlaying mechanisms.

Thyroid dysfunction and diabetes mellitus are prevalent endocrine disorders that often coexist and influence each other. The role of spexin (SPX) in diabetes and obesity is well documented, but its connection to thyroid function is less understood. This study investigates the influence of exercise (EX) and SPX on thyroid hypofunction in obese type 2 diabetic rats. Rats were divided into normal control, obese diabetic sedentary, obese diabetic EX, and obese diabetic SPX groups, with subdivisions for M871 and HT-2157 treatment in the latter two groups. High-fat diet together with streptozotocin (STZ) injection induced obesity and diabetes. The EX group underwent swimming, and the SPX group received SPX injections for 8 wk. Results showed significant improvements in thyroid function and metabolic, oxidative, and inflammatory states with EX and SPX treatment. The study also explored the involvement of galanin receptor isoforms (GALR)2/3 in SPX effects on thyroid function. Blocking GALR2/3 receptors partially attenuated the beneficial effects, indicating their interaction. These findings underscore the importance of EX and SPX in modulating thyroid function in obesity and diabetes. Comprehending this interplay could enable the development of new treatment approaches for thyroid disorders associated with obese type 2 diabetes. Additional research is necessary to clarify the exact mechanisms connecting SPX, EX activity, and thyroid function.NEW & NOTEWORTHY This study proves, for the first time, the beneficial effects of SPX on thyroid dysfunction in obese diabetic rats and suggests that SPX mediates the EX effect on thyroid gland and exerts its effect mainly via GALR2.