Myostatin alters with exercise training in diabetic rats; possible interaction with glycosylated hemoglobin and inflammatory cytokines.

The role of myostatin (MSTN) in the regulation of energy homeostasis has been known and that MSTN inhibition can attenuate the development of diabetes. However, the response of MSTN to exercise in type 1 diabetes (T1DM) is unknown. This study aimed to investigate the alteration of MSTN following aerobic exercise training in diabetic rats and its possible interaction with glycosylated hemoglobin (HbA1c) and inflammatory cytokines. Forty-eight male Wistar rats were divided into non-diabetic untrained, non-diabetic trained, diabetic untrained and diabetic trained groups. To induce T1DM, rats received an intraperitoneal injection of STZ (60 mg·kg-1). Treadmill exercise was performed for six weeks, five days/week. HbA1c was estimated, MSTN mRNA expression in skeletal muscle was measured, and plasma MSTN and inflammatory cytokines including interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) were determined. Results revealed a significant decrease of HbA1c and plasma inflammatory cytokines (IL-6, TNF-α and IL-1β) followed by a significant decrease of plasma and skeletal muscle MSTN in diabetic trained rats versus non-diabetic untrained and diabetic untrained rats after the experimental period. Moreover, in diabetic untrained and diabetic trained rats, a significantly positive correlation (change versus change) of plasma MSTN with HbA1c and plasma IL-6, TNF-α and IL-1β was found. In conclusion, this study indicated that aerobic exercise training by a decrease of HbA1c and plasma IL-6, TNF-α and IL-1β could decrease MSTN levels in plasma and skeletal muscle in T1DM. Furthermore, the effective influence of exercise may be reflected by changes of MSTN in diabetic rats.