The Effect of Acute and Chronic Thermotherapy on Type 2 Diabetic Skeletal Muscle Gene Expression and Inflammatory Markers

Abstract

Background: Type 2 diabetes (T2D) is a chronic illness associated with resistance to or defective insulin secretion. This study investigates the effects of thermotherapy on cell viability, gene expression and inflammation in skeletal muscle cell lines. Methods: Healthy and T2D human skeletal muscle cell lines (HSMM and D-HSMM, respectively) were subjected to acute or chronic thermo-therapy (AT or CT, respectively). CT consisted of a 30 min exposure to 40 °C, three times a week for three weeks; AT was a one-time exposure. Results: A significant decrease in D-HSMM cell viability percentage followed AT; however, no significant change occurred in CT. HSMM yielded the highest elevations of genes following CT. In D-HSMM, both treatments yielded gene upregulation. Both treatments significantly down-regulated IL-1β, IL-6, IL-10 and TNF-α in HSMM. AT significantly decreased IL-1β, IL-6 and upregulated IL-10 and TNF-α levels in D-HSMM, while CT yielded a reduction in IL-4, TNF-α and an upregulation of IL-6 and IL-10. Conclusions: An increase in gene expression indicates actin activity and cellular responses, suggesting an increase in transcriptional regulation. The upregulation of IL-6 and IL-10 in D-HSMM negatively correlated with a decrease in TNF-α and IL-1β, indicating improved adverse inflammatory effects associated with the disease.