Abstract
BACKGROUND: This study was designed to test the therapeutic effect of swimming exercise on grip strength, muscle cross-section of quadriceps, and trabecular bone volume of the femur among STZ-induced type 1 diabetic rats, independent of insulin therapy. METHODS: Sprague-Dawley rats were divided into three groups: control group (CON), diabetes mellitus group (DM), and diabetes mellitus plus exercise group (DM+EX). Type 1 Diabetes was established with intraperitoneal injection of streptozotocin (50 mg/kg body weight). The DM+EX group received progressive swimming exercise five days a week for 12 weeks. RESULTS: Both the DM and DM+Ex groups displayed hyperglycemia, with no statistically significant difference in blood glucose levels observed between these two groups. Compared to the control group (CON), the DM group demonstrated significant reductions in grip strength and quadriceps cross-sectional area (P<0.05), which was reversed by swimming exercise (P<0.05). Micro-CT analysis of the femoral bone revealed that the DM group had significantly lower BV/TV and Tb.N, compared with the CON group (P<0.05), while exhibiting a significant increase in trabecular spacing (Tb.Sp). In contrast, the DM+Ex group showed significant increases in BV/TV (P<0.01) and Tb.N (P<0.01) compared to the DM group, along with a significant decrease in Tb.Sp (P<0.001). CONCLUSION: Swimming exercise may reverse the loss of grip strength, muscle cross-sectional area, and trabecular bone volume in STZ-induced type 1 diabetic rats - independent of insulin therapy.