Background: Type 2 Diabetes (T2D) in the elderly is an epidemic that significantly impacts global health. This experimental study aimed to compare the responses of microRNA-133a (miR-133a) in different tissues and of Runt-related transcription factor 2 (Runx2) in bone marrow tissue following resistance and endurance training in old rats with High-Fat Diet and Streptozotocin (HFD/STZ)- induced type 2 diabetes.

Materials and Methods: T2D was induced by HFD/low-dose STZ in 30 male Wistar rats (21-monthold, Mean±SD weight 418±43 g). The rats received HFD (55%, 31%, and 14% of energy from fat, carbohydrate, and protein, respectively; 5.2 kcal/g). The diets continued for eight weeks in both groups. Over week four, the rats in the group with HFD/STZ-induced T2D received treatment with low-dose STZ. After one week of familiarity with the laboratory environment, they were randomly divided into three groups: Diabetic Endurance Training (DET, n=10), Diabetic Resistance Training (DRT, n=10), and Diabetic Control (DC, n=10). The eight weeks of endurance training protocol comprised five sessions of moderate-intensity training (60%-75% velocity at maximal oxygen uptake (vVO2max) and low intensity (30%-30% vVO2max). In 60% Maximum Voluntary Carrying Capacity (MVCC), the resistance group climbed the ladder 14-20 times with 1-minute rest, five days a week.

Results: The results of the 1-way ANOVA test showed no significant change in serum miR-133 expression (P=0.411) and muscle tissue (P=0.077) following resistance and endurance training. However, significant differences were observed in bone marrow miR-133 expression (P=0.003) and Runx2 gene expression (P=0.002) between groups. Tukey’s post hoc tests showed that the bone marrow miR-133 expression had a significant increase following eight weeks of resistance training compared to the endurance training (P=0.006) and control (P=0.002) groups, and bone marrow Runx2 gene expression in rats exposed to resistance training compared to the endurance training (P=0.044) and the control (P=0.018) groups.

Conclusion: It seems that longer periods of exercise are required for cellular changes in the metabolism of these tissues after these exercise protocols. This topic should be studied in future research.