Patients with type 2 diabetes show a greater decline in muscle mass, muscle strength, and functional capacity with aging

Background: The loss of muscle mass with aging reduces muscle strength, impairs functional capacity, and increases the risk of developing chronic metabolic disease. It has been suggested that the development of type 2 diabetes results in a more rapid decline in muscle mass, strength, and functional capacity. Objective: To investigate the impact of type 2 diabetes on muscle mass, strength, and functional capacity in an older population. Methods: Muscle mass (DXA and muscle biopsies), strength (1-repetition maximum), functional capacity (sit-to-stand test and handgrip strength), and reaction time performance (computer task) were compared between 60 older men with type 2 diabetes (71 1 years) and 32 age-matched normoglycemic controls (70 1 years). Data were analyzed using ANCOVA to adjust for several potential confounders. Results: Leg lean mass and appendicular skeletal muscle mass were significantly lower in older men with type 2 diabetes (19.1 0.3 and 25.9 0.4 kg, respectively) compared with normoglycemic controls (19.7 0.3 and 26.7 0.5 kg, respectively). Additionally, leg extension strength was significantly lower in the group with type 2 diabetes (84 2 vs 91 2 kg, respectively). In agreement, functional performance was impaired in the men with type 2 diabetes, with longer sit-to-stand time (9.1 0.4 vs 7.8 0.3 seconds) and lower handgrip strength (39.5 5.8 vs 44.6 6.1 kg) when compared with normoglycemic controls. However, muscle fiber size and reaction time performance did not differ between groups. Conclusion: Older patients with type 2 diabetes show an accelerated decline in leg lean mass, muscle strength, and functional capacity when compared with normoglycemic controls. Exercise intervention programs should be individualized to specifically target muscle mass, strength, and functional capacity in the older population with type 2 diabetes.