Changes and Risk Factors of Skeletal Muscle Mass and Strength in Patients with Type 2 Diabetes over 60 Years Old: A Cross-Sectional Study from China

Abstract

Objective. The accelerate loss of skeletal muscle mass, strength, and function, named sarcopenia, is a progressive and generalised skeletal muscle disorder, and it is always associated with increased outcomes including falls, frailty, and disability. Diabetes mellitus is associated with significant muscle and physical complications. We aimed at clarifying the changes and risk factors of skeletal muscle mass and strength in elderly with type 2 diabetes. Methods. The study consisted of patients with type 2 diabetes ( $n=120$ ) and an older general population ( $n=126$ ). The skeletal muscle mass and muscle strength, as well as the serum levels of chronic inflammation, oxidative stress, homocysteine, and insulin-like factor-1 were assessed, and the correlation and regression analysis were conducted to evaluate outcomes. Results. T2DM patients exhibited lower muscle strength compared with the non-T2DM subjects ( $P<0.01$ ). Among T2DM patients, serum IGF-1 levels were positively correlated with muscle strength ( $r=0.255$ , $P<0.01$ ) and muscle mass ( $r=0.209$ , $P<0.05$ ), levels of 8-OHdG were inversely correlated with muscle strength ( $r=-0.252$ , $P<0.01$ ), and there was a negative association between HCY and muscle mass ( $r=-0.185$ , $P<0.05$ ). Muscle mass and strength of patients with higher education level were significantly higher than those with lower education level ( $P<0.05$ ), in male patients, muscle mass and muscle strength were significantly lower in smokers ( $P<0.01$ ), and muscle mass was lower in chronic drinkers ( $P<0.05$ ). Conclusions. These findings suggest that diabetic patients may be more susceptible to sarcopenia at an older age. And it also provides evidences that among elderly with diabetes mellitus, oxidative damage and HCY as well as IGF-1 are important predictors of age-dependent sarcopenia.