Prevalence and determinant factors of sarcopenia in middle aged and elderly patients with type 2 diabetes mellitus in Beijing

Objective To investigate the prevalence of sarcopenia in middle aged and elderly patients with type 2 diabetes (T2DM) and clarify the associated risk factors. Methods From January 2016 to March 2018, 1 125 T2DM patients over 50 years old in endocrinology departments of nine hospitals in Beijing were enrolled in this study with system random sampling method. All patients, including 586 males and 539 females, were grouped into middle aged group (50-59 years), young elderly group (60-74 years) and elderly group (over 75 years) by age. Body composition was measured with bioimpedance analysis. Low muscle mass was defined as the appendicular skeletal muscle mass index below 7.18 kg/m2 in men and 5.73 kg/m2 in women. Low muscle strength was defined as grip strength below 29.5 kg in men and 21.2 kg in women. Sarcopenia was defined with low muscle mass coexisted with low grip strength. Chi-square test was used to compare the prevalence difference between groups. Multivariate Logistic regression was used for correlation analysis. Results (1) The detection rate of low muscle mass in all participants was 14.0%(157/1 125),which was significantly higher in male than that in female(18.3% vs 9.3%, χ2=18.867, P<0.05). (2) The detection rate of low grip strength in all participants was 36% (405/1 125), which was significantly higher in male than that in female (50.3% vs 20.4%, χ2=109.183, P<0.05). (3) The prevalence of sarcopenia in all participants was 8.5%(96/1 125), which was significantly higher in male than that in female (12.8% vs 3.9%, χ2=28.509, P<0.05). The prevalence of sarcopenia were 4.4%(21/475), 8.9%(49/548), 25.5%(26/102) in middle aged group, young elderly group and elderly group, respectively (χ2=47.984, P<0.05). The sarcopenic prevalence in male was obviously higher than that in female in young elderly and elderly group (χ2=9.872-16.325, all P<0.05). (4) Logistic regression analysis showed that men, aging, low body mass index (BMI) and high glycated hemoglobin A1c (HbA1c) were risk factors associated with sarcopenia. The risk of sarcopenia increased obviously in patients older than 75 years (OR=4.992, 95%CI: 2.448-10.179) or whose HbA1c was over 10% (OR=3.563, 95%CI:1.526-8.322) . Conclusions The risk of low muscle mass and low muscle strength increases in aged and elderly patients with T2DM. Low BMI, aging, high HbA1c were risk factors associated with sarcopenia in elderly patients with T2DM. Key words: Diabetes mellitus, type 2; Sarcopenia; Aged; Body mass index