The age-dependent decrease in muscle mass and function is known as sarcopenia. The risk of sarcopenia is higher in patients with diabetes, and assessment of muscle mass and function is especially important in patients with diabetes. Recent reports suggest that the phase angle (PhA), which is obtained from bioelectrical impedance analysis (BIA), may be a good marker of not only muscle mass but also muscle function in healthy people. However, the clinical significance of PhA in patients with diabetes has not been fully investigated. Therefore, we evaluated the association of PhA with muscle mass, muscle strength, and physical performance in 159 patients with type 2 diabetes (male 102; female 57) aged 40 to 89 years. We measured PhA and appendicular skeletal muscle index (SMI) by BIA and handgrip and leg extension strength and performed the Short Physical Performance Battery (SPPB). In a simple correlation analysis, both right and left PhA correlated with SMI, handgrip and leg extension strength, and SPPB score, and in multiple regression analysis, PhA on each side correlated with SMI and ipsilateral handgrip strength. These data suggest that PhA may be a useful marker of muscle mass, muscle strength, and physical performance in patients with type 2 diabetes. A large-scale prospective study should be performed to confirm the results and clarify the clinical usefulness of PhA in patients with diabetes.
Keywords: Muscle mass; Muscle strength; Phase angle; Physical performance; Type 2 diabetes.