[Purpose] This study assessed the effects of type 2 diabetes without diabetic polyneuropathy on muscle strength according to body composition in middle age patients. [Subjects and Methods] This study included 45 non-diabetic individuals (control group) and 50 patients with type 2 diabetes (DM group), 40 to 64 years of age. The body composition was examined, including the leg muscle volume (LMV), which was the sum of the lower-limb muscle mass. The muscle strength was also examined, and the knee extension force (KEF), ankle dorsiflexion force (ADF). The KEF and ADF were normalized to the bodyweight, and the total leg muscle force (TLMF) were calculated by combining the KEF and ADF. The leg muscle quality (LMQ) was calculated as the TLMF normalized with the LMV. [Results] While no significant differences were found in the LMV between groups, the body mass index were higher in the DM group than in the control group. Significant differences were observed in %KEF, %ADF, and the LMQ in the DM group, with 15.8%, 18.7%, and 11.5% lower values than those in the control group, respectively. [Conclusion] The results of this study may demonstrate that muscle weakness occurs before diabetes progresses to a severe condition.
Keywords: Diabetes mellitus; Middle aged; Muscle weakness.