Reduced Sit-to-Stand Power Despite Preserved Leg-Press Force–Velocity Characteristics in Older Adults with Type 2 Diabetes

Older adults with type 2 diabetes mellitus (T2DM) may exhibit early neuromuscular impairment, but the relative contribution of functional performance, mechanical capacity, body composition, and metabolic status remains unclear. This matched cross-sectional study compared 31 older adults with T2DM and 31 non-diabetic controls matched by age, sex, and body mass index (BMI). Participants completed assessments of physical function, sit-to-stand (STS)-derived muscle power, lower-limb force–velocity profiling during leg press, dual-energy X-ray absorptiometry, and fasting blood analyses. Between-group differences were examined using independent-samples t-tests, while exploratory discriminant and receiver operating characteristic (ROC) analyses were performed to evaluate within-sample group classification. Compared with controls, participants with T2DM showed longer 5-STS time (p = 0.001) and lower absolute and relative STS power (both p ≤ 0.01). In contrast, leg-press maximal force (F0) and maximal power (Pmax) did not differ between groups, while maximal and optimal velocity were higher in the T2DM group (both p = 0.026). The T2DM group also showed lower peripheral fat mass, a higher android-to-gynoid ratio (AND/GYN), higher fasting glucose, and lower insulin and HOMA-β values. Exploratory analyses suggested that a combined model including relative STS power, V0, HOMA-β, and AND/GYN ratio showed higher within-sample classification performance than relative STS power or leg-press maximal power alone. These findings suggest that STS-derived functional power may provide additional information on lower limb function beyond leg-press force–velocity profiling when characterizing functional status in older adults with T2DM.