Obesity, but not metabolic control, is associated with muscle strength and endurance in diabetic older adults

The objective of this study is to investigate the association between muscle function, body composition, and metabolic control in adults with type 2 diabetes mellitus (DM2).

Forty-eight individuals with DM2 were divided into four groups according to the severity of obesity (body mass index [BMI]: lean [LN, n = 10], overweight [OW, n = 16], obese class I [OBI, n = 15], and obese class II [OBII, n = 7]). Absolute peak torque (TQ), relative peak torque (TQ/body weight [BW]), total work (TW), and fatigue index (FI) were assessed by means of an isokinetic dynamometer during concentric knee extensor contraction. Spearman's correlation coefficients were used to estimate the association between measurements.

Although OBII had higher insulin levels than both LN and OW groups, no significant differences were found between groups for TQ, TQ/BW, TW, and FI, as well as between metabolic variables and muscle measurements. There was a positive correlation between BMI and TQ (r_s = .45) and resistance tests, between BMI and TQ (r_s = .43), and TW (r_s = .37).

Metabolic variables do not correlate with muscle strength and endurance in DM2. However, severity of obesity measured by the BMI is positively associated with muscle force-generating capacity and endurance.