Adiposity is inversely associated with strength in older adults with type 2 diabetes mellitus

Key summary pointsAim To explore the association between adiposity, muscle strength and physical performance in community-dwelling older adults with type 2 diabetes mellitus. Findings We showed that adiposity, assessed as either body fat percentage derived from dual-energy X-ray absorptiometry or waist circumference, was inversely associated with muscle strength. Message Due to the potential bidirectional relationship between type 2 diabetes mellitus and sarcopenia, the assessment of muscle function and quality should be considered to prevent loss of independence and physical disability in older adults with type 2 diabetes. Background and purpose Several biological mechanisms describing the pathway to mobility disability and functional decline in older adults with type 2 diabetes mellitus (T2DM) have been postulated, including skeletal muscle atrophy and the concurrent accumulation of fat mass. Therefore, we explored the association between adiposity, muscle strength and physical performance in community-dwelling older adults with T2DM. Methods Adiposity was measured by waist circumference (WC) or body fat percentage (BF %) derived from dual-energy X-ray absorptiometry (DXA). The Short Physical Performance Battery (SPPB) and gait speed were used to evaluate lower extremity physical function. Muscle strength was assessed using hand-grip strength (HGS) or chair stands. Multiple regression analysis was used to examine the association between measures of adiposity, SPPB score, gait speed, HGS and chair stands adjusted for age, gender and total appendicular skeletal muscle (ASM). Results A total of n = 87 participants (71.2 +/- 8.2 years; BMI 29.5 +/- 5.8 kg/m(2); BF % 37.8 +/- 7.3%) were included in this cross-sectional analysis. Pearson's correlation coefficients revealed that BF% was negatively associated with hand-grip strength (r = - 0.430; P < 0.001) and total ASM (r = - 0.223; P = 0.03), but positively associated with increased time to compete chair stands (r = 0.366; P < 0.001). After adjusting for age, gender and total ASM, WC and BF% were inversely associated with HGS (WC: beta = -0.385; P = 0.001; BF% beta = - 0.487; P < 0.001). Similarly, in the adjusted model, both WC and BF% were positively associated with increased time to complete chair stands (WC: beta = 0.479; P < 0.001; BF% beta = 0.415; P = 0.002). Conclusion Adiposity, independent of the criteria used, was inversely associated with muscle strength, suggesting that adiposity negatively influences muscle quality in older adults with T2DM. Screening for poor muscle strength and quality has the potential to facilitate early exercise and dietary interventions aimed at preserving muscle function in older adults with T2DM.