Comparing bone and muscle parameters in community-dwelling older adults with obesity, with or without type 2 diabetes mellitus.

Abstract

Obesity is common in type 2 diabetes mellitus (T2DM) and is associated with lower fracture risk. However, older adults with T2DM have higher fracture rates, suggesting distinct effects of T2DM on musculoskeletal health. We aimed to compare associations between components of T2DM and musculoskeletal health in community-dwelling older adults with obesity, with and without T2DM. This cross-sectional study included adults aged ≥60 years with self-reported obesity (body mass index [BMI] ≥30 kg/m²). Physical function was assessed by short physical performance battery (SPPB), handgrip strength, stair-climb and jumping mechanography. Dual-energy X-ray absorptiometry (DXA) measured body composition and areal BMD (aBMD). High-resolution peripheral quantitative computed tomography (HR-pQCT) assessed tibial bone densitometry and microarchitecture. Among 116 participants, 40 (34 %) had T2DM with a higher proportion of females (80 %) compared to those without T2DM (63 %). T2DM participants had higher glucose (31 % mmol/L, p < 0.0001), HbA1c (15 %, p < 0.0001) and HOMA-IR (136 %, p < 0.0001), and exhibited lower hand grip strength (11 % ± 10 %, p = 0.036), SPPB scores (5 % ± 2 %, p = 0.044), stair-climb power (5 % ± 2 % W/kg, p = 0.010) and vertical jump power (2 % ± 8 % W/kg, p = 0.038) compared to counterparts. There were no differences between groups for bone outcomes except increased total hip aBMD (10 % ± 0.2 % g/cm², p = 0.026) and trabecular thickness (5 % ± 0.03 % mm, p = 0.017). In all participants, total fat mass was associated with impaired physical function, while appendicular lean mass was positively associated with muscle power but negatively associated with cortical BMD. Older adults with obesity and T2DM demonstrate impaired muscle function and power, but have similar bone health and body composition, compared with those with obesity alone.