Sarcopenia definitions and their association with fracture risk in older Swedish women

The purpose of this study was to investigate the prevalence of three sarcopenia definitions and their associations with fracture risk in older Swedish women when adjusted for fracture risk assessment (FRAX)-based risk factors; 2,883 women with a mean age of 77.8 years were included. Sarcopenia was defined based on the Sarcopenia Definitions and Outcomes Consortium (SDOC; low handgrip strength [kg] and gait speed (m/s)), revised European Working Group on Sarcopenia in Older People (EWGSOP2; low appendicular lean mass index, appendicular lean mass [ALM]/height; kg/m2], and hand grip strength [kg]), and Asian Working Group for Sarcopenia (AWGS; low ALM (kg), and hand grip strength [kg]) definitions. Femoral neck T-score was obtained from dual-energy X-ray absorptiometry. All fractures, confirmed by X-ray or medical record review, were subsequently categorized as major osteoporotic fractures (MOFs) and hip fractures. Deaths were verified through regional registers. The total follow-up time was 6.4 +/- 1.3 (mean +/- SD) yr. Cox regression (hazard ratios [HR] and 95% CIs) analyses were performed with adjustment for age, FRAX variables, and femoral neck T-score. Sarcopenia prevalence was 4.5% (n = 129) according to SDOC, 12.5% (n = 360) for EWGSOP2, and 10.3% (n = 296) defined by AWGS. Individuals with sarcopenia defined by SDOC had a higher mortality risk than individuals without sarcopenia (HR: 3.41; 95% CI: 2.51, 4.62) after adjusting for age and FRAX variables. Sarcopenia according to EWGSOP2 and AWGS was not associated with an increased fracture risk after adjusting for age and FRAX variables. Individuals with sarcopenia defined by SDOC had a higher risk for any fractures (HR: 1.48; 95% CI: 1.10, 1.99) and MOF (HR: 1.42; 95% CI: 1.03, 1.98) compared with individuals without sarcopenia after adjusting for clinical risk factors used in FRAX. In conclusion, sarcopenia defined by SDOC, incorporating muscle function/strength, was the only sarcopenia definition associated with fracture risk in older women. This study aimed to investigate the risk of sarcopenia on fracture risk in older Swedish women. Data were utilized from 2,883 women aged 75-80 yr in the Swedish Sahlgrenska University Hospital Prospective Evaluation of Risk of Bone Fractures cohort. Sarcopenia was defined using three different definitions, including the Sarcopenia Definitions and Outcomes Consortium (SDOC), which includes grip strength and gait speed, while the revised European Working Group on Sarcopenia in Older People (EWGSOP2) and the Asian Working Group for Sarcopenia (AWGS) definitions include appendicular lean mass measured by dual-energy X-ray absorptiometry and grip strength. The results demonstrated that SDOC-defined sarcopenia was associated with a higher mortality risk, with increased risk of any fractures, and major osteoporotic fractures, whereas the EWGSOP2 and AWGS definitions were not associated with fracture risk. In summary, the study demonstrates that sarcopenia defined by SDOC, considering muscle function and strength, rather than lean mass, was the only investigated sarcopenia definition associated with fracture risk.