Background
Sarcopenia is often characterised as low muscle mass with low muscle strength or function. Reported prevalence estimates for sarcopenia vary depending on the criteria used. We aimed to examine sarcopenia prevalence using different definitions and assess the agreement between the definitions in a sample of older Australian women.
Methods
Participants were 358 women aged 60-95 years from the Geelong Osteoporosis Study. Handgrip strength (HGS) was measured by dynamometer (Jamar) and appendicular lean mass (ALM) by whole-body DXA (Lunar ProdigyPro). We used the definitions of the European Working Group on Sarcopenia in Older People (EWGSOP 1, 2)1,2 and the United States Foundation for the National Institutes of Health (FNIH)3 to identify sarcopenia. Sarcopenia was determined by low HGS and low ALM/height2 (EWGSOP1,2), and low HGS and low ALM/BMI (FNIH). Prevalence estimates were standardised according to the Australian population (2011). The agreement between definitions was assessed using the kappa coefficient (ƙ).
Results
Low HGS was identified for 138 (38.5%) women using EWGSOP1, and 67(18.7%) using EWGSOP2 and FNIH. Low ALM/height2 was identified for 37(11.5%) women using EWGSOP1, 22 (6.8%) using EWGSOP2, and 68 (21.1%) had low ALM/BMI. For each definition, the prevalence of sarcopenia increased with age (Figure). Age-standardised prevalence estimates for sarcopenia were 6.3% (95% CI 3.8-8.8) using EWGSOP1, 3.3% (1.9-4.7) using EWGSOP2 and 5.5% (3.1-7.9) using FNIH. There was moderate agreement between EWGSOP1 and EWGSOP2 (ƙ=0.70), but poor agreement between FNIH and EWGSOP1 (ƙ=0.18) and EWGSOP2 (ƙ=0.19).
Conclusions
Although the 95% CIs overlapped, the point estimates for sarcopenia prevalence according to EWGSOP2 identified fewer women than EWGSOP1, with FNIH estimates between the two. Further work is needed to harmonise the criteria for sarcopenia and decide whether or not cut-points should be population-specific.