Sarcopenia prevalence and associations with mortality and hospitalisation by various sarcopenia definitions in 85-89 year old community-dwelling men: a report from the ULSAM study

Background: Operational definitions of sarcopenia, i.e. loss of muscle function and mass, have been proposed by the European Working Group on Sarcopenia in Older People (EWGSOP) and the Foundation for the National Institutes of Health Sarcopenia Project (FNIH). The aim of this study was to analyse the prevalence and outcome, i.e. all-cause mortality and hospitalisation, of sarcopenia and its diagnostic components in octogenarian community-dwelling men. Methods: In total 287 men, aged 85-89 y, participating in the Uppsala Longitudinal Study of Adult Men (ULSAM) underwent Dual X-ray Absorptiometry (DXA), measurement of hand grip strength (HGS), gait speed (GS), and a five-times chair stand test (CS). Sarcopenia and probable sarcopenia were defined according to EWGSOP (2010), EWGSOP2 (2018), and FNIH (2014). All-cause mortality and hospitalisations over 3 years were registered. Results: Sarcopenia according to EWGSOP, EWGSOP2 and FNIH was observed in 21%, 20%, and 8% of the men, respectively, while probable sarcopenia (EWGSOP2; eq. reduced muscle strength only) was seen in 73%. Sarcopenia (EWGSOP) and probable sarcopenia (EWGSOP2) were associated with increased mortality (HR 1.95, 95% CI 1.12-3.40 and HR 3.26, 95% CI 1.38-7.70, respectively). Probable sarcopenia (EWGSOP2) was associated with days of hospitalisation (RR 2.12, 95% CI 1.36-3.30), whereas sarcopenia according to FNIH showed an association with the number of hospitalisations (RR 1.75, 95% CI 1.10-2.81). Conclusions: In very old men, reduced muscle strength, i.e. probable sarcopenia, was common and associated with mortality and length of stay during hospitalisation. When combined with low muscle mass (according to DXA), i.e. sarcopenia, the various definitions were associated more weakly with the adverse outcomes. The findings support the emphasis on reduced muscle strength as the major determinant of sarcopenia.