Dynapenia and sarcopenia identify walking speed decline in women but not in men.

ABSTRACT

OBJECTIVE: To determine the best indicator of mobility decline between dynapenia, low skeletal muscle mass index (SMMI), and sarcopenia defined by the EWGSOP2 using different cutoff points for grip strength. METHODS: A longitudinal study was conducted with a follow-up of eight years, involving 2,680 individuals aged 60 and older who participated in the ELSA study with a walking speed greater than 0.8 m/s at baseline. Dynapenia was defined using different cutoff points for grip strength. SMMI was defined by the 20th percentile of the entire ELSA sample distribution and sarcopenia was defined based on the EWGSOP2, using different cutoff points for grip strength. Mobility was analysed using the walking speed test. RESULTS: Over time, the greatest decline in walking speed occurred in dynapenic women with grip strength < 17 kg (-0.005 m/s per year; 95 % CI -0.01 to -0.001) and < 20 kg (-0.007 m/s per year; 95 % CI -0.01 to -0.001). With regards to sarcopenia, the greatest walking speed decline occurred in women with probable sarcopenia when defined by grip strength < 17 kg [(-0.006 m/s per year; 95 % CI -0.01 to -0.001) or grip strength < 20 kg (-0.007 m/s per year; 95 % CI -0.01 to -0.001)]. Dynapenia in men as well as low SMMI and sarcopenia in men and women did not enable identifying the risk of mobility decline. CONCLUSION: Dynapenia and probable sarcopenia defined by grip strength < 17 kg and < 20 kg enabled identifying walking speed decline over time only in women.