Low physical activity is a risk factor for sarcopenia: a cross-sectional analysis of two exercise trials on community-dwelling older adults

Background Physical inactivity is an important factor in the development of sarcopenia. This cross-sectional study explores the prevalence of sarcopenia and associations of physical activity (PA) with sarcopenia in two exercise trial populations. These study groups are clinically meaningful community-dwelling populations at increased risk for sarcopenia: older adults not meeting the PA guidelines and those with a recent hip fracture (HF). Methods Data from 313 older adults who did not meet the PA guidelines (60% women; age 74.5 ± 3.8, body mass index 27.9 ± 4.7) and 77 individuals with HF diagnosed on average 70 ± 28 days earlier (75% women; age 79.3 ± 7.1, body mass index 25.3 ± 3.6) were included in this study. Grip strength and muscle mass (Dual-energy X-ray absorptiometry [DXA] in older adults not meeting the PA guidelines and bioimpedance analysis in participants with HF) were used to assess sarcopenia according to the European Working Group in Older People 2019 (EWGSOP2) criteria. The current level of PA was self-reported using a question with seven response options in both study groups and was measured with a hip-worn accelerometer for seven consecutive days in older adults not meeting the PA guidelines. Results The prevalence of sarcopenia and probable sarcopenia was 3% ( n = 8) and 13% ( n = 41) in the older adults not meeting the PA guidelines and 3% ( n = 2) and 40% ( n = 31) in the HF group, respectively. In the age- and sex-adjusted logistic regression model, the lowest levels of self-reported PA were associated with increased probable sarcopenia and sarcopenia risk in older adults not meeting the PA guidelines (OR 2.8, 95% CI, 1.3–6.1, p = 0.009) and in the HF group (OR 3.9, 95% CI, 1.4–11.3, p = 0.012). No significant associations between accelerometer-measured PA and probable sarcopenia or sarcopenia were found. Conclusions Probable sarcopenia is common among community-dwelling older adults not meeting the PA guidelines and very common among individuals recovering from HF who are able to be involved in exercise interventions. In addition, since low PA is associated with higher probable sarcopenia and sarcopenia risk, it is recommended to screen for sarcopenia and promote regular physical activity to prevent sarcopenia in these populations.