Accelerometer-Determined Physical Behavior Metrics and their Associations with Sarcopenia among Oldest-Old Adults

INTRODUCTION: Sarcopenia is a loss of muscle function and muscle mass which frequently occurs among the oldest-old adult population (aged 85+ years). The analysis of accelerometer-determined physical behavior volumes and patterns of oldest-old adults might provide novel insights into the associations with sarcopenia and its components. METHODS: A total of 145 participants in the primary sample and 87 participants in the subsample with a mean age of 88.2 (2.5) years from the Health, Aging, and Body Composition study cohort provided cross-sectional data of handgrip strength, appendicular lean mass, gait speed, and accelerometry. Probable, confirmed, and severe sarcopenia were assessed based on the revised definition of the European Working Group on Sarcopenia in Older People 2. Binomial logistic and multivariate linear regression models as well as dose-response analyses were applied and adjusted for demographics, accelerometer wear time, lifestyle factors, and chronic health conditions. RESULTS: Oldest-old adults with higher total volumes of moderate to vigorous physical activity (MVPA) (OR=0.74, 95% CI 0.62 to 0.89) showed a lower likelihood for a probable sarcopenic condition in the primary sample. Likewise, patterns of higher accumulated time spent in MVPA bouts of less than 10 minutes (OR=0.78, 95% CI 0.64 to 0.95) and MVPA bouts of at least 10 minutes (OR=0.78, 95% CI 0.63 to 0.98) were also related with lower odds of probable sarcopenia. A 2.1 times (95% CI 1.01 to 4.35) higher likelihood for confirmed sarcopenia was observed among participants who spent 60 minutes more per day in sedentary behavior (SB). Furthermore, 2.9 times (95% CI 1.05 to 8.02) greater odds of severe sarcopenia were identified following each 0.1 higher active-to-sedentary transition probability (ASTP). Focusing on individual sarcopenic components, higher total activity counts, higher MVPA, higher light intensity physical activity (LIPA), lower SB, and lower ASTP were related with better gait speed. CONCLUSION: The total volume of MVPA, whether accumulated in short sporadic bouts or prolonged bouts, was associated with lower odds of probable sarcopenia. Higher LIPA, lower SB, and a less fragmented activity pattern might also be related with a lower likelihood of sarcopenia status and better physical performance among oldest-old adults