Twenty four-hour activity cycle in older adults using wrist-worn accelerometers: The seniors-ENRICA-2 study

Objectives This study aimed: (a) to provide a detailed description of sleep, sedentary behavior (SED), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) over the complete 24-hours period using raw acceleration data in older adults; and (b) to examine the differences in the 24-hours activity cycle by sex, age, education, and body mass index (BMI). Methods Population-based cohort comprising 3273 community-dwelling individuals (1739 women), aged 71.8 +/- 4.5 years, participating in the Seniors-ENRICA-2 study. Participants wore a wrist-worn ActiGraph GT9X accelerometer for 7 consecutive days, and the raw signal was processed using the R-package GGIR. Results Participants reached 21.5 mg as mean acceleration over the whole day; 32.3% (7.7 h/d) of time was classified as sleep, 53.2% (12.7 h/d) as SED, 10.4% (148.6 min/d) as LPA, and 4.1% (59.0 min/d) as MVPA. No marked differences were found in sleep-related variables between socio-demographic and BMI groups. However, women showed higher LPA but lower SED and MVPA than men. Moreover, SED increased whereas LPA and MVPA decreased with age. Participants with obesity (BMI >= 30 kg/m(2)) accumulated more SED and less LPA and MVPA than those without obesity. As expected, adherence to physical activity recommendations varied widely (9.2%-76.6%) depending on the criterion of MVPA accumulation. Conclusion Objective assessment of the 24-hour activity cycle provides extensive characterization of daily activities distribution in older adults and may inform health-promotion interventions in this population. Women, the oldest old, and those with obesity offer relevant targets of strategies to improve lifestyle patterns.