Association between accelerometer-measured amplitude of rest-activity rhythm and future health risk: a prospective cohort of the UK Biobank

Background The health effects of rest-activity rhythm are of major interest to public health, but its associations with health outcomes remain elusive. We aimed to examine the associations between accelerometer-measured rest-activity rhythm amplitude and health risks among the general UK population. Methods We did a prospective cohort analysis of UK Biobank participants aged 43-79 years with valid wrist-worn accelerometer data. Low rest-activity rhythm amplitude was defined as the first quintile of relative amplitude; all other quintiles were classified as high rest-activity rhythm amplitude. Outcomes of interest were defined using International Classification of Diseases 10th Revision codes and consisted of incident cancer and cardiovascular, infectious, respiratory, and digestive diseases, and all-cause and disease-specific (cardiovascular, cancer, and respiratory) mortality. Participants with a current diagnosis of any outcome of interest were excluded. We assessed the associations between decreased rest-activity rhythm amplitude and outcomes using Cox proportional hazards models. Findings Between June 1, 2013, and Dec 23, 2015, 103 682 participants with available raw accelerometer data were enrolled. 92 614 participants (52 219 [56.4%] women and 40 395 [42.6%] men) with a median age of 64 years (IQR 56-69) were recruited. Median follow-up was 6.4 years (IQR 5.8-6.9). Decreased rest-activity rhythm amplitude was significantly associated with increased incidence of cardiovascular diseases (adjusted hazard ratio 1.11 [95% CI 1.05-1.16]), cancer (1.08 [1.01-1.16]), infectious diseases (1.31 [1.22-1.41]), respiratory diseases (1.26 [1.19-1.34]), and digestive diseases (1.08 [1.03-1.14]), as well as all-cause mortality (1.54 [1.40-1.70]) and disease-specific mortality (1.73 [1.34-2.22] for cardiovascular diseases, 1.32 [1.13-1.55] for cancer, and 1.62 [1.25-2.09] for respiratory diseases). Most of these associations were not modified by age older than 65 years or sex. Among 16 accelerometer-measured rest-activity parameters, low rest-activity rhythm amplitude had the strongest or second-strongest associations with nine health outcomes. Interpretation Our results suggest that low rest-activity rhythm amplitude might contribute to major health outcomes and provide further evidence to promote risk-modifying strategies associated with rest-activity rhythm to improve health and longevity.