Rest-activity rhythms, sleep dimensions, and mortality in adults with cardiovascular-kidney-metabolic syndrome: A survey-weighted NHANES cohort study.

Objectives

To examine rest-activity rhythms and objective sleep dimensions with all-cause mortality, with heart-disease mortality as a supportive secondary outcome, among adults with cardiovascular-kidney-metabolic syndrome.

Methods

We analyzed National Health and Nutrition Examination Survey 2011-2014 data linked to mortality through 2019 among adults with archived cardiovascular-kidney-metabolic stages 1 to 4. Rest-activity rhythm metrics (interdaily stability, intradaily variability, relative amplitude) and sleep parameters (duration, efficiency, timing variability) were derived from wrist-worn actigraphy. Survey-weighted Cox models incorporated mobile examination center weights, strata, and primary sampling units.

Results

Among 3061 participants, 274 all-cause and 79 heart-disease deaths occurred. Higher intradaily variability was associated with higher all-cause mortality (hazard ratio [HR] per 0.1 unit, 1.15; 95% confidence interval [CI], 1.08-1.23), whereas higher relative amplitude was associated with lower mortality (HR per 0.1 unit, 0.74; 95% CI, 0.66-0.82). Longer mean sleep duration (HR per hour, 0.82; 95% CI, 0.74-0.91) and higher sleep efficiency (HR per 0.1-unit increase, 0.70; 95% CI, 0.57-0.86) were associated with lower all-cause mortality, whereas greater sleep-midpoint variability was associated with higher all-cause mortality (HR per hour, 1.26; 95% CI, 1.04-1.52). Associations of relative amplitude and mean sleep duration with all-cause mortality were nonlinear. Heart-disease mortality findings were supportive.

Conclusions

Greater rest-activity rhythm fragmentation, lower rest-activity rhythm amplitude, and several sleep dimensions were associated with all-cause mortality. These findings do not establish causality or clinical thresholds.