Longevity & AgingIrregular Sleep Schedules Rival Sleep Duration as a Cardiometabolic Risk Factor
A comprehensive 2025 review in Circulation Research examines how sleep irregularity — inconsistent timing and duration from night to night — contributes to cardiometabolic disease and early death. Drawing on large prospective studies, clinical trials, and mechanistic research, author Tianyi Huang finds that variable sleep patterns are robustly associated with obesity, metabolic syndrome, type 2 diabetes, cardiovascular disease, and all-cause mortality. Notably, sleep irregularity may predict cardiometabolic risk as strongly as, or more strongly than, total sleep duration alone. Proposed pathways include circadian disruption, hormonal dysregulation, behavioral changes, and psychological stress. Key gaps include unstandardized measurement tools, scarce intervention data, and incomplete mechanistic understanding.
