Umbrella Review Associates Insomnia with 26% Higher Stroke Risk Across 1.3 Million Participants

The review aggregated existing systematic reviews and conducted new meta-analyses on stroke, hospitalization, and occupational injury. Six stroke studies entered the meta-analysis, yielding a hazard ratio of 1.26 with wide between-study variation. Hospitalization data from three studies produced an odds ratio of 1.28. Broader synthesis connected insomnia to depression, suicidal behavior, and all-cause dementia, with more consistent signals for Alzheimer’s than vascular dementia.

Prior meta-analyses placed diagnostic insomnia prevalence near 22%. The current work highlights definitional heterogeneity across cohorts and sparse adjustment for hypnotic use or bidirectional mental-health pathways. These gaps limit causal inference and leave residual confounding by socioeconomic status, inflammation, and vascular risk factors unaddressed.

Observational designs cannot exclude reverse causation or shared genetic liability. Next steps require large-scale RCTs of insomnia therapies with stroke and dementia incidence as primary endpoints, plus objective sleep monitoring to reduce misclassification.

Health systems should integrate sleep assessment into vascular-risk protocols while awaiting interventional confirmation.