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To nap or not? Evidence from a meta-analysis of cohort studies of habitual daytime napping and health outcomes
PRISMA-style meta-analysis (44 cohort studies; n≈1.86M adults) reporting habitual daytime napping associates with higher risks of all-cause mortality, cardiovascular disease, metabolic disease, and cancer, while naps <30 min were not linked to those risks in the authors’ pooled framing.
Design
- Databases: PubMed, Web of Science, Embase, Cochrane (inception → 2024-03-09)
- Included: 44 cohort studies, 1,864,274 participants (ages 20–86; mean 56.4 y)
Pooled headline (abstract)
- Habitual napping linked to higher pooled risk of all-cause mortality, CVD, metabolic disease, and cancer
- Lower pooled risk of cognitive impairment and sarcopenia (interpret with inclusion heterogeneity)
- Duration split: ≥30 min naps associated with higher risks of mortality, CVD, and metabolic disease; <30 min showed no significant associations for those endpoints in the abstract’s summary
Evidence hygiene
- Observational evidence—reverse causation (subclinical illness → long naps) and undiagnosed sleep apnea are perennial confounders
- Pair with acute cognitive nap meta-analyses (Dutheil et al. 2021) and alternate duration cut-point cohort MA (Wang et al. 2024, PMID 39413101) before changing behavior
Outcomes
- All-Cause Mortality RiskPooled cohort narrative: habitual napping associated with higher all-cause mortality risk versus non-nappers in included studies; <30 min nap subgroup reported null for mortality/CVD/metabolic signals in abstract summary.
- otherAbstract: napping duration ≥30 min associated with higher risks of all-cause mortality, cardiovascular disease, and metabolic disease versus <30 min band (see primary paper for effect metrics and models).