To evaluate whether daytime napping is associated with an increased risk of ischemic stroke.

Daytime napping is a common behavior globally, yet its impact on cerebrovascular outcomes remains uncertain. While some studies suggest restorative benefits, others raise concerns about increased vascular risk. Clarifying this association is important for public health recommendations.

A systematic search of PubMed was conducted using the terms “ischemic stroke” and “nap.” We included observational studies comparing the incidence of ischemic stroke between habitual nappers and non-nappers. Odds ratios (OR) with 95% confidence intervals (CI) were pooled using a random-effects model with the restricted maximum likelihood (REML) estimator. Between-study heterogeneity was assessed using Cochran’s Q and I² statistics. Potential publication bias was evaluated using fail-safe N methods.

Two studies (n = 43,992 participants) were included. In Zhou et al. (2020), 793 strokes occurred among 19,742 nappers versus 325 strokes among 12,008 non-nappers. In Wu et al. (2024), 1,177 strokes occurred among 8,702 nappers versus 317 strokes among 2,550 non-nappers. The fixed-effect model indicated a significant association between napping and stroke (OR = 0.258; 95% CI: 0.165–0.351; p < 0.001). However, the random-effects model showed a non-significant association (OR = 0.253; 95% CI: –0.052 to 0.558; p = 0.10), with low heterogeneity (I² = 0.9%). Fail-safe N analyses suggested limited robustness (Rosenthal’s N = 0; Orwin’s N = 2), indicating susceptibility to publication bias.