Associations of afternoon naps with progression of advanced cardiovascular-kidney-metabolic syndrome among Chinese adults aged 45 years and above

Cardiovascular-kidney-metabolic (CKM) syndrome poses a significant and growing public health challenge. While sleep disturbances are recognized as a risk factor, the role of daytime napping in the progression of CKM syndrome remains unclear. We utilized data from the China Health and Retirement Longitudinal Study (CHARLS), a nationally representative cohort. This study included 9,810 participants for cross-sectional analysis and 4,990 participants free of advanced CKM syndrome at baseline for longitudinal analysis. Nap duration was categorized into four groups: 0, 1–29, 30–89, and ≥ 90 min. Advanced CKM syndrome (stages 3–4) was defined according to the American Heart Association criteria. Multivariable logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). In the longitudinal analysis, a short afternoon nap (1–29 min) was associated with a 35.3% reduction in the risk of incident advanced CKM syndrome compared to non-napping (adjusted OR = 0.647, 95% CI 0.451–0.928). This protective association was particularly significant in males (OR = 0.645, 95% CI 0.432–0.964) and individuals who were married or partnered (OR = 0.734, 95% CI 0.545–0.988). Furthermore, for older adults over 60 years of age, a moderate nap duration (30–89 min) was also linked to a lower risk (OR = 0.664, 95% CI 0.476–0.927). The cross-sectional analysis yielded consistent results. Sensitivity analyses confirmed the robustness of these findings. Short afternoon napping is associated with a reduced risk of developing advanced CKM syndrome in middle-aged and older Chinese adults, highlighting its potential as a target for primary prevention strategies aimed at mitigating CKM syndrome risk in an aging population.