Non-linear association between average daily sleep duration and cardiovascular disease in patients with diabetes or...

The relationship between sleep duration and cardiovascular disease (CVD) has garnered increasing attention, yet its specific shape and quantitative characteristics remain poorly defined in populations with disordered glucose metabolism-namely diabetes and prediabetes-who face substantially elevated cardiovascular risk.

This cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) 2017-2020. The study population comprised 7,835 participants with diabetes or prediabetes. Logistic regression was applied to adjust for demographic, behavioural, and metabolic confounders. Smooth curve fitting and segmented threshold effect analyses were further employed to characterise the dose-response relationship in detail.

Compared with the reference sleep duration of 7-9 h/day, both short (< 7 h) and long (≥ 9 h) sleep were independently associated with significantly higher odds of CVD, with fully adjusted odds ratios of 1.27 (95% CI: 1.03-1.56, P = 0.024) and 1.37 (95% CI: 1.11-1.69, P = 0.004), respectively. A significant non-linear relationship with a clear threshold was identified, with an inflection point at 8.36 h/day. Below this threshold, each one-hour increase in sleep was associated with an 11% reduction in CVD risk (OR = 0.89, 95% CI: 0.83-0.96, P = 0.004); above it, each additional hour corresponded to a 27% higher risk (OR = 1.27, 95% CI: 1.13-1.42, P < 0.001). This non-linear threshold effect was consistently observed across secondary outcomes, including coronary artery disease, heart failure, and stroke.

This study reveals a non-linear association between daily sleep duration and CVD risk in patients with diabetes or prediabetes. Both insufficient and excessive sleep are associated with an increased CVD odds, indicating a nonlinear pattern. Further research is warranted to delve into the causal mechanisms.

The online version contains supplementary material available at https://doi.org/10.1007/s40200-026-02120-1.