Association between social jet lag and estimated 10-year cardiovascular risk: a population-based study of data from the National Health and Nutrition Examination Survey

This cross-sectional study investigates the association between social jet lag (SJL), a measurement of chronotype misalignment between workdays and free days, and estimated 10-year cardiovascular risk based on the National Health and Nutrition Examination Survey (2017–2020 cycle). SJL was measured as the absolute difference between the mid-sleep timepoints on workdays and free days. The Framingham risk score (FRS) was calculated using seven variables and used to estimate 10-year cardiovascular risk. Weighted generalized linear regressions and restricted cubic splines (RCS) analysis were used to investigate the association between SJL and the FRS. Subgroup analyses were performed to identify potential interactions. Overall, 4,037 participants were included. The median SJL was 0.8 h, and 42.8% of the participants had SJL ≥ 1 h. When SJL was considered as a continuous variable, greater SJL was associated with a higher FRS (β = 0.20, 95% CI 0.02–0.38, p = 0.015). Similarly, individuals with SJL ≥ 1 h had a significantly higher FRS than those with SJL < 1 h (β = 0.40, 95% CI 0.10–0.73, p = 0.005). The RCS analysis indicated a positive linear relationship between SJL and the FRS (pnon-linear = 0.798). Subgroup analyses did not reveal any interactions. This cross-sectional study suggested that greater SJL was linked to higher FRS, but the association appeared to be modest. Further prospective studies are required to determine causality.