Delayed bedtime on workdays is associated with an increased prevalence of gallstones: a population-based study

OBJECTIVES: The relationship between sleep and gallstones (GS) has rarely been reported. We aimed to investigate whether sleep traits are associated with the prevalence of GS. METHODS: A cross-sectional study was conducted using data from the National Health and Nutrition Examination Survey 2017-2020. Participants aged ≥ 20 years with complete information on sleep and GS questionnaires were enrolled. Binary logistic regression analyses were performed to investigate the relationship between sleep traits and GS while adjusting for confounding factors. Stratified and interaction analyses were conducted to evaluate whether factors such as age, gender, race, education, marital status, body mass index, smoking, and comorbidities modified the association. RESULTS: A total of 7329 participants were included in this study, and 736 had a self-reported history of GS. In the fully adjusted model, we found that each hour of delay in workday bedtime was associated with an 8.60% increase in the odds of GS (OR = 1.09; 95% CI: 1.02-1.15, P = 0.026). Compared to individuals with a workday bedtime between 18:00-≦20:00, those sleeping later, between 22:00-≦24:00 faced higher odds of GS (OR = 5.82; 95% CI: 1.63-20.83, P = 0.035), while the odds were even greater for those sleeping between 24:00-≦06:00 (OR = 6.68; 95% CI: 1.76-25.36, P = 0.032). Subgroup analyses revealed that age acted as an effect modifier in the relationship between workday bedtime and GS. In participants aged > 40 years, the odds of GS increased significantly with delayed workday bedtime (OR = 1.14; 95% CI: 1.07-1.22, P = 0.009). Furthermore, the fully adjusted model found no significant association between wake-up time, sleep duration, or sleep disorders and the prevalence of GS. CONCLUSION: Delayed workday bedtime is associated with a higher prevalence of GS. Age modifies the association between workday bedtime and the prevalence of GS. Notably, for individuals aged > 40 years, the odds of GS increased significantly with delayed bedtime on workdays.