Association between sleep duration on workdays and kidney stone expulsion in US adults: insights from the national health and nutrition examination survey 2007-2020.

Objective: This cross-sectional study aimed to investigate the association between weekdays/workdays sleep duration (SDW) and kidney stone expulsion (KSE) in adults with kidney stones. Methods: We utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted from 2007 to March 2020 (pre-pandemic). Adults aged ≥20 years with confirmed kidney stones were included. SDW served as the primary exposure variable, while KSE was the outcome. Multivariable logistic regression and restricted cubic spline (RCS) regression were employed to explore the SDW-KSE relationship. Results: A total of 2,040 participants with KSE and 1,966 without KSE were analyzed. In both unadjusted and fully adjusted logistic regression models, SDW was significantly associated with a lower odds of KSE (OR: 0.81 [0.77, 0.84] and 0.80 [0.74, 0.86], respectively). RCS analysis showed a non-linear association between SDW and KSE (p = 0.01). In the fully adjusted model, the odds of KSE decreased sharply with SDW beyond seven hours (OR: 0.69 [0.59, 0.80]). Conclusions: In this nationally representative sample, longer SDW was associated with a reduced likelihood of KSE. However, given the cross-sectional nature of our study, this association does not imply causality. Further experimental and longitudinal research is needed to elucidate the causal pathways and underlying mechanisms linking SDW and KSE.