Joint association of sleep duration and physical activity with constipation: a cross-sectional study

Background: Sleep duration and physical activity (PA) may play a pivotal role in gastrointestinal functions. It remains unclear how they function in constipation. This study aims to assess the independent and combined associations of sleep duration and PA with the risk of constipation, using data from the National Health and Nutrition Examination Survey (NHANES) 2007-2010. Methods: A total of 5590 (unweighted data) participants were included in the analysis. Sleep duration was categorised as insufficient (<7 hours/d), sufficient (7-8h/d), and excessive (>8 hours/d). Physical activity was converted to metabolic equivalent (MET) minutes of moderate to vigorous PA per week, classified as inactive (<600 MET-minutes/week) and active (≥600 MET-minutes/week). Constipation was defined based on stool consistency using the Bristol Stool Form Scale. Multivariable logistic regression models were used to estimate the odds ratios (ORs) for constipation. Results: In multivariable-adjusted models, sufficient sleep duration and active PA was associated with reduced ORs of constipation. Subgroup analysis found this association was more pronounced in male population older than or equal to 60 (sufficient sleep (OR = 0.14; 95% CI = 0.02-0.75, P = 0.047) and active PA (OR = 0.27; 95% CI = 0.08-0.93, P = 0.050)), but not younger adults and female participants. Furthermore, active PA was always associated with a lower risk of constipation, no matter how long the sleep duration was (insufficient sleep (OR = 0.13; 95% CI = 0.03-0.57, P = 0.030), sufficient sleep (OR = 0.04; 95% CI = 0.01-0.21, P = 0.006), and excessive sleep (OR = 0.02; 95% CI = 0.00-0.42, P = 0.038)). Conclusions: Sufficient sleep as well as active PA were associated with lower risk of constipation, independently or jointly. This finding was more pronounced in male population older than or equal to 60, but not younger adults and female participants.