Protective association of healthy lifestyle behaviours with incident functional constipation: A population-based prospective cohort study

Introduction: The combined effect of some modifiable lifestyle factors on incident functional constipation (FC) is uncertain. This study aimed to evaluate the combined association between healthy lifestyle behaviours and FC incidence. Methods: This population-based prospective cohort study involved 107,457 adults aged 40-70 years who had no FC diagnosis at baseline from the UK Biobank study. The exposure was a sum of five healthy lifestyle behaviours: never smoking, optimal sleep, high level of vigorous physical activity, high dietary quality, and moderate alcohol intake. The outcome was the incidence of FC. The Cox proportional hazards regression model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for their associations. Results: During a median follow-up of 11.7 years, 3591 (3.3%) incident FC cases were recorded. Compared to not exhibiting any of the five healthy lifestyle behaviours, the multivariable adjusted HRs (95% CI) associated with having 1, 2, and 3-5 behaviours for FC incidence were 0.81 (0.74-0.90), 0.72 (0.65-0.80), and 0.60 (0.54-0.67), respectively (P for trend<0.001). Never smoking (HR 0.83, 95% CI 0.77-0.88, P<0.001), high level of vigorous physical activity (HR 0.79, 95% CI 0.74-0.85, P<0.001), and optimal sleep (HR 0.79, 95% CI 0.71-0.87, P<0.001) demonstrated significant independent inverse associations with FC incidence. Discussion: Adopting a higher number of healthy lifestyle behaviours is significantly associated with a reduced incidence of FC in the middle-aged and elderly population, indicating their potential to be a primary prevention strategy. Future research should explore underlying mechanisms and replicate our investigation across diverse populations.