Association between physical activity intensity and nocturia risk: the mediating role of mental health

BACKGROUND: Nocturia is a prevalent condition that adversely affects overall health. Identifying modifiable lifestyle factors influencing nocturia risk is crucial. This study aimed to examine the association between physical activity intensity and nocturia risk, and to evaluate potential mediating effects of inflammation, oxidative stress, and mental health. METHODS: We conducted a cross-sectional study using data from the 2007–2018 National Health and Nutrition Examination Survey. A total of 26,686 participants aged ≥ 20 years with complete data on physical activity, nocturia, and covariates were included. Physical activity intensity was categorized as vigorous (≥ 75 min/week), moderate (≥ 150 min/week but < 75 min vigorous), or inactive. Sedentary behavior was defined as ≥ 480 min/day sitting. The primary outcome was nocturia (≥ 2 voids/night); progression was defined as ≥ 3 voids/night. Multivariable logistic regression models assessed associations. Subgroup and stratified analyses explored effect modifiers. Mediation analysis evaluated whether mental health, inflammation, and oxidative stress mediated associations. RESULTS: Among 26,686 participants (49% males; 26% aged ≥ 60), both moderate- and vigorous-intensity activity were associated with lower odds of nocturia (OR: 0.893, 95% CI: 0.823–0.968; OR: 0.818, 95% CI: 0.742–0.902). For progression, ORs were 0.792 (95% CI: 0.676–0.927) and 0.818 (95% CI: 0.691–0.969), respectively. Subgroup analyses showed interactions by gender and smoking. The inverse association was significant only among non-sedentary individuals. Mental health accounted for 25% of the association, inflammation 4.8%, and oxidative stress 2.7%. CONCLUSIONS: Higher physical activity intensity is associated with lower nocturia risk. Promoting physical activity could aid in nocturia prevention and management.