Daytime sleepiness and the association between nocturia and depressive symptoms: A cross-sectional study.

Nocturia is associated with sleep disturbance and depressive symptoms, but the role of daytime sleepiness in this relationship remains unclear. This study examined the relationships among nocturia, sleep duration, daytime sleepiness, and depressive symptoms, with particular attention to the indirect associations through sleep duration and daytime sleepiness. Data from the 2015 to 2023 National Health and Nutrition Examination Survey were analyzed. Depressive symptoms were assessed using the Patient Health Questionnaire-9 and categorized as none or minimal, mild, moderate, moderately severe, or severe. Survey-weighted logistic regression was used to examine factors associated with nocturia. Interaction and direct and indirect association analyses were performed using linear regression and structural equation modeling with bootstrap confidence intervals. Among 17,731 participants, 6479 (36.5%) reported nocturia. Analyses involving daytime sleepiness included 12,634 participants. Nocturia frequency and daytime sleepiness were associated with higher Patient Health Questionnaire-9 scores, and a significant interaction was observed between them (β = 0.12, P < .001). The indirect association through sleep duration was not statistically significant (P = .083). The indirect association through daytime sleepiness was β = 0.136 (P < .001), representing 21.15% of the total association between nocturia and depressive symptoms. Nocturia was associated with depressive symptoms, and an indirect association through daytime sleepiness was observed. The temporal relationship among nocturia, daytime sleepiness, and depressive symptoms remains to be determined.