Mediating Effect of Serum Uric Acid in the Association Between Nocturia and Mortality

Abstract

Purpose: Nocturia is increasingly recognized as a natural consequence of aging and is commonly observed in the context of systemic dysfunction, with growing evidence linking it to elevated mortality risk. This study aims to elucidate whether serum uric acid (sUA) acts as a mediator in this associative pathway. Methods: This study used population-based data from 2005 to 2014 to investigate the association between nocturia and mortality, incorporating sUA as a potential mediator. Using data from 12,522 participants, sUA levels were categorized into quartiles (Q1–Q4) to assess dose–response relationships in the context of nocturia and mortality. Results: Participants in higher sUA quartiles were older and exhibited a greater burden of metabolic risk factors, including higher body mass index, waist circumference, and blood pressure. After adjustment, Cox regression analysis revealed a significant association between nocturia and increased all-cause and cardiovascular mortality. Restricted cubic spline regression indicated a J-shaped association between elevated sUA and increased mortality. Additionally, mediation analysis demonstrated that sUA partly mediated the relationship between nocturia and mortality. Conclusions: Nocturia independently predicts mortality, irrespective of metabolic status and sUA levels. These findings underscore the pivotal mediating role of sUA, highlighting the necessity of an integrated approach to nocturia management. Future research should prioritize interventional strategies that target metabolic dysfunction as a means to reduce nocturia-associated mortality risk.