Association between magnesium depletion score and overactive bladder among U.S. Adults using data from NHANES 2005–2018

Overactive bladder (OAB) is a common condition that significantly affects quality of life. Magnesium deficiency may influence muscle and nerve functions, potentially contributing to bladder dysfunction. This study aimed to examine whether magnesium depletion is associated with OAB symptoms among U.S. adults. We analyzed data from 28,621 participants aged 20-80 years in the National Health and Nutrition Examination Survey (NHANES) 2005-2018. OAB symptoms were assessed using a standardized questionnaire, and magnesium depletion was evaluated using a magnesium depletion score (MgDS). Logistic regression models adjusted for demographic, lifestyle, and clinical factors were employed to explore the association. Higher MgDS was significantly associated with an increased risk of OAB. In the fully adjusted model, each one-point increase in MgDS was linked to 9% higher odds of OAB (OR = 1.09, 95% CI 1.03-1.15, p = 0.002). Compared to the low MgDS group, individuals in the middle MgDS group had 17% higher odds of OAB (OR = 1.17, 95% CI 1.03-1.33, p = 0.02), while those in the high MgDS group had 20% higher odds (OR = 1.20, 95% CI 1.05-1.38, p = 0.01). Subgroup analyses indicated that this association was particularly pronounced in females, non-smokers, middle-aged adults (40-60 years), and individuals with obesity (BMI ≥ 30 kg/m²). Our findings suggest that magnesium depletion is associated with increased OAB risk in U.S. adults; however, due to the cross-sectional nature of this study, causality cannot be inferred and further prospective studies are needed.