The impact of microalbuminuria on overactive bladders: Results from a community-based four-year longitudinal study in Japan.

AIMS To investigate the longitudinal association of microalbuminuria with overactive bladder (OAB). METHODS This longitudinal study investigated 561 participants of the Iwaki Health Promotion Project in both 2015 and 2019 in Japan. Microalbuminuria and OAB symptoms were assessed using the urine albuminuria creatinine ratio (ACR) and the overactive bladder symptom score (OABSS), respectively. Urine ACR was defined as high if ≥9.3 mg/gCr. Differences in OABSS between 2015 and 2019 were evaluated as ∆OABSS. Participants were divided into two groups according to ΔOABSS: high (ΔOABSS > 1) and control (≤1). We used baseline data acquired in 2015, such as urine ACR, the Pittsburgh Sleep Quality Index (PSQI), and arterial stiffness expressed by brachial-ankle pulse wave velocity (baPWV). Predictive factors of a ΔOABSS > 1 were assessed by multivariable logistic regression analysis. RESULTS This study included 332 women and 229 men. Of those, 86 (34 males and 52 females) were classified into the ΔOABSS > 1 group. There were significant group differences in age, renal function, and hemoglobin A1c. Participants in the ΔOABSS > 1 had a higher prevalence of PSQI > 5, baPWV ≥ 1400 seconds/cm, and urine ACR ≥ 9.3 mg/gCr (49% vs 20%, P = .001) than those in the control group. Multivariable analysis revealed that PSQI > 5 (odds ratio [OR], 2.57; 95% confidence interval [CI], 1.15-4.60; P = .002) and urine ACR ≥ 9.3 mg/gCr (OR, 1.93; 95% CI, 1.15-3.23; P = .013) were independent risk factors for ΔOABSS > 1. CONCLUSIONS Microalbuminuria may be an independent risk indicator for OAB symptom exacerbation.