Is type-2 diabetes mellitus associated with overactive bladder symptoms in men with lower urinary tract symptoms?

OBJECTIVE To elucidate the relationship between type-2 diabetes mellitus (DM) and overactive bladder symptoms in men with lower urinary tract symptoms (LUTS), after adjusting for the impact of age and prostate volume. MATERIALS AND METHODS Data were obtained from a prospectively maintained database of 905 first-visit patients with LUTS and benign prostatic hyperplasia. After excluding those with comorbidities that may affect urinary symptom, we selected 139 patients with type-2 DM and 139 nondiabetic controls matched by propensity scoring for age and prostate volume. RESULTS There were no differences in voided volume and maximal flow rate between the 2 groups, whereas residual urine volume was significantly higher in DM patients than controls (29.34 ± 26.99 mL vs 22.45 ± 23.25 mL; P = .028). The total International Prostatic Symptom Score was significantly higher in DM patients than controls (17.80 ± 7.60 vs 15.88 ± 7.05; P = .031). Storage (7.45 ± 3.21 vs 6.58 ± 3.11; P = .024) and postmicturition (2.57 ± 1.49 vs 2.19 ± 1.59; P = .045) symptom scores were higher in DM patients than controls, whereas the groups had similar voiding symptom scores (P = .104). Among storage symptoms, DM patients had higher frequency (P = .010) and nocturia (P = .003) scores but similar urgency scores. The Overactive Bladder Symptom Score was also significantly higher in DM patients; this difference was due to a higher nocturia (but not urgency) score. CONCLUSION DM patients with LUTS and benign prostatic hyperplasia had greater storage and postmicturition symptoms than age and prostate volume-matched controls. The disparity in storage symptoms was mainly because of frequency and nocturia rather than urgency.