Association of overactive bladder and C-reactive protein levels. Results from the Boston Area Community Health (BACH) Survey

Study Type - Aetiology (cohort) Level of Evidence 3a What's known on the subject? and What does the study add? Evidence of chronic inflammation in benign prostatic hyperplasia suggests a role of inflammation in the development of lower urinary tract symptoms. However, few studies have investigated the association of inflammation and overactive bladder in both men and women. Results of this population-based study show a consistent association of increased C-reactive protein levels with overactive bladder in both men and women. These results support the hypothesized role of inflammation in the development of overactive bladder. OBJECTIVE To investigate the association between overactive bladder (OAB) and C-reactive protein (CRP) in a population-based sample of men and women. SUBJECTS AND METHODS Epidemiological survey of urological symptoms among men and women aged 30-79 years. A multi-stage stratified cluster design was used to randomly sample 5503 adults from the city of Boston. Analyses were conducted on 1898 men and 1854 women with available CRP levels. The International Continence Society defines OAB as 'Urgency with or without urge incontinence, usually with frequency and nocturia.' OAB was defined as: (1) urgency, (2) urgency with frequency, and (3) urgency with frequency and nocturia. Odds ratios (OR) and 95% confidence intervals (95% CI) of the CRP and OAB association were estimated using logistic regression. RESULTS Prevalence of OAB increased with CRP levels in both men and women. In men, adjusted ORs (95% CI) per log ₁₀(CRP) levels were 1.90 (1.26-2.86) with OAB defined as urgency, 1.65 (1.06-2.58) with OAB defined as urgency and frequency, and 1.92 (1.13-3.28) with OAB defined as urgency, frequency and nocturia. The association was more modest in women with ORs (95% CI) of 1.53 (1.07-2.18) for OAB as defined urgency, 1.51 (1.02-2.23) for OAB defined as urgency and frequency, and 1.34 (0.85-2.12) for OAB defined as urgency, frequency and nocturia. CONCLUSIONS Results show a consistent association of increasing CRP levels and OAB among both men and women. These results support our hypothesis for the role of inflammation in the development of OAB and a possible role for anti-inflammatory agents in its treatment.