Sex differences in risk factors for interstitial cystitis/painful bladder syndrome in patients with lower urinary tract symptoms in China

Aim The aim of the present study was to identify sex differences of risk factors for interstitial cystitis (IC)/painful bladder syndrome (PBS) in patients with lower urinary tract symptoms (LUTS) without urinary tract infection or benign prostate hyperplasia in China. Patients and Methods A total of 954 outpatients with LUTS presenting for care to urology clinics in many hospitals on a national scale were surveyed using a standardized questionnaire. The definitions for PBS, based on the O'Leary–Sant IC symptom and problem indices, was used. The prevalence of possible risk factors was analysed using the Fisher's exact test, Pearson's χ2-test and binary logistic regression methods. Results Of the multicentre patients surveyed (491 women and 463 men), 44.7 per cent (427/954) met the criteria for PBS. There was a significant difference between women and men [51.7 per cent (254/491) vs 37.3 per cent (173/463), P > 0.05]. After adjusting for confounding factors, bladder pain was found to be significantly associated with the consumption of stimulatory foods [odds ratio (OR): 3.85, 95 per cent confidence interval (CI): 1.58–9.36, P = 0.003] and anorectal disease (OR: 2.76, 95 per cent CI: 1.09–7.04, P = 0.03) in women. Caffeine beverage intake (OR: 3.54, 95 per cent CI: 1.54–8.12, P = 0.003) was identified the only modifiable association noted in a multivariate analysis of men. Factors in men significantly associated with an increased risk of IC/PBS were the consumption of caffeinated beverages (OR: 1.43, 95 per cent CI: 1.16–1.75, P = 0.001) and holding in urine (OR: 1.18, 95 per cent CI: 1.03–1.36, P = 0.034). Conclusions A higher incidence of IC was founded in LUTS outpatients without urinary tract infection or benign prostate hyperplasia in China. Stimulating foods, irritable bowel, gynaecologically-infected diseases and anorectal disease are potential risk factors for IC/PBS in women. Caffeinated beverages and holding in urine are potential risk factors for IC/PBS in men.