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 chi(2)-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.