Interstitial cystitis is associated with vulvodynia and sexual dysfunction--a case-control study.

Introduction: Dyspareunia and sexual dysfunction are common in women with urological disorders. The study of comorbidity between interstitial cystitis (IC) and vulvodynia seems to be relevant to understand the mechanism generating pain in these conditions.

Aim: To conduct a case-control study for evaluating vulvodynia and sexual dysfunction in women with IC.

Methods: Forty-seven women with new diagnosis (National Institutes of Health [NIH]/National Institute of Diabetes and Digestive and Kidney Diseases [NIDDK] Criteria) of IC were compared with 188 age-matched, negative controls. Each woman completed a semi-structured interview and the Female Sexual Function Index (FSFI). A gynecological examination to assess vulvodynia (cotton swab testing) and genital health (vulvoscopy, Pap smear, culture, and vaginal health index score [VHIS]) was performed.

Main Outcome Measures: Prevalence of vulvodynia, sexual function, and sociodemographic/gynecological variables significantly associated with IC.

Results: Spontaneous or provoked vulvodynia was reported by 23.4% and 74.5% of IC cases, respectively. Sexual function was significantly impaired (median total FSFI score: IC cases 16.85 ± 8.73 vs. controls 27.34 ± 6.41; P<0.0001) in sexually active women, and 23.4% of IC cases as compared to 9% of controls reported no sexual activity in the year preceding the study (χ(2) for trend=38.2, P<0.0001). VHIS was highly impaired in women with IC in comparison with controls (P<0.0001). Variables significantly associated with IC were a diagnosis of menopause (odds ratio [OR]=31.2, 95% confidence interval [CI]=8.1-120.5), past (OR=4.6, 95% CI=1.74-12.1) or current (OR=6.9, 95% CI=2.1-22.1) oral contraceptive use, and a histologically confirmed diagnosis of endometriosis (OR=3.7, 95% CI=1.1-12.7).

Conclusion: We found an increased prevalence of vulvodynia among women with recently diagnosed IC; both conditions seem to have profound consequences on women's sexual function. A potential role for sex hormone-dependent mechanisms into the comorbidity of vulvar and bladder pain is proposed, but further research is warranted.