Interstitial cystitis/painful bladder syndrome (IC/PBS) is a common female urological disease that is a chronic syndrome characterized by the presence of pain in the urinary bladder and pelvis accompanied by frequency, urgency, and nocturia [1]. Treatments for these symptoms include behavioral therapy, pharmacotherapy, physical therapy, and injection therapy [2,3], but transient and palliative treatments are commonly performed [4]. These conditions aggravate the mental health as well as the physical function of patients and also impair the patients' overall quality of life [5].

Impaired sexual function has been reported to be more prevalent in women who have IC/PBS [6]. According to one study, at least 54% of women with IC/PBS responded that they refused to have sexual intercourse [7,8]. More than 70% of patients with interstitial cystitis responded that the disease had a detrimental effect on their sex lives [9]. As one of the causative factors of these reports, the relation between pain and sexual function has received increased interest in recent years.

We conducted a questionnaire-based, cross-sectional study to examine in detail whether pain and voiding symptoms are correlated with the sex lives of patients with IC/PBS.

A total of 87 female patients diagnosed with IC/PBS after visiting the bladder clinic of our medical institution for voiding difficulty from March 2005 to February 2007 were enrolled in the current study. Of these patients, 39 patients were menopausal and 3 of them were treated with hormone replacement therapy. A diagnosis of IC/PBS was made on the basis of the concept of IC/PBS proposed by the ICS in 2002 [10], for which medical history, urinalysis, voiding diaries, voiding cystourethrography, cystoscopy, urine cytology, and urodynamic studies were used. The number of patients who underwent cystoscopy and hydrodistention was 36 (41.4%). Interstitial cystitis was diagnosed in 18 patients on the basis of the presence of congestion or glomerulation. The remaining 67 patients had cases of painful bladder syndrome. Each patient was asked to fill out a Bristol female lower urinary tract symptom (BFLUTS) questionnaire [11].

The questionnaire was translated into Korean and its validity was authenticated [12]. The Korean version of the questionnaire comprised 34 questions (20 questions about voiding symptoms, 4 questions about sexual activity, and 10 questions about daily activities). Each symptom was scored by using a 4- or 5-point scale based on the corresponding criteria that a higher score was correlated with the severity of symptoms. Every patient answered 'yes' to having 'recent sexual activity.' To identify the correlations between the categories indicating voiding symptoms or pain severity and those associated with sexual activity, an age-adjusted partial correlation analysis (age-adjusted Pearson correlation test) was performed. To analyze the correlation between menopause and pain and sexual symptoms, independent t-tests were used. A statistical analysis was performed by using SPSS 15.0, and values of p<0.05 were considered statistically significant.

The mean age of the patients was 51.0±14.7 years (range, 28-74 years), and at the time of diagnosis the mean disease duration was 103±21.2 days (range, 63-147 days).

Correlations between patient age, pain in the pelvic area, and sex life were examined. A mild positive correlation was found between patient age and vulvodynia (r=0.232, p=0.045). There was a moderate negative correlation between age and dyspareunia (r=-0.302, p=0.008).

Differences in symptoms related to pain, IC/PBS, and sexual activity between non-menopausal women and menopausal women were analyzed by use of the independent t-test (Table 1). The symptoms of patients treated with hormone replacement therapy were not significantly different from those of the other menopausal women (p>0.05). The average age of the non-menopausal women was 40.93±6.83 years (range, 28-54 years) and that of the menopausal women was 59.83±6.67 years (range, 49-74 years). Vulvodynia scores were worse in menopausal women than in non-menopausal women (0.76±1.05 vs. 1.27±1.07, p=0.047) but dyspareunia scores were better (1.69±1.13 vs. 1.03±1.17, p=0.016).

Correlations between age-adjusted symptoms of IC/PBS and sexual activity were examined. Frequency was positively correlated with vulvodynia (r=0.258, p=0.038) and with discomfort with one's sex life (r=0.403, p=0.001). There was also a positive correlation between urgency and discomfort with sexual activity (r=0.346, p=0.005). Correlations between pelvic pain and sex life were examined and only vulvodynia showed a positive correlation (r=0.259, p=0.037) (Table 2).

Age-adjusted comparisons of symptoms related to sexual life were made in association with the symptoms associated with pain. Inhibited sex life (r=0.491, p<0.001) and dyspareunia (r=0.401, p=0.001) showed positive correlations with vulvodynia (Table 3). Dyspareunia had positive correlations with vulvodynia (r=0.401, p=0.001), inhibited sex life (r=0.604, p<0.001), and leakage during sexual intercourse (r=0.400, p<0.001).

An analysis of items related to symptoms of IC/PBS and lifestyle were also made. Frequency affected daily tasks (r=0.410, p=0.001), travel (r=0.425, p<0.001), social life (r=0.502, p<0.001), and overall life activities (r=0.464, p<0.001). It also had a detrimental effect on the quality of life (r=0.359, p=0.003). Urgency showed a significant positive correlation with daily life activities (r=0.377, p=0.002), travel (r=0.484, p<0.001), physical activity (r=0.359, p=0.003), social life (r=0.466, p<0.001), overall life (r=0.442, p<0.001), and quality of life (r=0.275, p=0.023). Pelvic pain showed a correlation with daily life (r=0.308, p=0.011), restricted travel (r=0.270, p=0.026), and impairment of overall life (r=0.294, p=0.015); in addition, it showed a correlation with quality of life (r=0.223, p=0.034) (Table 4).

The etiology of sexual dysfunction is assumed to be various in patients with IC/PBS, and the development of pain may be one cause. In addition to pelvic pain, many researchers have reported that chronic pain leads to sexual dysfunction. According to one study, sexual dysfunction was present in 73% of male and female patients with chronic pain [13]. According to another study, the greater the severity of pain, the greater the degree of sexual dysfunction [14].

Similar results have been observed in patients with chronic prostatitis/chronic pelvic pain syndrome, of whom 25% complained of erectile dysfunction, 33.4% complained of ejaculatory dysfunction, and 41.6% complained of both [15]. The patients who had both erectile dysfunction and ejaculatory dysfunction were found to have severe chronic prostatitis/chronic pelvic pain syndrome [15]. According to a study conducted by Aubin et al [16], when a comparison was made between 72 male patients with type 3 chronic pelvic pain syndrome and 98 normal, asymptomatic controls, the patient group had high incidence of lower sexual desire and a lower frequency of sexual intercourse than the control group. Also in the patient group, the degree of arousal response was relatively low. Rosenbaum reported that the pelvic muscles are involved in arousal and orgasms in both male and female patients [17]. The authors noted that the pelvic hypertonus muscles were important constituents for provoking the occurrence of dyspareunia. In this study, the severity of symptoms (such as pelvic pain, vulvodynia, and dyspareunia) caused increased symptoms associated with sexual function.

Pain and fear induce tension in pelvic muscles and the disorder of intravulvar insertion in women. This leads to dyspareunia and trauma in the vagina and external genitalia [18]. During sexual intercourse, physical irritation to the urethra and urinary bladder causes discomfort and increases the symptoms of IC/PBS [8,19]. From an embryological perspective, there is a relationship between urinary system problems and reproductive system problems in that one system can contribute to the development of problems in the other [8,19]. From a neurophysiological perspective, once the inflammatory stimulations are repeated, they cause pain following chronic changes in neurotransmission, mechanisms of pain control, and tissue responses [20]. These stimulatory factors affect the mechanisms associated with pain. A persistent presence of these stimulations converts the pelvic pain to neurological pain (which eventually leads to chronic pain syndrome), contributing to the impairment of sexual function [18]. These theories can be confirmed on the basis of the significant correlations between pelvic pain, voiding pain, vulvodynia, and dyspareunia.

In the present study, the occurrence of dyspareunia was shown to have a tendency to decrease with age (r=-0.302, p=0.008), compared with other types of pain for which occurrence increases with age. Menopausal women also showed worse pain during intercourse than did non-menopausal women. Although the frequency of sexual intercourse was not measured, the above results might originate from the fact that the frequency of sexual intercourse and sexual interest decrease with age.

No current studies have established the etiology of IC/PBS, and the sexual dysfunction of IC/PBS patients may be hypothesized to result from a combination of complex factors, including physical, psychological, and social factors. As shown in this study, IC/PBS contributes to the impairment of sexual function to some extent. In women with chronic interstitial cystitis, sexual dysfunction was more prevalent than in healthy women and was shown to impair the quality of life [6].

An analysis of the responses to the current study questionnaire showed that 44.0% of the respondents had no vulvodynia. In regard to the effects of voiding-related problems on sexual dysfunction, 25.6% had no sexual intercourse, 38.5% had no problems with sexual intercourse, and 33.8% had no dyspareunia. A total of 40.3% of the patients experienced urinary incontinence during sexual intercourse. These findings cannot confirm the correlation of IC/PBS with the sex lives of patients. However, frequency, urgency, and pelvic pain were correlated with vulvodynia and impaired sex life. These results indicate that symptoms of IC/PBS are closely associated with symptoms associated with sexual life.

This study had some limitations. First, this was a cross-sectional study. A case-control study or cohort study may reveal more accurate results. Second, the BFLUTS questionnaire was designed to investigate the severity and adverse effects of lower urinary tract symptoms. For a more accurate evaluation, adding other questionnaires to represent female sexual function (e.g., female sexual function index) could be helpful.

According to some studies, treatment of patients with IC/PBS results in improved sexual function and quality of life. Nickel et al reported that sexual function was the key factor in determining the quality of life in elderly patients with interstitial cystitis [1]. The authors also noted that the goal of treatment should focus on sexual dysfunction and stated that the improvement of symptoms of IC/PBS should accompany improvement of sexual function [21]. In patients with sexual dysfunction presenting with IC/PBS, treatment should be approached in many directions, including psychological and social aspects; additionally, consultation with specialists in relevant fields may be beneficial.

Bladder pain and lower urinary tract symptoms (LUTS) related to IC/PBS had a negative correlation with sexual function. Physicians should consider not only pain relief and control of LUTS but also sexual life improvement when counseling or treating patients with IC/PBS.