We characterized and compared the impact of clinical phenotypic associations between interstitial cystitis/painful bladder syndrome and controls in relation to potentially related conditions, particularly irritable bowel syndrome, fibromyalgia and chronic fatigue syndrome.
Female patients with interstitial cystitis/painful bladder syndrome and controls with no interstitial cystitis/painful bladder syndrome completed a biopsychosocial phenotyping questionnaire battery which included demographics/history form, self-reported history of associated conditions, and 10 validated questionnaires focused on symptoms, suffering/coping and behavioral/social factors.
Questionnaires were completed by 205 patients with interstitial cystitis/painful bladder syndrome and 117 controls matched for age. Prevalence of self-reported associated condition diagnosis in interstitial cystitis/painful bladder syndrome vs controls was irritable bowel syndrome 38.6% vs 5.2%, fibromyalgia 17.7% vs 2.6% and chronic fatigue syndrome 9.5% vs 1.7% (all p <0.001). In the interstitial cystitis/painful bladder syndrome cohort 50.3% reported no other associated condition, 24.4% had interstitial cystitis/painful bladder syndrome + irritable bowel syndrome only, 2.5% had interstitial cystitis/painful bladder syndrome + fibromyalgia only, 1.5% had interstitial cystitis/painful bladder syndrome + chronic fatigue syndrome only, while 20.2% had multiple associated conditions. As the number of associated conditions increased (ie localized, regional, systemic), pain, stress, depression and sleep disturbance increased while social support, sexual functioning and quality of life deteriorated. Anxiety and catastrophizing remained increased in all groups. Symptom duration was associated with this apparent phenotypic progression.
Irritable bowel syndrome, fibromyalgia and chronic fatigue syndrome are more prevalent in patients with interstitial cystitis/painful bladder syndrome than in asymptomatic control subjects, and result in significant impact. There are at least 3 distinct clinical phenotypes based on identification of overlapping syndrome patterns. A suggestion that remains to be proven with longitudinal studies is that there may be progression over time from an organ centric to a regional and finally to a systemic pain syndrome with progression of symptom severity, and deterioration of cognitive and psychosocial parameters.