Nonbladder syndromes as risk factors for BPS/IC

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Editor's Commentary - Numbers and types of nonbladder syndromes as risk factors for interstitial cystitis/painful bladder syndrome
Tue, 05 April 2011
Philip M. Hanno, MD

BERKELEY, CA (UroToday.com) - Are Non-Bladder Pain Syndromes Risk Factors for BPS/IC?

Case series have shown BPS/IC to be associated with syndromes that do not include bladder symptoms. John Warren and colleagues from Baltimore and Birmingham, Alabama, in an important paper with a superb discussion and collection of references, explored clues to the pathogenesis of BPS/IC by examining the interaction of numbers and types of non-bladder pain syndromes (NBS) preceding onset of BPS/IC. The study material was gleaned from the “Events Preceding Interstitial Cystitis” NIDDK study that identified and investigated medical records of 312 women patients with BPS symptoms of less than one year duration from 12 months before the index date. Three hundred thirteen matched controls were also recruited.

The odds ratios for BPS/IC increased with increasing numbers of NBSs. Of those with a single NBS, allergy was most often the NBS (63% of 48 cases). Of those with 3-4 NBSs, depression, chronic pelvic pain, and migraine affected large numbers of cases. Of those with 5-9 NBSs, fibromyalgia, chronic fatigue syndrome, irritable bowel syndrome, and panic disorder were prominent. Thus the population of NBS varied with the number of NBS. Of the cases, only 22/312 had no NBS compared to 55/313 of the controls.

The researchers closely examined their data and concluded that there were 3 major findings:

• The risk of BPS/IC increased with increasing number of antecedent NBSs. Whether one NBS prompted the appearance of others, a common pathogenesis contributed to each NBS, or they were each independent of the other is not clear. It is known however that those with antecedent fibromyalgia were more likely than those without to have chronic fatigue syndrome, irritable bowel syndrome, sicca syndrome, migraine, panic disorder, chronic pelvic pain, allergy, and depression.
• The risk of BPS/IC was unchanged by types of NBSs present. This led the authors to postulate that indeed, there may be a shared pathogenesis among these nonbladder syndromes. Similarities include symptom-based diagnoses, prominent pain in most, women overrepresented, often unremarkable histologic findings, nondiagnostic laboratory tests, commonality of fatigue, exacerbation by stress, and unknown etiology.
• By number of NBSs, types of NBSs formed a pattern. Allergy was overrepresented in those with only 1 or 2 syndromes, and fibromyalgia, irritable bowel, and chronic fatigue were overrepresented in those with more than 5 syndromes (70 cases vs. 23 controls).

This is an excellent paper and worth a close read. I was surprised by how many of the control population were affected by these NBSs. This is an area begging for further study.

Authors: Warren JW, Wesselmann U, Morozov V, Langenberg PW
PubMed Abstract: 21295246