Epidemiology

• Rate of IC in Vulvodynia Patients May Be Very High
  Kahn BS, Tatro C, Parsons CL, Willems JJ. Prevalence of Interstitial Cystitis in Vulvodynia Patients Detected by Bladder Potassium Sensitivity. J Sex Med. 2009 Oct 20. [Epub ahead of print]
  Some 80 percent of vulvodynia patients may have IC. The estimate is based on results of the potassium sensitivity test and Pelvic Pain and Urgency/Frequency (PUF) questionnaire in 122 vulvodynia patients. Of those, 102 (84 percent) had positive results of the test and 97 (80 percent) had urologic symptoms. Although not all IC experts think this test is definitive for IC, other studies have indicated that the rate of vulvodynia is high in IC and vice versa. In fact, some speculate that vulvar pain may often be referred from the bladder, and it has been estimated that almost half of IC patients have vulvar pain. Although the prevalence needs to be confirmed with further study, the co-occurrence is high, so IC deserves more consideration as a possibility in patients who are getting vulvodynia diagnoses.

• Age, Time to Diagnosis Make a Difference in Symptoms
  Zámecník L, Hanus T, Pavlík I, Dundr P, Povýsil C. Statistical analysis of symptoms, endoscopy and urothelial morphology in 58 female bladder pain syndrome/interstitial cystitis patients. Urol Int. 2009;83(2):193-9. Epub 2009 Sep 10.
  At a Czech hospital, the kind of treatment didn’t make a difference in outcomes for IC patients over the long term, but age and the time it took to get a diagnosis did. Urologists there followed up 58 patients for 6 to 7 years who had “histologically diagnosed” IC. Of those, 31 got oral medications and 27 got heparin instillations. Treatment, no matter which type, was helpful. But nothing about the patients seemed to correlate with how severe their symptoms were over the course of the disease except for older age and the amount of time they lived with IC before they got their diagnosis and treatment.

• Symptoms, Outcomes Don’t Correlate with European Definition
  Richter B, Hesse U, Hansen AB, Horn T, Mortensen SO, Nordling J. Bladder pain syndrome/interstitial cystitis in a Danish population: a study using the 2008 criteria of the European Society for the Study of Interstitial Cystitis. BJU Int. 2009 Sep 14. [Epub ahead of print]
  Investigators tried to correlate the European Society for the Study of Interstitial Cystitis (ESSIC) definition of bladder pain syndrome/IC (BPS/IC) with symptoms, outcomes, and other characteristics; however , their evaluation was inconclusive based on this population of Danish patients. The analysts looked at the medical records of 359 patients with IC referred to the Department of Urology at Copenhagen University Hospital in Herlev from 1966 to 2008. All patients had pain, 75 percent had to get up at night to urinate at least twice, 42 percent had bladder capacities less than about two cups (under anesthesia), 53 percent had high numbers of mast cells in the bladder muscle, and 50 percent had fibrosis (similar to hardening or scarring) of the bladder. Patients who had a lot of mast cells in the bladder muscle, bladder fibrosis, and frequency at night had undergone more intense treatments. Bladder capacity and glomerulations (pinpoint bleeding) did not correlate with treatment intensity. Nevertheless, said the investigators, they could not draw any valid conclusions because of study limitations.

• Cystoscopy, Biopsy May Help Characterize Disease
  Wyndaele JJ, Van Dyck J, Toussaint N. Cystoscopy and bladder biopsies in patients with bladder pain syndrome carried out following ESSIC guidelines. Scand J Urol Nephrol. 2009 Aug 25:1-5. [Epub ahead of print]
  Somewhat unlike the study of Danish patients, these Belgian urologists found that in patients with severe disease, although there was no relationship between how bad the bladder looked during cystoscopy and hydrodistention and the appearance of bladder tissue under the microscope, there was a relationship the cystoscopic appearance and inflammatory infiltration, numbers of mast cells in the bladder muscle, and swelling in the bladder stromal layer. The investigators performed the tests recommended in the European Society for the Study of Interstitial Cystitis/Painful Bladder Syndrome (ESSIC) guidelines for investigating and further typing of what they term bladder pain syndrome (BPS), including cystoscopy and hydrodistention and examination of bladder biopsy specimens. They did this for 50 patients whose scores on the O’Leary-Sant Symptom and Problem Index were high (more than 12) and who rated their pain at more than 7 out of 10. Despite some correlations, there were patients with severe symptoms who had normal-looking bladders cystoscopically and microscopically. Also, there was a strong relationship between bladder capacity and inflammation, mast cell counts, bladder bleeding, and the overall appearance of the bladder. These urologists concluded that to further “type” BPS, cystoscopy and hydrodistention and bladder biopsies may be mandatory. Whether the type correlates with the success of particular treatments remains to be researched.

• IC Is Common in Teens, Young Women with Pelvic Pain
  Rackow BW, Novi JM, Arya LA, Pfeifer SM. Interstitial cystitis is an etiology of chronic pelvic pain in young women. J Pediatr Adolesc Gynecol. 2009 Jun;22(3):181-5.
  Forty percent or more of teen girls and young women with pelvic pain may have IC.  That estimate comes from a small study, but because the criteria for IC may have been strict, the figure might even be low.  These gynecologists looked at records of 28 girls and women ages 13 to 25 who came to the clinic, had chronic pelvic pain, and underwent both laparoscopy and cystoscopy with hydrodistention.  They made a diagnosis of IC based on symptoms plus glomerulations seen during cystoscopy and hydrodistention.  Among those women, 93 percent (26) had urinary symptoms, including frequency (75 percent), nighttime urination (32 percent), urgency (25 percent), and painful urination (18 percent).  They considered 11 patients (39 percent) to have IC.  Eighteen patients (64 percent) had endometriosis, and 7 (25 percent) of those had both IC and endometriosis.  Twenty-three (82 percent) had painful periods, and 12 of 25 (48 percent) sexually active women had painful intercourse.  The gynecologists said doctors should evaluate the bladder as a cause of pelvic pain when teenage girls and young women have chronic pelvic pain and urinary frequency or painful intercourse.

• Prevalence of PBS in Japan Estimated at 0.265 Percent
  Inoue Y, Mita K, Kakehashi M, Kato M, Usui T. Prevalence of painful bladder syndrome (PBS) symptoms in adult women in the general population in Japan. Neurourol Urodyn. 2009 Mar 3. [Epub ahead of print]
  Through a web-based survey, these researchers gathered information about symptoms of painful bladder syndrome (PBS) from some 32,000 Japanese women 20 to 88 years old.  Of these, 76.6 percent had negligible symptoms, 17.3 percent had mild symptoms, 5.6 had moderate symptoms, and 0.5 had severe symptoms.  Based on that information, the possible prevalence was pegged at 0.265 percent.  The authors noted this estimate is in line with the prevalence reported for adult women in Western countries.

• PBS More Common in Older Women
  Lifford KL, Curhan GC. Prevalence of Painful Bladder Syndrome in Older Women. Urology. 2008 Dec 30. [Epub ahead of print]
  Unlike a previous analysis of the prevalence of IC/PBS from a very large population study, this analysis of a different study finds that the prevalence of PBS increases with age.  In fact, it seems to rise progressively from 1.7 percent in women younger than age 65 to 4.0 percent in women aged 80 and older.  This estimate is based on answers nurses gave to a question about bladder and pelvic pain in the Nurses Health Study, which included some 4,000 women who answered a supplemental questionnaire related to the question on the general questionnaire that some 67,000 women answered.  This analysis also showed that, for most women, the symptoms were moderate to severe.  Only 14.8 percent said symptoms were mild, but for 29.0 percent they were moderate, and for 56.2 percent, they were severe.  A previous analysis of data from the National Health and Nutrition Examination Survey (NHANES) III concluded that the prevalence was actually higher in younger women age 25 to 44 than in peri- or postmenopausal women up to age 75.  But the prevalence in that study, too, was high in the oldest women.  That analysis was presented at the American Urological Association's annual meeting in 2005.
  
  
• Other Conditions Common in IC -- and Travel Together
  Warren JW, Howard FM, Cross RK, Good JL, Weissman MM, Wesselmann U, Langenberg P, Greenberg P, Clauw DJ. Antecedent Nonbladder Syndromes in Case-Control Study of Interstitial Cystitis/Painful Bladder Syndrome. Urology. 2008 Nov 7.
  As part of the Epidemiology of IC (EPIC) Study, these researchers looked for other conditions IC patients might have before their IC diagnosis.  They found 11 to be more common in IC patients than healthy controls: allergy, depression, migraine, irritable bowel syndrome (IBS), panic disorder, endometriosis, asthma, fibromyalgia/chronic widespread pain (FM-CWP), chronic fatigue syndrome (CFS), vulvodynia, and sicca (Sjögren's) syndrome.  Since the rates of those syndromes in IC patients (except for vulvodynia) were similar to the rates already published in other studies of patients who have IC, these researchers think that, for many patients, these syndromes develop before IC, not after.  Also, many more IC patients (78 percent) than controls (45 percent) had multiple syndromes, and certain syndromes often clustered together.  The most common cluster was FM-CWP, CFS, sicca syndrome, and IBS.  In addition, patients who had any of these were more likely to have some other syndrome, such as migraine, chronic pelvic pain, depression, or allergy.  Very few patients had only pelvic syndromes before their IC came on.
  
  The authors said they were surprised by that low prevalence of pelvic-only syndromes before IC.  And, when this study was discussed at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) symposium last June, other researchers were surprised that these syndromes seemed to occur so often before IC.  They pointed to data showing that patients who have had IC for a long time have more of these syndromes than those who haven't had IC long, implying that these problems develop later.
  
  What does all that mean?  The answers aren't clear, but the authors speculated that the associated syndromes, even the pelvic ones, aren't the result of the pelvic organs' "crosstalk" through nerves.  The syndromes could be unrelated but simply share some genetic or environmental risk factors.  Another possibility is that some of these syndromes are risk factors for IC.  Still another possibility is that these syndromes and IC are different manifestations of the same disease.  Although these findings don't prove the case, the authors said the data are consistent with the idea that these syndromes share some central nervous system abnormality that leads to heightened processing of pain and other sensory signals.
  
  
• More Pain, Fewer Voiding Problems with Sex Abuse History
  Seth A, Teichman JM. Differences in the Clinical Presentation of Interstitial Cystitis/Painful Bladder Syndrome in Patients With or Without Sexual Abuse History. J Urol. 2008 Sep 17. [Epub ahead of print]
  Rather than trying to connect sexual abuse with IC, this study tried to determine whether IC is any different in patients who have a history of sexual abuse and those who don't.  In general, patients who had been abused had more pain and fewer voiding problems.  In the 119 women studied, 30 or 25 percent had a history of sexual abuse, which is about the national average.  Those who had been abused didn't have to urinate as often and voided larger volumes of urine than those who had not.  Abused patients also had more tenderness over the bladder in their genital area, and in their pelvic floor muscles, and scored worse on sexual function.  There were no differences between the two groups of patients in terms of age, how long they had had their symptoms, the volume of their bladders on hydrodistention, and their scores on the Pelvic Pain and Urgency/Frequency (PUF) Patient Symptom Scale and the O'Leary-Sant Symptom and Problem Indexes.
  
  
• Pelvic Pain Found to be Common in Australian Women
  Pitts MK, Ferris JA, Smith AM, Shelley JM, Richters J. Prevalence and correlates of three types of pelvic pain in a nationally representative sample of Australian women. Med J Aust. 2008 Aug 4;189(3):138-43.
  This survey of adult premenopausal Australian women showed that pelvic pain is common.  Among the 1,983 women aged 15 to 49 who were still menstruating and sexually active, 72 percent had painful periods, 14 percent had pain with intercourse, and 22 percent had other kinds of chronic pelvic pain.  Only 23 percent reported no pelvic pain of any kind.  The study did not distinguish IC from other chronic pelvic pain conditions, which may indicate that IC is still not well known or well recognized in the general medical community in Australia.  It may also imply that many physicians think of chronic pelvic pain only as gynecologic.
  
  
• PBS Estimated at One Percent in China
  Song Y, Zhang W, Xu B, Hao L, Song J. Prevalence and correlates of painful bladder syndrome symptoms in Fuzhou Chinese women. Neurourol Urodyn. 2008 Jul 31. [Epub ahead of print]
  These gynecologists in Fuzhou, China, randomly surveyed 6,066 women aged 20 and older and were able to use information from 4,684 to estimate symptoms of painful bladder syndrome (PBS).  Based on their answers on the Bristol Female Lower Urinary Tract Symptoms questionnaire, the investigators estimated that the prevalence of PBS was 0.98 percent, a rate that is similar to recent epidemiologic studies in the West.  Having had more than two children, having diabetes, and smoking correlated with symptoms.  Smoking was also correlated with PBS in a US study.  Because China's one-child policy was instituted in 1979, women with more than two children are likely to be older.