Inflammatory bowel disease in northern Alberta. An epidemiologic study

Roles of healthcare professionals in the management of chronic gastrointestinal diseases with a focus on primary care: A systematic review

Background and aim

Inflammatory bowel disease (IBD) refers to a group of complex and chronic conditions that requires long‐term care delivered by a group of healthcare professionals through a multidisciplinary care model. We conducted a systematic review to examine and understand the role of healthcare professionals in the primary care management of IBD, and identify the gaps in IBD management that could be filled by primary care providers such as general practitioners (GPs) and pharmacists.

Methods

The search strategy retrieved published studies from five databases, and eligible articles were assessed for quality. A gray literature search of the websites of organizations was also undertaken.

Results

Twenty‐one studies were included, of which 19 were peer‐reviewed research articles and two reports were from organizational bodies. Although studies have shown the roles of GPs, pharmacists, dietitians, and psychologists in IBD management, nurses and gastroenterologists were the key drivers delivering specialized care to IBD patients. Many key services are accessible only for hospital inpatients (tertiary care) or through outpatient clinics (secondary care) with an absence of a multidisciplinary approach including GPs and pharmacists.

Conclusion

Gastroenterologists and nurses have an important role in the delivery of care to patients with chronic gastrointestinal diseases including IBD, coeliac disease, irritable bowel syndrome, and functional dyspepsia. The role of nurses includes provision of specialized care to IBD patients, as well as supportive care such as education, monitoring of therapy, and ongoing assistance. The available evidence shows many opportunities for primary care providers to play a more active role in the management of IBD patients.

Autonomically mediated anti-inflammatory effects of electrical stimulation at acupoints in a rodent model of colonic inflammation

BACKGROUND

Acupuncture has been widely accepted for treatments of many diseases. This study was performed to determine effects and mechanisms of electroacupuncture (EA) by chronically implanted electrodes at acupoint ST36 on colonic inflammation induced by TNBS in rats.

METHODS

After intrarectal administration of TNBS, the rats were treated with sham-EA, EA1/EA2 (two sets of parameters) for 3 weeks. Disease activity index (DAI), macroscopic and microscopic lesions, plasma levels of TNF-α, IL-1β and IL-6 were observed as evaluation of inflammatory responses. The autonomic function was assessed by analysis of the heart rate variability.

RESULTS

(a) Vagal activity was significantly increased with both acute and chronic EA1/EA2; (b) DAI was significantly decreased with both chronic EA1 and EA2, and EA2 was more potent than EA1 (P < 0.05); (c) The macroscopic score was 6.4 ± 0.6 with sham-EA and reduced to 4.9 ± 0.1 with EA1 (P < 0.05) and 4.0 ± 0.2 with EA2 (all P < 0.05). The histological score was 4.05 ± 0.58 with sham-EA and remained unchanged (3.71 ± 0.28) with EA1 (P > 0.05) but reduced to 3.0 ± 0.3 with EA2 (P < 0.01); (d) The plasma levels of TNF-α, IL-1β and IL-6 were significantly decreased with EA2.

CONCLUSIONS

Electrical stimulation at ST36 improves colonic inflammation in TNBS-treated rats by inhibiting pro-inflammatory cytokines via the autonomic mechanism.

Incidence, Clinical Presentation, and Associated Factors of Microscopic Colitis in Northern France: A Population-Based Study

OBJECTIVE

To date, there are no epidemiological data on microscopic colitis (MC) in France. The aim of this study was to determine the incidence of MC in the Somme department in Northern France, to evaluate clinical characteristics, and to search for risk factors for both collagenous colitis (CC) and lymphocytic colitis (LC).

DESIGN

Between January 1, 2005, and December 31, 2007, four pathology units in the Somme department recorded all new cases of MC diagnosed in patients living in the area. Colonic biopsies were reviewed by 4 pathologists together. For each incident case, demographic, clinical, endoscopic, and biological data were collected according to methodology of the EPIMAD registry.

RESULTS

One hundred and thirty cases of MC, including 87 CC and 43 LC, were recorded during the three-year study. The mean annual incidence for MC was 7.9/10⁵ inhabitants, 5.3/10⁵ inhabitants for CC, and 2.6/10⁵ inhabitants for LC. Annual standardized incidence of Crohn's disease and ulcerative colitis in the EPIMAD registry during the same period (2005-2007) were 7.4/10⁵ and 4.9/10⁵, respectively. Median age at diagnosis was 63 years for MC, 70 for CC, and 48 for LC. The female-to-male gender ratio was 3.5 for MC, 4.1 for CC, and 2.6 for LC. Median time to diagnosis was 8 weeks. Chronic diarrhea and abdominal pain were, respectively, present in 93 and 47 % of the cases. An autoimmune disease was associated in 28 % of MC cases. At diagnosis, proton pump inhibitor treatment was more often reported in CC than in LC (46 vs 16 %; p = 0.003). Budesonide was effective on diarrhea in 77 % of patients, and thirteen percent of patients became steroid dependent.

CONCLUSION

This population-based study shows that the incidence of MC in France is high and similar to Crohn's disease incidence and confirms that this condition is associated with female gender, autoimmune diseases, and medications.

Fluoride: a risk factor for inflammatory bowel disease?

Although the association between inflammatory bowel disease (IBD) and oral hygiene has been noticed before, there has been little research on prolonged fluoride exposure as a possible risk factor. In the presented cases, exposure to fluoride seems indirectly associated with higher incidence of IBD. Fluoride toxicology and epidemiology documents frequent unspecific chronic gastrointestinal symptoms and intestinal inflammation. Efflux genes that confer resistance to environmental fluoride may select for IBD associated gut microbiota and therefore be involved in the pathogenesis. Together these multidisciplinary results argue for further investigation on the hypothesis of fluoride as a risk factor for IBD.

Inflammatory Bowel Disease: Historical Perspective, Epidemiology, and Risk Factors

Inflammatory bowel disease (IBD) describes a group of closely related yet heterogeneous predominantly intestinal disease processes that are a result of an uncontrolled immune mediated inflammatory response. It is estimated that approximately one and a half million persons in North America have IBD. Pathogenesis of IBD involves an uncontrolled immune mediated inflammatory response in genetically predisposed individuals to a still unknown environmental trigger that interacts with the intestinal flora. There continues to be an enormous amount of information emanating from epidemiological studies providing expanded insight into the occurrence, distribution, determinants, and mechanisms of inflammatory bowel disease.

The epidemiology of inflammatory bowel disease

BACKGROUND AND AIMS

The inflammatory bowel diseases (IBD), Crohn's disease (CD) and ulcerative colitis (UC), are chronic relapsing disorders of unknown aetiology. The aim of this review is to present the latest epidemiology data on occurrence, disease course, risk for surgery, as well as mortality and cancer risks.

MATERIAL AND METHODS

Gold standard epidemiology data on the disease course and prognosis of patients with inflammatory bowel disease (IBD) are based on unselected population-based cohort studies.

RESULTS

The incidence of ulcerative colitis (UC) and Crohn's disease (CD) has increased overall in Europe from 6.0 per 100,000 person-years in UC and 1.0 per 100,000 person-years in CD in 1962 to 9.8 per 100,000 person-years and 6.3 per 100,000 person-years in 2010, respectively. The highest incidence of IBD is found on the Faroe Islands. Overall, surgery rates have been declining over the last decades, partly due to aggressive medical therapy. Among IBD patients, mortality risk is increased by up to 50% in CD when compared to the background population, but this is not the case for UC. In CD, 25 - 50% deaths are disease-specific deaths, e.g. malnutrition, postoperative complications and intestinal cancer. In UC, disease-specific causes of deaths include colorectal cancer (CRC), and surgical and postoperative complications. The risk of CRC and small bowel cancer is increased two- to eightfold among IBD patients. Various subgroups carry increased risk of malignancy, e.g. those with persistent inflammation, long-standing disease, extensive disease, young age at diagnosis, family history of CRC and co-existing primary sclerosing cholangitis. The risk of extra-intestinal cancers, including lymphoproliferative disorders (LD) and intra- and extrahepatic cholangio carcinoma, is significantly higher among IBD patients.

CONCLUSION

In recent years, self-management and patient empowerment, combined with evolving eHealth solutions, has utilized epidemiological knowledge on disease patterns and has been improving compliance and the timing of adjusting therapies, thus optimizing efficacy by individualizing medication in the community setting.

Inflammatory bowel disease among Bedouin Arabs in southern Israel: urbanization and increasing prevalence rates

BACKGROUND AND AIM

Inflammatory bowel disease (IBD) has been associated with genetic and environmental factors, including urban living. IBD was rare in the Israeli Bedouin community 30 years ago. Over recent decades, a large proportion of this community has undergone a transition from a nomadic to a western lifestyle. Our aim was to carry out an updated evaluation of the clinical and epidemiological features of IBD in the Bedouin sector of southern Israel.

METHODS

All Bedouin patients with a known diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) were included in the retrospective study.

RESULTS

The cohort included 31 CD patients and 31 UC patients. The mean age of the patients at diagnosis was 29±10.9 and 35±17.5 years for CD and UC, respectively. The prevalence rate for CD was 15.5/100,000 and the incidence rate was 0.8-3.55/100,000. Fourteen of the CD patients (45%) had ileal disease and 64.5% had inflammatory disease behavior according to the Montreal classification. Eleven of the CD patients (35%) were treated with anti-TNF-α and 26% had undergone surgery. Over the previous decade, the prevalence of UC was 14/100,000 and the incidence was 0.5-2.39/100,000. Eighteen UC patients (58%) had left-sided colitis. Three (9.7%) had undergone total colectomy for severe disease.

CONCLUSION

We found an increased prevalence of IBD in the Bedouin population, associated with their change in lifestyle over previous decades. However, the prevalence is still markedly lower than that in other population groups. A high percentage of patients were treated with anti-TNF-α and/or surgery.

The characteristics of ulcerative colitis associated with autoimmune pancreatitis

GOALS

To determine the prevalence of ulcerative colitis (UC) in autoimmune pancreatitis (AIP) patients in a tertiary referral hospital and to compare the clinical and pathologic characteristics and outcomes of UC associated with AIP (AIP-UC) and UC patients.

BACKGROUND

Recently, it was suggested that UC is associated with AIP. However, the prevalence of UC in AIP, together with the clinical characteristics and outcomes of AIP-UC are not clear.

STUDY

We retrospectively reviewed the medical records of AIP patients diagnosed at the Asan Medical Center.

RESULTS

Of the 104 patients with AIP, 6 (5.8%) were also diagnosed with UC. Serum immunoglobulin G (IgG) and IgG4 were elevated in 1 patient (16.7%), respectively, and 4 (66.7%) showed idiopathic duct-centric pancreatitis (type 2 AIP). Compared with 24 matched patients with UC only, AIP-UC patients had a lower body mass index (P=0.003), higher C-reactive protein levels (P=0.048), and higher Mayo scores (P=0.006) at diagnosis of UC. Two AIP-UC patients (33.3%), but none with UC only showed increased infiltration of IgG4-positive cells into the colonic tissues (P=0.006). During follow-up, 2 AIP-UC patients (33.3%) underwent colectomy and 1 (16.7%) died, but no colectomies or deaths occurred in the UC only group.

CONCLUSIONS

AIP patients seem to have a higher risk of UC compared with the general population. The increased IgG4-positive cellular infiltration in the colonic tissue suggests that UC may be an extrapancreatic manifestation of AIP.

The prevalence of inflammatory bowel disease in an Israeli Arab population

AIMS

To determine the prevalence of inflammatory bowel disease among the 1.5 million Arab residents in Israel who represent 20% of the total population.

METHODS

Family physicians in all Arab towns and villages were contacted to obtain information on patients with inflammatory bowel disease. Relevant clinical data were retrieved and updated to December 31, 2009.

RESULTS

Information was obtained from 23/71 municipalities approached (representing 200,000 out of 1.5 million Arabs). There were 64 confirmed cases of Crohn's disease indicating a prevalence rate of 32/100,000. The rate of smoking within this cohort was lower than in the general population (1.5% vs. 40%; P<0.001). There were 44 confirmed cases of ulcerative colitis with a prevalence rate of 22/100,000. The percentage of active smokers in this cohort was 18%. Clinical remission or mild activity was observed in 75% of patients in both cohorts at the time of the survey. Fourteen patients (21%) had undergone surgery for Crohn's disease, whereas none had undergone surgery for ulcerative colitis. Twenty-eight (42%) patients with Crohn's disease and 20 (45%) with ulcerative colitis were on maintenance therapy with 5-aminosalicylic acid. Only 18% with Crohn's disease and 6.8% with ulcerative colitis had received anti-tumor necrosis factor. The most prevalent extra-intestinal manifestations were perianal disease (18%) in Crohn's disease, and arthralgia or arthritis (6.8%) in ulcerative colitis.

CONCLUSIONS

We found a low prevalence rate of inflammatory bowel disease in the Israeli Arab population.

The incidence and prevalence of inflammatory bowel disease among U.S. veterans: a national cohort study

BACKGROUND

Temporal trends in incidence and prevalence of Crohn's disease (CD) and ulcerative colitis (UC) in the United States have been reported only in regional populations. The Veterans Affairs (VA) health care system encompasses a national network of clinical care facilities. The aim of this study was to identify temporal trends in the incidence and prevalence of CD and UC among VA users using national VA data sets.

METHODS

Veterans with CD and UC were identified during fiscal years 1998 to 2009 in the national VA outpatient and inpatient files. Incident and prevalent cases were identified by diagnosis code, and age-standardized and gender-standardized annual prevalence and incidence rates were estimated using the VA 1998 population as the standard population.

RESULTS

The total of unique incident cases were 16,842 and 26,272 for CD and UC, respectively; 94% were men. The average annual age-standardized and gender-standardized incidence rate of CD was 33 per 100,000 VA users (range, 27-40), whereas the average for UC was 50 per 100,000 VA users (range, 36-65). In 2009, the age-standardized and gender-standardized point prevalence rate of CD was 287 per 100,000 VA users, whereas the point prevalence of UC was 413 per 100,000 VA users.

CONCLUSIONS

Prevalence of CD and UC increased 2-fold to 3-fold among VA users between 1998 and 2009. The incidence of UC decreased among VA users from 1998 to 2004 but has remained stable from 2005 to 2009. The incidence of CD has remained stable during the observed time period.

Etiology of inflammatory bowel disease: a unified hypothesis

Inflammatory bowel disease (IBD), including both ulcerative colitis (UC) and Crohn's disease (CD), emerged and dramatically increased for about a century. Despite extensive research, its cause remains regarded as unknown. About a decade ago, a series of findings made me suspect that saccharin may be a key causative factor for IBD, through its inhibition on gut bacteria and the resultant impaired inactivation of digestive proteases and over digestion of the mucus layer and gut barrier (the Bacteria-Protease-Mucus-Barrier hypothesis). It explained many puzzles in IBD such as its emergence and temporal changes in last century. Recently I further found evidence suggesting sucralose may be also linked to IBD through a similar mechanism as saccharin and have contributed to the recent worldwide increase of IBD. This new hypothesis suggests that UC and CD are just two symptoms of the same morbidity, rather than two different diseases. They are both caused by a weakening in gut barrier and only differ in that UC is mainly due to increased infiltration of gut bacteria and the resultant recruitment of neutrophils and formation of crypt abscess, while CD is mainly due to increased infiltration of antigens and particles from gut lumen and the resultant recruitment of macrophages and formation of granulomas. It explained the delayed appearance but accelerated increase of CD over UC and many other phenomena. This paper aims to provide a detailed description of a unified hypothesis regarding the etiology of IBD, including the cause and mechanism of IBD, as well as the relationship between UC and CD.

Increasing incidence and prevalence of the inflammatory bowel diseases with time, based on systematic review

BACKGROUND & AIMS

We conducted a systematic review to determine changes in the worldwide incidence and prevalence of ulcerative colitis (UC) and Crohn's disease (CD) in different regions and with time.

METHODS

We performed a systematic literature search of MEDLINE (1950-2010; 8103 citations) and EMBASE (1980-2010; 4975 citations) to identify studies that were population based, included data that could be used to calculate incidence and prevalence, and reported separate data on UC and/or CD in full manuscripts (n = 260). We evaluated data from 167 studies from Europe (1930-2008), 52 studies from Asia and the Middle East (1950-2008), and 27 studies from North America (1920-2004). Maps were used to present worldwide differences in the incidence and prevalence of inflammatory bowel diseases (IBDs); time trends were determined using joinpoint regression.

RESULTS

The highest annual incidence of UC was 24.3 per 100,000 person-years in Europe, 6.3 per 100,000 person-years in Asia and the Middle East, and 19.2 per 100,000 person-years in North America. The highest annual incidence of CD was 12.7 per 100,000 person-years in Europe, 5.0 person-years in Asia and the Middle East, and 20.2 per 100,000 person-years in North America. The highest reported prevalence values for IBD were in Europe (UC, 505 per 100,000 persons; CD, 322 per 100,000 persons) and North America (UC, 249 per 100,000 persons; CD, 319 per 100,000 persons). In time-trend analyses, 75% of CD studies and 60% of UC studies had an increasing incidence of statistical significance (P < .05).

CONCLUSIONS

Although there are few epidemiologic data from developing countries, the incidence and prevalence of IBD are increasing with time and in different regions around the world, indicating its emergence as a global disease.

Epidemiology and natural history of inflammatory bowel diseases

In the West, the incidence and prevalence of inflammatory bowel diseases has increased in the past 50 years, up to 8-14/100,000 and 120-200/100,000 persons, respectively, for ulcerative colitis (UC) and 6-15/100,000 and 50-200/100,000 persons, respectively, for Crohn's disease (CD). Studies of migrant populations and populations of developing countries demonstrated a recent, slow increase in the incidence of UC, whereas that of CD remained low, but CD incidence eventually increased to the level of UC. CD and UC are incurable; they begin in young adulthood and continue throughout life. The anatomic evolution of CD has been determined from studies of postoperative recurrence; CD begins with aphthous ulcers that develop into strictures or fistulas. Lesions usually arise in a single digestive segment; this site tends to be stable over time. Strictures and fistulas are more frequent in patients with ileal disease, whereas Crohn's colitis remains uncomplicated for many years. Among patients with CD, intestinal surgery is required for as many as 80% and a permanent stoma required in more than 10%. In patients with UC, the lesions usually remain superficial and extend proximally; colectomy is required for 10%-30% of patients. Prognosis is difficult to determine. The mortality of patients with UC is not greater than that of the population, but patients with CD have greater mortality than the population. It has been proposed that only aggressive therapeutic approaches, based on treatment of early recurrent lesions in asymptomatic individuals, have a significant impact on progression of these chronic diseases.

Factors associated with ileoanal pouch failure in patients developing early or late pouch-related fistula

BACKGROUND

The natural history of a pouch-related fistula in terms of timing of its development and its impact on pouch survival is poorly defined.

OBJECTIVE

This study aimed to evaluate factors associated with the time of onset of ileoanal pouch-related fistulas and predictors of pouch failure after the development of fistulas.

DESIGN

This study is an evaluation of prospectively collected data from a cohort of patients with pouch-related fistulas.

SETTING

Patients were identified from a prospective ileoanal pouch database, with data recorded from 1983 to 2009.

PARTICIPANTS

Patients who participated had developed a fistula after ileoanal pouch surgery. Patients were classified according to the time of onset, origin, and target of pouch fistulas into "early" and late" groups.

MAIN OUTCOME MEASURE

Ileoanal pouch failure was the main outcome measure.

RESULTS

Three hundred six patients (158 early-onset, 148 late-onset) with 373 pouch-related fistulas were identified. The early-onset group had a higher mean body mass index (P = .013) and more patients in this group developed a postoperative leak (P < .001), whereas diagnosis revision to Crohn's disease was more frequent in the late-onset group (P = .018). Overall, pouch failure occurred in 89 (29%) patients. Major abdominal procedures were more common in the early-onset group (18 vs 6%). There was no difference in pouch failure between the early- and late-onset groups (P = .24). On multivariate analysis, a current Crohn's diagnosis (P < .001), major fistula (P = .022), history of colectomy before ileoanal pouch (P = .005), handsewn anastomosis (P = .008), anastomotic leak (P = .012), and body mass index over 30 (P = .018) were independent risk factors for failure. No individual risk factor for failure was separately associated with either early or late fistula groups.

CONCLUSIONS

The timing and etiology of pouch fistula appear to be interrelated. There is a temporal association between procedure-related sepsis and early and delayed diagnosis of Crohn's disease and late fistula development. Cause of the fistula and associated factors rather than timing after IPAA is associated with long term pouch retention.

Epidemiology of pediatric inflammatory bowel disease: a systematic review of international trends

BACKGROUND

Temporal trends in the incidence of pediatric-onset inflammatory bowel disease (IBD) are controversial and a wide range of estimates have been reported worldwide. We conducted a systematic review of research describing the epidemiology of childhood-onset IBD to assess changes in incidence rates over time and to evaluate international differences.

METHODS

The following electronic databases were searched for articles published 1950-2009: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane IBD/Functional Bowel Disorders Group Specialised Trial Register. All included studies reported incidence or prevalence of IBD, Crohn's disease (CD) or ulcerative colitis (UC). Two authors independently completed the data extraction form for each eligible study. Choropleth maps demonstrated the international incidence of IBD, CD, and UC. Incidence of CD and UC was graphed using data from studies reporting rates in multiple time periods.

RESULTS

The search yielded 2209 references and review resulted in 139 included studies from 32 countries. A wide range of incidence was reported internationally; however, rates of IBD were not described in most countries. Twenty-eight studies (20.1%) used statistical analysis to assess trends over time, and 77.8% reported statistically significantly increased incidence of pediatric IBD. Of studies calculating statistical trends in CD incidence, 60% reported significantly increased incidence. Of similar UC studies, 20% reported significantly increased incidence.

CONCLUSIONS

Globally rising rates of pediatric IBD (due primarily to the rising incidence of CD) was demonstrated in both developed and developing nations; however, most countries lack accurate estimates. Analyzing incidence trends may help identify specific environmental and genetic risk factors for pediatric IBD.

Racial differences in disease extent and severity in patients with ulcerative colitis: a retrospective cohort study

INTRODUCTION

Ulcerative colitis (UC) is increasing in African-Americans (AA). The objectives of this study were to assess disease extent and severity in UC by race.

METHODS

Disease extent and severity was assessed in UC outpatients evaluated at the University of Maryland and Baltimore VA from 1997 to 2005.

RESULTS

About 197 patients were identified; 47 were AA (23%). Of AA, 23% had proctitis, 23% had left-sided colitis, and 53% had extensive colitis compared to 10%, 31%, and 59% of Caucasians, respectively (P = 0.056). African-Americans were less likely to ever receive steroids (45% versus 62%; P = 0.065), be treated with > or = 2 courses of steroids (54% versus 68%; P = 0.242) or be steroid dependant (33% versus 46%; P = 0.304). After adjustment, only female gender (OR 0.32, [0.16-0.66]) and age at diagnosis (OR 2.50, [1.28-4.90]) were associated with extensive colitis. Being seen at UMMS (OR 5.10, [2.60-10.10]) was associated with steroid use.

CONCLUSION

Race was not associated with extent of colitis or disease severity in UC.

Infliximab for ulcerative colitis in children and adolescents

GOALS

To evaluate the efficacy of infliximab treatment in children and adolescents with ulcerative colitis (UC) defined as short and long-term clinical response and surgical avoidance.

BACKGROUND

Infliximab has been found to be effective at improving clinical symptoms, sparing steroid use, and inducing remission in children with medically refractory Crohn's disease. Several retrospective studies in children have shown clinical improvement with colectomy avoidance, but the numbers have been small.

STUDY

Medical records of all patients with steroid-resistant or dependent UC who received infliximab 5 to 10 mg/kg in a 36-month period at Children's Hospital and Regional Medical Center, Seattle, Washington were reviewed. Response to the medication was defined by posttreatment recategorization into Trulove and Witts "mild" category or better. The duration of response was defined as time between infusion and clinical relapse or colectomy.

RESULTS

Forty children and adolescents aged 2 to 20 years, received infliximab during the study period. Duration of follow-up ranged from 1 to 36 months with a median of 19 months. Four patients were lost to follow-up. Seventy percent of subjects responded to infliximab. Infliximab responders proceeded to surgery less frequently than nonresponders (P<0.001). No laboratory variables correlated with response. Infliximab was well tolerated.

CONCLUSIONS

Most children and adolescents with steroid-resistant or dependent UC respond to infliximab with clinical improvement. Response to infliximab also delays and may prevent need for surgery. Laboratory and clinical indicators do not predict response. Infliximab has a role in clinical improvement and surgery avoidance in pediatric patients with UC.

The incidence of inflammatory bowel disease in a rural region of Southern Germany: a prospective population-based study

OBJECTIVE

Although important advances in understanding the aetiology and pathogenesis of inflammatory bowel disease (IBD) have been made, many questions remain unanswered. As the most recent data available on the incidence of IBD in Germany were collected about 15 years ago, we set up a new population-based cohort to determine current incidence data for a defined region in Germany and to establish a basic cohort for prospective follow-up.

METHODS

All patients living in the region of Oberpfalz newly diagnosed with IBD between 1 January 2004 and 31 December 2006 were included in this study by setting up a network of reporting clinicians and general practitioners in hospitals as well as in private practices. Demographic and clinical characteristics such as age at first diagnosis, localization of the disease, extraintestinal manifestations or family history on IBD were documented. Age-adjusted incidence rates are presented with 95% Poisson confidence intervals (CIs), based on the European standard population.

RESULTS

In total, 286 newly diagnosed patients with IBD were reported in this region, 168 patients suffering from Crohn's disease (CD), 105 patients with ulcerative colitis. Age-standardized incidence rates were 11.0/10(5) (95% CI: 9.1-11.6) for IBD, 6.6/10(5) (95% CI: 5.6-7.7) for CD and 3.9/10(5) (95% CI: 3.2-4.7) for ulcerative colitis. Peak incidences were found in the age interval of 16-24 years for both diseases, predominantly for CD. Age at first diagnosis was lower, extraintestinal manifestations and a positive family history on IBD were more common in patients with CD.

CONCLUSION

The incidence rate in IBD seems to be stable in Germany as compared with previously reported data, as is the remarkable predominance of CD. Prospective follow-up studies will be based on this incidence cohort.

Prevalence of Inflammatory Bowel Disease in the Canton of Vaud (Switzerland): A population-based cohort study

BACKGROUND AND AIMS

Because of the changing epidemiology of Inflammatory Bowel Diseases (IBD), we set out to characterize the population-based prevalence of Crohn's Disease (CD) and Ulcerative Colitis (UC) in a defined population of Switzerland.

METHODS

Adult IBD patients were identified by a cross-matched review of histological, hospital and gastroenterologist files throughout a geographical defined population (Canton of Vaud). Demographic factors statistically significantly associated with prevalence were evaluated using a stepwise Poisson regression analysis. Results were compared to IBD prevalence rates in other population-based studies and time trends were performed, based on a systematic literature review.

RESULTS

Age and sex-adjusted prevalence rates were 205.7 IBD (100.7 CD and 105.0 UC) cases per 10(5) inhabitants. Among 1016 IBD patients (519 CD and 497 UC), females outnumbered males in CD (p<0.001), but males were more represented in elderly UC patients (p=0.008). Thus, being a male was statistically associated with UC (Relative Risk (RR) 1.25; p=0.013), whereas being a female was associated with CD (RR 1.27; p=0.007). Living in an urban zone was associated with both CD and UC (RR 1.49; p<0.001, 1.63; p<0.001, respectively). From 1960 to 2005, increases in UC and CD prevalences of 2.4% (95%CI, 2.1%-2.8%; p<0.001) and 3.6% (95%CI, 3.1%-4.1%; p<0.001) per annum were found in industrialised countries.

CONCLUSIONS

Extrapolating our data to all of Switzerland yields an estimate of 12,000 IBD cases for the country, or 1 in 500 inhabitants. Our study gives support to an increase in IBD prevalence in Europe.

Disparities in the use of immunomodulators and biologics for the treatment of inflammatory bowel disease: a retrospective cohort study

BACKGROUND

Treatment disparities between African Americans (AA) and Caucasians exist in multiple diseases. There are limited studies in inflammatory bowel disease (IBD). Our objectives were to assess differences in IBD therapies between AA and Caucasians, controlling for disease severity.

METHODS

We identified outpatients with ulcerative colitis (UC) or Crohn's disease (CD) evaluated at the University of Maryland and the Baltimore Veterans Affairs Medical Center from 1997-2005. We assessed medications used and the presence of covariates by race.

RESULTS

We identified 406 patients; 102 were AA (25%). AA were less likely to receive steroids (56% versus 68%; P = 0.02), mercaptopurine/azathioprine (6-MP/AZA) (28% versus 40%; P = 0.03), infliximab (IFX) (10% versus 20%; P = 0.03), or either 6-MP/AZA or IFX (28% versus 44%; P = 0.005). Age at diagnosis <40 (odds ratio [OR] 2.22, 95% confidence interval [CI] 1.06-4.54), steroid use (OR 4.75, 95% CI 1.93-11.7), and CD (OR 6.25, 95% CI 3.22-12.5) were positively associated with IFX use, while AA (OR 0.50, 95% CI 0.23-1.08) was negatively associated with IFX use. Age at diagnosis <40 (OR 1.84, 95% CI 1.12-3.23), steroid use (OR 10.2, 95% CI 5.37-19.2), and CD (OR 2.32, 95% CI 1.43-3.20) were positively associated with either 6-MP/AZA or IFX use, while AA (OR 0.57, 95% CI 0.32-1.01) was negatively associated with 6-MP/AZA or IFX use.

CONCLUSIONS

There were trends toward lower odds of treatment with IFX or either 6-MP/AZA or IFX in AA when compared with Caucasians. Further studies are needed to determine if these differences are due to less severe disease in AA patients or due to disparities in care.

Inflammatory bowel disease in the South Asian pediatric population of British Columbia

BACKGROUND

Geographical differences, population migration, and changing demographics suggest an environmental role in prevalence, modulation, and phenotypic expression of inflammatory bowel disease (IBD).

AIM

To determine the incidence of IBD and disease subtype in the pediatric South Asian population in British Columbia (BC) compared with non-South Asian IBD patients in the same geographic area.

METHODS

Chart review with data collected for all patients <or=16 yr of age diagnosed with IBD at B.C. Children's hospital, January 1985 to June 2005. Age, gender, family history, duration of symptoms, type, and extent of disease were extracted. Identified South Asian subjects were prospectively interviewed.

RESULTS

Seventy-five South Asian patients were diagnosed with IBD, 48% Crohn's disease (CD), 33.3% ulcerative colitis (UC), and 18.7% with indeterminate colitis (IC), in contrast to 71%, 18.8%, and 10.2%, respectively, in the non-South Asian population. The incidence rate for South Asian IBD patients, for the period 1996-2001 was 15.19/10(5) (6.41/10(5) for CD, 6.70/10(5) for UC, and 2.08/10(5) for IC) compared with 5.19/10(5) for the non-South Asian IBD group (3.69/10(5), 0.96/10(5), and 0.54/10(5), respectively). The South Asian male/female ratio was significantly different from that observed for the rest of the population.

CONCLUSION

These data suggest a significantly higher incidence of IBD in the South Asian pediatric population compared with the rest of the BC pediatric population, with a different pattern of phenotypic expression, a male predominance, and more extensive colonic disease. These data suggest a potential effect of migration, and environmental and lifestyle change on the incidence of IBD and disease subtype.

Inflammatory bowel disease genetics: Nod2

The inflammatory bowel diseases (IBD) are comprised of two major subphenotypes, Crohn's disease (CD) and ulcerative colitis (UC). A significant role for genetic factors in IBD was established from epidemiologic studies and, more recently, the identification of well-established disease associations, notably the association of Nod2 (CARD15) polymorphisms with CD. The mapping to CD of Nod2 variants that alter protein function represents one of the earliest, most well-established, associations in complex genetic disorders. Since the initial discovery, genotype-phenotype correlations, definition of Nod2 expression and signaling pathways, association studies in other, related disorders, and features of Nod2 deficiency in murine models have been reported. Taken together, the Nod2 association to CD provides an illustrative model of the role of single gene variants in disease pathogenesis for common, complex multigenic disorders. Here we review general aspects of IBD genetics with particular focus on the role of Nod2 in CD.

Clinical epidemiology of inflammatory bowel disease in Lebanon

BACKGROUND

The objectives of this study were to determine the prevalence and incidence of inflammatory bowel disease (IBD) in a representative Lebanese cohort and to describe practice prevalence trends, disease characteristics, and impact on quality of life (QoL) of IBD patients in Lebanon.

METHODS

All of a university-based health program's 2000-2004 computerized records that listed a diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) were reviewed. In addition, data on patients seen in the gastroenterology clinics and data from the IBD registry at the American University of Beirut Medical Center (AUBMC) from the same period were analyzed.

RESULTS

Of 15,073 insured individuals, 8 had a diagnosis of CD and 16 of UC, giving an age-adjusted prevalence of 53.1 per 100,000 people for CD and 106.2 per 100,000 people for UC. The mean age at diagnosis for patients with CD and UC was 28.8 +/- 11.1 and 32.0 +/- 13.4 years, respectively, and there was a slight female predominance. The mean annual incidence was 4.1 per 100,000 people for UC and 1.4 per 100,000 people for CD (range, 0-6.9/100,000 for both). Of the 10,383 patients seen in the gastroenterology clinic from 2000 to 2004, 251 (2.4%) had IBD (142 UC, 100 CD, and 9 indeterminate), a ratio that trended upward over time (range, 1.8%-2.7%). The median IBD Quality-of-Life (IBDQ) questionnaire score was 124.9 +/- 30.5, indicating that the disease had a moderately severe impact on QoL.

CONCLUSIONS

The prevalence of IBD in this representative Lebanese cohort falls in the intermediate range of that reported for white populations in Europe and North America. Future studies are needed to examine local risk factors, disease genotypes and phenotypes, and epidemiologic time trends. The psychosocial burden of IBD in Lebanon appears significant.

Estimation of the period prevalence of inflammatory bowel disease among nine health plans using computerized diagnoses and outpatient pharmacy dispensings

BACKGROUND

There are few contemporary estimates of prevalence rates for inflammatory bowel disease (IBD) in diverse North American communities.

METHODS

We estimated the period prevalence of IBD for January 1, 1999, through June 30, 2001, among 1.8 million randomly sampled members of nine integrated healthcare organizations in the US using computerized diagnoses and outpatient pharmaceutical dispensing. We also assessed the positive predictive value (PPV) and sensitivities of 1) the case-finding algorithm, and 2) the 30-month sampling period using medical chart review and linkage to a 78-month dataset, respectively.

RESULTS

The PPV of the case-finding algorithm was 81% (95% confidence interval [CI], 78-87) and 84% (95% CI, 79-89) in two different organizations. In both, the sensitivity of the optimal algorithm, compared with the most inclusive, exceeded 90%. The sensitivity of the 30-month sampling period compared with 78 months was 61% (95% CI, 57-64) in one organization. Applying a slightly more sensitive case-finding algorithm, the average period prevalence of IBD across the nine organizations, standardized to the age- and gender-distribution of the US population, 2000 census, was 388 cases (95% CI, 378-397) per 100,000 persons (range 209-784 per 100,000; average follow-up 26 months). The prevalence of Crohn's disease, ulcerative colitis, and unspecified IBD was 129, 191, and 69 per 100,000, respectively.

CONCLUSIONS

The observed average prevalence was similar to prevalence proportions reported for other North American populations (369-408 per 100,000). Additional research is needed to understand differences in the occurrence of IBD among diverse populations as well as practice variation in diagnosis and treatment of IBD.

Update on the incidence and prevalence of Crohn's disease and ulcerative colitis in Olmsted County, Minnesota, 1940-2000

BACKGROUND

We previously reported that the prevalence of Crohn's disease (CD) and ulcerative colitis (UC) in Olmsted County, Minnesota, had risen significantly between 1940 and 1993. We sought to update the incidence and prevalence of these conditions in our region through 2000.

METHODS

The Rochester Epidemiology Project allows population-based studies of disease in county residents. CD and UC were defined by previously used criteria. County residents newly diagnosed between 1990 and 2000 were identified as incidence cases, and persons with these conditions alive and residing in the county on January 1, 2001, were identified as prevalence cases. All rates were adjusted to 2000 US Census figures for whites.

RESULTS

In 1990-2000 the adjusted annual incidence rates for UC and CD were 8.8 cases per 100,000 (95% confidence interval [CI], 7.2-10.5) and 7.9 per 100,000 (95% CI, 6.3-9.5), respectively, not significantly different from rates observed in 1970-1979. On January 1, 2001, there were 220 residents with CD, for an adjusted prevalence of 174 per 100,000 (95% CI, 151-197), and 269 residents with UC, for an adjusted prevalence of 214 per 100,000 (95% CI, 188-240).

CONCLUSION

Although incidence rates of CD and UC increased after 1940, they have remained stable over the past 30 years. Since 1991 the prevalence of UC decreased by 7%, and the prevalence of CD increased about 31%. Extrapolating these figures to US Census data, there were approximately 1.1 million people with inflammatory bowel disease in the US in 2000.

Investigating the hygiene hypothesis as a risk factor in pediatric onset Crohn's disease: a case-control study

BACKGROUND AND OBJECTIVES

Evidence for the hygiene hypothesis in the etiology of Crohn's disease (CD) is unclear. We investigated the relationship between infection-related exposures and risk for CD in children.

METHODS

A hospital-based case-control was carried out. Newly-diagnosed cases of CD (n = 194), less than 20 yr of age were recruited from the gastroenterology clinic of a large-pediatric inflammatory bowel disease (IBD) center in Montreal, Canada. Orthopedic patients pair-matched (n = 194) for timing of diagnosis and area of residence were recruited as controls. Information on infection-related exposures between birth and disease diagnosis was ascertained by administering a structured questionnaire to the mother and the index subject. The relationship between the frequency and timing of infection-related exposures with CD was studied.

RESULTS

The mean age (SD) at diagnosis was 12.3 (5.1). CD was more common after 10 yr of age. Gender distribution was similar between comparison groups. In multivariate conditional logistic regression, family history of IBD (odds ratio (OR) = 4.6; 95% confidence interval (CI) = 1.6-13.3), age (OR = 1.2; 95% CI = 1.1-1.3), and owning a pet (OR = 2.0; 95% CI = 0.9-4.5) were associated with risk for CD, whereas regular use of a personal towel (OR = 0.5; 95% CI = 0.2-0.9) and lesser crowding in homes (OR = 0.3; 95% CI = 0.1-0.8) were protective. Day-care attendance during the first 6 months of life and "physician-diagnosed infections" between 5 and 10 yr of age were associated with increased risks for CD.

CONCLUSIONS

Infection-related exposures seem to enhance risk for CD in children. The timing of these exposures during early childhood may be relevant to the etiology of pediatric CD.

Recent advances in the etiology and treatment of inflammatory bowel disease

Crohn's disease and ulcerative colitis, together comprising the inflammatory bowel diseases, currently affect up to 2 million people in the western developed countries. The pathogenesis of the disease is a complex one in which genetic, immunogenic, microbial and environmental factors contribute to the etiology of the disease. Recent advances in understanding the molecular mechanisms that determine this complex entity have provided insight for promising new therapies.

Hospitalization, surgery, and readmission rates of IBD in Canada: a population-based study

BACKGROUND

We aimed to define the rates of hospitalization and readmission for inflammatory bowel disease in Canada.

METHODS

The data source was Statistics Canada Person Oriented Information Database (1994-2001). The number of stays for a diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) by ICD-9-CM code 555 or 556 was extracted (and assessed when CD or UC was the first diagnosis or was 1 of 16 diagnoses on the patient discharge abstract). Age-, gender-, and disease-specific rates of hospitalization, length of stay, readmission, and surgery were assessed.

RESULTS

The age-adjusted hospitalization rate for CD declined over 1994-2001 from 29.2 to 26.9/100,000 but was stable for UC at 12.6-13.3 per 100,000. In the 7 yr, 39.4% of CD patients (21.3-24.0%/yr) and 33.7% of UC patients (18.5-20.3%/yr) got readmitted at least once. The average length of stay declined from 10.3 (1994-1995) to 9.1 days (2000-2001) (p = 0.029) in CD and in UC declined from 12.2 to 10.1 days (p = 0.054). Of all hospitalizations, major surgery occurred in 48% of CD (44.8-49.8% per yr) and 55% of UC (51.5-59.0% per yr).

CONCLUSIONS

Rates of hospitalization declined slightly for CD over the 7 yr but still remained twice as great as the rates for UC. Approximately 20% of CD and UC subjects got readmitted per year and over 7 yr approximately 35% got readmitted. Major surgery was a more common reason for hospitalization in UC than in CD.

Unemployment and disability in patients with moderately to severely active Crohn's disease

GOALS

Unemployment and disability rates in Crohn's disease patients from the ACCENT I trial were assessed. Factors associated with employment and disability status were explored.

BACKGROUND

Limited data regarding unemployment and disability status in patients with active Crohn's disease are available.

STUDY

Baseline data were used to assess unemployment and disability rates. Logistic regression analysis examined factors that were associated with employment and disability status. Analysis of variance was used to compare quality of life.

RESULTS

The baseline full-and part-time employment rates were 48% and 13%, respectively, with 39% of patients unemployed and 25% receiving disability compensation. Only 14% of 225 unemployed patients felt well enough to work if a job were available. Younger age, female gender, shorter disease duration, and prior bowel resection predicted a higher likelihood of unemployment. Younger age and female gender also predicted a higher likelihood of not being employed full-time. Prior bowel resection predicted a higher likelihood of receiving disability compensation. Quality of life (Inflammatory Bowel Disease Questionnaire, Short Form-36) scores were significantly higher in employed patients.

CONCLUSIONS

Patients with moderately to severely active Crohn's disease had low employment and high disability rates. Given their economic importance, assessment of these outcomes should be integrated into future evaluations of therapy, including clinical trials.

Clinical epidemiology of inflammatory bowel disease: Incidence, prevalence, and environmental influences

Although the incidence and prevalence of ulcerative colitis and Crohn's disease are beginning to stabilize in high-incidence areas such as northern Europe and North America, they continue to rise in low-incidence areas such as southern Europe, Asia, and much of the developing world. As many as 1.4 million persons in the United States and 2.2 million persons in Europe suffer from these diseases. Previously noted racial and ethnic differences seem to be narrowing. Differences in incidence across age, time, and geographic region suggest that environmental factors significantly modify the expression of Crohn's disease and ulcerative colitis. The strongest environmental factors identified are cigarette smoking and appendectomy. Whether other factors such as diet, oral contraceptives, perinatal/childhood infections, or atypical mycobacterial infections play a role in expression of inflammatory bowel disease remains unclear. Additional epidemiologic studies to define better the burden of illness, explore the mechanism of association with environmental factors, and identify new risk factors are needed.

CARD15 genetic variation in a Quebec population: prevalence, genotype-phenotype relationship, and haplotype structure

The caspase recruitment domain gene (CARD15) was recently identified as the underlying gene associated with the IBD1 locus that confers susceptibility to Crohn disease (CD). CARD15 is related to the NOD1/Apaf-1 family of apoptosis regulators, and three sequence variants (Arg702Trp, Gly908Arg, and Leu1007fsinsC) in the gene were demonstrated to be associated with CD. We collected a cohort of 231 patients with CD and 71 healthy control individuals from the Canadian province of Quebec, to determine the prevalence of these sequence variants in an independent population. Clinical records of all patients were systematically reviewed, and detailed phenotypic information was obtained. All patient DNA samples were genotyped for the three variants, thus enabling an analysis of genotype-phenotype correlations. In this cohort, 45.0% of patients with CD carried at least one variant in the CARD15 gene, compared with 9.0% of control individuals (P<10-7). Allele frequencies of Arg702Trp, Gly908Arg, and Leu1007fsinsC were 12.9%, 5.2%, and 10.3% in patients with CD, compared with 4.2%, 0.7%, and 0.7% in control individuals, respectively. Importantly, CARD15 mutants were seen with equal frequency in patients with familial and sporadic CD. Analysis of the relationship between genotype and phenotype convincingly demonstrates that CARD15 variants are significantly associated with ileal disease involvement, as opposed to strictly colonic disease (P<.001). Moreover, we were able to determine the haplotype structure surrounding this disease gene by genotyping 45 single-nucleotide polymorphisms (SNPs) in a 177-kb region that contained the CARD15 gene. This structure helps clarify the history of these causal mutations. Finally, this analysis shows that CARD15 involvement with CD is detectable by use of publicly available SNPs alone.

Epidemiology of inflammatory bowel disease--methodological considerations

The causes and mechanisms of action of inflammatory bowel disease have, so far, eluded discovery. Epidemiological studies have shown that ulcerative colitis tends to level off, whereas Crohn's disease tends to increase. Some of these changes may be due to diagnostic practices and increasing awareness of the disease and Crohn's colitis. The disease varies according to geographical location and a distribution along a north-south axis has been suggested. The differences may be due to study design, or may reflect differences in lifestyle, diet or be due to genetic predisposition triggered by environmental factors. Epidemiological studies designed to investigate such interactions may provide clues to its aetiology. Inflammatory bowel disease could, therefore, serve as a model for the importance of epidemiology when to test or reject the hypothesis of aetiology.

Epidemiology of inflammatory bowel disease

The incidence of IBD has either continued to increase or has stabilized at a high rate in most developed countries, whereas the incidence continues to rise in regions where IBD had been less common. The prevalence has continued to increase as a result of a combination of previously rising incidence and improved survival. Regardless of the exact prevalence, the burden of disease in North America and Europe is significant. Studying the patterns of geographic variation and age and gender distribution may yield important clues to the cause of IBD.

The epidemiology and natural history of Crohn's disease in population-based patient cohorts from North America: a systematic review

AIM

To quantify, through systematic review, the epidemiology and natural history of Crohn's disease in North America.

METHODS

The selected articles contained: (i) population-based samples of patients followed from the time of diagnosis; and (ii) objective diagnostic criteria for disease. Studies on the natural history of Crohn's disease also contained sufficient follow-up.

DATA COLLECTION AND ANALYSIS

For prevalence studies, data on the incidence, prevalence, gender and age at diagnosis were extracted. For natural history studies, data on the disease activity, use of medications and surgery were extracted.

MAIN RESULTS

The prevalence of Crohn's disease in North America ranges from 26.0 to 198.5 cases per 100,000 persons. The incidence rates range from 3.1 to 14.6 cases per 100,000 person-years. Most patients have a chronic intermittent disease course, while 13% have an unremitting disease course and 10% have a prolonged remission. Less than half require corticosteroids at any point. During any given year, approximately 10% are treated with corticosteroids and 30% are treated with 5-aminosalicylates. Up to 57% of patients require at least one surgical resection.

CONCLUSIONS

Between 400,000 and 600,000 patients in North America have Crohn's disease, and the natural history is marked by frequent exacerbations requiring treatment with corticosteroids, 5-aminosalicylate products and surgery.

Crohn's disease and Mycobacterium avium subsp. paratuberculosis: current issues

Crohn's disease is a chronic debilitating inflammatory bowel disease of unknown etiology. Proposed causes include bacterial or viral infection, diet or exposure to tobacco smoke, genetic abnormality, and immune dysfunction. The bacterium Mycobacterium avium subsp. paratuberculosis (Map) has received much research attention as a potential cause of the disease. Map causes Johne's disease in ruminants. The pathology of Johne's disease superficially resembles that of Crohn's disease in humans. Some researchers have shown evidence of Map in intestinal tissues of Crohn's disease patients. Studies are in progress to investigate the possibility that Map exists in milk from infected cows and survives pasteurization. This is a controversial subject with the potential for media attention and public outcry. We examined the current literature and concluded that insufficient evidence exists at this time to implicate any one factor, including Map in milk, as the definitive cause of Crohn's disease. The high degree of uncertainty in this issue requires regulators to recognize the need for effective risk communication as ongoing research provides additional information about the disease.

Epidemiology of inflammatory bowel disease in Asia

Studies of Asians in Asia show relatively low incidence rates for ulcerative colitis and Crohn's disease compared with North America and Europe. The prevalence of ulcerative colitis in migrant South Asians in Europe is similar to Europeans, whereas the prevalence of Crohn's disease for migrant South Asians in Europe is decreased compared with Europeans. The prevalence for both ulcerative colitis and Crohn's disease in Japan and Korea is relatively low. There are no obvious differences in age or sex distribution or rates of familial aggregation, and there are no significant differences in the clinical characteristics and natural history of ulcerative colitis and Crohn's disease in Asians compared with other racial groups with inflammatory bowel disease.

Medical treatment: does it influence the natural course of inflammatory bowel disease?

It is difficult to predict the clinical course of inflammatory bowel disease (IBD). Moderately sick Crohn's disease (CD) patients and patients with distal ulcerative colitis (UC) may get better even without medical or surgical treatment. Once better, they may continue in remission even without treatment. If they are not treated, there are several factors that predict whether they will maintain remission. Most patients will probably alternate between remission and relapse, with 10% having a relapse-free course after 10 years, and only 1% having a continuously active course. Frequent relapses initially are associated with active disease later on, but the disease activity course is independent of the response to the initial medical treatment. There is a cumulative frequency of operation of 50-80% and of reoperation of 33% in CD, which suggests that CD has a more serious course than UC. In UC, the overall probability of surgery is 33% for pancolitis and 10% for proctitis within 5 years of diagnosis, and the majority of patients are operated on within the first few years. Maintenance treatment with sulphasalazine (SASP) and 5-aminosalicylic acid (5-ASA) in UC has reduced relapse rates to about half over a 1-year follow-up period. The use of 5-ASA for maintenance of CD has been shown to result in only a modest therapeutic gain, while azathioprine and 6-mercaptopurine (6-MP) improve the relapse frequency for at least 3 years whilst on treatment. Changes in disease distribution in UC are part of the natural course of the disease, which should have implications for medical treatment strategies, and affects the risk of colectomy and colonic cancer. Certain enviromental factors are thought to determine disease activity and disease outcome in UC and CD. Patient compliance with prescribed medication and clinical check-ups must be considered another non-specific variable affecting the clinical outcome. IBD frequently requires potent medication with side effects that limit patients' acceptance. Such patients often resort to medicinal herbs, acupuncture, and homeopathy, which may alter the expected course.

Military history of patients with inflammatory bowel disease: an epidemiological study among U.S. veterans

OBJECTIVES

The military history of patients with inflammatory bowel disease (IBD) contains types of exposure that are not available through other sources and may provide clues about the as-yet unknown etiology of IBD. We therefore sought to describe the epidemiology of IBD among veterans, with particular emphasis on their military history.

METHODS

A case-control study compared 10,544 IBD patients and 42,026 controls with respect to age, gender, ethnicity, time period of military service, military duty in Vietnam, status as prisoner of war, and exposure to Agent Orange.

RESULTS

Subjects with Crohn's disease were younger than those with ulcerative colitis or without IBD (odds ratio: 0.85; 95% confidence interval [CI]: 0.83-0.87). Both types of IBD affected female veterans significantly more often than male veterans, the relative female predominance being more pronounced in Crohn's disease than ulcerative colitis (0.70; 0.61-0.81 vs 0.83; 0.71-0.96). Whites were more prone to develop both types of IBD than nonwhites (2.46; 2.27-2.68 vs 2.11; 1.95-2.27). Military duty in Vietnam and a status as prisoner of war both exerted a protective influence against Crohn's disease (0.84; 0.75-0.96 and 0.60; 0.41-0.87, respectively), but not ulcerative colitis.

CONCLUSIONS

The results are consistent with the hypothesis that exposure to poor sanitation decreases the future risk of developing Crohn's disease.

Crohn's disease in Olmsted County, Minnesota, 1940-1993: incidence, prevalence, and survival

BACKGROUND & AIMS

Many centers worldwide have reported an increased incidence of Crohn's disease, but population-based data in North America are sparse. We studied the incidence and prevalence of Crohn's disease in Olmsted County, Minnesota, and examined temporal trends in incidence and survival.

METHODS

Residents diagnosed with Crohn's disease between 1970 and 1993 were incidence cases, and residents with Crohn's disease who were alive on January 1, 1991, were prevalence cases. Cases from previous studies were reconfirmed. Rates were adjusted using 1990 U.S. Census figures for whites. Incidence trends were evaluated with a Poisson regression model. Survival from diagnosis was compared with that expected for U.S. north-central whites.

RESULTS

Between 1940 and 1993, 225 incidence cases were identified, for an adjusted incidence rate of 5.8 per 100,000 person-years. On January 1, 1991, there were 145 residents with Crohn's disease, an adjusted prevalence rate of 133 per 100,000, 46% higher than that seen in 1980. Incidence rates before 1964 were significantly lower than those of 1989-1993. Observed survival was less than expected (P = 0.007).

CONCLUSIONS

The incidence of Crohn's disease has stabilized since the 1970s at a rate higher than that seen previously. Prevalence has increased by 46% since 1980. Overall survival is slightly decreased.

Multiple sclerosis patients have peripheral blood CD45RO+ B cells and increased intestinal permeability

Increased intestinal permeability and the CD45RO isoform expression of the leukocyte common antigen on peripheral blood CD20+ B cells are found in Crohn's disease. Others have observed that multiple sclerosis (MS) patients may have an increased risk of coacquisition of Crohn's disease. The aim of this study was to identify an association between these diseases using peripheral blood CD45 isoform expression and intestinal permeability in MS. Lactulose/mannitol permeability and peripheral blood CD20+ B cell CD45RO expression were defined in healthy controls, MS patients, and patients coincidentally affected by MS and Crohn's or MS and ulcerative colitis (UC). Five of 20 MS patients had increased intestinal permeability, a finding not previously reported. High levels of CD45RO were found on circulating CD20+ B cells from patients with MS. This has not been reported previously in MS and is found in very few other conditions. Eight patients with coincident MS and Crohn's disease or MS and UC were studied. Coincident MS and UC patients expressed CD45RO on CD20+ B cells, a finding not identified in UC patients alone. A subgroup of MS patients has increased intestinal permeability. These patients express CD45RO CD20+ B cells, also found in Crohn's disease.

Incidence of Crohn's disease in four counties in southeastern Norway, 1990-93. A prospective population-based study. The Inflammatory Bowel South-Eastern Norway (IBSEN) Study Group of Gastroenterologists

BACKGROUND

Standardized criteria for Crohn's disease (CD) have only recently been developed, and prospective community-based incidence studies have been performed only during the past 3 decades. Geographic variations in incidence may therefore be due to differences in study design.

METHODS

From 1 January 1990 to 31 December 1993 all new cases of CD in four counties in southeastern Norway were prospectively registered.

RESULTS

A total of 225 new cases yielded an annual incidence of 5.8/10(5), with the highest incidence in mixed rural-urban areas. A peak of 11.2/10(5) in the annual incidence was found for the age group 15 to 24 years, with no significant differences in the overall annual incidence by gender. An average duration of 6 months of disease before diagnosis was unchanged during the 4 years. About half of the patients had isolated colonic disease, and one-quarter had isolated small-bowel disease.

CONCLUSIONS

This study confirms the high incidence figures for Scandinavia, with a particularly high incidence in mixed rural-urban areas. Ileocolonoscopy improves the accuracy of the diagnosis and of the determination of disease extent, which may have therapeutic implications for the treatment and follow-up of patients.

Incidence of ulcerative colitis and indeterminate colitis in four counties of southeastern Norway, 1990-93. A prospective population-based study. The Inflammatory Bowel South-Eastern Norway (IBSEN) Study Group of Gastroenterologists

BACKGROUND

The incidence of ulcerative colitis (UC) has been difficult to interpret because prospective studies have only been performed during the past 3 decades. Geographic variations may therefore be due to differences in study design.

METHOD

From 1 January 1990 to 31 December 1993 all new cases of UC in four counties in southeastern Norway were prospectively registered. Cases diagnosed as indeterminate colitis (IND) when endoscopy and histopathology were inconclusive or diverged with regard to diagnosis of UC or Crohn's disease (CD) were also included in the study.

RESULTS

A total of 525 cases of UC and 93 cases of IND yielded an mean annual incidence of 13.6/10(5) and 2.4/10(5), respectively. There were differences in incidence between counties, and a peak of 21.5/10(5) in the annual incidence was found for the age group 25 to 34 years in UC. The distribution was about equal for each of the groups proctitis and left-sided and extensive colitis. The time interval from onset of symptoms to diagnosis was 4 months.

CONCLUSION

In this study one of the highest incidences of UC in the world has been found. The classification 'indeterminate colitis' seems reasonable to use in some of the cases to prevent misclassification at the initial stage of diagnosis.

Inflammatory bowel disease in older patients

The onset of UC and CD may occur later in life. Although making the diagnosis of IBD in the elderly can be challenging, the clinical course, natural history, and response to treatment are similar for older and younger patients. In fact, both UC and CD tend to be less extensive in older patients, a feature that may contribute to the overall favorable prognosis for elderly patients with IBD. Overall mortality rates for both UC and CD appear to be similar to that of the general population except for those few patients that present with severe initial disease. Typical features of IBD in the elderly are summarized in Table 3. The differential diagnosis of IBD in the elderly includes infectious causes of enterocolitis, ischemic colitis, and diverticular disease as well as several other mimics of IBD. Awareness of the possibility of late-onset disease and the unique manifestations of disease in the elderly contributes to accurate diagnosis and timely treatment.

Has smoking changed the epidemiology of ulcerative colitis?

The influence of smoking on the risk of developing ulcerative colitis is well documented. Compared with lifetime non-smokers, the risk is reduced in smokers and increased in ex-smokers. During the past 50 years general smoking habits have changed considerably. The proportions of smokers and ex-smokers among men and women have undergone significant changes and, consequently, probably also their risk of ulcerative colitis. A review of 56 earlier epidemiologic studies of ulcerative colitis from 1930 to 1990 showed that the sex distribution in ulcerative colitis has changed from an earlier female predominance that has now been replaced by a male predominance. In contemporary pediatric studies no such changes were seen. We propose that these changes in adults are not related to the disease per se but to an extrinsic factor affecting adults but not children--namely smoking.