Inflammatory bowel disease: an uncommon problem in Singapore

A Systematic Review on the Increasing Incidence of Inflammatory Bowel Disease in Southeast Asia: Looking Beyond the Urbanization Phenomenon

The incidence of inflammatory bowel disease (IBD) has been increasing in Southeast Asia (SEA) in tandem with its economic growth and urbanization over the past 2 decades. Specific characteristics of IBD in SEA are similar to East Asia and the West, such as the declining ratio of ulcerative colitis to Crohn's disease. However, exceptionally low familial aggregation is seen. Smoking is also not a common risk factor in patients with Crohn's disease. The incidence of perianal disease is higher in SEA than in Australia and is comparable to the West. In a multiracial population, such as Singapore and Malaysia, Indians have the highest incidence and prevalence rates, which are likely to be due to important putative mutations. For instance, a higher frequency of the NOD2 predisposing mutation SNP5 and IBD risk allele IGR2198a and IGR2092a were found in Indians. Although differences in the genetic constitution play an important role in the epidemiology and prognosis of IBD in SEA, the emergence of this disease offers a unique opportunity to identify potential exposomes that contribute to its pathogenesis.

Defining and measuring multimorbidity in primary care in Singapore: Results of an online Delphi study

Multimorbidity, common in the primary care setting, has diverse implications for both the patient and the healthcare system. However, there is no consensus on the definition of multimorbidity globally. Thus, we aimed to conduct a Delphi study to gain consensus on the definition of multimorbidity, the list and number of chronic conditions used for defining multimorbidity in the Singapore primary care setting. Our Delphi study comprised three rounds of online voting from purposively sampled family physicians in public and private settings. Delphi round 1 included open-ended questions for idea generation. The subsequent two rounds used questions with pre-selected options. Consensus was achieved based on a pre-defined criteria following an iterative process. The response rates for the three rounds were 61.7% (37/60), 86.5% (32/37) and 93.8% (30/32), respectively. Among 40 panellists who responded, 46.0% were 31-40 years old, 64.9% were male and 73.0% were from the public primary healthcare setting. Based on the findings of rounds 1, 2 and 3, consensus on the definition of a chronic condition, multimorbidity and finalised list of chronic conditions were achieved. For a condition to be chronic, it should last for six months or more, be recurrent or persistent, impact patients across multiple domains and require long-term management. The consensus-derived definition of multimorbidity is the presence of three or more chronic conditions from a finalised list of 23 chronic conditions. We anticipate that our findings will inform multimorbidity conceptualisation at the national level, standardise multimorbidity measurement in primary care and facilitate resource allocation for patients with multimorbidity.

Paediatric inflammatory bowel disease in a multiracial Asian country

INTRODUCTION

This study examined the characteristics and trends in the incidence of inflammatory bowel disease (IBD) among children in Singapore.

METHODS

We retrospectively reviewed all patients under 18 years diagnosed with IBD over a 14-year period. Information on demographics, disease presentation, laboratory findings, radiological investigations, and endoscopic and histological findings were obtained from the patients' medical records.

RESULTS

32 patients were diagnosed with IBD, 30 of whom had Crohn's disease and 2 had ulcerative colitis. The incidence of IBD rose from an initial rate of 2.2 per 100,000 patients in the year 2000 to a peak of 11.4 patients per 100,000 patients by 2008. Median age of onset of symptoms was 10.5 years. There were more boys (63%) than girls in the group and a higher representation of Indians (34.4%). The most common presenting symptoms were abdominal pain (87.5%), diarrhoea (75.0%) and weight loss (71.9%). Extraintestinal manifestations such as fever and arthralgia were found in over 50% of patients. The most common physical findings were perianal abnormalities (56.3%), mouth ulcers (37.5%) and growth failure (15.6%). Abnormal laboratory findings such as low albumin, raised erythrocyte sedimentation rate, anaemia, thrombocytosis and high C-reactive protein were found in nearly half of the patients. Endoscopic and histological findings showed that a majority of patients (90.6%) also had evidence of inflammation in the upper gastrointestinal tract.

CONCLUSION

Paediatric IBD is on the rise. The higher occurrence in Indians, earlier onset and more florid presentation may suggest different genetic and environmental influences specific to Asian children.

Emerging inflammatory bowel disease in saudi outpatients: a report of 693 cases

BACKGROUND/AIM

Inflammatory bowel disease (IBD) is a chronic disease of unknown etiology and considered traditionally as a disease of the western world. Recently, rising trends have been observed in countries previously known to have a low prevalence and incidence. The aim of this study is to collect epidemiological data on IBD outpatients and to add data from the Kingdom of Saudi Arabia (KSA) to the available IBD literature.

PATIENTS AND METHODS

The medical records of 693 Saudi patients with IBD over a period of 17 years, between 1993 and 2009, were reviewed. The demographic and clinical data and methods of diagnosis were retrieved.

RESULTS

The total number of patients in this cohort was 693. It constituted 238 (34.3%) ulcerative colitis (UC) and 455 (65.7%) Crohn's disease (CD) patients. UC was steady throughout the years, whereas only 1.2 CD patients were diagnosed per year in the first 11 years, and 73.7 per year in the last six years. The median age of UC patients was 34 years, ranging from 10 to 80 years with a peak between 21 and 40 years and in CD it was 27 years, ranging from 11 to 73 years with a peak between 11 and 30 years. There was a male preponderance of 1.5:1 and 2:1, respectively. The rest of the data is discussed in this study.

CONCLUSION

IBD is no longer a rare disease in KSA. UC is in a steady state, whereas CD is increasing significantly and far outnumbering UC.

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.

Stress and animal models of inflammatory bowel disease--an update on the role of the hypothalamo-pituitary-adrenal axis

Chronic psychosocial stress has been repeatedly shown in humans to be a risk factor for the development of several affective and somatic disorders, including inflammatory bowel diseases (IBD). There is also a large body of evidence from rodent studies indicating a link between stress and gastrointestinal dysfunction, resembling IBD in humans. Despite this knowledge, the detailed underlying neuroendocrine mechanisms are not sufficiently understood. This is due, in part, to a lack of appropriate animal models, as most commonly used rodent stress paradigms do not adequately resemble the human situation and/or do not cause the development of spontaneous colitis. Therefore, our knowledge regarding the link between stress and IBD is largely based on rodent models with low face and predictive validity, investigating the effects of unnatural stressors on chemically induced colitis. These studies have consistently reported that hypothalamo-pituitary-adrenal (HPA) axis activation during stressor exposure has an ameliorating effect on the severity of a chemically induced colitis. However, to show the biological importance of this finding, it needs to be replicated in animal models employing more clinically relevant stressors, themselves triggering the development of spontaneous colitis. Important in view of this, recent studies employing chronic/repeated psychosocial stressors were able to demonstrate that such stressors indeed cause the development of spontaneous colitis and, thus, represent promising tools to uncover the mechanisms underlying stress-induced development of IBD. Interestingly, in these models the development of spontaneous colitis was paralleled by decreased anti-inflammatory glucocorticoid (GC) signaling, whereas adrenalectomy (ADX) prior to stressor exposure prevented its development. These findings suggest a more complex role of the HPA axis in the development of spontaneous colitis. In the present review I summarize the available human and rodent data in order to provide a comprehensive understanding of the biphasic role of the HPA axis and/or the GC signaling during stressor exposure in terms of spontaneous colitis development.

Prevalence of inflammatory bowel disease in two districts of Sri Lanka: a hospital based survey

Background

Inflammatory bowel disease (IBD) is being increasingly diagnosed in Asia. However there are few epidemiological data from the region.

Methods

To determine prevalence and clinical characteristics of IBD, a hospital-based survey was performed in the Colombo and Gampaha districts (combined population 4.5 million) in Sri Lanka. Patients with established ulcerative colitis (UC) and Crohn's disease (CD), who were permanent residents of these adjoining districts, were recruited from hospital registries and out-patient clinics. Clinical information was obtained from medical records and patient interviews.

Results

There were 295 cases of IBD (UC = 240, CD = 55), of which 34 (UC = 30, CD = 4) were newly diagnosed during the study year. The prevalence rate for UC was 5.3/100,000 (95% CI 5.0-5.6/100,000), and CD was 1.2/100,000 (95% CI 1.0-1.4/100,000). The incidence rates were 0.69/100,000 (95% CI 0.44-0.94/100,000) for UC and 0.09/100,000 (95% CI 0.002-0.18/100,000) for CD. Female:male ratios were 1.5 for UC and 1.0 for CD. Mean age at diagnosis was (males and females) 36.6 and 38.1y for UC and 33.4 and 36.2y for CD. Among UC patients, 51.1% had proctitis and at presentation 58.4% had mild disease. 80% of CD patients had only large bowel involvement. Few patients had undergone surgery.

Conclusions

The prevalence of IBD in this population was low compared to Western populations, but similar to some in Asia. There was a female preponderance for UC. UC was mainly mild, distal or left-sided, while CD mainly involved the large bowel.

Inflammatory bowel disease: a survey of the epidemiology in Asia

Inflammatory bowel disease (IBD) has long been considered a disease that affects predominantly a Western population. The incidence and prevalence rates from Asian populations are much lower in comparison. More recent data, however, have shown significantly higher rates in Asians and time trend studies have shown an increase in the incidence of ulcerative colitis (UC) and a similar but lower rise in Crohn's disease (CD). The epidemiological changes that are taking place mirror that of the Western experience seen 50 years previously and seem to occur in parallel with the rapid socioeconomic development taking place in Asia. It appears that certain racial groups are more prone than others to develop IBD. For instance, Indians in South-East Asia have higher rates compared to Chinese and Malays. While there is host genetic predisposition, environmental factor(s) may be responsible for this difference. Migrant studies of South Asians in the UK, where second-generation immigrants have assumed incidence rates as high as the indigenous whites and Asian Jews who develop high incidence rates comparable to Jews from Europe or North America in Israel point to the role of environmental factors. It is unclear which specific factors are responsible. Studies have suggested a change in diet to a more Westernized one may underlie this epidemiological change in the Asian population. It is likely that there are racial groups amongst Asians who are more susceptible to IBD and who will demonstrate a higher frequency of IBD when exposed to putative environmental factors.

Inflammatory bowel diseases: A disease (s) of modern times? Is incidence still increasing?

Inflammatory bowel diseases (IBD) are a heterogeneous group of diseases, not always easy to diagnose, even more difficult to classify, and diagnostic criteria are not always uniform. Well done population-based studies are not abundant, and so comparisons among different geographical areas or populations are not always very reliable. In this article, we have reviewed epidemiological studies available on the world’s population while making a critical review of published data.

Epidemiology and clinical characteristics of ulcerative colitis in Chinese population: experience from a single center in Hong Kong

BACKGROUND AND AIM

Rising incidence and prevalence of ulcerative colitis (UC) had been observed in Asian countries. We conducted a study in an Asian center, aiming to describe the epidemiology and clinical characteristics of UC in local Chinese population.

METHODS

This is a retrospective analysis of patients with diagnosis of UC in our hospital from June 1990 to December 2006. The diagnosis of UC has to satisfy the internationally accepted criteria. All patients were Chinese residents in a well-defined catchment area. Clinical and epidemiological data were obtained from medical records and patient interviews.

RESULTS

Seventy-three Chinese UC patients had been managed in our hospital. The hospital-based prevalence had risen by three times over a 10-year period, but no definite rising incidence can be demonstrated. The mean age at diagnosis was 40.6 years and the median duration of disease is 72 months. In our patient cohort, 38.4% had ulcerative proctitis and 26% had left-sided UC, whereas 35.6% had extensive UC at presentation. The majority presented with mild (39.7%) or moderate (30.2%) disease activity, but 27.4% presented with severe disease. Two patients (2.7%) present with fulminant disease with one of them developed toxic megacolon. Extra-gastrointestinal manifestations occurred in 13.7%. During the follow-up period, most patients (86.3%) were in disease remission. Four patients (5.5%) underwent colectomy, four patients (5.5%) died, and two patients (2.7%) were lost to follow up.

CONCLUSION

The prevalence but not the incidence of UC is rising in Chinese population. It usually affects young patients and a substantial proportion of patients presented with severe and fulminant disease. The disease activity of most Chinese patients can be controlled with medical treatment, though a small proportion of patients need surgery or have fatal outcome.

Ulcerative colitis in China: retrospective analysis of 3100 hospitalized patients

BACKGROUND AND AIMS

This retrospective study analyzed the clinical characteristics of hospitalized patients with ulcerative colitis (UC) in China.

METHODS

A total of 3100 hospitalized patients with UC admitted to 23 hospitals in China from 1990 to 2003 were retrospectively investigated and their clinical characteristics were analyzed.

RESULTS

A male/female ratio of 1.34/1.00 was found in the 3100 patients, who had an average age of 44 +/- 15.1 years at diagnosis. Of the patients, 2972 (95.9%) had active UC. Active UC was mild in 35.4% of the 2972 patients, moderate in 42.9% and severe in 21.7%. Of the 2726 patients with a description of their lesion extent, 14.8% had proctitis, 26.4% had proctosigmoiditis, 25.0% had left-sided colitis, 6.3% had extensive colitis, 25.8% had pancolitis and 1.7% had regional colitis. The predominant complaints of the patients with UC were bloody diarrhea (48.2%), abdominal pain (67.3%) and mucus stools (58.4%). Among these patients, 13.6% had extraintestinal manifestations and 9.6% had related complications. A differential diagnosis was difficult to make, as there were 19 varieties of the disease; infectious enterocolitis had a misdiagnosis rate of 22.9% before admission. The main medications for UC in China were aminosalicylates (66.8%) and steroids (42.8%). Only 94 (3%) of the patients required colectomy and only 19 (0.6%) died of UC.

CONCLUSIONS

Compared with UC in Western countries, ulcerative colitis in China has some differences in clinical characteristics. Therefore, a further population-based epidemiological study is required to determine the prevalence and incidence rates of UC in China.

Functional bowel disorders in rotating shift nurses may be related to sleep disturbances

OBJECTIVES

To compare the frequency and severity of bowel disturbances between rotating shift and regular day nurses and to determine whether functional bowel disorders (FBD) were related to sleep disturbances.

METHODS

Sixty regular day and 58 rotating shift nurses answered three standardized questionnaires: the Gastrointestinal Symptom Questionnaire; the Hospital Anxiety and Depression Scale; and the Irritable Bowel Syndrome Symptoms Evaluation Questionnaire, which included the Sleep Questionnaire, on the frequency and severity of gastrointestinal symptoms, sleep disturbances and psychological distress. Responses to these questions were numerically rated and the sums of individual symptom scores under the respective categories were computed and analysed using statistical tests, as appropriate.

RESULTS

Although 22 out of 58 rotating shift nurses (38%) had FBD, only 12 out of 60 regular day nurses (20%) had it (P=0.04). The mean FBD symptom score (P<0.002), sleep disturbance score (P<0.0001) and anxiety score (P<0.002) were all significantly higher among the rotating shift nurses. FBD symptom scores were positively correlated with the sleep disturbance (P=0.0001), anxiety (P=0.0001), depression (P=0.0001), well-being (P=0.0001), fatigue (P=0.0001), and somatic pain scores (P=0.0001). Sleep disturbance (P=0.04), decreased well-being (P=0.04), anxiety (P=0.02), and somatic pain (P=0.03) were independent predictors of FBD symptoms.

CONCLUSION

FBD were more common and severe among rotating shift nurses. The FBD symptom score was positively and independently correlated with the sleep disturbance score, suggesting that poor sleep might be associated with increased FBD symptoms in rotating shift nurses.

Crohn’s disease in adults: Observations in a multiracial Asian population

AIM: To determine the demography and clinical presentation of CD and secondly to determine any differences in the prevalence between the different ethnic groups in a multiracial Asian population.

METHODS: Patients with CD who were seen in 2001–2003 in the University of Malaya Medical Centre (UMMC) were enrolled in this study. Prevalence of disease was calculated for the group as a whole and by race with hospital admissions per ethnic group as the denominator.

RESULTS: Thirty-four patients were diagnosed to have CD. Basic demographic data of patients; male:female 17:17; mean age 29.1 years (±13.5 years); ethnic group: Malays 5 (14.7%), Chinese 12 (35.3%) and Indians 17 (50%). Twenty-six (76.5%) were diagnosed under the age of 40 and 8 (23.5%) were diagnosed over the age of 40. Location of the disease was as follows: ileocolonic 13 (38.2%), terminal ileum only 9 (26.5%), colon only 8 (23.5%), and upper gastrointestinal 4 (11.8%). Sixteen (47.1%) had penetrating disease, 9 (26.5%) had stricturing disease and 9 (26.5%) had non-penetrating and non-stricturing disease. The hospital admission prevalence of CD was 26.0 overall, Indians 52.6, Chinese 6.9, and Malays 9.3 per 10⁵ admissions per ethnic group. The difference between Indians and Malays: [OR 5.67 (1.97, 17.53) P < 0.001] was statistically significant but not between the Indians and the Chinese [OR 1.95 (0.89, 4.35) P = 0.700]. The difference between the Chinese and the Malays was also not statistically significant. [OR 2.90 (0.95, 9.42) P = 0.063].

CONCLUSION: The clinical presentation of CD is similar to the Western experience. Although the overall prevalence is low, there appears to be a clear racial predominance among the Indians.

Crohn's disease runs a more aggressive course in young Asian patients

BACKGROUND

Crohn's disease is a heterogeneous inflammatory bowel disease. The impact of age at diagnosis on the clinical course of patients varies widely as reported in the Western literature. Using the Vienna Classification, we seek to determine whether young Crohn's disease patients in an Asian population followed a different clinical course than old patients.

METHODS

The case records of 100 Crohn's disease patients who were treated at the Inflammatory Bowel Disease Center, Singapore General Hospital, were studied retrospectively. The age group and location of disease and behavior according to the Vienna classification were determined at diagnosis.

RESULTS

A1 group (age <40 years) defined as "young" and A2 group (age > or =40) defined as "old" contained 65 and 35 patients, respectively. Median age for the young group was 27.4 years and that for the old group was 52.6 years. Of the young patients, 66.7% flared at least once compared with 28.6% of the old patients, odds ratio of 5.0 (P < 0.001). Young patients were more likely to be steroid dependent (20.0% of A1 versus 8.6% of A2, P = 0.14), received azathioprine (38.5% of A1 versus 5.7% of A2, P < 0.001) and experienced complications (31% of A1 versus 20% of A2, P = 0.25)-numerically higher rates that did not reach statistical significance. There was no significant difference between the age groups for the location and behavior of disease as well as requirement for surgery.

CONCLUSION

In this first Asian study looking specifically at the impact of age at diagnosis of Crohn's disease, we found that young patients underwent a more aggressive clinical course.

Ulcerative colitis in a multiracial Asian country: Racial differences and clinical presentation among Malaysian patients

AIM: TO determine the prevalence of ulcerative colitis (UC) in Malaysian patients and to establish the spectrum of the disease seen in Malaysian patients.

METHODS: Data were obtained retrospectively from a review of the medical records of in- and out-patients with a diagnosis of UC at the University Hospital, Kuala Lumpur between 1985 and 1998.

RESULTS: There were 45 confirmed cases of UC, of which 3 were foreigners, who were excluded from analysis. Thirty new cases of UC were diagnosed during the study period. Their mean age at presentation was 33.0 ± 10.0 years. The highest prevalence of UC was 17.9/100 000 hospital admissions in the Indians, followed by 11.2/100 000 hospital admissions in the Chinese. The lowest prevalence was 3.7/100 000 hospital admissions in the Malays. The prevalence of UC was significantly higher in the Indians and the Chinese when compared with the Malays with an OR of 4.89 (CI = 2.02-12.24; c2 = 15.45,P < 0.001) and 3.06 (CI = 1.24-7.78; c2 = 6.30; P = 0.012) respectively. The extent of colonic disease was similar in the Malay and Indian patients. In contrast, distal or left-sided colitis predominated in the Chinese with an OR of 8.17 (95%CI = 1.31-64.87; c2 = 5.53, P = 0.02). Extraintestinal manifestations were uncommon (11.9%).

CONCLUSION: UC is an uncommon disease in Malaysia, but racial differences exist. The Indians had the highest prevalence of UC with the Chinese demonstrating the least extensive disease.

The epidemiology and phenotype of Crohn's disease in the Chinese population

BACKGROUND

Inflammatory bowel disease is uncommon in Southeast Asia but is increasing in incidence. The epidemiology and phenotype of Crohn disease (CD) in the Chinese population is not well-known. The purpose of this study was to determine the incidence, temporal trend, clinical features, risk factors, extraintestinal manifestations, and the treatment of CD in the Chinese population of Hong Kong.

METHODS

We performed a single-center study of consecutive definite CD cases based on internationally accepted criteria, with strict exclusion of infective enterocolitis.

RESULTS

Eighty Chinese CD patients were recruited, characterized by male gender predominance (male:female ratio 2.5:1), no association with ever smoking (OR 1.02, 95% CI: 0.54-1.92), absence of familial clustering (0%), high proportion of upper gastrointestinal tract disease proximal to the terminal ileum (19%), and a low proportion of isolated terminal ileal disease (4%). The mean age at diagnosis was 33 years. Forty-five percent of patients had penetrating disease, 18% stricturing disease, and 37% had nonstricturing, nonpenetrating disease. Twenty-five percent of patients had at least 1 extraintestinal manifestation, and there was a high rate of ankylosing spondylitis (9%). The incidence of CD was 1.0 per 100,000 and has increased by 3 fold during the past decade. The age-adjusted incidence was 3.0 per 100,000 (95% CI: 2.3-3.7 per 100,000).

CONCLUSIONS

The incidence of CD in the Chinese is increasing. There are some notable epidemiological and phenotypic differences between Chinese CD with Caucasian CD including the lack of familial clustering, male predominance, and higher proportion of upper GIT involvement and lower frequency of isolated terminal ileal disease.

Review article: helminths as therapeutic agents for inflammatory bowel disease

Over the last decade major advances have been made in our understanding of the mechanisms and mediators of inflammation that hold the promise of the development of new therapies for inflammatory disease. While much is to be gleaned from the application of new technologies, assessment of the age-old host-parasite relationship may also provide insights on how to counter pathological inflammatory events. In the case of inflammatory bowel disease [particularly Crohn's disease, which is associated with T helper 1 (Th1) events] it is proposed that infection with parasitic helminths would be beneficial: the paradigm being that of immune deviation, where Th2 cytokines mobilized in response to the helminth will prevent or antagonize the disease-promoting Th1 events in the gut. The situation is unlikely to be this simple. Here we review and critique the data in support of helminth therapy for inflammatory bowel disease, drawing attention to the gaps in knowledge and presenting a view on how the field may be advanced. While the concept of helminth therapy may be superficially unappealing, this review may convince the reader of the value of more extensive analyses of the impact of helminth infection on enteric inflammation.

Incidence and prevalence of ulcerative colitis in Punjab, North India

INTRODUCTION

Ulcerative colitis occurs worldwide. It is considered common in most of Europe and North America and uncommon in most of the developing Asian countries. The incidence/prevalence of ulcerative colitis varies not only according to geographical region but also with race and ethnicity. There are no reported data from India on the incidence of the disease and its prevalence.

MATERIAL AND METHODS

A house to house survey was conducted by questionnaire, formulated to enquire about symptoms that are suggestive of ulcerative colitis. Those with prolonged diarrhoea with or without rectal bleeding were considered as suspected cases. These suspected cases were subjected to video sigmoidoscopy/colonoscopy and rectal biopsy. In addition, patients already diagnosed and receiving treatment for ulcerative colitis, encountered during the survey, were reviewed. Resurvey of the same areas was conducted after a one year interval to detect new cases. Using direct methods, standardised rates were calculated using world standard population weights 22, 18, 16, 12, 12, 9, 7, 3, and 1 for each 10 year age group. Standardised rates were also obtained separately for males, females, and combined populations, using the Punjab state 1991 population census data. Rates were also estimated according to UK 2000 population data. Ninety five per cent confidence intervals (95% CI) of prevalence and incidence rates of ulcerative colitis were estimated under the assumption that the distribution of cases followed a Poisson probability model.

RESULTS

A total population of 51 910 were screened from January to March 1999. We identified 147 suspected cases and of these 23 were finally established as ulcerative colitis cases, giving a crude prevalence rate of 44.3 per 100 000 inhabitants (95% CI 29.4-66.6). A second visit to the same areas after one year identified 10 suspected cases in a population of 49 834. Of these, three were confirmed as "definite" ulcerative colitis giving a crude incidence rate of 6.02 cases per 100 000 inhabitants (95% CI 1.2-17.6).

CONCLUSIONS

This is the first population based study from India reporting on the incidence and prevalence of ulcerative colitis. The disease frequency is not much less than that reported from Europe and North America.

Intestinal nematode infection ameliorates experimental colitis in mice

Epidemiological studies suggest that inflammatory bowel disease (IBD) is common in developed countries and rare in countries where intestinal nematode infections are common. T cells are critical in many immune responses, including those associated with IBD and nematode infection. Among the distinct T helper (Th) cell subsets, Th1-type immune response is predominantly associated with Crohn's disease, while many nematode infections generate a strong Th2 response. The reciprocal cross regulation between Th1 and Th2 cells suggests that generation of a Th2 response by nematodes could prevent or reduce the effects of Th1-mediated diseases. In the present study, we investigated the effect of polarizing the immune response toward the Th2 type, using intestinal nematode infection, on subsequent experimental colitis. Mice were infected with the intestinal nematode Trichinella spiralis and allowed to recover before colitis was induced with dinitrobenzene sulfonic acid. The mice were sacrificed postcolitis to assess colonic damage macroscopically, histologically, and by myeloperoxidase (MPO) activity and Th cytokines. Prior nematode infection reduced the severity of colitis both macroscopically and histologically together with a decreased mortality and was correlated with a down-regulation of MPO activity, Th1-type cytokine expression in colonic tissue, and emergence of a Th2-type immune response. These results indicate a protective role of nematode infection in Th1 cell-driven inflammation and prompt consideration of a novel therapeutic strategy in IBD based on immunological distraction.

Clinical characteristics of ulcerative colitis in Singapore, a multiracial city-state

BACKGROUND

Ulcerative colitis (UC) is rare in Asia. Singapore is an ethnically heterogeneous city-state with a population made up of Chinese (77%), Indians (7.5%), and Malays (14%). This study describes and compares the characteristics of Chinese, Malay, and Indian patients with UC.

STUDY

Retrospective chart review was performed of 235 patients seen in the largest tertiary care hospital in Singapore between 1971 and June 2000.

RESULTS

There were 169 (72%) Chinese, 24 (10%) Malays, and 42 (18%) Indians with UC. Male-to-female ratio was 1.8:1 (150:85). Most patients in all three races presented between the ages of 20 and 39 years. No bimodal peak in the age at presentation was seen. The median period from onset of symptoms to diagnosis was 1 month in all three races. More Malay (57%) and Indian (55%) patients had colitis extending proximal to splenic flexure at presentation compared with Chinese (32%) patients (p = 0.04). There were more Indian patients (29%) with severe disease at onset compared with Chinese (12%) and Malay (22%) patients (p = 0.035). Thirty-one percent of patients had only one episode of colitis, 12% were steroid dependent, and 4% were steroid refractory. Proctocolectomy was needed in 31 (18.3%) Chinese, 3 (12.5%) Malay, and 4 (9.5%) Indian patients. Extraintestinal manifestations were found in 6% of the Chinese, 12% of Malay patients, and 14% of Indian patients. The most common extraintestinal manifestation was arthritis, present in 6.4% of patients.

CONCLUSION

There were more Indians with UC than expected in this population. Whereas Indian and Malay patients have more extensive and severe disease at presentation than Chinese patients, this does not predict for more refractory disease or a greater need for surgery.

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.

Does the failure to acquire helminthic parasites predispose to Crohn's disease?

Two polarized patterns (Th1 and Th2) of cytokines regulate inflammatory responses. Each cytokine pattern inhibits production of the opposing pattern. Lymphocytes from inflamed intestine due to Crohn's disease secrete a Th1 pattern of cytokines. Crohn's disease is most prevalent in highly industrialized countries with temperate climates. It occurs rarely in tropical third world countries with poor sanitation. We propose that exposure to an environmental agent predisposes individuals to Crohn's disease. Parasitic worms (helminths) are common in tropical climates and in populations subject to crowding and poor sanitation. Children are most subject to helminthic colonization. Many helminths live within or migrate through the human gut where they interact with the mucosal immune system. The host mounts a mucosal response that includes Th2 cytokine production limiting helminthic colonization. Helminths and their eggs probably are the most potent stimulators of mucosal Th2 responses. The Th2 response provoked by parasitic worms can modulate immune reactions to unrelated parasitic, bacterial, and viral infections. Many people in developed countries now live in increasingly hygienic environments, avoiding exposure to helminths. Perhaps failure to acquire these parasites and experience mucosal Th2 conditioning predisposes to Crohn's disease, which is an overly active Th1 inflammation.

Racial differences in the prevalence of ulcerative colitis and Crohn's disease in Singapore

BACKGROUND

The aim of this study was to determine the prevalence rates of inflammatory bowel disease in the different races in Singapore.

METHODS

The patients studied consisted of 58 people with an established diagnosis of ulcerative colitis (UC) and Crohn's disease (CD) as determined by a combination of clinical, radiological, endoscopic and histological criteria. The patients were residents of a well-defined geographical area in the northern part of Singapore and had been referred to the single regional hospital. Epidemiological data including sex, age, ethnicity, family history and disease type and extent were collected from case records and patient interviews.

RESULTS

There were 37 UC and 21 CD patients. Of the patients with UC, 67.5% were Chinese, 13.5% were Malay and 19% were Indian. The CD group consisted of 81% Chinese, 9.5% Malay and 9.5% Indian patients. The study population from which the patients were drawn was approximately 0.5 million in size.

CONCLUSIONS

The overall prevalence of UC was 6 per 100,000 and of CD was 3.6 per 100,000 in Singapore. There were disproportionately more Indians suffering from UC, with a prevalence of 16.2 per 100,000 in comparison with six per 100,000 for Chinese and seven per 100 000 for Malays. The relative risk of UC in Indians is 2.9-fold greater than for the Chinese (CI= 1.25-6.7) which was statistically significant. This trend was not seen for CD.

Prevalence of gastrointestinal symptoms in a multiracial Asian population, with particular reference to reflux-type symptoms

OBJECTIVE

Data on the epidemiology of chronic gastrointestinal symptoms in the East are limited. The aims of this study were to estimate the prevalence of chronic gastrointestinal symptoms in Singapore and to determine whether ethnic differences in the prevalence of these symptoms exist.

METHODS

A cross-sectional survey, using a reliable and valid questionnaire, was carried out in a race-stratified random sample of residents aged 21-95 yr (mean+/-SD, 40+/-1 yr) in a Singaporean town; 93% responded (n=696).

RESULTS

The ethnic-adjusted prevalence of chronic abdominal pain, frequent dyspepsia, irritable bowel syndrome, chronic constipation, chronic diarrhea, and frequent reflux were 5.7% (95% confidence interval [CI], 3.3-8.1), 7.9% (95% CI, 5.0-10.8), 2.3% (95% CI, 0.8-3.9), 3.9% (95% CI, 1.9-5.9), 4.5% (95% CI, 2.3-6.7), and 1.6% (95% CI, 0.6-2.6), respectively. There were no ethnic differences in the prevalence of any of these symptom categories except for reflux-type symptoms, which were more common among Indians (7.5%; 95% CI, 4.4-11.7) than Chinese (0.8%; 95% CI, 0.1-3.0) or Malays (3.0%; 95% CI, 1.26.1).

CONCLUSION

The prevalence of all types of chronic gastrointestinal symptoms in the general population of Singapore was low compared with those in the West. Chronic gastrointestinal symptoms were equally prevalent in the three major ethnic groups except for reflux-type symptoms, which were more common among Indians than Chinese or Malays.

Peptic ulcer disease in the 1990s: an Asian perspective

Peptic ulcer disease is still a common disease in many parts of Asia, although it is less common today than it was 2-3 decades ago. Contrary to this general trend, peptic ulcers are on the rise in the elderly, particularly elderly females. Two important factors that could explain the observed changes in the trends of peptic ulcer disease are: Helicobacter pylori and NSAID. The seroprevalence of H. pylori, determined in three previous studies, would appear to have decreased over the last few decades, while NSAID and aspirin are used increasingly for arthritis, cerebrovascular disease and coronary artery disease. The major complication of peptic ulcer disease is gastrointestinal haemorrhage and in the 1990s endoscopic haemostatic therapy has replaced surgery as the treatment of choice. Treatment of peptic ulcer disease caused by H. pylori is directed at eradication of H. pylori itself; four classes of drug regimens are currently available for this. Antibiotic resistance, particularly metronidazole resistance, is an important factor that determines the outcome of therapy. Metronidazole resistance is reported to be present in 50% of all strains of H. pylori in Hong Kong and Singapore, and is present in 80-90% of all strains in India. Eradication rates in Asia, may for this reason, differ from those in the West, if the regimen contains metronidazole. Treatment of NSAID-associated ulcer consists of discontinuation of NSAID, if possible, and administration of anti-secretory drugs such as H2 blockers, proton pump inhibitors or mucosal protective agents. Co-prescription with misoprostol has been shown to reduce the risk of NSAID-induced ulcer. New NSAID or NO NSAID are being developed with few gastrointestinal side effects.

The pattern of functional and organic disorders in an Asian gastroenterological clinic

The aim of the present study was to determine the pattern of structural and functional disorders encountered in an Asian gastroenterological clinic and to compare this pattern with findings from Western centres. Consecutive new patients (totalling 2384) attending the clinics of two consultant gastroenterologists were studied. Of these, 2141 suffered from gastroenterological problems. One thousand and sixty-three (49.6%) had structural diseases, the commoner ones being liver disease, peptic ulcer, malignancy, haemorrhoids and gallstones. The remainder who were found to have no structural disease (n = 1078; 50.4%) were deemed to have functional disorders including non-ulcer dyspepsia, irritable bowel, simple constipation and functional diarrhoea. The proportions of functional and structural disease were similar to those in the West. Major differences included a higher frequency of hepatoma and a lower frequency of inflammatory bowel disease and gastro-oesophageal reflux in the present series.