Authors: Leong RW, Lau JY, Sung JJ.

Institution: Department of Gastroenterology, The University of New South Wales, Bankstown-Lidcombe Hospital, Sydney, NSW, Australia. repertleong@hotmail.com

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.

Conclusion: 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. Copyright 2004 Lippincott Williams & Wilkins

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15472528&query_hl=35&itool=pubmed_docsum

Authors: Fonager K, Sorensen HT, Olsen J.

Institution: Danish Epidemiology Science Centre, University of Aarhus, Denmark.

Background: The incidence of inflammatory bowel disease (IBD) in Denmark is considered to be among the highest in Europe. However, the diseases are relatively rare and therefore it would be useful if existing registers could replace ad hoc examination in the surveillance of IBD.

Results: A total of 2806 patients with Crohn's disease (CD) and 8125 with ulcerative colitis (UC) were identified. The mean incidence for CD was 4.6 (5.4 for women and 3.7 for men) per 100,000 per year, with a peak incidence in younger women. The incidence increased in most age groups with the highest increase in older women. The mean incidence for UC was 13.2 (13.4 for women and 13.0 for men) per 100,000 per year, with the highest incidence in older men. A decreasing tendency in the incidence was present in most age groups.

Conclusions: The present study found an increasing incidence for CD and a stable incidence with a tendency to decrease for UC. Comparison with ad hoc studies indicates that it is possible to use the Danish National Registry of Patients in the surveillance of IBD, especially for CD.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9363521&query_hl=19

Authors: Bjornsson S, Johannsson JH.

Institution: Department of Medicine, Reykjavik Hospital, Iceland.

Background: Two separate nationwide, retrospective epidemiological studies of inflammatory bowel disease (IBD) in Iceland over a combined 40-year period, 1950-1989, have shown a continually rising incidence. The main objective of this study was to investigate the incidence of IBD prospectively for the 5-year period 1990-1994 to determine whether there still was an ongoing increase.

Results: A total of 215 cases of UC and 72 cases of CD were diagnosed, yielding a mean annual incidence for UC 16.5/100000 (95% confidence interval (CI) 14.4-18.9), and for CD 5.5/100000 (95% CI 4.3-7.0). The highest combined age related incidence for UC was 28.7/100000 in the group aged 30-39 years, and for CD 8.5/100000 in the groups aged 10-19 and 20-29 years. The most common extent in UC was proctosigmoid and the most frequent localization in CD was colonic only.

Conclusions: This prospective study demonstrates a continuing and statistically significant increase in the incidence of both UC and CD in Iceland. The general changes identified for a few previously suggested environmental factors do not allow any firm conclusions as to their role in the observed increase in incidence. It is possible that there are some other causative factor(s).

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10656207&query_hl=19

Authors: Bjornsson S, Johannsson JH, Oddsson E.

Institution: Dept. of Medicine, Reykjavik Hospital, Iceland.

Background: A previous nationwide epidemiologic study of inflammatory bowel disease (IBD) in Iceland in 1950-79 showed a low but steadily rising incidence. The incidence of IBD in Iceland in 1980-89 was investigated and compared with reports from neighboring countries.

Results: The mean annual incidence of ulcerative colitis (UC) was 11.7/100,000, and that of CD 3.1/100,000. The highest age-specific incidence of UC was in the group 30-39 years old and for CD in the group 60-69 years old. The most frequent involvement at diagnosis of UC was proctitis only, in 54%, and in CD colon only, in 54.7% of the patients.

Conclusions: This study shows a continuing increase in the incidence of both diseases. Compared with the period 1970-79, there has been an almost twofold increase in the mean annual incidence of UC and more than a threefold increase of CD, a statistically significant increase in both instances.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9489911&query_hl=11

Authors: Mate-Jimenez J, Munoz S, Vicent D, Pajares JM.

Institution: Department of Gastroenterology, Hospital de la Princesa, Universidad Autonoma de Madrid, Spain.

Summary: We retrospectively investigated the annual incidence and prevalence of inflammatory bowel disease (IBD) from 1981 to 1988 in an urban and a rural area of central Spain. Two hundred and eighty-one patients presented with IBD; 193 ulcerative colitis (UC) and 88 Crohn's disease (CD) (prevalence 43.4/100,000 and 19.8/100,000, respectively). Of these patients, 168 were diagnosed for the first time during the study period.

One hundred and eleven UC and 57 CD (incidence 3.16/100,000 and 1.61/100,000 respectively). Within the urban area, the UC incidence was 3.15/100,000 and the CD 1.87/100,000. In the rural area, the incidence for the UC was 3.25/100,000 and 0.86/100,000 for the CD. No sex differences were found. The incidence rates have increased significantly (p < 0.05) for CD in the study period. However, for UC rates did not change. During 1986-1988, the patient's age at the time of diagnosis was significantly lower than that of 1981-1983 (p < 0.05).

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8113581&query_hl=11

Authors: Molinie F, Gower-Rousseau C, Yzet T, Merle V, Grandbastien B, Marti R, Lerebours E, Dupas JL, Colombel JF, Salomez JL, Cortot A.

Institution: Registre des Maladies Inflammatoires Chroniques de l'Intestin (EPIMAD), Service d'Epidemiologie et de Sante Publique, Hopital Calmette, CHR&U de Lille, 59037 Lille Cedex, France.

Background: Northern France was characterised by a high incidence of Crohn's disease (CD) and a low incidence of ulcerative colitis (UC) according to the first inquiry undertaken in the late 1980s.

Results: During 1988-99, 7066 cases of IBD were recorded (56.8% CD, 37.7% UC, and 5.5% indeterminate colitis). Mean annual incidence rate of CD increased from 5.2/100,000 inhabitants in 1988-90 to 6.4 in 1997-99 (adjusted p for trend <0.001). In contrast, the incidence of UC decreased from 4.2 to 3.5 (adjusted p for trend <0.001). The ileocolonic subtype of CD increased by 25% even though median age at diagnosis and frequency of digestive investigations were not different.

Conclusions: Contrary to what has been reported in other countries in Northern Europe, the incidence of CD increased by 23% in 12 years in Northern France while that of UC decreased by 17% during the same period. This indicates that some factors which influence IBD frequency (in both directions) are still at work in this area of Europe, and that further studies aimed at identifying these should be performed. The rising incidence of CD could enhance the burden of this disease on the public health system in France.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15138211&query_hl=5

Authors: Manousos ON, Koutroubakis I, Potamianos S, Roussomoustakaki M, Gourtsoyiannis N, Vlachonikolis IG.

Institution: Dept. of Gastroenterology, University Hospital of Heraklion, Greece.

Background: There has been an impression from published work that Crohn's disease is less common in southern than in northern Europe. A low incidence of Crohn's disease has been observed in Greece, but conclusive data are still lacking.

Results: The mean annual incidence of the disease for the years 1990-94 was 3.0 per 10(5) inhabitants. During the study period the incidence increased from 1.9/10(5) in 1990 to 3.8/10(5) in 1994. The male to female ratio was 2.4:1. The age group 25-34 years had the highest age-adjusted incidence (6.3/10(5)). The incidence of Crohn's disease was also found to be higher in smokers, in urban areas, and in people with high educational level.

Conclusion: Crohn's disease is common in Heraklion, Crete. The findings of the study are discussed in relation to those of other European countries.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8789900&query_hl=2

Authors: Armitage E, Drummond HE, Wilson DC, Ghosh S.

Institution: Gastrointestinal Unit, Department of Medical Sciences, University of Edinburgh, Western General Hospital, Edinburgh, EH4 2XU, UK.

Objective: A previous study reported a three-fold rise in the incidence of juvenile-onset Crohn's disease in Scottish children and a marginal fall in ulcerative colitis between 1968 and 1983. The present study aimed to document the incidence of juvenile-onset inflammatory bowel disease between 1981 and 1995 and examine temporal trends between 1968 and 1995 in Scotland.

Results: During the 15 year period 1981-1995, 438 incident cases of Crohn's disease and 227 of ulcerative colitis were identified, giving standardized incidences of 2.5 cases and 1.3 cases per 100,000 population per year for Crohn's disease and ulcerative colitis respectively. On 31 December 1995 there were 150 children < or = 16 years of age with Crohn's disease and 101 with ulcerative colitis, giving crude prevalences of 13.7 cases per 100,000 population for Crohn's disease and 9.2 for ulcerative colitis. The continuing rise in Crohn's disease incidence between 1981 and 1995 fits that predicted by linear trend analysis of the 1968-1983 data. The incidence of Crohn's disease in the 12-16 age range almost doubled between 1981 and 1995 and was greater for males than females. Ulcerative colitis incidence was thought to show a slight fall in the 1968-1983 data, but this is reversed in the 1981-1995 data.

Conclusion: The incidence of juvenile-onset Crohn's disease continues to rise in Scotland and the prevalence has increased by 30% since 1983. Unlike the previous report from Scotland, the incidence of juvenile-onset ulcerative colitis also is apparently rising. Whether this represents a real rise in incidence, or merely the inclusion of milder cases which were not previously hospitalized remains uncertain.

Study link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11742192&query_hl=2