Epidemiology of Inflammatory Bowel Disease in Iran: The Distance and the Difference in the Incidence of the Diseases Are Decreasing Due to the Globalization
Annals of Colorectal Research: December 30, 2013, 1 (3); 114-115
October 30, 2013
Article Type: Letter
October 8, 2013
October 8, 2013
T. Epidemiology of Inflammatory Bowel Disease in Iran: The Distance and the Difference in the Incidence of the Diseases Are Decreasing Due to the Globalization,
Ann Colorectal Res.
Copyright © 2013, Colorectal Research Center and Health Policy Research Center of Shiraz University of Medical Sciences. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/) which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.
Taghavi et al. (
1) reported in their retrospective analytical study, about multiple epidemiological factors of inflammatory bowel disease (IBD) in Southern Iran. They revealed an increasing number of IBD patients with no significant change in onset of diagnosis lag time. In addition, they found a correlation between type of disease and positive family history, and observed an age range of 20-29 as a peak of age-specific distribution for IBD and no second peak at the age of 60. The authors’ two further interesting observations are the dominancy of left-sided colitis and the incredible frequent use of infliximab (57%) in Crohn’s disease (CD). The prevalence and incidence of IBD seems to be stable in the high incidence areas like North America or Northern Europe; however an increasing number of cases is recorded in Southern and Eastern Europe and in Asia. In these regions, the emergence of ulcerative colitis (UC) is followed by CD. Siew et al. ( 2) reported about geographical variations of IBD among countries. The highest incidence rates have been noted in Northern Europe, UK and North America and in the Pacific countries- mainly New-Zealand and Australia, which may be explained by the similar lifestyle and the grade of industrialization in these areas. The frequency of IBD is increasing in the westernized Asian countries, like China, South Korea, India, and Iran. Obvious differences have been established in the incidence rates of IBD between the European countries. The highest incidence has been shown in Iceland and Faroe Islands in the north and in Crete and Sicily in the south of Europe. Recent studies from Hungary revealed increasing incidence of IBD in our previously low incidence areas. The mean incidence rates were 8.9/105 person-year for CD and 11.9/105 person-year for UC, respectively. Extension of UC at diagnosis was proctitis in 26.8%, left-sided colitis in 50.9%, and pancolitis in 22.3%, while the first location of CD was ileal in 20.2%, colonic in 35.6 and ileocolonic in 44.2%. Stenosing or penetrating type at diagnosis occurred in 35.6% of the cases. Approximately 11% of patients were presented with family history of IBD. They observed one peak incidence in the 21-30-year-old population. Approximately 10 years ago, left sided colitis was the leading form in the Central-Eastern European area like in Iran recently, however, according to the newest Epicom data ( 3), also in this region, pancolitis became as frequent as in the Western part of Europe. Since the extent of the disease is one of the strictest prognostic factors, more complications and operations can be expected in our region. It will be interesting to follow whether a similar tendency will occur in Iran too. And what is about the infliximab use in more than every second CD patient? It is difficult to imagine a different, very aggressive behavior of CD occurred in Iran, some other personal factors might be the explanation of this world record overuse of anti-TNF there.
In conclusion, incidence and prevalence of IBD is increasing in low incidence areas like Eastern Europe or Asia. The estimated prevalence of IBD is approximately 0.3% of the European population with geographic variation (
4). It is not clearly obvious that the rise of the frequency of IBD presents a real change or is a consequence of improved diagnostic techniques and awareness of physicians; however IBD represents an important public health problem, as it may affect young population that inhibits education, work ability and social life, and may lead to decreased quality of life.