Changing Epidemiology and Future Challenges of Inflammatory Bowel Disease in Asia

ABSTRACT

In the past decade, many countries in Asia, in particularly in East Asia, are experiencing a progressive rise in the incidence and prevalence of inflammatory bowel disease (IBD). Improved physician awareness and diagnostic methods are unlikely to fully account for this rapid increase. This epidemiological shift is likely to relate to industralization, westernization of lifestyles and changes in eating habits, as part of the socioeconomic development in Asia, although many of these putative environmental factors have not been formally investigated in Asian cohorts. Genetic factors for IBD differ between Asia and the West. NOD2/CARD15 mutation, repeatedly observed in the Caucasian populations, is not associated with Crohn's disease in Asian populations. Familial clustering is generally uncommon in Asia but it is expected to increase as the IBD prevalence in this region rises. Ethnic-racial differences of IBD have been described and Indians appear to be most affected in South-East Asia. Clinical manifestation of IBD in Asia resemble the Western population in general, but with some differences, including higher prevalence of males and ileocolonic disease, lower disease severity, surgical rates and extraintestinal manifestations. These differences may relate to time factor, genetic background and environmental factors. This review summarises recent epidemiological data of IBD including environmental factors associated with the development of IBD in Asia. Future research focusing on studying the epidemiology of IBD in an area of rapidly increasing prevalence such as Asia will allow the opportunity to identify potential risk factors and provide a better understanding of the aetiology of disease in the Asian population.