In what they called the first comparative epidemiologic study of inflammatory bowel disease across the region, researchers calculated an incidence of 1.37 cases/100,000 people in Asia, and 23.67 cases/100,000 people in Australia.
And despite the fact that these rates are dwarfed by Western nations, "these figures still represent a clinically important disease burden, considering that 20 years ago, IBD [inflammatory bowel disease] was rare or almost nonexistent in Asia," wrote Siew C. Ng, Ph.D., in the July issue of Gastroenterology (doi: 10.1053/j.gastro.2013.04.007).
Source: American Gastroenterological Association
In the report Dr. Ng of the Chinese University of Hong Kong, and her colleagues looked at data from the Asia-Pacific Crohn’s and Colitis Epidemiology (ACCESS) study.
That database included information from 21 centers in 12 cities in nine countries, including China, Australia, Hong Kong, and Thailand.
Specifically, the researchers focused on incident IBD cases diagnosed between April 1, 2011, and March 31, 2012, all of which were confirmed clinically as well as endoscopically, histologically, and radiographically.
The researchers found that during the 1-year period, there were 419 new IBD cases, including 232 (55.4%) classified as ulcerative colitis (UC), 166 (39.6%) as Crohn’s disease (CD), and 21 (5.0%) undetermined.
That translated to a crude annual overall incidence of IBD of 1.37/100,000 people (95% CI: 1.25-1.51) in Asia, and 23.67 (95% CI: 18.46-29.85) in Australia.
The authors then looked at individual patient demographics.
Overall, the mean age at the time of diagnosis was 39 years, with a median number of months from symptom onset to diagnosis of 5 months in Asia and 6 months in Australia.
They also found that while inflammatory disease phenotype was reported in 66% of patients in Asia, it was found in 88% of Australian patients (P = .005).
Indeed, 3% of patients in Asia reported a family history of IBD, compared with 17% of patients in Australia (P less than 0.001).
Severity of disease was also catalogued. Penetrating disease characterized 19% and 2% of cases in Asia and Australia, respectively (P = .012).
Meanwhile, stricturing disease was diagnosed in 17% of Asian cases and 10% of Australian cases (P = .277), and perianal disease in 18% and 12% of Asians and Australians, respectively (P = .356).
Finally, the researchers looked at treatment patterns between Asia and Australia, and found that while use of antibiotics, immunosuppressives, and biologic therapy were similar, mesalazine (79% vs. 62%; P less than .012) and corticosteroids (62% vs. 28%; P less than .0001) were more commonly prescribed in Australia than in Asia.
According to Dr. Ng, in a region that is host to more than 4.2 billion people, "The emerging incidence in Asia offers a unique opportunity to study etiologic factors, particularly factors associated with Western lifestyle, including improved home amenities, refrigeration, consumption of protein- and carbohydrate-rich diets, widespread use of antibiotics, vaccination, and industrial pollution."
She added: "The complex disease behavior for CD in Asia has major implications for local health care planning and resource allocation."
The authors disclosed no conflicts of interest. The study was supported by Ferring Pharmaceuticals, maker of mesalazine, which is used in IBD.
