ORLANDO — Inflammatory bowel disease has become a global disease since the turn of the century, with incidence plateauing in the West, but increasing in the developing world, according to a speaker at the World Congress of Gastroenterology at ACG 2017.
The patterns of IBD incidence observed in newly developed nations in Asia, Africa, and South America are “analogous” to those observed in the West at the end of the 20th century, Gilaad Kaplan, MD, MPH, associate professor at University of Calgary in Canada, said during his presentation.
This research was also recently published in the Lancet.
“For decades we have seen the incidence of IBD increase during the 20th century in the Western world, and now we’re seeing a paradigm shift in the incidence of IBD at the turn of the 21st century,” Kaplan said during his presentation.
To update a prior systematic review and “provide a global perspective on the epidemiology of IBD in the 21st century,” Kaplan and colleagues systematically reviewed medical literature published from 1990 through 2016. They created Choropleth maps to visualize the incidence of both Crohn’s disease and ulcerative colitis during this period, and performed temporal trend analyses to calculate the annual percentage change in incidence.
The 119 incidence studies and 69 on prevalence included in the analysis showed IBD prevalence was still highest in the Western world, exceeding 0.3% of the total population in North America and most countries in Europe. However, Kaplan and colleagues saw a “paradigm shift” in the incidence, with 70% of Crohn’s disease studies and 83% of ulcerative colitis studies showing IBD incidence was either stable or declining across North America, Europe, and Oceania.
“We can see at the turn of the 21st century the incidence of Crohn’s disease and of ulcerative colitis is coalescing between three and 15 per 100,000,” Kaplan said. While some studies did report greater incidences, “we’re starting to see a ceiling on the incidence that ranges between 20 to 30 per 100,000,” he added.
Additionally, the data showed IBD incidence is lower overall but increasing over time in newly industrialized nations across Asia, Africa and South America.
For example, Brazil had an 11.1% annual increase in Crohn’s disease (95% CI; 4.8-17.8) and a 14.9% annual increase in UC (95% CI; 10.4-19.6) between 1988 and 2012. Similarly, Taiwan had a 4% annual increase in Crohn’s (95% CI; 1-7.1) and a 4.8% annual increase in UC (95% CI; 1.8-8) between 1998 and 2008, and South Korea had a 13.8% annual increase in Crohn’s (95% CI, 8.7-19) and a 9.5% annual increase in UC (95% CI, 2.7-16.7) between 1991 and 2005.
“This rise in incidence over time creates a very important question for us to answer: ‘Will the incidence of IBD in newly industrialized countries mirror the progression of IBD in the Western world during the 20th century?” If so, the implications for countries like China and India that have populations that exceed over a billion people, will be profound,” Kaplan said.
“As newly industrialized countries have become Westernized, IBD has emerged and its incidence is rising. We have yet to see the peak of these incidence levels in these countries, and therefore these countries are going to have to prepare their clinical infrastructure, resources and personnel to manage this costly and complex disease.”
Additionally, Kaplan called for research focused on identifying environmental factors associated with the “Westernization” of society “that will identify avenues to help us prevent the development of IBD.” – by Adam Leitenberger
Siew N, et al. Abstract 10. Presented at: World Congress of Gastroenterology at American College of Gastroenterology Annual Scientific Meeting; Oct. 13-18, 2017; Orlando, FL.
Siew N, et al. Lancet. 2017;doi:10.1016/S0140-6736(17)32448-0.
Disclosures: The researchers report no relevant financial disclosures.