IBD in transition: a decade of data from the Malaysian Kinta Valley cohort

Inflammatory bowel disease (IBD) is emerging in the Asia-Pacific region including Malaysia. The aim of this study is to compare the current incidence and prevalence of IBD in Malaysia from the previous decade, as well as comparing the incidence rates between the urban and rural population.

Kinta Valley was selected as the urban catchment area while Hilir Perak was selected for the rural catchment area within the same state. Patients newly diagnosed with IBD were prospectively recruited, and all confirmed IBD cases were included for the prevalence analysis. Baseline demographic information and disease characteristics were recorded.

The crude incidence rates of IBD, ulcerative colitis (UC), Crohn disease (CD) and IBD unclassified (IBD-U) in Kinta Valley were 1.13, 0.45, 0.60, and 0.08 per 100 000 person-years, respectively, compared to 0.68, 0.46, and 0.20 per 100 000 person-years in 2013. The incidence of UC:CD was 0.75:1 compared to 2.3:1 from the previous study. The prevalence rates were 15.08, 10.13, 4.84, and 0.11 for IBD, CD, UC, and IBD-U per 100 000 population, respectively. The matching incidence rates in a nearby rural area were higher, at 3.29, 1.88, 1.41, and 0.47 per 100 000 person-years, respectively, but the overall incident cases were very low.

Our findings suggest an increasing incidence of IBD in Malaysia, in keeping with the second stage of the global evolution of IBD. There is a potential shift in the relative incidence of CD compared to UC, but larger population studies are required for confirmation.