Epidemiology of Inflammatory Bowel Disease in India: The Great Shift East

Abstract

Background: Inflammatory bowel disease (IBD), once considered to be a Western disease, is increasingly being reported from India and other Asian countries. The present review summarizes epidemiology and disease characteristics of IBD in India with reference to other Asian countries and the West.

Summary: India is projected to have one of the highest disease burden of IBD across the globe. The overall genetic risk and microbial signature in Indian IBD patients are similar to those of patients in the West as demonstrated by the similar incidence of IBD in second-generation Indian immigrants and matching perturbations in the structural and functional component of gut microbiota in Indian studies. The concept of the hygiene hypothesis continues to remain controversial with Indian studies demonstrating contradictory findings. The disease characteristics, long-term outcomes including the risk of colorectal cancer, and the effect of pregnancy on IBD and vice versa in Indian patients with IBD are in general similar with few differences. Unlike patients in the West, very few Indian patients have a positive family history.

Key message: The Indian disease pattern is going through a phase of epidemiological transition with a surge in the incidence of IBD. The epidemiology and disease characteristics of IBD mirror the patterns observed in the West.

Keywords: Colorectal cancer; Crohn disease; Genetics; Pregnancy; Ulcerative colitis.

Fig. 1

Estimated disease burden of IBD in 6 countries from Asia, North America, or Europe calculated for reference year 2010.

Fig. 2

Comparison of the incidence of ulcerative colitis in Asian immigrants and the local population in Ontario, Canada.

Fig. 3

Comparison of disease extent of ulcerative colitis among studies in India and Asia.

Fig. 4

Comparison of disease location (a) and disease behaviour (b) of Crohn disease among Indian studies and the ACCESS study. L1, terminal ileal; L2, colonic; L3, ileocolonic; L4, proximal small intestinal. B1, inflammatory disease; B2, structuring disease; B3, fistulizing disease.

Fig. 5

Cumulative probability of colectomy after 10, 20, and 30 years in studies from India (2015), a meta-analysis (2001) [103], and a population-based cohort from the West.