Observational Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 28, 2019; 25(40): 6145-6157
Published online Oct 28, 2019. doi: 10.3748/wjg.v25.i40.6145
Ethnic differences in inflammatory bowel disease: Results from the United Kingdom inception cohort epidemiology study
Ravi Misra, Jimmy Limdi, Rachel Cooney, Samia Sakuma, Matthew Brookes, Edward Fogden, Sanjeev Pattni, Naveen Sharma, Tariq Iqbal, Pia Munkholm, Johan Burisch, Naila Arebi
Ravi Misra, Samia Sakuma, Naila Arebi, Gastroenterology, St. Mark’s Hospital and Academic Institute, London HA1 3UJ, United Kingdom
Jimmy Limdi, The Pennine Acute Hospitals NHS Trust, Institute of Inflammation and Repair, University of Manchester, Manchester BL9 7TD, United Kingdom
Rachel Cooney, Tariq Iqbal, Gastroenterology, University Hospitals Birmingham, Birmingham B12 2TH, United Kingdom
Matthew Brookes, Gastroenterology, Royal Wolverhampton NHS Trust, London WV10 0QP, United Kingdom
Edward Fogden, Gastroenterology, Sandwell and West Birmingham Hospitals, Birmingham B71 4HJ, United Kingdom
Sanjeev Pattni, Gastroenterology, University Leicester Hospitals, Leicester LE1 5WW, United Kingdom
Naveen Sharma, Gastroenterology, Heartlands Hospital, Birmingham B9 5SS, United Kingdom
Pia Munkholm, Johan Burisch, Department of Gastroenterology, North Zealand University Hospital, Frederikssund 3600, Denmark
Author contributions: Misra R and Arebi N designed the study; Misra R analysed the data; Sakuma S supervised the study centres; Misra R and Arebi N wrote the paper; all authors critically appraised the paper and recruited patients to the study.
Institutional review board statement: The study was approved by the London Northwest NHS Trust and National Research Ethics Service (REC number14/EM/1290).
Informed consent statement: All study participants, or their legal guardian, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: There are no conflicts of interest.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Ravi Misra, BSc, MRCP, Doctor, Consultant Gastroenterologist, Department of Gastroenterology, St. Mark’s Hospital and Academic Institute, Watford Rd, Harrow, London HA1 3UJ, United Kingdom. rm399@ic.ac.uk
Telephone: +44-208-8695328
Received: June 3, 2019
Peer-review started: June 3, 2019
First decision: July 21, 2019
Revised: August 1, 2019
Accepted: September 9, 2019
Article in press: September 9, 2019
Published online: October 28, 2019
Processing time: 147 Days and 13.2 Hours
ARTICLE HIGHLIGHTS
Research background

Epidemiological studies have described the difference in inflammatory bowel disease (IBD) epidemiology in ethnic groups. However, the studies are predominantly single centre and retrospective. In the United Kingdom the last IBD incidence study was performed over 20 years ago.

Research objectives

To describe the incidence and phenotype of IBD in the United Kingdom by ethnic group.

Research methods

A prospective inception cohort study over the course of one year in seven urban centres in the United Kingdom was performed. Standardised methods across all centres were employed for case ascertainment. Data was entered real time on the Epicom database.

Research results

Of 339 patients were diagnosed with IBD over the year study period across a population of 2271406 adults. The crude incidence of IBD, ulcerative colitis (UC) and Crohn’s disease for the total population was 17.0/100000, 11.3/100000 and 5.3/100000 respectively. The age adjusted incidence of UC in the Indian subgroup was almost three times the White European population (20.5/100000 and 7.5/100000 respectively). Indians were significantly more likely to have extensive disease (41.7% vs 52.7%, P = 0.03)

Research conclusions

The Indian subgroup are particularly at risk of developing UC with a pan-colonic phenotype. These findings support the hypothesis of an environmental trigger in a genetically susceptible population. Financial planning and the provision of healthcare services should be reflexive to the local population and may differ according to the ethnic make-up of the background population.

Research perspectives

Future studies should incorporate detailed dietary assessment prior to diagnosis to identify modifiable dietary risk factors. Studying early environmental factors in the paediatric population may yield clues to disease pathogenesis in the Indian migrant group. A prospective incidence study in India is required to provide a comparator to the observed trends.