Retrospective Cohort Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jan 28, 2020; 26(4): 404-415
Published online Jan 28, 2020. doi: 10.3748/wjg.v26.i4.404
Trends and risk factors of elderly-onset Crohn’s disease: A nationwide cohort study
Jung Min Moon, Eun Ae Kang, Kyungdo Han, Seung Wook Hong, Hosim Soh, Seona Park, Jooyoung Lee, Hyun Jung Lee, Jong Pil Im, Joo Sung Kim
Jung Min Moon, Eun Ae Kang, Seung Wook Hong, Hosim Soh, Seona Park, Jooyoung Lee, Hyun Jung Lee, Jong Pil Im, Joo Sung Kim, Department of Internal Medicine, Liver Research Institute, Seoul National University College of Medicine, Seoul 03080, South Korea
Kyungdo Han, Department of Biostatistics, College of Medicine, The Catholic University of Korea, Seoul 06591, South Korea
Author contributions: Moon JM, Kang EA, Han K and Kim JS made the conception and designed the study; Moon JM, Kang EA, Han K, Hong SW, Soh H, Park S and Kim JS made the data acquisition, analysis and interpretation; Moon JM, Kang EA, Han K, Hong SW, Soh H and Park S drafted and revised the article; Moon JM, Kang EA, Han K, Hong SW, Soh H, Park S, Lee J, Lee HJ, Lim JP and Kim JS made the final approval of the article submitted.
Institutional review board statement: The study was approved by the Institutional Review Board of the University of Seoul National University Hospital (IRB number: H-1703-107-840).
Informed consent statement: The subjects’ information in the database was de-identified before the investigator accessed the data, thus informed consent was waived.
Conflict-of-interest statement: The authors declare no conflicts of interest for this article.
Data sharing statement: No additional data are available.
STROBE statement: Authors have read the STROBE Statement-checklist of items and the manuscript was prepared and revised accordingly.
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:
Corresponding author: Eun Ae Kang, MD, Doctor, Department of Internal Medicine, Liver Research Institute, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul 03080, South Korea.
Received: November 1, 2019
Peer-review started: November 1, 2019
First decision: December 23, 2019
Revised: January 9, 2020
Accepted: January 15, 2020
Article in press: January 15, 2020
Published online: January 28, 2020
Research background

The incidence of inflammatory bowel disease (IBD) is increasing worldwide, including in Asia. Crohn’s disease (CD) has a high incidence at younger ages, but as the life expectancy increases, people in the Montreal classification A3 category (age over 40), especially the elderly-onset CD, receive greater clinical attention.

Research motivation

Disease phenotypes vary by age of onset, but few studies have investigated epidemiological and phenotypic differences in the older people. Given that environmental factors play a pivotal role in the elderly compared with the young, analyzing the nature and environmental risk factors of elderly CD can provide important information in understanding the multifactorial causes of the IBD.

Research objectives

We aimed to assess the trend and risk factors of middle-age and elderly-onset CD in nationwide population-based cohort study, using the claim data of South Korea.

Research methods

We conducted a retrospective cohort study to evaluate the incidence trends and risk of CD in those over the age of 40 in South Korea. Using both the International Classification of Diseases, 10th revision and rare, intractable disease registration program codes from National Health Insurance Service database, newly diagnosed CD patients were analyzed and compared to non-CD cohort. Hazard ratio was calculated with adjustment to age, sex, diabetes, hypertension, smoking, alcohol consumption, regular exercise, body mass index, anemia, chronic kidney disease (CKD) and dyslipidemia.

Research results

Out of 14060821 subjects screened, a total of 1337 cases of newly diagnosed CD was analyzed. During the median follow-up period of 7.4 years, we found that four factors including ex-smoking, anemia, chronic kidney disease and lower body mass index were in relation to increased risk of CD and three factors including alcohol consumption, physical activity and dyslipidemia were in relation to decreased risk of CD.

Research conclusions

This study suggests several potential predictive markers associated with CD incidence. Most analyzed factors associated with CD development in the middle-aged and the elderly were found to be less relevant for older people. However, ex-smoking and anemia have proven to be strong associative markers even in the elderly population. We can assume that certain factors interact at the preclinical stage of ongoing inflammation in the IBD pathogenesis, thus careful monitoring of these factors is necessary.

Research perspectives

We hypothesized that certain markers could be particularly associated with elderly-onset CD and conducted a large epidemiological study involving more than 10 million Koreans to investigate a wide range of factors. Based on our findings, we can create grounds for future prospective studies to assess the causal relationship, eventually leading to a better understanding about the pathogenesis of elderly IBDs in Asian population.