Retrospective Cohort Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Oct 7, 2020; 26(37): 5661-5672
Published online Oct 7, 2020. doi: 10.3748/wjg.v26.i37.5661
Periodontitis combined with smoking increases risk of the ulcerative colitis: A national cohort study
Eun Ae Kang, Jaeyoung Chun, Jee Hyun Kim, Kyungdo Han, Hosim Soh, Seona Park, Seung Wook Hong, Jung Min Moon, Jooyoung Lee, Hyun Jung Lee, Jun-Beom Park, Jong Pil Im, Joo Sung Kim
Eun Ae Kang, Department of Internal Medicine and Institute of Gastroenterology, Yonsei University College of Medicine, Seoul 03722, South Korea
Jaeyoung Chun, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06229, South Korea
Jee Hyun Kim, Department of Internal Medicine, Bundang CHA Medical Center, CHA University School of Medicine, Seoul 13496, South Korea
Kyungdo Han, Department of Statistics and Actuarial Science, Soongsil University, Seoul 06978, South Korea
Hosim Soh, Seona Park, Seung Wook Hong, Jung Min Moon, Jooyoung Lee, Hyun Jung Lee, Jong Pil Im, Joo Sung Kim, Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul 03080, South Korea
Jun-Beom Park, Department of Periodontics, the Catholic University of Korea College of Medicine, Seoul 06591, South Korea
Author contributions: Kang EA, Chun J, Kim JH and Han K completed the conception and design of the study; Kim JH, Han K, Soh H, Park S, Hong SW, Moon JM and Lee J completed the acquisition, analysis and interpretation of data; Kang EA and Chun J drafted and revised the article; Kang EA, Chun J, Lee HJ, Park JB, Im JP and Kim JS completed 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, No. 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: 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 that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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: Jaeyoung Chun, MD, Assistant Professor, Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University College of Medicine, Yeonju-ro 63-gil, Gangnam-gu, Seoul 06229, South Korea.
Received: May 18, 2020
Peer-review started: May 18, 2020
First decision: July 29, 2020
Revised: August 7, 2020
Accepted: September 16, 2020
Article in press: September 16, 2020
Published online: October 7, 2020
Research background

Environmental factors in addition to genetic and immunological factors are known to influence on the development of inflammatory bowel disease (IBD) including Crohn’s disease (CD) and ulcerative colitis (UC). The effects of etiologies such as smoking, alcohol consumption, age and comorbidities on the occurrence of chronic intestinal inflammation may vary based on race and gender.

Research motivation

Gut dysbiosis is associated with IBD as a cause or result and is related to oral microflora. Oral disease can occur as an extra-intestinal manifestation of IBD. However, the risk of developing IBD in patients with periodontitis remains unclear.

Research objectives

We aimed to evaluate the risk of developing IBD in patients with periodontitis and to determine the combined effect of risk factors on the development of IBD associated with periodontitis.

Research methods

Using database of the National Health Insurance and National Health Screening Program in South Korea in 2009, we compared people with and without periodontitis and evaluated newly diagnosed IBD in both group during follow-up period until 2017. All 9950548 people over the age of 20 who received a national health check in 2009 were included. Periodontitis was defined using the International Classification of Disease 10th revision (ICD-10). CD and UC were defined using ICD-10 and rare intractable disease codes specific to South Korea.

Research results

Out of 9950548 individuals, a total of 1092825 subjects (11.0%) had periodontitis. The periodontitis group was older and had a higher male proportion. During the median follow-up period of 7.26 years, people with periodontitis had a significantly higher risk of developing UC than those without periodontitis. In a subgroup analysis, current smokers aged 65 and older with periodontitis had a 1.9-fold increase in UC risk than non-smokers aged 65 and older without periodontitis.

Research conclusions

Periodontitis is highly associated with the risk of developing UC, especially in current smokers over 65. It suggests that periodontitis and current smoking are a potential combined risk factor for the development of elderly-onset UC.

Research perspectives

Based on the results of this study, we need future prospective studies to focus on the synergistic impacts of the environmental risk factors on elderly onset UC in terms of complex interaction of oral and intestinal microflora. Ultimately, it can lead to a better understanding of the pathogenesis of IBD.