Smoking, Alcohol consumption, and 24 Gastrointestinal Diseases: Mendelian Randomization Analysis
Abstract
Background: Whether the positive associations of smoking and alcohol consumption with gastrointestinal diseases are causal is uncertain. We conducted this Mendelian randomization (MR) to comprehensively examine associations of smoking and alcohol consumption with common gastrointestinal diseases.
Methods: Genetic variants associated with smoking initiation and alcohol consumption at the genome-wide significance level were selected as instrumental variables. Genetic associations with 24 gastrointestinal diseases were obtained from the UK Biobank, FinnGen study, and other large consortia. Univariable and multivariable MR analyses were conducted to estimate the overall and independent MR associations after mutual adjustment for genetic liability to smoking and alcohol consumption.
Results: Genetic predisposition to smoking initiation was associated with increased risk of 20 of 24 gastrointestinal diseases, including 7 upper gastrointestinal diseases (gastroesophageal reflux, esophageal cancer, gastric ulcer, duodenal ulcer, acute gastritis, chronic gastritis and gastric cancer), 4 lower gastrointestinal diseases (irritable bowel syndrome, diverticular disease, Crohn's disease and ulcerative colitis), 8 hepatobiliary and pancreatic diseases (non-alcoholic fatty liver disease, alcoholic liver disease, cirrhosis, liver cancer, cholecystitis, cholelithiasis, acute and chronic pancreatitis), and acute appendicitis. Fifteen out of 21 associations persisted after adjusting for genetically-predicted alcohol consumption. Genetically-predicted higher alcohol consumption was associated with increased risk of duodenal cancer, alcoholic liver disease, cirrhosis, and chronic pancreatitis; however, the association for duodenal ulcer did not remain after adjustment for genetic predisposition to smoking initiation.
Conclusion: This study provides MR evidence supporting causal associations of smoking with a broad range of gastrointestinal diseases, whereas alcohol consumption was associated with only a few gastrointestinal diseases.
Funding: The Natural Science Fund for Distinguished Young Scholars of Zhejiang Province; National Natural Science Foundation of China; Key Project of Research and Development Plan of Hunan Province; the Swedish Heart Lung Foundation; the Swedish Research Council; the Swedish Cancer Society.
Data availability
Data analyzed in the current study are publicly available GWAS summary-level data. The specific information and link could be found in Table S1. The code and curated data for the current analysis are available at https://github.com/XixianRuan/smoking_gi.
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Data Related to Association studies of up to 1.2 million individuals yield new insights into the genetic etiology of tobacco and alcohol useGWAS and Sequencing Consortium of Alcohol and Nicotine use (GSCAN).
Article and author information
Author details
Funding
National Natural Science Foundation of China (81970494)
- Xiaoyan Wang
Key Project of Research and Development Plan of Hunan Province (2019SK2041)
- Xiaoyan Wang
Hjärt-Lungfonden (20210351)
- Susanna C Larsson
Vetenskapsrådet (2019-00977)
- Susanna C Larsson
Cancerfonden
- Susanna C Larsson
Natural Science Fund for Distinguished Young Scholars of Zhejiang Province (LR22H260001)
- Xue Li
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Human subjects: Included studies had been approved by corresponding institutional review boards and ethical committees, and consent forms had been signed by all participants.
Copyright
© 2023, Yuan et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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