Anorexia and bulimia in relation to ulcerative colitis: a Mendelian randomization study

Qiang Su; Jian Li; Yun Lu; Min Wu; Jiang Liang; Zhenxiang An

doi:10.3389/fnut.2024.1400713

Anorexia and bulimia in relation to ulcerative colitis: a Mendelian randomization study

Front Nutr. 2024 Jul 10:11:1400713. doi: 10.3389/fnut.2024.1400713. eCollection 2024.

Authors

Qiang Su^#¹, Jian Li^#¹, Yun Lu¹, Min Wu¹, Jiang Liang^{1

2}, Zhenxiang An^{1

2}

Affiliations

¹ The First Clinical Medical College of Guizhou University of Traditional Chinese Medicine, Guiyang, China.
² The First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China.

^# Contributed equally.

Abstract

Background: Evidence for anorexia and bulimia in relation to the risk of ulcerative colitis (UC) is limited and inconsistent. The objective of this research was to utilize bi-directional, two-sample Mendelian randomization (MR) analysis to predict the causal association between anorexia nervosa and bulimia nervosa with UC.

Methods: The genome-wide association studies (GWAS) provided data for anorexia and bulimia from the UK Biobank, utilizing single-nucleotide polymorphisms (SNP) as instrumental variables. Additionally, genetic associations with UC were collected from various sources including the FinnGen Biobank, the UK Biobank and the International Inflammatory Bowel Disease Genetics Consortium (IIBDGC). The main analytical approach utilized in this study was the inverse-variance-weighted (IVW) method. To evaluate horizontal pleiotropy, the researchers conducted MR-Egger regression and MR-PRESSO global test analyses. Additionally, heterogeneity was assessed using the Cochran's Q test.

Results: This study found a negative association between genetically predicted bulimia (OR = 0.943, 95% CI: 0.893-0.996; p = 0.034) and the risk of UC in the IIBDGC dataset, indicating that individuals with bulimia have approximately a 5.7% lower risk of developing UC. No association was observed in the other two datasets. Conversely, genetically predicted anorexia was not found to be causally associated with UC. In bi-directional Mendelian randomization, UC from the IIBDGC dataset was negatively associated with the risk of anorexia (OR = 0.877, 95% CI: 0.797-0.965; p = 0.007), suggesting that UC patients have approximately a 12.3% lower risk of developing anorexia, but not causally associated with bulimia.

Conclusion: Genetically predicted bulimia may have a negative association with the onset of UC, while genetically predicted anorexia does not show a causal relationship with the development of UC. Conversely, genetically predicted UC may have a negative association with the development of anorexia.

Keywords: Mendelian randomization; anorexia; bulimia; eating disorder; ulcerative colitis.

Grants and funding

The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. This study was funded by the National Administration of Traditional Chinese Medicine of China, Fifth Batch of the National Clinical Excellence Training Program for Traditional Chinese Medicine Practitioners [Program Number: State TCM Education Letter (2022) No. 1]; the Traditional Chinese Medicine Spleen and Stomach Disease Scientific and Technological Innovation Talent Team Construction at Guizhou University of Traditional Chinese Medicine [Program Number: Gui TCM TD Hezi (2022) No. 005].