Am J Gastroenterol. 2024 Jan 26. doi: 10.14309/ajg.0000000000002675. Online ahead of print.

Fangyu Li ¹, Yukiko Yano ¹, Lola Étiévant ², Carrie R Daniel ³, Shreela V Sharma ⁴, Eric L Brown ⁴, Ruosha Li ⁵, Erikka Loftfield ¹, Qing Lan ⁶, Rashmi Sinha ¹, Baharak Moshiree ⁷, Maki Inoue-Choi ¹, Emily Vogtmann ¹

Author information

¹Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute; Bethesda, MD, USA.

²Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute; Bethesda, MD, USA.

³Department of Epidemiology, The University of Texas MD Anderson Cancer Center; Houston, TX, USA.

⁴Department of Epidemiology, Human Genetics and Environmental Sciences, School of Public Health, University of Texas Health Science Center at Houston; Houston, TX, USA.

⁵Department of Biostatistics and Data Science, School of Public Health, University of Texas Health Science Center at Houston; Houston, TX, USA.

⁶Occupational and Environmental Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute; Bethesda, MD, USA.

⁷Division of Gastroenterology, Hepatology, and Nutrition, Atrium Health, Wake Forest University, Charlotte, North Carolina; Charlotte, NC, USA.

Abstract

Objective: Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders, but few studies have evaluated mortality risks among individuals with IBS. We explored the association between IBS and all-cause and cause-specific mortality in the UK Biobank.

Methods: We included 502,369 participants from the UK Biobank with mortality data through 2022. IBS was defined using baseline self-report and linkage to primary care or hospital admission data. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality using multivariable Cox proportional hazards regression models within partitioned follow-up time categories (0-5, >5-10, and >10 years).

Results: A total of 25,697 (5.1%) participants had a history of IBS at baseline. After a median follow-up of 13.7 years, a total of 44,499 deaths occurred. Having an IBS diagnosis was strongly associated with lower risks of all-cause (HR=0.70, 95% CI=0.62-0.78) and all cancer (HR=0.69, 95% CI=0.60-0.79) mortality in the first 5-years of follow-up. These associations were attenuated over follow-up, but even after 10 years of follow-up, associations remained inverse (all-cause: HR=0.89, 95% CI=0.84-0.96; all cancer: HR=0.87, 95% CI=0.78-0.97) after full adjustment. Individuals with IBS had decreased risk of mortality from breast, prostate, and colorectal cancer in some of the follow-up time categories.

Conclusion: We found that earlier during follow-up, having diagnosed IBS was associated with lower mortality risk, and the association attenuated over time. Additional studies to understand whether specific factors, such as lifestyle and healthcare access, explain the inverse association between IBS and mortality are needed.