Overweight/obesity and gastrointestinal disease incidence in Denmark-a cohort study.

Objective: Obesity is associated with various gastrointestinal (GI) conditions. Because of the epidemic rise of obesity, we examined associations between overweight/obesity and incidence of individual GI diseases.

Design: Cohort study.

Setting: Denmark, 1997-2018.

Participants: Using nationwide healthcare registries, we identified All Danes ≥18 years with a hospital diagnosis of overweight/obesity. We created an age- and sex-matched general population comparison cohort.

Exposure: A diagnosis code of overweight/obesity.

Main outcomes and measures: We compared the incidence of hospital-diagnosed GI diseases from 1 year after overweight/obesity diagnosis.

Results: We included 129 466 patients with overweight/obesity (70.9% female, median age 49.3 years). Their incidence rate of GI disease was 30.1 per 1000 person years (95% CI: 29.8-30.5) vs 16.7 (95% CI: 16.5-16.8) for comparators, yielding an adjusted hazard ratio (aHR) of 1.7 (95% CI: 1.7-1.7). The aHRs indicated elevated risk of all GI disease sub-types in the overweight/obesity cohort, including cholelithiasis: 2.8 (95% CI: 2.7-2.9), cholecystitis: 2.6 (95% CI: 2.4-2.8), acute pancreatitis: 2.2 (95% CI: 2.0-2.4), stomach ulcer: 2.0 (95% CI: 1.9-2.1), cirrhosis: 1.5 (95% CI: 1.3-1.7), and obesity-associated GI cancer: 1.2 (95% CI: 1.2-1.3). The aHR for any GI disease was 1.4 (95% CI: 1.4-1.5) in men and 1.9 (95% CI: 1.8-1.9) in women. Among patients 18 to <30 years, the aHR was 2.6 (95% CI: 2.5-2.7) vs 1.3 (95% CI: 1.3-1.4) among individuals ≥70 years.

Conclusions and relevance: Overweight/obesity is a risk factor for a wide range of GI diseases and is expected to become an even greater clinical challenge in the future.