Adiposity, diabetes, and lifestyle factors are known to be associated with gastroesophageal reflux disease (GERD) in observational studies.

Yuan and Larsson designed a two-sample Mendelian randomization analysis to ascertain if these associations are causal. Investigators selected independent genetic variants associated with body mass index (BMI), waist circumference (with and without adjustment for BMI), type 2 diabetes, smoking, and alcohol, coffee and caffeine consumption at the genome-wide significance level as instrumental variables.

Summary-level data for GERD were available from a genome-wide association meta-analysis of 71,522 GERD cases and 261,079 controls of European ancestory from the UK Biobank and QSkin Sun and Health studies.

The odds ratio (OR) of GERD was 1.49 for one standard deviation (SD) rise in BMI, 1.07 for one-unit increase in log-transformed OR of type 2 diabetes, and 1.41 for one SD escalation in the prevalence of smoking initiation.

There appeared to be suggestive associations with GERD for higher genetically predicted waist circumference (OR for one SD increase, 1.14) and caffeine consumption (OR for 80 mg increase, 1.08).

Genetically predicted waist circumference adjusted for BMI, alcohol or coffee consumption did not seem to be linked to GERD.

The study points to the causal roles of adiposity, diabetes, and smoking, and a possible role of high caffeine consumption in GERD development.

Source: Yuan S, Larsson SC. Adiposity, diabetes, lifestyle factors and risk of gastroesophageal reflux disease: a Mendelian randomization study. Eur J Epidemiol. 2022 Feb 4.