Symptoms related with gastroesophageal reflux disease (GERD) have been shown to be associated with increased risk for coronavirus disease 2019 (COVID-19).

A study was conducted to examine the possibility of a shared genetic basis between GERD and COVID-19 outcomes. With the help of published GWAS data for GERD (78 707 cases; 288 734 controls) and COVID-19 susceptibility (up to 32 494 cases; 1.5 million controls), Ong et al evaluated the genetic relationship between GERD and three COVID-19 outcomes, including risk of developing severe COVID-19, COVID-19 hospitalization and overall COVID-19 risk.

The genetic correlation was explored between GERD and COVID-19 outcomes followed by Mendelian randomization (MR) analyses to determine a genetic causality. Conditional analyses helped assess whether known COVID-19 risk factors (obesity, smoking, type-II diabetes, coronary artery disease) can explain the relationship between GERD and COVID-19.

• Investigators noted small to moderate genetic correlations between GERD and COVID-19 outcomes (rg between 0.06 and 0.24).
• According to MR analyses, there was an OR of 1.15 for severe COVID-19; 1.16 for risk of COVID-19 hospitalization; and 1.05 for overall risk of COVID-19 per doubling of odds in developing GERD.
• The genetic correlation between GERD and COVID-19 was mildly attenuated towards the null after adjusting for obesity and smoking.

Susceptibility for GERD and risk of COVID-19 hospitalization were found to have a genetic correlation, with MR findings pointing to a potential causal role.

The genetic association between GERD and COVID-19 was partly attenuated after accounting for obesity, consistent with the fact that obesity is a risk factor for both diseases.

Source: Ong JS, Gharahkhani P, Vaughan TL, et al. Assessing the genetic relationship between gastro-esophageal reflux disease and risk of COVID-19 infection. Hum Mol Genet. 2022 Feb 3;31(3):471-480.