Based on genetic data, causal associations were reported between idiopathic pulmonary fibrosis (IPF) and several comorbidities, with gastroesophageal reflux disease (GERD) greatly contributing to the risk of IPF, a recent bidirectional Mendelian randomization study published in “CHEST Journal” elucidated. People with pulmonary (pulmonary hypertension, chronic obstructive pulmonary disease [COPD] and lung cancer) and extra-pulmonary comorbidities (coronary artery disease, gastroesophageal reflux disease [GERD] and depression) have a high burden of IPF.

Jiahao Zhu et al. searched the PubMed database to find out likely IPF-related comorbid conditions. The summary statistics from the biggest genome-wide association research for these ailments till date in two-sample t-tests were used to perform the bidirectional Mendelian randomization (MR) analysis. The study outcomes were confirmed with the help of numerous MR methods under diverse assumptions in models, replication datasets for IPF and secondary phenotypes.

Overall twenty-two comorbidities with available genetic data were considered. Assuring evidence for 2 comorbidities and suggestive evidence for 4 comorbidities were found. GERD, hypothyroidism and venous thromboembolism (VTE) were linked with a higher probability of IPF, on the other hand, COPD was linked causally with a lower probability of IPF. IPF showed causal relations with a greater risk of lung cancer, but a lower risk of high blood pressure (hypertension).

The causal effect of COPD on IPF and of IPF on hypertension was supported by the analyses of lung function parameters and blood pressure measures. The study authors concluded upon the need for future research to figure out the possible mechanisms of these involvements.