Although gastroesophageal reflux disease (GERD) and idiopathic pulmonary fibrosis (IPF) may be related, the association between the 2 disorders is most likely confounded, particularly by smoking. A meta-analysis and literature search were conducted, with observational studies selected if they permitted the calculation of a measure of association that related GERD to IPF. Results of the analysis were published in CHEST.
Recognizing that the relationship between GERD and IPF is controversial in nature, investigators sought to examine evidence regarding this association by performing a systematic review and analysis, with particular attention paid to the methodological quality of the observational studies reported.
The controversy stems from the fact that current guidelines recommend that clinicians prescribe regular antacid treatment for these patients, whereas 2 recent meta-analyses on the use of antacid therapy in patients with IPF have been inconclusive.
A total of 18 case-control studies, which included 3206 patients with IPF and 9368 control patients, fulfilled the inclusion criteria of the meta-analysis. According to the findings of the meta-analysis, GERD is associated with IPF (odds ratio, 2.94; 95% CI, 1.95-4.42; P homogeneity <.0001). The results remained consistent regardless of the data sources (eg, clinical studies vs databases) or the type of controls involved (eg, healthy volunteers, patients with respiratory diseases other than interstitial lung disease, or individuals with non-IPF interstitial lung disease).
In addition, in a meta-regression, after controlling for smoking, IPF and GERD were not shown to be related. The proportion of smokers and ex-smokers was higher in the IPF group than in the control group in all but 3 studies, which supports a positive association between GERD and IPF.
The investigators concluded that although IPF and GERD may be related, the association between the 2 conditions is likely ambiguous, particularly with respect to an individual’s smoking status. Additional interventional and observational studies that target GERD in patients with IPF are warranted to further establish a possible relationship between the 2 disorders.
Bédard Méthot D, Leblanc É, Lacasse Y. Meta-analysis of gastroesophageal reflux disease and idiopathic pulmonary fibrosis [published online August 15, 2018]. CHEST. doi:10.1016/j.chest.2018.07.038