GERD therapy associated with IPF survival in small study (AJRCCM)

GERD Treatment Improves Survival in Idiopathic Pulmonary Fibrosis?

GERD is extremely common in people with idiopathic pulmonary fibrosis, and chronic microaspiration has long been suspected of playing a role in the pathogenesis of IPF.

In a retrospective review, Joyce Lee, Jay Ryu, Harold Collard et al collected records on 84 patients with idiopathic pulmonary fibrosis from UCSF, and 120 from Mayo (n=204). Patients were roughly similar between centers in disease severity and demographics.

34-45% of patients had either symptoms or a diagnosis of gastroesophageal reflux disease (GERD). Half of those were taking proton pump inhibitors.

In unadjusted analyses, having a GERD diagnosis or being treated for GERD with medication or fundoplication were associated with longer survival.

On adjusted Cox regression analysis, taking medication for GERD retained an association with a longer survival time. Percent-predicted forced vital capacity and diffusion capacity were each also independently associated with longer survival after adjustment.

Authors point to a 2006 case series of four patients with IPF who improved after medical GERD treatment, and another 2006 series of 19 IPF patients who improved after Nissen fundoplication, as further intriguing data suggesting GERD treatment might improve survival in IPF. They also acknowledge the possibility of lead time bias or unmeasured confounders in this small analysis, and that their data should be considered preliminary and needing future study. (The other possibility I’d suggest that they didn’t is that GERD and aspiration cause a distinct, less lethal form of IPF.)

They argue an unmeasured confounder is unlikely because “it would have to exist at both centers,” which makes sense. But something caused the unadjusted observed association between GERD and IPF to disappear on adjusted analysis. What was it?

Clinical takeaway: GERD is highly prevalent among people with IPF, and it’s plausible that in some people, it causes or makes IPF worse. Proton pump inhibitors’ risk associations with community acquired pneumonia and hip fractures seem low in relation to their potential risks vis-a-vis IPF (especially considering IPF patients’ reduced life expectancy during which to get pneumonia or a fracture). This study is anything but definitive, but some physicians prescribe PPIs to all their patients with IPF based on the potential contribution of chronic microaspiration to ongoing fibrosis.