NEW YORK (Reuters Health) – Patients with idiopathic pulmonary fibrosis often have gastroesophageal reflux (GER), and use of medication to treat this condition is associated with increased survival, researchers report in the American Journal of Respiratory and Critical Care Medicine online June 23.
“These findings further support the hypothesis that GER and chronic microaspiration may play important roles in the pathobiology of idiopathic pulmonary fibrosis,” conclude Dr. Joyce S. Lee, with the University of California San Francisco, and colleagues.
They explain that the cause of idiopathic pulmonary fibrosis remains unknown, but it has been suggested that chronic tracheobronchial aspiration of small amounts of gastric secretions causes repetitive sub-clinical injury to the lung leading to fibrosis.
To see if GER-related factors are in fact associated with pulmonary fibrosis, the team retrospectively analyzed data on a cohort of 204 patients with idiopathic pulmonary fibrosis seen at two centers over a 7-year period. Mean age was 70, 69% were men, most were overweight, and 71% were current or former smokers.
Symptoms of gastroesophageal reflux were present in 34% of the group and 45% had a history of GER disease, the researchers report. At the time of diagnosis, 47% were on a proton pump inhibitor or H2 blocker, and 5% had had a Nissen fundoplication.
Median survival time for the whole cohort was 1079 days. After adjustment, use of GER medication was seen to be significantly associated with longer survival, with a mortality hazard ratio of 0.47 (p=0.03).
Furthermore the radiologic fibrosis score was 14% in those taking GER medication vs 19% in those not on such treatment (p=0.01), the investigators found.
They comment that there are several possible explanations for the findings. “The most straightforward is also the most controversial; that the treatment of GER is beneficial to survival in IPF (idiopathic pulmonary fibrosis).”
Another possibility is confounding by unknown variables, or that GER may develop as a consequence of pulmonary fibrosis.
“The results of our study need validation to confirm the association between reported GER medication use and survival time,” Dr. Lee and colleagues acknowledge. “If our results are validated, future studies should look beyond association and address how the treatment of GER might affect survival in IPF.”
Gastroesophageal Reflux Therapy is Associated with Longer Survival in Idiopathic Pulmonary Fibrosis
Am J Respir Crit Care Med 2011.