Current PPI use — especially recently initiated use — was associated with higher risk.
Observational studies have suggested that the use of proton-pump inhibitors (PPIs) may increase the risk for community-acquired pneumonia (CAP). Danish investigators assessed the association between PPIs and CAP in a population-based study; they compared more than 7600 patients hospitalized for CAP with 34,000 age- and sex-matched controls.
Eleven percent of cases and 5% of controls were current users of PPIs. Current use of a PPI was significantly associated with CAP (adjusted odds ratio, 1.5), and the association was stronger within 7 days after starting PPI use (AOR, 5.0); past PPI use was not associated with CAP. Interestingly, there was no association between current PPI use and CAP for cases in which airborne pathogens, such as Streptococcus pneumoniae and Haemophilus influenzae, were demonstrated. Finally, no dose-response relationship was found.
Comment: In this case-control study, current PPI use was associated with CAP. A potential mechanism by which PPIs may increase susceptibility to infections is inhibition of the "gastric acid barrier." This hypothesis is supported by the study’s finding that CAP secondary to airborne microbes was not associated with PPI use. However, as the authors note, case patients had substantially higher rates of comorbidities, and incomplete adjustment for these potential confounders may also explain the current finding.
— Jamaluddin Moloo, MD, MPH
Published in Journal Watch General Medicine May 31, 2007
Gulmez SE et al. Use of proton pump inhibitors and the risk of community-acquired pneumonia: A population-based case-control study. Arch Intern Med 2007 May 14; 167:950-5.