Risk of community-acquired pneumonia and the use of statins, ace inhibitors and gastric acid suppressants: A population-based case-control study

Purpose: Previous studies have shown that treatment with gastric acid suppressants may be associated with an increased risk of pneumonia whilst the use of statins and ACE inhibitors (ACEI) may decrease the risk of acquiring pneumonia. The evidence is conflicting however. Our aim was to investigate the effect of these drugs on pneumonia using population-based data from the UK. Methods: We conducted a general population-based case-control study using the health improvement network (THIN), a comprehensive UK general practice database. Conditional multiple logistic regression was used to assess the association between the exposures and pneumonia. Results: After adjusting for potential confounders, a current prescription for statins was associated with a significant reduction in the risk of pneumonia (adjusted OR 0.78, 95% CI 0.65-0.94). Similarly, a current prescription for ACEI was associated with a reduction in the risk of pneumonia (adjusted OR 0.75, 95% CI 0.65-0.86). Contrary to previous study results we did not find a significant association between current prescription for histamine 2 receptor antagonist (H₂RA) and pneumonia risk (adjusted OR 1.14, 95% CI 0.92-1.40) but current prescriptions for proton pump inhibitors (PPI) were associated with an increased risk of pneumonia (adjusted OR 1.55, 95% CI 1.38-1.77). Conclusions: Statins and ACE inhibitors were associated with a lower risk of pneumonia but these effects were smaller than those observed in previous studies. People prescribed a PPI, but not an H₂RA at an increased risk of acquiring pneumonia.