The Association Between Antihypertensive Drug Use and Hospitalization for Pneumonia in the General Population: A Case-Crossover Study Using the National Health Insurance Database of Korea

BACKGROUND: Previous studies have reported an association between pneumonia risk and the use of certain drugs. We investigated the relationship between antihypertensive drugs and pneumonia in the general population. METHODS: This case-crossover study utilized the nationwide data of South Korea. We included participants who were hospitalized for pneumonia. A single case period was defined as 30 days before pneumonia onset, and two control periods were established (90–120 and 150–180 days before pneumonia onset). Further, we performed sensitivity and subgroup analyses (according to the presence of diabetes, documented disability, and whether participants were aged ≥ 70 years). We used conditional logistic regression models adjusted for covariates, such as angiotensin-converting-enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), other antihypertensives, statins, antipsychotics, benzodiazepine, and the number of outpatient visits. RESULTS: In total, 15,463 subjects were included in this study. ACE inhibitors (adjusted odds ratio [aOR], 0.660; 95% confidence interval [CI], 0.558–0.781), ARBs (aOR, 0.702; 95% CI, 0.640–0.770), and other antihypertensive drugs (aOR, 0.737; 95% CI, 0.665–0.816) were significantly associated with reduced pneumonia risk. Subgroup analyses according to the presence of diabetes mellitus, documented disability, and whether participants were aged ≥ 70 years consistently showed the association of antihypertensives with a reduced risk of hospitalization for pneumonia. CONCLUSION: All antihypertensive drug types were related to a lower risk of hospitalization for pneumonia in the general population. Our results implied that frequent medical service usage and protective immunity were primarily related to a reduced risk of pneumonia in the general population of South Korea.