Introduction: Angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARBs) are renin angiotensin system inhibitors (RASi) which can reduce the proinflammatory-vasoconstricting activity of ACE/angiotensin II and enhance the anti-inflammatory-vasodilatory activity of ACE2/angiotensin 1-7. These drugs may be protective across a range of respiratory infections including bacterial and viral pneumonias. We examined long-term use of ACEi/ARBs on the risk of first pneumonia hospitalization and pneumonia-related death in Chinese patients with type 2 diabetes (T2D). Methods: Prospective analysis of 16,285 Chinese T2D patients with new RASi use observed between 2001 and 2019. Overlap weighting was performed to balance baseline characteristics. We used time-dependent Cox model to estimate the hazard ratio (HR) of outcomes while adjusting for the time-varying covariates. Results: There were 6,379 (39.2%) ACEi-users only, 4,065 (25.0%) ARBs-users and 5,841 (35.9%) non RASi-users. During a median observation of 7.6 years, 6.1% had first pneumonia hospitalization, 1.3% died during or within one month of pneumonia hospitalization and 17.6% died from other causes. No association was observed between RASi use and first pneumonia hospitalization. However, RASi-users had lower risk for pneumonia-related death (HR 0.51, 95% CI 0.35-0.76) than non-users [ACEi-users only: HR 0.53 (0.34-0.81);ARBs-users: HR 0.58 (0.32-1.04)]. We also noted reduced risk for all-cause death in RASi-users (HR 0.60, 95% CI 0.54-0.67) [ACEi-users only: HR 0.61 (0.54-0.69);ARBs-users: HR 0.67 (0.57-0.79)]. Conclusions: Long-term use of RASi was associated with reduced risk of pneumonia-related death and all-cause death, but not first pneumonia hospitalization, in Chinese patients with T2D. Relevance to other respiratory infections such as coronavirus-disease 2019 (COVID-19) merits further investigation.
Long-Term Renin-Angiotensin System Inhibitor Use and Risk of Pneumonia and Pneumonia-Related Death in Type 2 Diabetes