Opposite effects of statins on the risk of tuberculosis and herpes zoster in patients with diabetes: A population‐based cohort study

Aims It remains uncertain whether statin use is associated with the risks of tuberculosis (TB) and herpes zoster in patients with type 2 diabetes. This study aims to assess the effects of statins vs nonstatin lipid‐lowering agents on the risk of these infectious diseases in patients with diabetes. Methods Participants in the Taiwan National Health Insurance Research Database diagnosed with type 2 diabetes in 2001–2013 were classified as statin users, nonstatin users and lipid‐lowering drug‐free groups. Participants were observed for incident TB and herpes zoster from diabetes diagnosis until treatment crossover or December 2013. Statin user and nonstatin user were the time‐dependent variables in Cox regression analysis. Results Over 240 782 person‐years of observation, statin users (n = 17 696) were associated with a lower TB risk than nonstatin users (n = 5327) and the drug‐free group (n = 22 316) (adjusted hazard ratio [aHR]: 0.66; 95% confidence interval [CI]: 0.44–0.99 and aHR: 0.57; 95% CI: 0.44–0.73). Compared with nonstatin users, statin users showed a dose‐dependent association with TB risk (low‐potency statin users, aHR: 0.692; 95% CI: 0.455–1.053; high‐potency users, aHR: 0.491; 95% CI: 0.241–0.999). Statin users presented with a higher risk of herpes zoster than nonstatin users and the drug‐free group (aHR: 1.23; 95% CI: 1.01–1.50 and aHR: 1.20; 95% CI: 1.09–1.33). The risks of TB and herpes zoster were not statistically different between nonstatin users and the drug‐free group. Conclusion Compared with nonstatin drugs, statin use was specifically associated with a decreased risk of TB but a moderately increased risk of herpes zoster in this cohort study.