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.