Effects of statins on all-cause mortality at different low-density-lipoprotein cholesterol levels in Asian patients with type 2 diabetes

Objective: To investigate the effects of statins on all-cause mortality risk at different low-density lipoprotein cholesterol (LDL-C) levels, and to compare the mortality risk between statin users and non-users with identical LDL-C levels in a type 2 diabetes cohort.

Methods: In total, 10,582 outpatients aged ≥18 years with type 2 diabetes mellitus (T2DM) between 2009 and 2012 were enrolled in this retrospective cohort study in central Taiwan. All-cause mortality events were followed up until the end of 2014. According to the medical records during the follow-up period, the patients were classified into statin (+) and statin (−) groups. Patients were categorized into different LDL-C segments based on their mean LDL-C levels during the 2.8-year follow-up.

Results: Non-cardiovascular mortality accounted for more than half the deaths. Overall, statin therapy significantly reduced the all-cause mortality risk in both univariable and multivariable models (hazard ratios = 0.39 and 0.38, respectively). Sub-group analyses showed that the lowest mortality risk occurred in the 80–89 mg/dL segment in the statin (−) group and in the 90–99 mg/dL segment in the statin (+) group. Statin therapy significantly reduced the mortality risk at all LDL-C levels except for low LDL-C (<60 mg/dL).

Conclusions: In addition to reducing LDL-C levels, statin therapy reduced all-cause mortality risk in Taiwanese patients with T2DM. Statins further reduced the mortality risk at most LDL levels. However, at low LDL-C levels, the positive effects of statins may have been nullified.