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

Abstract

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.

Keywords:

• Low-density lipoprotein cholesterol
• Statin
• Type 2 diabetes mellitus
• All-cause mortality

Transparency

Declaration of funding

This manuscript was not funded.

Declaration of financial/other interests

The authors have disclosed that they have no significant relationships with or financial interests in any commercial companies related to this study or article. CMRO peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Acknowledgments

We gratefully acknowledge the nurses and diabetes educators of the Department of Endocrinology and Metabolism of Taichung Veterans General Hospital for their diligent work on collecting data and elaborately educating patients. This manuscript was edited by Wallace Academic Editing.