Do Statins Counteract the Effect of Antidiabetic Drugs? Results of the SCEAD Study

PURPOSE: Diabetes and dyslipidemia are leading causes of mortality and morbidity. According to international guidelines, statins are the cornerstone of treatment in patients with diabetes and/or dyslipidemia. However, statins and antidiabetic agents have opposite pharmacological effects, because statins, particularly atorvastatin and rosuvastatin, impair glucose homeostasis, increasing the risk of new-onset diabetes, whereas antidiabetic drugs improve glycemic homeostasis. The aim of this study was to investigate the effect of atorvastatin, rosuvastatin, and pitavastatin on glucose homeostasis in patients with type 2 diabetes mellitus (T2DM) and dyslipidemia during stable treatment with hypoglycemic drugs. MATERIALS AND METHODS: The study was conducted as a pilot, prospective, randomized, open label, parallel group with blinded-endpoints (PROBE) study. Of 180 recruited patients with T2DM and dyslipidemia, 131 were randomized to atorvastatin (n=44), rosuvastatin (n=45), and pitavastatin (n=42) and treated for 6 months. RESULTS: Fasting plasma glucose (FPG) marginally decreased in patients assigned to atorvastatin (-3.5 mg/dL, p=0.42) and rosuvastatin (-6.5 mg/dL, p=0.17), while it decreased much more in patients treated with pitavastatin (-19.0 mg/dL, p<0.001). Mean glycated hemoglobin A1c (HbA1c ) values remained unchanged during treatment with atorvastatin (-0.10%, p=0.53) and rosuvastatin (0.20%, p=0.40), but were significantly reduced with pitavastatin (-0.75%, p=0.01). Atorvastatin, rosuvastatin, and pitavastatin significantly lowered (p<0.001) plasma levels of total cholesterol, low-density lipoprotein-cholesterol, and triglycerides, while high-density lipoprotein-cholesterol (HDL-C) levels increased significantly (p=0.04) only in the pitavastatin group. CONCLUSION: The results of the present study suggest that pitavastatin affects FPG and HbA1c less than atorvastatin and rosuvastatin in patients with T2DM and concomitant dyslipidemia. Lipid-lowering efficacies were not significantly different among the three statins, with the exception of HDL-C, which increased significantly with pitavastatin. Although the pharmacological mechanism of pitavastatin on glucose homeostasis in patients with T2DM during stable antidiabetic therapy is not known, it can be assumed that pitavastatin has less drug interaction with hypoglycemic agents or that it increases plasma levels of adiponectin.