Deterioration of glucose homeostasis in type 2 diabetic patients one year after beginning of statins therapy

ObjectiveWe evaluated the long-term effects of rosuvastatin and simvastatin on insulin sensitivity and secretion in patients with well-controlled type 2 diabetes.MethodsAfter a 3 weeks run-in, 27 eligible patients were randomly assigned to receive either rosuvastatin 20 mg daily (Group 1) or simvastatin 20 mg daily (Group 2) for 6 months; thereafter they were switched to the other treatment for additional 6 months. Patients were recruited among individuals attending the outpatient service of the Diabetology Unit of the “Policlinico Tor Vergata” University Hospital, Rome, Italy. Serum lipids, glucose and insulin, glycated hemoglobin, C-reactive protein, TNF-α, leptin, adiponectin, insulin sensitivity by euglycemic-hyperinsulinemic clamp, β-cells function by HOMA-β were assessed at months 0, 6 and 12. Additionally, endothelial function was assessed by use of the brachial artery reactivity technique.ResultsBesides marked reduction in lipid levels, glycated hemoglobin significantly increased from baseline after 12 months in both Group 1 (+0.8 ± 0.2%, p < 0.001) and Group 2 (+0.9 ± 0.3%; p < 0.001). Similar trends were observed for fasting glucose in both groups. No changes in insulin sensitivity were detected throughout the study, whereas HOMA-β significantly decreased from baseline after 12 months in both Group 1 (−21.9%, p < 0.01) and Group 2 (−38.9%; p < 0.001). In addition, both treatments similarly decreased C-reactive protein and leptin, as well as improved endothelial function. No changes in anthropometric measures were observed.ConclusionsIn well-controlled type 2 diabetic patients both rosuvastatin and simvastatin significantly impaired glycemic control and insulin secretion, without affecting insulin sensitivity.

► Simvastatin and rosuvastatin do not affect insulin-resistance in type 2 diabetes. ► Some evidence for negative effects on insulin secretion, impairing glucose control. ► Comparable effects on glucose regulation despite difference in LDL reduction. ► Confirmed beneficial effects of both statins on endothelium and inflammation.