Effetti vascolari e metabolici delle statine in una coorte di pazienti affetti da diabete tipo 2 e dislipidemia secondaria

The effects of statins on glucose metabolism are controversial. In particular, it is not clear if statins may affect insulin sensitivity besides LDL-cholesterol and vascular reactivity improvement in diabetic patients. The present randomized, double-blind trial has been direct to evaluate the acute effects of rosuvastatin compared to simvastatin on glucose control, insulin-sensitivity and endothelial function in diabetic patients with untreated dyslipidemia. Twenty non obese male subjects (aged 56±8, mean±SD) with type 2 diabetes in OAD treatment and dyslipidemia were given rosuvastatin 20 mg (Group R, n=10) or simvastatin 20 mg (Group S, n=10) daily for one month. The following data were collected at baseline and after follow-up (differences in mean values assessed by t-test for paired data): BMI, waist circumference, fasting glucose, HbA1c, lipid profile, hs CRP, fibrinogen, leptin, adiponectin, insulin sensitivity assessed by euglycemic hyperinsulinemic clamp and endothelial function evaluated by brachial artery reactivity technique (BART). At baseline, subjects in the two arms had comparable anthropometric parameters, were in good glycemic control (Group R: fasting glucose 139±24 mg/dl, HbA1c 6.4±0.6%. Group S: fasting glucose 135±25 mg/dl, HbA1c 6.6±0.4%) with mild dyslipidemia (Group R: total cholesterol 197±17 mg/dl, HDL 37±5 mg/dl, LDL 136±13 mg/dl, triglycerides 127±83 mg/dl. Group S: total cholesterol 210±27 mg/dl, HDL 44±8 mg/dl, LDL 144±22 mg/dl, triglycerides 126±30 mg/dl). After 30 days of treatment, LDL-cholesterol decreased of 55% in Group R (56±13 mg/dl, p<0.001) and 38% in Group S (84±12 mg/dl, p<0.001) and HDL-cholesterol raised of 8% (39±5 mg/dl) and 9% (47±11 mg/dl), respectively (p<0.05 for both). No patients changed OAD therapy or modified their own life-style habits. In both arms fasting glucose and HbA1c did not differ from baseline, as well as insulin sensitivity assessed by glucose disposal during euglycemic hyperinsulinemic clamp (Group R: 4.2±1.0 vs 4.9±1.7 mg/Kg/min. Group S: 6.1±2.7 vs 6.4±2.3 mg/Kg/min, p=NS). All two treatment arms significantly improved flow-mediated dilation (Group R: 7.0±3.0% vs 10.3±0.6%, p=0.005. Group S 7.6±3.3% vs 11.4±2.3%, p=0.01), while no statistical differences from baseline were detected in both groups in hs CRP, fibrinogen, leptin and adiponectin concentrations. In conclusion, these preliminary data on patients with type 2 diabetes and mild untreated hypercholesterolemia showed that short-treatment (30 days) with rosuvastatin 20 mg or simvastatin 20 mg daily do not affect glucose control and insulin sensitivity, faced to a marked reduction in LDL-cholesterol and an improvement of vascular reactivity.