Additive effects of Simvastatin beyond its effects on LDL cholesterol in hypertensive type 2 diabetic patients

BACKGROUND: Experimental evidence indicates that statins might have direct vascular effects independently from low-density lipoprotein (LDL) cholesterol reduction and we reported that the reduction in urinary albumin excretion rate during Simvastatin treatment in type 2 diabetic patients was not correlated with LDL-cholesterol decrease. However in humans there are no data regarding possible additional effects of Simvastatin on blood pressure and urinary albumin excretion beyond its capacity to lower serum cholesterol. PATIENTS AND METHODS: Twenty-six microalbuminuric hypertensive type 2 diabetic patients (diastolic blood pressure - after four months wash-out from the previous antihypertensive therapy - consistently > 90 and < 100 mmHg; plasma LDL-cholesterol > 3.9 and < 6.5 mmol L-1) were enrolled in the study. In random order, these patients received Simvastatin (20 mg day-1) or Cholestyramine (6 g three times a day) for a period of 10 months and after three months of wash-out (cross-over) the sequence was reversed for an additional 10 months. Blood pressure, lipid parameters, glycated haemoglobin and urinary albumin excretion were measured during the study. Additionally, in eight patients, urinary glycosaminoglycan excretion (GAG) was also measured during the study. RESULTS: Simvastatin and Cholestyramine were equally effective in reducing total and LDL cholesterol. Only during Simvastatin treatment a significant reduction in diastolic blood pressure and both 24 h urinary albumin and GAG excretion rates were observed, while no significant changes were seen with Cholestyramine treatment. CONCLUSIONS: Our results clearly show for the first time that the reduction of blood pressure, together with 24 h urinary albumin excretion rate - two established cardiovascular risk factors, obtained during Simvastatin therapy in hypertensive type 2 diabetic patients - is in large part independent from the reduction of LDL Cholesterol.