The effects of lipid-lowering drug therapy on cardiovascular responsiveness in type 2 diabetic patients

Type 2 diabetes is associated with a high prevalence of dyslipidaemia and a high incidence of cardiovascular disease. Lipid lowering therapy with HMG Co-A reductase inhibitors (statins) reduce the risk of cardiovascular events in type 2 diabetic and non-diabetic patients, effects which are believed to be partly due to improvements in vascular function. The aetiology of abnormal vascular function in type 2 diabetics is likely to be multifactorial and the pattern of vascular dysfunction in type 2 diabetes may differ from that which occurs in non-diabetic patients with dyslipidaemia. Abnormalities in endothelium derived hyperpolarising factor (EDHF) mediated vasodilation in resistance vessels may be more prominent in both type 1 and type 2 diabetes than in non-diabetic patients with endothelial dysfunction. The effects of lipid lowering therapy on vascular responsiveness may differ in type 2 diabetic patients from those found in non-diabetic patients. Statin therapy does not appear to improve responses to endothelial dependent vasodilators in type 2 diabetics, but may alter the ratio between nitric oxide (NO) and EDHF mediated responses. Fibrate therapy improves flow mediated dilation of brachial arteries in type 2 diabetic patients, but only appears to improve endothelium dependant vasodilator responses in resistance vessels when given in conjunction with co-enzyme Q.