ABSTRACT
Coen D.A. Stehouwer Department of Internal Medicine and Institute for Cardiovascular Research, VU University Medical Centre, 1081 HV Amsterdam, the Netherlands
INTRODUCTION
The risk of microangiopathy in diabetic patients is highest in those with the most severe hyperglycaemia. Hyperglycaemia, however, is a necessary but not a sufficient cause of clinically important microangiopathy. Hypertension is an additional major cause, and smoking, hypercholesterolaemia, diabetic dyslipidaemia (i.e., low high density lipoprotein (HDL) cholesterol and high triglycerides), obesity and hyperhomocysteinaemia may also contribute. Risk of macroangiopathy, as in non-diabetic individuals, is related to general risk factors for atherothrombosis, such as age, smoking, hypertension, hypercholesterolaemia, dyslipidaemia, obesity and hyperhomocysteinaemia. Risk factors for micro-and macroangiopathy thus show much overlap except that risk of macroangiopathy does not appear to be strongly related to hyperglycaemia, although this is controversial [1-8]. Hypertension, dyslipidaemia and obesity are seen more often in patients with type 2 than in those with type 1 diabetes. In addition, the latter three risk factors occur together more commonly than expected by chance and are thus said to cluster in the metabolic syndrome, which further consists of insulin resistance, hyperinsulinaemia, and impaired fibrinolysis. In both types of diabetes, risk of macroangiopathy is strongly determined by the presence of nephropathy, even in its early stages (microalbuminuria), which identifies a group
of patients at very high risk of developing severe complications, i.e., proliferative retinopathy, renal insufficiency, severe neuropathy, and cardiovascular disease. On the other hand, a substantial fraction of diabetic patients, perhaps 50%, will never develop this cluster of severe complications, i.e. they appear “protected”.
