Introduction

Diabetes mellitus owes much of its morbidity and most of its mortality to the late complications of the condition. These are predominantly vascular in origin and include diabetic retinopathy, the commonest cause of blindness in people of working age in our society, and diabetic nephropathy, an increasingly common cause of renal failure as well as premature peripheral vascular, cerebrovascular and coronary artery disease. The person with diabetes is approximately three times as likely to suffer a heart attack, at least twice as likely to suffer a stroke and 20 times as likely to have a limb amputated.

It is common to refer to the vascular disease associated with diabetes as either microangiopathy (involving the microcirculation) or macroangiopathy, i.e. arterial disease. It is none the less likely that diabetes affects the whole circulation although little work has been done on the impact of the condition on venous function or lymphatic function. Macroangiopathy includes atherosclerosis which is typified by its prematurity, its multisegmental and distal nature and by the fact that women of premenopausal age are not spared as they commonly are in the absence of diabetes. Macroangiopathy also includes arteriosclerosis and may be regarded as a manifestation of accelerated ageing of the vasculature in diabetes.

Both micro- and macroangiopathy exhibit certain stages in their evolution.