The changing epidemiology of diabetic microangiopathy in type 1 diabetes

Diabetic microvascular complications in the kidney and the eye are a major burden for diabetic patients due to increased morbidity and mortality. Furthermore, diabetic nephropathy is the leading cause of end-stage renal disease and diabetic retinopathy is the leading cause of blindness in younger patients, representing a major public health concern. During the past two decades beneficial effects of, in particular, aggressive antihypertensive control and strict glycaemic control have been demonstrated in randomised controlled clinical trials. Technological improvements in diabetes care have made good metabolic control easier to achieve. Has this led to an improved prognosis? In observational studies from dedicated centres, a decrease from 47 to 13% has been reported in the incidence of proliferative diabetic retinopathy after 20–25 years of diabetes, and the incidence of overt diabetic nephropathy after 20 years has decreased from 28 to 5.8%. Even functional and morphological remission of diabetic nephropathy has been reported. Despite this, recent population-based studies have failed to demonstrate a decrease in the incidence of blindness caused by diabetes, and the incidence of end-stage renal disease has progressively increased. This may, in part, be the result of a combination of increasing numbers of diabetic patients and a lag phase between improvement in management and a decline in end-stage complications. It is of concern, however, that the results from specialised centres may not apply to routine diabetes care. It is, therefore, mandatory that the beneficial effects of pharmacological and non-pharmacological interventions demonstrated in clinical trials and recommended by treatment guidelines are translated into clinical practice to ensure a widespread improvement in prognosis.