BLOOD-PRESSURE, RETINOPATHY AND URINARY ALBUMIN EXCRETION IN IDDM - THE EURODIAB IDDM COMPLICATIONS STUDY

Several studies have shown an association between blood pressure and n ephropathy, but few have been large enough to examine whether, or how, this relation is influenced by retinopathy. We have therefore examine d the independent relations of blood pressure to urinary albumin excre tion and retinopathy in a cross-sectional observational study of over 3000 insulin-dependent diabetic patients (the EURODIAB IDDM Complicati ons Study). The relation of blood pressure to urinary albumin excretio n differed strikingly between patients with (46%) and without (54%) re tinopathy. In those with retinopathy, mean urinary albumin excretion r ate was normal (<20 mu g/min) below median diastolic pressure (75 mmHg ) and increased steeply (p < 0.001) with blood pressure above this lev el. However, in patients without retinopathy, mean albumin excretion r ate was normal across the range of diastolic pressure. This finding co uld not be explained by differences in glycaemic control or duration o f diabetes between patients with and without retinopathy. These data i dentify a subgroup of patients whose high risk of nephropathy may refl ect abnormal renal vulnerability to mildly raised blood pressure. Reti nopathy is a close correlate of this vulnerability. Detection of even mild retinopathy, together with raised blood pressure, may be importan t in assessing nephropathy risk.