Increased prevalence of proliferative retinopathy and cardiovascular autonomic dysfunction in IDDM patients with proteinuria.

The purpose of the present cross-sectional clinical study was to evaluate the prevalence of retinopathy in Type 1 diabetic patients without nephropathy and with different degrees of nephropathy. In addition we investigated the association between retinopathy, nephropathy, and other variables, and studied the importance of cardiovascular autonomic dysfunction to these conditions. 76 Type 1 diabetic patients were investigated. All patients were initially selected on the basis of body weight, and 47 proteinuric patients were further selected for age, diabetes duration and the duration of insulin treatment (see Table 1). Proteinuric diabetic patients were categorized by degree of nephropathy, i.e. for incipient nephropathy (proteinuria of less than 0.5 g/day), for overt nephropathy (proteinuria of more than 0.5 g/day), and for renal failure (serum creatinine of more than 103 mumol/l). Retinopathy was assessed by ophthalmoscopy. Cardiovascular autonomic dysfunction (CAD) was assessed by heart rate variations, 30:15 ratios, the Valsalva maneuver, and systolic blood pressure fall upon standing. Our findings revealed increased prevalence of retinopathy in patients with more advanced stages of nephropathy. CAD abnormalities exhibited increased prevalence among proteinuric patients. Our data clearly revealed differences between proteinuric and non-proteinuric patients. In both proteinuric and non-proteinuric patients there were found correlations of retinopathy with diabetes duration, and only in proteinurics was retinopathy correlated with kidney function, systolic blood pressure and CAD findings. In patients in identical stages of nephropathy, increased prevalence of CAD abnormalities was shown in patients suffering from proliferative retinopathy. Thus our data suggest that CAD abnormalities might be related in some way to both the proliferative retinopathy and to diabetic nephropathy.