Microalbuminuria and severity of diabetic retinopathy in type 1 diabetic patients: association and relationship with some risk factors.

To investigate the relationship between microalbuminuria and severity of retinal damage, we studied 86 Albustix-negative insulin-dependent diabetic patients whose disease duration was more than 5 years (age 31.9 +/- 10.9 years; duration 14.7 +/- 7.1 years). Retinopathy was evaluated by fluorescein angiography in four groups of patients: a) 37 (43%) without retinopathy, b) 29 (34%) with background retinopathy, c) 10 (12%) with pre-proliferative retinopathy and d) 10 (12%) with proliferative retinopathy. Microalbuminuria (urinary albumin excretion > 30 mg/24 h) was calculated from timed 24-h urine collection and measured by a radioimmunoassay method. Microalbuminuria was found in 20 patients (23%); 16 of whom showed both retinopathy and microalbuminuria. Diabetic retinopathy was more frequent than microalbuminuria (57% vs 23%). The prevalence of microalbuminuria was significantly higher in the proliferative retinopathy group compared to the group without retinopathy (p < 0.0005) and the background retinopathy group (p < 0.007). The frequency of diabetic retinopathy was significantly higher (p < 0.04) in patients with than without microalbuminuria. These results indicate that microalbuminuria is associated with the presence and severity of diabetic retinopathy in insulin-dependent diabetic patients.