'Microalbuminuria' in type I (insulin-dependent) diabetic patients with and without retinopathy.

We investigated the frequency of microalbuminuria (albumin excretion rate, AER greater than 15 micrograms/min) ('overnight' urine collection and radioimmunological evaluation) and its relation to retinopathy (assessed by fluorangiography) in 113 type I (insulin-dependent) diabetic subjects (aged 31 +/- 13 years; diabetes duration 11 +/- 7 years), all Albustix-negative. Sixty eight patients (60.2%) were free of retinal lesions, 31 (27.4%) had background retinopathy and 14 (12.4%) had proliferative retinopathy. Microalbuminuria was found in 25 patients (22%). Fifteen patients (13%) showed both retinopathy and microalbuminuria. Fifteen % (10/68) of the patients with no retinopathy and sixteen % (5/31) of those with background retinal lesions had microalbuminuria, while 29% (4/14) of the patients with proliferative retinopathy were normoalbuminuric. Among the 29 patients with diabetes for less than five years, 1 had retinopathy and 4 had microalbuminuria. Out of 15 patients with both retinopathy and microalbuminuria, 13 (87%) had had diabetes for more than 10 years. Diabetic retinopathy is more frequent than microalbuminuria (40 vs 22%). Although the linkage between retinopathy and microalbuminuria is weak, after ten years of diabetes the two complications may frequently coincide.