Relationship between nephropathy, retinopathy, and autonomic neuropathy in patients with Type I diabetes

Seventy-two Type I diabetic patients were divided into three groups according to 24 hour urinary albumin excretion (UalbV, mean of three urine collections): normoalbuminuric group 1 (n = 49, $\text{UalbV ≤}\text{26 mg}\text{24 h}$), microalbuminuric group 2 (n = 16, $\text{26 < UalbV ≤}\text{250 mg}\text{24}$ h), proteinuric group 3 (n = 7, $\text{UalbV >}\text{250 mg}\text{24 h}$). Fluorescein angiography and three cardiovascular autonomic tests were performed. Relative frequencies of ocular findings (no retinopathy/simplex retinopathy/preproliferative and proliferative retinopathy) were determined in each group: group 1 (0.31/0.63/0.06), group 2 (0.56/0.38/0.06), and group 3 (0/0.43/0.57). The most severely affected autonomic function was observed in group 3 (p < 0.01 vs. group 1). Significant partial correlations were found between UalbV and retinopathy (p < 0.01), UalbV, and autonomic neuropathy (p < 0.05), retinopathy and autonomic neuropathy (p < 0.01), and blood pressure and UalbV and/or autonomic neuropathy (p < 0.01). No correlation was found between the variables and the previous 15 months' metabolic control. The results suggest that nephropathy, retinopathy, and autonomic neuropathy are signs of a generalized diabetic microangiopathic process whose progression may be influenced by factors other than diabetes duration and metabolic control.