Diabetic foot patients with and without retinopathy and plasma oxidative stress.

OBJECTIVE: The first aim of this study was to evaluate some plasma oxidative stress markers in diabetic patients (type2 diabetes mellitus) with peripheral arteriopathy. Secondly, these patients were divided into two groups considering the presence or absence of retinopathy. The differences in the levels of the oxidative stress parameters could be important to select patients prone to develop multiple vascular complications, including retinopathy. PATIENTS AND METHODS: Forty hospitalized type II diabetic patients, aged between 40 and 70, with stage III or IV foot ulceration according to the Wagner classification, had an ophthalmologic evaluation for retinopathy. Among them, 23 were with retinopathy with different grades of severity and 17 were without retinopathy. Twenty healthy subjects served as a control group. Fasting plasma glucose, glycosylated hemoglobin, serum fructosamine, total serum proteins, serum uric acid and plasma ceruloplasmin levels were determined and compared.
RESULTS: Plasma levels for fasting glucose, glycosylated hemoglobin, ceruloplasmin and serum concentrations for fructosamine and uric acid were significantly increased in diabetic foot patients vs. control subjects. Comparing the two groups of patients, with and without retinopathy, the concentrations of ceruloplasmin and uric acid were significantly increased in diabetic patients with retinal disease. In diabetic patients with retinopathy, positive correlations were calculated between glycated hemoglobin and fructosamine concentrations and between glycated hemoglobin and ceruloplasmin.
CONCLUSION: Diabetic foot patients with retinopathy have increased plasma levels of uric acid and ceruloplasmin. These plasma compounds could be important in the pathogenesis of retinal disease. Two aspects should be considered when these high values are analysed. First, these antioxidant compounds may become prooxidant in diabetic vascular environment. Secondly, it is not known whether these modified plasma oxidative stress parameters are cause or effect in diabetic complication development.