[Evaluation of nitric oxide metabolites concentration in patients with type I diabetes]

Nitric oxide (NO) mainly known as a relaxing factor, serves a wide variety of other functions in different tissues. It is quickly metabolized to NO2- and NO3- in humans. The aim of the study was to estimate plasma nitrite anion (NO2-) concentration in type 1 diabetic patients. The study was performed in 30 well metabolically controlled patients (18 female and 12 male, aged 30.2 +/- 10.6 years, duration of diabetes 8.4 +/- 6.8 years. HbA1c 6.5 +/- 1.2%) (group A) and 20 poorly metabolically controlled patients (12 female and 8 male, aged 29.8 +/- 9.8 years, duration of diabetes 8.0 +/- 4.8 years, HbA1c 11.2 +/- 1.6%) (group B). The concentration of NO2- was measured with the use of a calorimetric micromethod, where nitrate reductase catalyses the conversion of NO3- to NO2-. The NO2- plasma concentration was significantly higher in diabetic patients in comparison to controls. The highest NO2- concentration was noticed in the group of well metabolically controlled diabetic patients (group A, group B, healthy subjects: 41.99 +/- 4.02, 33.33 +/- 2.44, 16.68 +/- 2.16 mumol/l, respectively, p < 0.05, p < 0.0001). The nitrite concentrations did not correlate with HbA1c (r = -0.03, p > 0.05). The results support the concept that metabolism of nitrite oxides in diabetes is disturbed independently from the degree of metabolic control.