Introduction: Despite that numerous investigations on the nature of diabetic microangiopathy were carried out, its pathomechanism remains unclear.
Objective: The aim of the study was to analyze the relation between early diabetic microangiopathy and the proinflammatory cytokines, NAG and its A and B isoforms in blood and urine in children diagnosed with diabetes mellitus type 1.
Material and methods: The study was carried out on the group of 56 children with diabetes mellitus 1 (age 13.6+/-3.74) and 35 healthy children selected as the controls. All the patients had 24 hrs albuminuria, HbA1c, C-peptide as well as the NAG enzyme and its A and B isoforms serum and urine activities measured. Additionally, all the children had TNF-a and IL6 level in serum measured. Each patient had 24 hrs blood pressure monitored and underwent ophthalmologic examination.
Results: Children with long-standing diabetes mellitus and retinopathy (group 1, n=15) were older and were characterized by a statistically significant longer duration of the disease and higher HbA1c level in comparison with the patients who presented with no sign of diabetic retinopathy (group 2, n=41). In the group 1 statistically significant higher TNF-alpha serum level (p=0.01), NAG (p=0.002) and its isoforms A (p=0.007) and B (p=0.001) urine activities were measured in relation to the group 2. Additionally the level of IL-6 and NAG and its isoforms A and B serum activities were higher in group 1 than in group 2, however the differences were of no statistical significance. Moreover the children from group 2 in comparison with the healthy controls showed statistically significant higher TNF-alpha serum activity (p=0.016) and NAG (p<0.001) and its A (p<0.001) and B (p<0.001) isoforms both serum and urine activities.
Conclusions: The occurrence of the detectable serum TNF-alpha activity in children with diabetes mellitus type 1 showing no sign of diabetic retinopathy and nephropathy and no microalbuminuria with the concomitant increase of NAG and its isoforms serum and urine activities might point toward prompt occurrence of these changes in the eye and the kidneys.