Clinical immunology
Proangiogenic factors in obese patients with type 1 diabetes

Obesity is regarded as one of the main factors predisposing for type 2 diabetes. Recently many studies have shown that obesity and insulin resistance take part in pathogenesis of diabetes type 1 in children and adolescents. Angiogenin, TNF-α and VEGF are considered inducers of neovascularization. The levels of these cytokines may increase during the course of obesity and this may accelerate the progression of microvascular complications.

Since there are no data concerning the influence of obesity on the clinical status of patients with an established diabetes, we aimed to investigate the relationship between the level of three cytokines (angiogenin, VEGF, TNF-α) and body weight in diabetic children with reference to their clinical status and complications. The study was carried on 44 children with long-standing diabetes mellitus type 1 and on 30 healthy children as a control group. All the children had their daily urine albumin secretion, HbAlc, C-peptide measured; 24 hrs blood pressure monitoring and ophthalmologic examination has been done. Body mass index values were compared to the appropriate centile charts. Serum level of vascular endothelial growth factor (VEGF), angiogenin and TNF-α (Tumor Necrosis Factor alpha) was measured by ELISA method.

Overweight patients with type 1 diabetes had significantly higher HbA1c, total serum cholesterol, LDL cholesterol, tryglicerides, CRP and albumin levels than their healthy counterparts. Instead, these patients had lower HDL cholesterol level and higher systolic and diastolic blood pressure. In addition, the study group had higher VEGF level, higher TNF-α level and higher angiogenin level compared to normal-weight individuals and control group. Interestingly, obese diabetic type 1 patients more often suffered from the late diabetic complications (41% vs. 4%).

Concluding, elevated levels of angiogenin, VEGF and TNF-α may constitute disadvantageous factors in development of diabetic complications. Analyzed cytokines have negative effect on the course of the disease, and coexisting overweight accounts for the secondary risk factor for vascular complications. Thus, it is of great importance to monitor body-weight and to prevent overweight in patients with type 1 diabetes.