Predictors of microvascular complications in children and adolescents with type I diabetes mellitus

Diabetes mellitus is characterized by microangiopathy and increased angiogenic response. Several angiogenic factors are involved in vascular endothelial growth. This work was designed to study serum levels of angiogenic factors: vascular endothelial growth factor [VEGF], basic fibroblast growth factor [bFGF], angiogenin and transforming growth factor-beta 1 [TGF-beta1] and their relationship to metabolic control in children and adolescents with type I diabetes mellitus and to evaluate whether these angiogenic factors can predict and identify cases at greater risk to develop diabetic retinopathy or persistent microalbuminuria in a follow-up period of 12 months. The present study included 20 type I diabetic cases aged 6-18 years and 15 healthy controls. Diabetic cases were subjected to detailed history taking, clinical examination, fundus examination, electroretinography [ERG] and repeated estimation of glycosylated hemoglobin [HbA1C%] and fasting blood glucose in addition to urinary albumin excretion [UAE] ug/minute/1.73m[2] in repeated 24 hours collection of urine. These data were collected at the baseline [at the beginning of the study] and after 12 months follow-up period. Baseline investigations included the determination of blood urea, serum creatinine and assessment of serum angiogenic factors: VEGF, bFGF, angiogenin and TGF- beta1 by ELISA. At the beginning of the study, diabetic cases had significantly higher serum levels of VEGF, bFGF and angiogenin and significantly lower oscillatory potentials amplitude [Ops] than the control group. When diabetic cases were followed up for 12 months, 4/20 cases developed background retinopathy in fundus examination and 5/20 developed incipient nephropathy [persistent microalbuminuria] Development of microvascular complications was associated with significantly higher HbA1C%, serum VEGF, bFGF and angiogenin than uncomplicated cases. Furthermore, cases with diabetic retinopathy had significantly higher UAE and significantly lower baseline Ops than those without. Angiogenic factors as VEGF, bFGF and angiogenin and ERG examination could be used as predictors for identification of diabetic cases at high risk to develop diabetic retinopathy with a sensitivity of 75-100% and specificity of 81.25-93.75% and in prediction of incipient diabetic nephropathy with a sensitivity of 60-100% and a specificity of 86.67-93.33%. Angiogenic factors were correlated with HbA1C% and repeated blood glucose. The medical management of diabetes mellitus should be focused not only on metabolic control but also on measurement of angiogenic factors and ERG examination to predict cases at high risk of microvascular complications for early and more effective intervention that may include in the future antagonists to angiogenic factors

Antioxidant activity in hematological diseases in children

Several hematological diseases are accompanied by oxidant stress. The objective of this work was to study antioxidant status in children with some hematological diseases and to relate the results to metabolic alterations and complications of these diseases. Red blood cells glutathione content [GSH], glutathione-related enzymes, catalase, and superoxide dismutase [SOD], in addition to plasma total radical trapping antioxidant capacity [TRAP], and vitamins E and C in blood samples from 20 children with acute G-6-PD hemolytic anemia [favism] before transfusion, 20 with homozygous beta-thalassemia and 20 with acute lymphoblastic leukemia [ALL], in addition to 20 healthy children as controls. Children with favism as well as those with beta-thalassemia had significantly lower TRAP activity, GSH, catalase, vitamins E and C than the controls. Thalassemic cases had negative correlations between ferritin levels and vitamins E and C. On the other hand, leukemic cases showed TRAP activity that was not significantly different from the controls and increased activity of GSH peroxidase and reductase enzymes. It could be concluded that antioxidant defenses are not defective in ALL, however, a pronounced defect is present in cases with favism and beta-thalassemia major. Therefore, administration of antioxidants in addition to optimal iron chelation therapy may be warranted