الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Background: Diabetes mellitus is a group of metabolic disorders characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both. Diabetes can be classified into the following general categories:Type 1 diabetes : due to autoimmune-cell destruction, usually leading to absolute insulin deficiency, Type 2 diabetes :due to a progressive loss of b-cell insulin secretion frequently on the background of insulin resistance, Gestational diabetes mellitus (GDM) :diabetes diagnosed in the second or third trimester of pregnancy that was not clearly overt diabetes prior to gestation, Specific types of diabetes due to other causes, e.g., monogenic diabetes syndromes such as neonatal diabetes and maturity-onset diabetes of the young [MODY]),diseases of the exocrine pancreas such as cystic fibrosis and pancreatitis, and drug- or chemical-induced diabetes such as with glucocorticoid use, in the treatment of HIV/AIDS, or after organ transplantation. The pathogenesis of Type1 diabetes mellitus has been suggested to be a continuum that can be divided into stages that relate to the detection of autoantibodies and progress to β-cell destruction, dysglycaemia and finally, symptoms associated with hyperglycemia. Type1 diabetes mellitus occurs in four stages. Stage1: multiple islet antibodies, normal blood glucose, and presymptomatic, Stage2; multiple islet antibodies, raised blood glucose, and presymptomatic, Stage3; islet autoimmunity, raised blood glucose, and symptomatic Stage4, long standing type1diabetes. Type 1 diabetes mellitus in children classically presents with hyperglycemic symptoms, with one-third of cases presenting in DKA. The onset of symptoms can be sudden at the time of diagnosis, especially in youth. If not evaluated and treated promptly, it can become a medical emergency. Patients most commonly present hyperglycemic with polydipsia, polyuria, and polyphagia. Electrolyte abnormalities may also be present. If these symptoms are not recognized, patients will present in DKA requiring hospitalization and treatment with intravenous fluids, insulin, potassium, and careful monitoring. Type 1 diabetes is a serious disorder with very high morbidity and mortality. Over the long term, the vast majority of patients with this disorder will develop blindness, adverse cardiac events, end-stage renal disease, neuropathy, and in some cases, premature death. . Oxidative stress occurs when the balance between the amount of free radicals and antioxidant power of the body is disrupted, causing damage to membranes and vital biomolecules such as Deoxyribonucleic Acid (DNA), proteins and lipids. Oxidative stress has been shown to compromise the two major mechanisms failing during diabetes which are insulin secretion and insulin action. The process does not only promote the onset of diabetes but also exacerbates the disease condition and its associated complications. Experimental evidence implicates the role of reactive oxygen species (ROS) in impaired beta-cell function caused by autoimmune reactions, cytokines and inflammatory proteins in type 1 diabetes. Hyperglycemia has been noted to promote oxidative stress through de novo free radical generation and suppression of the antioxidant defense systems. In chronic hyperglycemic conditions, production of ROS is perpetuated and hence, the antioxidant enzymes and non-enzymatic antioxidants are severely suppressed in various tissues, which further exacerbate oxidative stress. Assessment of oxidative stress can be done by estimation of Malondialdehyde level in blood which is a highly reactive 3-carbon dialdehyde produced as byproduct of polyunsaturated fatty acid peroxidation and can combined with several function group on the molecule including protein, lipoprotein, DNA and RNA. Malondialdehyde assessment (MDA) maneuver is considered as one of most proper and reliable marker that determine oxidative stress in clinical situation.. on other hand the antioxidant can be assess by estimation of total antioxidant capacity (TAC) which give a relevant biological information about overall antioxidant capacity of the individual. Tight glycemic control is the most effective way of preventing or decreasing the complications of type 1 diabetes mellitus Aim of the work: The aim of this work is assessment of the oxidative status and its relationship with glycemic state which may help in early prediction and management to prevent complications of type 1 diabetes mellitus in children. Subjects and Methods: This study was comprised between: A total of 30 children with type 1 diabetes mellitus of both sex and age between 2-12 years old who were sequentially selected from patients attending outpatient clinic of Endocrinology Unit of Mansoura University Children’s Hospital in period between December 2020 to December 2021 according to the results of HbA1c, the studied diabetic group were further subdivided into: well controlled subgroup and poor controlled subgroup and 20 healthy children with matched age and sex served as control group from general pediatric clinic in Mansoura University Children’s Hospital All patients and controls were subjected to: Complete History taking which include age, sex and residence, Clinical examination, Lab Investigations including: Fasting and post prandial blood glucose levels estimation, HbA1c level, Serum Malondialdehyde (MDA) assay, Serum Total antioxidant capacity (TAC) assay.Results of the study revealed: No significant differences were recorded between cases and control group regarding all demographic features except a significance increase of the occurrence of T1DM among families of studied cases., The mean fasting blood glucose, mean postprandial blood glucose mean HBA1c and median duration of diabetes were 135.07 gm/dl, 161.8 mg/dl, 8.7 %, and 3.5 years respectively, The MDA and MDA/TAC ratio were significantly increased among cases compared with control group, No significant correlation was recorded between TAC, MDA, MDA/TAC ratio with Age and BMI among cases and control group., Oxidative status was significantly higher in poor diabetic control cases compared with well controlled cases, ROC curve was excellent for MDA and MDA/TAC ratio in differentiating cases form control with the best detected cut off point for MDA is 5.95 yielding sensitivity of 96.7% and specificity 95% with total accuracy is 96%. The best detected cut off point for MDA/TAC is 5.86 yielding sensitivity of 100% and specificity 100% with total accuracy is 98%. Conclusion: Children with T1DM was exposed to evidence of oxidative stress., Diabetic children with poor control glycemic state were exposed to higher oxidative stress than well controlled cases., Serum MDA level and MDA/TAC ratio were good indicators for oxidative status in children with T1DM.