الفهرس 
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Abstract
SUMMARY
Diabetes mellitus is a syndrome of metabolic disease
characterized by hyperglycemia. It is caused by deficiency of insulin
secretion or insulin action and resulting in abnormal metabolism of
carbohydrate, protein and fat. It is the most common endocrine
metabolic disorder of childhood and adolescence with important
consequence for physical and emotional development.
The WHO classification system was used to divide OM into
two major and distinct types IDDM (type I IDM) and NIDDM (type
2 OM). In this classification other classes of diabetes included: other
. types and impaired glucose tolerance as well as gestational diabetes
mellitus.
ADA (1996) and (1997) proposed some changes to the WHO
classification these changes are:
I-Elimination of the terms, 100M and NIDOM. However, the
terms type 1 and type 2 OM were proposed to be retained.
2- Inclusion under type 1 OM those cases due to an autoimmune
cause and those cases in which an etiology is not known.
3-More precise definition under type 2 OM of the form of OM that
’is the most prevalent ”in the United’ States and is due to insulin I resistance with insulin secretory defects.
Type 1 OM compromises approximately 5% to 10% of cases
in the DM syndrome. It is characterized by abrupt onset of sever i’~
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symptoms and dependence on exogenous insulin to prevent ketosis
and to preserve life, all of which are caused by absolute insulin
deficiency (insulinopenia).
Insulin dependent diabetes is initiated by the selective auto
immune destruction of pancreatic beta cells and both genetic and
environmental factors contribute to the development of the disease.
Genetic factors are thought to be of importance in the majority
of patients as expressed by the associated increase frequency of
certain histocompatibility locus antigen (HLA) on chromosome No.
6. in various groups of diabetic patients. The percent prevalence of
HLA-DQ and DR has been found to be increased compared with
. control population.
Evidence from clinical studies suggests a role of viral infection
in the pathogenesis of IDOM. Certain viruses have been associated
with B-cell destruction among them rubella, mumps, coxsachie B,
cytomegalovirus and other enteroviruses.
Evidence of immune destruction of the B-cells includes the
presence of TCA, TAA, fA-2 and GAO autantibodies. These
autantiodies are commonly used as sensitive markers to identity the
preclinical period of the disease.
The immunologic prediction of type ”I OM has also greatly
improved over the past years with development of anti-islet
autoantibody radioassays. ICA testing has faci Iitated the
identification of high-risk individual and forms the basis for most
current preventive trials. High-titer ICA is clearly a useful marker
fo: progression to OM in the general population. However, with the
use of a series of three autoantibodies (antibodies reacting with
GAD65, insulin, and ICA512/IA-2), prediction of risk ofDM among
first-degree relatives is enhanced.
New criteria for diagnosis of diabetes mellitus include:
1- Fasting plasma glucose 126 mg/dl.
2- 2h plasma glucose during the oral glucose tolerance lest
>200mg/dl.
Progress in the identification of persons at risk for the
development of type I DM has made possible the design of
preventive trials. Prevention trials may be primary (pre
autoimmunity), secondary (post autoimmunity, pre-Dvl) or tertiary
(post-OM). Much research has focused on improved methods of
glucose monitoring are the glucowatch, to measure interstitial fluid
glucose levels every twenty minutes and an implantable sensor that
monitors blood sugars every few minutes.
Advances in insulin delivery have included the availability of
new insulin analogues which more closely simulate endogenous
insulin release, with rapid acting analogs simulating the increase in
insulin production that normally occurs after meals. Phase III
clinical trials are in progress of a long-acting basal insulin without
peak actions to simulate the low dose continuous production of the
insulin which normally inhibits hepatic glucose production, In
addition, use of the insulin pump has ’increased markedly since
publication of the DCCT with the greatest increase being among
adolescents. In addition to advances in treatment of diabetes,
research has continued on curmg the disease using islet cell
transplantation and preventing ’the disease with agents such as
insulin (DPT-I Trial) and nicotinamide (ENDIT).
Gene therapy-based approaches add a new dimension to the
efforts aimed at specifically blocking the immunological attack
against the islets in genically at risk individuals or the
immunological response against transplanted allogenic islet.