لخّصلي

iabetes mellitus is a syndrome characterized pri- Dmarily by an absolute or relative deficiency of insulin and caused by various mechanisms re- sulting in hyperglycemia (1,2). The subdivision of diabetes mellitus into type I (insulin-dependent) and type II (non-insulin-dependent) diabetes is useful not only to in- dicate their different underlying etiologies (1,2) but also for treatment decisions and primary prevention. In both types of diabetes, a phase of latent susceptibility (3,4) is followed by preclinical dysfunction that can sometimes be identified; finally, clinical symptoms and signs appear. Especially during the first stage of latent susceptibility and the period of pre- clinical dysfunction, the possibility of primary prevention
may exist in both types of diabetes.
There probably is heterogeneity within the major types of
diabetes. In type I diabetes, subclass a, which has early onset, a slight male predominance, and may be initiated by an immune-mediated destructive process of the pancreatic (3- cells, can be differentiated from the rarer subclass b diabetes. This type has a later and more insidious age of onset, a female preponderance, a strong family history of autoimmune en- doc'rinopathy, and may be a primary autoimmune form of the disease characterized by persistence of islet cell antibodies (5).
Type II diabetes is classified into two subtypes: I) nonobese diabetes and 2) obese diabetes (1). Type II diabetes of the
young or Mason-type diabetes exists as a distinct entity of type II diabetes (6). Impaired glucose tolerance (IGT) is a category between normoglycemia and diabetes, based on ar- bitrarily chosen fasting blood glucose levels and levels 2 h after a glucose load (1). IGT is a deviation of the normal metabolic state, but it should not be considered a disease, although people with IGT are at high risk of developing overt type II diabetes mellitus.
Other types of diabetes, caused by entirely different path- ogeneses, exist in certain parts of Africa, South America, and Asia, e.g., malnutrition diabetes, pancreatic diabetes, and J (Jamaica)-type diabetes (7). Also, diabetes associated with certain conditions and syndromes, e.g., pancreatic dis- ease, diseases of hormonal etiology, drug- or chemically in- duced conditions, insulin-receptor abnormalities, and certain genetic syndromes (1,2) are known. These are uncommon, and their prevention is related to the prevention and treat- ment of the primary conditions in question and is, therefore, not discussed here.
PREVENTION STRATEGIES
Primary prevention and secondary prevention are established terms of preventive medicine (8). Primary prevention has been defined as all measures designed to reduce the incidence of a certain disease in a population by reducing the risk of