الفهرس 
PATHOPHYSIOLOGY OF DIABETES MELLITUSOnly 14 pages are availabe for public view
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Abstract
D
iabetes increases the risk for disorders that predispose individuals to hospitalization; including coronary artery, cerebrovascular and peripheral vascular diseases, nephropathy, infection, and lower-extremity amputations.
Hyperglycemia is common in acutely ill patients, including those treated in intensive care units (ICUs).The occurrence of hyperglycemia, in particular severe hyperglycemia, is associated with increased morbidity and mortality in a variety of groups of patients.
Hyperglycemia, be it secondary to diabetes, impaired glucose tolerance, impaired fasting glucose, or stress-induced is common in the critically ill patients.
Hyperglycemia and glucose variability in intensive care unit (ICU) patients has some experts calling for routine administration of intensive insulin therapy to normalize glucose levels in hyperglycemic patients. Others, however, have raised concerns over the optimal glucose level, the accuracy of measurements, the resources required to attain tight glycemic control (TGC), and the impact of TGC across the heterogeneous ICU population in patients with diabetes, previously undiagnosed diabetes or stress-induced hyperglycemia.
Increased variability in glucose levels during critical illness and the therapeutic intervention have recently been reported to have a deleterious impact on survival, particularly in non diabetic hyperglycemic patients.
The incidence of hypoglycemia (<40 mg/dL or 2.2 mmol) associated with TGC is reported to be as high as 18.7%, by Van den Berghe. in 2001 in a medical ICU, although application of various approaches and computer algorithms may improve this. The impact of hypoglycemia, particularly in patients with septic shock and those with neurologic compromise, warrants further evaluation.
Since the introduction of intensive insulin therapy (IIT) in the intensive care unit (ICU)-world by Van den Berghe in 2001, the concept of lowering morbidity and mortality by this intervention is a subject of a vivid discussion. Paramount effort has been put in numerous studies trying to corroborate the concept and to highlight probable mechanisms.
Although the results of randomized trials of intensive insulin therapy in ICU patients have been inconsistent, most of the data do not support the hypothesis of a survival benefit, and some data have suggested increased mortality. All the trials in which the targeted glucose concentration was 80 to 110 mg per deciliter showed increased rates of hypoglycemia. Moreover, marked hyperglycemia itself is associated with increased risks of adverse outcomes.
Pending more data to guide the development of optimal glucose levels, it is recommended that a target of 140 to 180 mg per deciliter (which is in accordance with the most recent guidelines), is the optimal blood glucose target in the ICU with the use of an established, preferably computerized insulin-infusion algorithm and close monitoring of glucose levels. In consideration of these moderate target levels, it is recommended that nutritional support be introduced gradually, preferably by the enteral route, and that infusion of substantial quantities of intravenous dextrose be avoided.