Diabetes

Diagnosis and Classification of Diabetes Mellitus
AMERICAN DIABETES ASSOCIATION
DEFINITION AND DESCRIPTION OF DIABETES MELLITUSdDiabetes is a group of metabolic diseases characterized by hy-perglycemia resulting from defects in in- sulin secretion, insulin action, or both. The chronic hyperglycemia of diabetes is associated with long-term damage, dys- function, and failure of different organs,especially the eyes, kidneys, nerves, heart, and blood vessels.
Several pathogenic processes are in- volved in the development of diabetes. These range from autoimmune destruc- tion of the b-cellsof the pancreas with consequent insulin deficiency to abnor- malities that result in resistance to insulin action. The basis of the abnormalities in carbohydrate, fat, and protein metabo- lism indiabetes is deficient action of in- sulin on target tissues. Deficient insulin action results from inadequate insulin se- cretion and/or diminished tissue respon- ses to insulin at one or more points inthe complex pathways of hormone action. Impairment of insulin secretion and de- fects in insulin action frequently coexist in the same patient, and it is often unclear which abnormality, if eitheralone, is the primary cause of the hyperglycemia.
Symptoms of marked hyperglycemia in- clude polyuria, polydipsia, weight loss, some- times with polyphagia, and blurred vision. Impairment of growth andsusceptibility to certain infections may also accompany chronic hyperglycemia. Acute, life-threaten- ing consequences of uncontrolled diabetes are hyperglycemia with ketoacidosis or the nonketotichyperosmolar syndrome.
Long-term complications of diabetes include retinopathy with potential loss of vision; nephropathy leading to renal failure; peripheral neuropathy with risk of foot ulcers,amputations, and Charcot joints; and autonomic neuropathy caus- ing gastrointestinal, genitourinary, and
cardiovascular symptoms and sexual dys- function. Patients with diabetes have an increased incidence...