Diabetes Mellitus & Endocrine Diseases

DIABETES MELLITUSDiabetes mellitus is a clinically and genetically heterogenous metabollic disease characterized by abnormally elevated blood glucose levels (hyperglycemia) and dysregulation of carbohydrate, protein and lipid metabolism.

Classification

PathophysiologyMediated by alterations of carbohydrate metabolism and insulin actioninsulin: hyperglycemiainsulin: hypoglycemiaCounterregulatory hormones: glucagon, catecholamines, growth hormone, thyroid hormone, glucocorticoidType 1 DMIdiopathic autoimmune destruction of pancreatic beta cells5%-10% of all DM cases, occur before 25 yoDependent on exogenously administered insulin for survivalTo meet cellular energy needs, fat is broken down releasing glycerol and free fatty acids. Glycerol is converted to glucose. Fatty acids are converted to ketones, resulting in increase ketone levels. Accumulation of ketones in body fluids, decreased pH, electrolyte loss and dehydration from excessive urination, alternation is bicarbonate buffer system result in diabetic ketoacidosis.Type 2 DMCharacterized by insulin resistance in peripheral tissue and defective insulin secretion by the pancreatic beta cells.Etiology (multifactorial): genetic, age, obesity, lack of exercise. Other risk factor: high caloric intake, sedentary lifestyleBy the time many type 2 DM patients are diagnosed, diabetic complications have already begunOther specific types of DMIt is caused by various specific genetic defects of beta cell function and insulin action, diseases of the exocrine pancreas, endocrinopathies, pancreatic dysfunction induced by drugs, chemicals or infections.Etiology of this category of DM is heterogenous because the abnormal glucose tolerance may be secondary to the precipitating condition or it may be apparently causal in a manner that still remains unclear.Gestational DMMild degree of fasting hyperglycemia or glucose intolerance during the third trimesterMost patients with gestational DM return to a normoglycemic state after parturitionClinical PresentationDiagnostic and Monitoring

ComplicationsThese complications are linked to sustained hyperglycemia, which can dramatically alter the function of multiple cell types and their extracellular matrix and thereby cause structural and functional changes in the affected tissues.

ManagementPrimary treatment goals : achieving normal blood glucose levels and prevention of DM complicationMainstays of diabetic care: diet, exercise, weight control, and medications. Weight reduction and exercise improve tissue sensitivity to insulin and allow its proper use by target tissuePrimary medication used in type 1 DM is insulin. Type 2 DM individuals frequently take oral medications, although many also use insulin to improve glycemic control

Several oral agents for treating DM

Sulfonylurea & repaglinide stimulates pancreatic insulin secretion. Metformin prevent glycogenolysis. Thiazolidinediones increasre tissue sensitivity to insulin. Acarbose slows the digestion and uptake of carbohydrate12All patients with type 1 DM use exogenous insulin. Insulin is taken via subcutaneous injection, most often with a syringe. Most common complication of insulin therapy is hypoglycemia. (blood glucose level fall to