GLUCOSE TOLERANCE
Glucose tolerance is indicated by the nature of the blood glucose curve following the administration of a test amount of glucose.There are three main types of diabetes:type 1 diabetes,type 2 diabetes and Gestational diabetes.Gestational diabetes :This is diabetes developed during the period of pregnancy and this usually resolves itself after the birth of the child
i Type 1 diabetes (insulin- dependent diabetes mellitus )
This is characterized by decreased glucose tolerance due to decrease secretion of insulin in response to the glucose challenge. This is manifested by elevated blood glucose levels hyperglycemia and glycosuria and may be accompanied by changes in fat metabolism. Tolerance to glucose declines not only in type 1 diabetes but in type 2 diabetes.
ii Type 2 diabetes mellitus (non- insulin- dependent diabetes,
mellitus; NIDDM);
This occurs, when your pancreas doesn’t produce enough insulin due to liver damaged; and in some infections. This often associated with obesity and raised level of plasma free fatty acids; under the influence of some drugs; the patient is usually over 40 years of age.
CONTROLLING OF DIABETES MELLITUS
The renal threshold for glucose is usually raised in a diabetic mellitus patient. The presence of glycosuria is frequently an indication of diabetes mellitus.
i Type 2 (non-insulin- dependent) diabetic mellitus:
Drugs such as tolbutamide stimulate insulin release by a mechanism different from that employed by glucose and have achieved widespread use in the treatment of type 2 ( non- insulin -dependent) diabetes mellitus. A receptor that binds this class of drugs has recently been cloned from the pancreatic B cells. This receptor is closely linked to the ATP sensitive k+ channels, this many explain the mechanism of action of this important class of drugs (Harper’s 25th edition pp 614).
ii Type 1 (insulin- dependent) diabetic mellitus
The precise cause of this type of diabetic has not been elucidated. A tentative scheme of the chain of events is the following. Patients with this type of diabetes have a genetic susceptibility, which may predispose to a viral infection. The infection and consequent inflammatory reaction apparently alter the antigenicity of the surface of the pancreatic B cells and set up an autoimmune reaction ,which means that the body immune system mistakenly turns against healthy cells such as insulin producing cells in the pancreas,and destroys them, involving both cytotoxic antibodies and T lymphocytes. This leads to widespread destruction of B cells, resulting in type I diabetes mellitus. The marked hyperglycemia, glucosuria, ketonemia and ketonuria confirmed the diagnosis of diabetic ketoacidosis. Thus, the clinical picture in diabetic ketoacidosis reflects the abnormalities in the metabolism of carbohydrates , lipid , protein ,K+, water and pH
(i) Carbonhydrate metabolism
There is decrease glucose uptake by certain tissues, increased glycogenolysis and increase glyconegenesis.
(ii) Lipid metabolism
Increase Lipolysis , increased fatty acid oxidation and increased production of ketone bodies.
(ii) Protein metabolism
There is decreased protein synthesis, increased catabolism of
protein.
(iv) K+, water, and pH
This is shown by decrease entry of K+ into cells, water loss secondary to glycosuria and Acidosis due to increased production of ketone bodies.
Treatment OF DIABETIC KETOACIDOSIS
The most important measures in treatment of diabetic ketoacidosis are intravenous administration of insulin and saline solution. The dosage might be intravenous insulin (10 units/h) added to 0.9% Nacl. And this should be monitored, incase, level of plasma glucose falling below 250mg/dL. In which glucose should be given. Kcl, also should be administered cautiously, with plasma K+ levels monitored every hour initially .
Continual monitoring of K+ levels is extremely important in the management of diabetic ketoacidosis because inadequate management of K+ balance is the main cause of death. Bicarbonate is not needed routinely but may be required if acidosis is very severe.
Diet and exercise are the most important aspects of controlling diabetes type1 and type 2,Plus insulin injection.
