Type II Diabetes:
Non-Insulin Dependent Diabetes Mellitus
and friends
Type II diabetes is the most common form of diabetes, making up about 90% of patients suffereing from diabetes. In short, type II patients suffer from impaired insulin action. Insulin is present in the blood, but the body's cells no longer react properly to insulin and therefore cannot use it. This phenomenon is generally referred to as "insulin resistance" or "insulin insensitivity" - disease is mostly a result of faulty insulin action rather than the levels of insulin in the blood (as is the case for type I). This is usually a result of abnormalities on the cell surface or within the cell, or both. The following is an outline of the etiological classification for type II.*
A. Deficient insulin action because of:
1. Intracellular defect of glucose disposal (most common)
2. Defects of insulin receptor function
a. Antibodies to insulin receptor
b. Mutations in insulin receptor
3. Different insulin structure (gene mutation)
4. Iatogenic (due to medical treatment)
5. Other - rare genetic disorders
B. Deficient insulin secretion because of
1. Defects of signaling
2. Partial destruction of beta-cells
As is evident in this outline, there may be several possible explanations for any one case of type II diabetes. What is not explored here is the large role that environmental factors play in the development of type II. Obesity and a sedentary lifestyle are particularly high-level risk factors. Risk also increases with age, possibly due to the wearing out of beta-cells. Other risk factors that have been identified are a family history of type II and high cholesterol. Studies have also shown that minorities have higher rates of type II.
Some type II diabetics are insulin-dependent and require exogenous insulin. All patients are asked to make lifestyle changes: increase activity, eat healthily, and reduce stress (good suggestions for all people). The outcomes of type II can be less severe but are more insiduous. Hyperglycemia is generally lower than that found in type I diabetics, and thus its effects take a little longer to manifest. Type II diabetics are generally older, obese, and sedentary, which can complicate and confound the outcomes of type II.
*Bennett, PH. Definition, Diagnosis, and Classification of Diabetes Mellitus and the Imparied Glucose Tolerance. from Kahn, CR & Weir, GC. (eds). Lea & Febiger: Philadelphia. 1994. Joslin's Diabetes Mellitus.
Gestational Diabetes
The causes of gestational diabetes have yet to be fully explored or understand. About 4% of pregnant women develop diabetes during their pregnancy. Sometimes the diabetes resolves itself after the birth and sometimes the woman remains diabetic. Treatment is the same as for type II diabetes, often requiring insulin treatment.
Other
Diabetes can also result from unrelated medical conditions and syndromes. Pancreatic disease almost always leads to diabetes because of the destruction of pancreatic tissue and the beta-cells contained within. Hormone abnormalities may also be to blame. Certain drugs or chemicals could bring about diabetes by affecting cells, insulin, or the pancreas. It is possible that genetic syndromes will lead to diabetes. Cases of diabetes caused by severe malnutrition have also been reported.