What should I know about Type 2 Diabetes Mellitus?
Diabetes mellitus, a term that means “the running through of sugar,” was first identified in the 1st century AD.(1) The disease was described in old books as “the melting down of flesh into urine.” Diabetes mellitus is a chronic condition where there is less insulin than what the body needs. This can be low insulin, a problem with the release of insulin, insulin that cannot work in the cells that need it, or insulin that is inactivated before it is able to function. Diabetes mellitus is a disease in which the body does not produce or does not use insulin effectively. It is not simply hyperglycemia, or too much glucose (sugar) in the blood.
Insulin is a hormone produced in the pancreas by the beta cells in the Islets of Langerhans. The release of insulin by these special cells is regulated by the amount of glucose in the blood. It is responsible for transporting glucose (from carbohydrates) into the cells for energy production. After a meal, when blood sugar increases, insulin release increases. Between meals, when blood sugar is low, insulin release is low. Insulin is released from the pancreas directly into the liver where some is used and some is broken down and eliminated from the body. The rest is released into the general blood circulation. By helping to move glucose into the cells, insulin decreases blood sugar. Insulin also decreases the breakdown of stored fat and builds triglycerides. Insulin is involved in the production of protein. The proper growth and development of children is dependent on insulin.
Diabetes can affect people of any age. It increases the risk of chronic conditions like heart disease, retinopathy (a disease of the retina) and blindness, peripheral neuropathies (a disease of the nervous system), circulation problems that can lead to amputation, problems with the immune system, and skin ulcers and poor wound healing.
Diabetes is diagnosed by lab tests, either a fasting plasma glucose (FPG) or a two-hour plasma glucose (OGTT – oral glucose tolerance test). There are two forms of diabetes mellitus: type 1 (also called IDDM, insulin dependent diabetes mellitus, or juvenile onset) and type 2 (NIDDM, non-insulin dependent diabetes, or adult onset).
Ninety percent of individuals with diabetes have type 2. Most of these individuals are over 40 years old. One in five patients is over the age of 65, and 80 percent are overweight.(2) Many patients have increased blood sugar seven to ten years before symptoms occur.
When something is wrong with a person's blood sugar regulation even if insulin is being produced by their pancreas, the individual probably has type 2 diabetes. People with type 2 do not need to depend on insulin injections to survive. Type 2 diabetes is not fully understood. Three physical abnormalities usually occur in type 2: insulin resistance, increased glucose production in the liver, and poor beta cell function. These can occur individually or in combination.
Insulin resistance appears to be the first stage of the disease. It means that insulin cannot help glucose go from the blood into the cells.(3) While the beta cells are able to release normal or even higher than normal amounts of insulin, glucose movement into the cells is sluggish and blood glucose slowly begins to rise. Therefore, blood sugar remains increased even with insulin being produced by the pancreas. Then the pancreas releases even more insulin, and hyperinsulinemia (too much insulin in the blood) begins.
This is likely due to a genetic defect that affects how insulin is used or the way it is transported to the cells. Insulin resistance is due to high insulin levels, not high glucose levels. Therefore, the individual is always hyperglycemic. Eventually, the beta cells “burn out” and insulin resistance may turn into diabetes.
Many people with ty