Originally Published Sept  2007

 

WHAT IS TYPE II DIABETES?

Type ll Diabetes, or Non-Insulin Dependent Diabetes Mellitus (NIDDM), is the most common form of Diabetes. While Type 1 or Insulin-Dependent Diabetes typically becomes evident in childhood and is due to an inborn lack or complete absence of insulin production, Type ll Diabetes typically becomes evident in adulthood and is significantly due to the patient's lifestyle. Of all diabetics, 85% to 90% are Type ll. In many countries, the incidence of Type ll Diabetes has been rising sharply in recent decades, while the average age of onset has been declining. Type ll Diabetes affects more than 17 million people in North America, over 20 million in Latin America and over 150 million worldwide.

The following information is supplied by the American Diabetic Association

TYPE ll DIABETES

The two major forms of diabetes are type 1 (previously called insulin-dependent diabetes mellitus (IDDM) or juvenile-onset diabetes) and type ll (previously called noninsulin-dependent diabetes mellitus (NIDDM) or maturity-onset diabetes).

INSULIN

Both diabetes type 1 and type ll share one central feature: elevated blood sugar ( glucose) levels due to absolute or relative insufficiencies of insulin, a hormone produced by the pancreas. Insulin is a key regulator of the body's metabolism. It normally works in the following way:

During and immediately after a meal the process of digestion breaks carbohydrates down into sugar molecules (of which glucose is one) and proteins into amino acids.

Right after the meal, glucose and amino acids are absorbed directly into the bloodstream, and blood glucose levels rise sharply. (Glucose levels after a meal are called postprandial levels.)

The rise in blood glucose levels signals important cells in the pancreas, called beta cells , to secrete insulin, which pours into the bloodstream. Within ten minutes after a meal insulin rises to its peak level.

Insulin then enables glucose and amino acids to enter cells in the body, particularly muscle and liver cells. Here, insulin and other hormones direct whether these nutrients will be burned for energy or stored for future use. (It should be noted that the brain and nervous system are not dependent on insulin; they regulate their glucose needs through other mechanisms.)

When insulin levels are high, the liver stops producing glucose and stores it in other forms until the body needs it again.

As blood glucose levels reach their peak, the pancreas reduces the production of insulin.

About two to four hours after a meal both blood glucose and insulin are at low levels, with insulin being slightly higher. The blood glucose levels are then referred to as fasting blood glucose concentrations .

TYPE II DIABETES

Type ll diabetes is most common form of diabetes, accounting for 90% of cases. An estimated 17 million Americans have type ll diabetes and half are unaware they have it. The disease mechanisms in type ll diabetes are not wholly known, but some experts suggest that it may involve the following three stages in most patients:

The first stage in type ll diabetes is the condition called insulin resistance; although insulin can attach normally to receptors on liver and muscle cells, certain mechanisms prevent insulin from moving glucose (blood sugar) into these cells where it can be used. Most type ll diabetics produce variable, even normal or high, amounts of insulin, and in the beginning this amount is usually sufficient to overcome such resistance.

Over time, the pancreas becomes unable to produce enough insulin to overcome resistance. In type ll diabetes the initial effect of this stage is usually an abnormal rise in blood sugar right after a meal (called postprandial hyperglycemia ). This effect is now believed to be particularly damaging to the body.

Eventually, the cycle of elevated glucose further impairs and possibly destroys beta cells, thereby stopping insulin production completely and causing full-blown diabetes. This is made evident by fasting hyperglycemia , in which elevated glucose levels are present most of the time.

TYPE I DIABETES

In type 1 diabetes, the disease process is more severe and onset is usually in childhood:

Beta-cells in the pancreas that produce insulin are gradually destroyed. Eventually insulin deficiency is absolute.

Without insulin to move glucose into cells, blood glucose levels become excessively high, a condition known as hyperglycemia.

Because the body cannot utilize the sugar, it spills over into the urine and is lost.

Weakness, weight loss, and excessive hunger and thirst are among the consequences of this "starvation in the midst of plenty."

Patients become dependent on administered insulin for survival.

DIABETES SECONDARY TO OTHER CONDITIONS

Conditions that damage or destroy the pancreas, such as pancreatitis, pancreatic surgery, or certain industrial chemicals can cause diabetes. Polycystic ovaries are highly associated with diabetes. Certain drugs can also cause temporary diabetes, including corticosteroids, beta-blockers, and phenytoin. Rare genetic disorders (Klinefelter's syndrome, Huntington's chorea, Wolfram's syndrome, leprechaunism, Rabson-Mendenhall syndrome, lipoatrophic diabetes, and others) and hormonal disorders (acromegaly, Cushing's syndrome, pheochromocytoma, hyperthyroidism, somatostatinoma, aldosteronoma) are associated with or increase the risk for diabetes.