Diet and Diabetes Mellitus

DIET AND DIABETES MELLITUS

Diabetes mellitus is the name for a group of serious and chronic (long-standing) disorders affecting the metabolism of carbohydrates. These disorders are characterized by hyperglycemia (abnormally large amounts of glucose in the blood). According to the American Diabetes Association, 23.6 million people in the United States have diabetes. An estimated 17.9 million people have been diagnosed with the disease with 5.7 million going undiag-nosed. There are approximately 57 million people with pre-diabetes. There were 1.6 million new cases of diabetes in people 20 years old and older diag-nosed in 2007 (American Diabetes Association [ADA]). It is a major cause of death; blindness; heart and kidney disease; amputations of toes, feet, and legs; and infections.

Hundreds of years ago, a Greek physician named it diabetes, which means “to flow through,” because of the large amounts of urine generated by victims. Later, the Latin word mellitus, which means “honeyed,” was added because of the amount of glucose in the urine.

Diabetes insipidus is a different disorder. It also generates large amounts of urine, but it is “insipid,” not sweet. This is a rare condition, caused by a damaged pituitary gland.

The body needs a constant supply of energy, and glucose is its primary source. Carbohydrates provide most of the glucose, but about 10% of fats and up to nearly 60% of proteins can be converted to glucose if necessary.

The distribution of glucose must be carefully managed for the mainte-nance of good health. Glucose is transported by the blood, and its entry into the cells is controlled by hormones. The primary hormone is insulin.

Insulin is secreted by the beta cells of the islets of Langerhans in the pancreas. When there is inadequate production of insulin or the body is unable to use the insulin it produces, glucose cannot enter the cells and it accumulates in the blood, creating hyperglycemia. This condition can cause serious complications.

Another hormone, glucagon, which is secreted by the alpha cells of the islets of Langerhans, helps release energy when needed by converting glycogen to glucose. Somatostatin is a hormone produced by the delta cells of the islets of Langerhans and the hypothalamus. All actions of this hormone are inhibitory. It inhibits the release of insulin and glucagons.

The amount of glucose in the blood normally rises after a meal. The pancreas reacts by providing insulin. As the insulin circulates in the blood, it binds to special insulin receptors on cell surfaces. This binding causes the cells to accept the glucose. The resulting reduced amount of glucose in the blood in turn signals the pancreas to stop sending insulin.