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Introduction to Diabetes
Diabetes is a metabolic disorder associated with defects in insulin secretion, insulin action, or both. Insulin is a hormone produced by the beta cells of the islets of Langerhans in the pancreas, and is needed to convert sugar, starches and other food into energy needed for daily life.
When food is digested, carbohydrates are broken down into sugar molecules which are absorbed into the bloodstream. This rise in blood glucose levels triggers the release of insulin. When there is insufficient insulin to convert these sugars into energy for tissues, it creates a starvation state within the body despite the fact that the body is being nourished. When glucose is unavailable, the tissues essentially starve. Meanwhile, the levels of sugar in the blood stream continue to climb, causing a condition called hyperglycemia.
Normal secretion of insulin is composed of two phases: "basal" and "postprandial". Basal insulin secretion refers to the amount of insulin that is needed between meals. It is composed of small and continuous pulses of insulin around 30 to 35 units per day in an average adult. Postprandial insulin secretion is triggered by eating and is composed of a high amplitude pulse, as compared with the basal secretion, leading to a sharp increase and decrease in the insulin level. The amount of postprandial insulin is mainly determined by the type and amount of food ingested.
Long-term complications of diabetes mellitus result from both microvascular (small blood vessel) and macrovascular (large blood vessel) damage in the body. The risk of cardiovascular disease is increased in people with diabetes. Of the more than 200,000 Americans with diabetes who die annually due to diabetes-related complications, most die of coronary heart disease or other cardiovascular conditions. Diabetes is a major cause of blindness, kidney disease, and limb amputation in the United States.
Although the cause of diabetes is not known, both genetics and environmental factors such as obesity and lack of exercise appear to play roles.
