Diabetes mellitus is really a group of different diseases that are characterized by elevated circulating blood glucose. Elevated blood glucose can occur by different mechanisms within the body, but once it is happening, there is damage caused to many different organs and tissues of the body. Most serious and common among these are damage to the small blood vessels that can affect the entire body, but are often most critical in their adverse effects on the heart, the retina, the kidneys, and the toes and feet. Additionally, nerve damage or neuropathy occurs, which can affect many different types of nerves, but most commonly the sensory nerves of the toes, feet and hands.
About 95% of all diabetes is called Type 2 diabetes, the kind that used to be known as “adult-onset diabetes”. Type 2 diabetes is characterized by elevated blood glucose and a resistance in the tissues to the effects of circulating insulin. About 80% of type 2 diabetes is related to excess weight and obesity. Approximately 26 million Americans have type 2 diabetes today. It is believed that 75 million people in the United States have type 2 diabetes that is yet undiagnosed.
Type 2 diabetes becomes more common as we gain weight and as we age. Some genetic predisposition to earlier development of type 2 diabetes also plays a role.
Type 1 diabetes, or what has been referred to as “juvenile diabetes” occurs in 5% or less of total diabetes cases. This typically stems from an autoimmune type condition resulting in the failure of the specific cells in the pancreas, the beta cells, which produce insulin. The lack of insulin production leads to elevated circulating blood glucose. It is not known exactly why some individuals develop an autoimmune attack on their own pancreatic beta cells (the insulin producing pancreas cells), but it is thought to occur in part due to genes and in part due to some environmental factors.
The third type of diabetes is called gestational diabetes and this is a special type of diabetes that occurs only during pregnancy.
Gestational diabetes occurs because another form of insulin resistance takes place that is related to the hormones of pregnancy and placental growth. There is an overlap with obesity-related type 2 diabetes as well during gestational diabetes. In most cases, after delivery, the gestational diabetes resolves. A woman who develops gestational diabetes is at higher risk of developing Type 2 diabetes later on.
Types of Diabetes
- Type 1 autoimmune disease affecting the pancreatic beta cells
- Type 2 related to weight gain, obesity and insulin resistance
- Gestational, occurring in pregnancy