The National Diabetes Information Clearinghouse estimated that 23.6 million people in the U.S. have diabetes. Diabetes comes in three forms: type 1, type 2 and gestational. Many of their symptoms and complications are the same, but they differ in the cause of insulin problems.
Insulin
Beta cells in the pancreas are the only cells in the body that synthesize and secrete the hormone insulin, which is critical to life. Prior to its discovery, those with type 1 diabetes died. The Nobel Prize was awarded to Frederick Banting and John Macleod for their discovery of insulin in 1923. They shared their prize with Charles Best and James Collip, who also participated in the discovery and isolation of insulin. The primary function of insulin is to maintain glucose homeostasis in the body.
Hyperglycemia
All types of diabetes cause hyperglycemia, which plays a role in the development of the complications that are also shared among all people with diabetes. The complications of diabetes are categorized into microvasculature complications and macrovasculature complications. The microvasculature complications are caused by progressive weakening of blood vessels and primarily affect the eyes, kidneys and nerves. The development and progression of the microvasculature complications are completely correlated to the severity and duration of hyperglycemia. The macrovasculature complications are caused by a hardening of the arteries and the buildup of fats and cholesterol on the walls of larger blood vessels, which invariably leads to cardiovascular disease. Hyperglycemia is partly causative of the macrovasculature complications, but other metabolic problems, such as high levels of circulating fat and cholesterol, also play a role in their development and progression. In all people with diabetes, the treatment goal is to maintain blood glucose levels in the normal range to decrease the risk of complications.
Type 1 Diabetes
Type 1 diabetes, also known as insulin-dependent diabetes or juvenile diabetes, is caused by an autoimmune disease in which the body’s own immune system attacks the cells in the pancreas that produce insulin. The American Diabetes Association reported that between 5 and 10 percent of those with diabetes are type 1 diabetic. The cause of type 1 diabetes is not completely known, but involves genetic and environmental factors. Type 1 diabetes is a disease of insulin deficiency, and the only treatment for type 1 diabetics is insulin therapy.
Type 2 Diabetes
Type 2 diabetes is a metabolic disorder that affects multiple systems in the body. More than 85 percent of diabetics have type 2 diabetes. The cause of hyperglycemia in type 2 diabetes is insulin resistance, which is a condition in which certain cells of the body do not respond well to insulin. The beta cells in the pancreas compensate by increasing the production and release of insulin. While insulin deficiency may not be apparent at the start of the disease, the cells in the pancreas that synthesize insulin eventually become compromised and die off. The factors known to contribute to type 2 diabetes are obesity, physical inactivity, poor diet and genetics. The symptoms and complications of type 2 diabetes can be managed by changes in lifestyle, such as weight loss, and anti-diabetic drugs, which may include insulin.
Gestational Diabetes
The ADA reported that 4 percent of all pregnant women develop gestational diabetes. In some women, hormones present at increased levels during pregnancy affect insulin sensitivity and cause insulin resistance. The high levels of glucose in women with gestational diabetes can increase insulin levels in the baby, and this can cause an increase in birth weight. Babies born to mothers with gestational diabetes have an increased risk of developing type 2 diabetes later in life. Also, women who have gestational diabetes are more likely to develop permanent diabetes.
