Type 1 Diabetes

Also known as: juvenile diabetes, insulin-dependent diabetes mellitus (IDDM), childhood diabetes, and ketosis prone diabetes (Note: some of these terms are now outdated).

Type 1 diabetes is an autoimmune disease that occurs when the insulin-producing beta-cells within the pancreas are gradually destroyed and eventually fail to produce insulin. Insulin is a hormone that helps the body's cells use glucose for energy. Blood glucose (or blood sugar) is manufactured from the food we eat (primarily carbohydrates) and by the liver. If glucose can't be absorbed by the cells, it builds up in the bloodstream instead, and high blood sugar is the result. Over time, the high blood glucose levels of uncontrolled diabetes can be toxic to virtually every system of the body.

Because type 1 diabetes is frequently diagnosed in childhood, it is sometimes referred to as juvenile diabetes. However, it can develop at any age throughout adulthood. Early diagnosis is important to prevent some of the more serious complications of diabetes, which include heart disease, blindness, high blood pressure, nerve damage, and kidney failure. In addition to following an exercise and healthy eating plan, individuals with type 1 diabetes require insulin injections.

The causes of type 1 diabetes are complex and still not completely understood. People with type 1 diabetes are thought to have an inherited, or genetic, predisposition to the disease. Researchers believe that this genetic predisposition may remain dormant until it is activated by an environmental trigger such as a virus or a chemical. This starts an attack on the immune system that results in the eventual destruction of the beta cells of the pancreas.

There are several subtypes of type 1 diabetes, including type 1A diabetes, idiopathic diabetes (type 1B), and latent autoimmune diabetes of adulthood (LADA). The basic treatment (i.e., insulin injections) is the same for all.

Diabetes Cause and Risk Factors

Researchers have identified several genes associated with the development of type 1 diabetes. The prevailing belief about the etiology, or cause, of type 1 diabetes is that although someone may have a genetic predisposition for developing type 1 diabetes, it takes an environmental trigger (e.g., virus, toxin, drug) to set the autoimmune process in motion that destroys insulin-producing pancreatic beta cells and causes type 1 diabetes.

Risk factors for developing type 1 diabetes may include:

• Family history. A child that has a parent or sibling with type 1 diabetes has a 2 to 6% greater risk of developing the disease (the risk is higher if both a parent and sibling or an identical twin have type 1 diabetes).
• Autoimmune diseases. The presence of other autoimmune disorders, such as thyroid disease and celiac disease, raises the risk of type 1 diabetes.
• Early cessation of breastfeeding and/or exposure to cow's milk. Clinical research indicates that breastfeeding at least three months decreases the risk of type 1 diabetes. Some studies have also found that exposure to cow's milk or cow's milk-based formula before one year of age may increase diabetes risk, although other studies have not borne out the link.
• Ethnicity. In America, Caucasians have a greater risk of type 1 diabetes than African-Americans, Native Americans, Asian-Americans, and Hispanics. Worldwide, Finland and Sardinia have the highest incidence of type 1 diabetes.
• History of childhood viruses. Viruses that have been associated with type 1 diabetes as environmental triggers include coxsackie B, enteroviruses, adenovirus, rubella, cytomegalovirus, and Epstein-Barr virus.

References

1. Davis MK. "Breastfeeding and chronic disease in childhood and adolescence." Pediatr Clin North Am. 2001 Feb;48(1):125-41, ix. Review.
2. Kimpimaki T, Erkkola M, Korhonen S, Kupila A, Virtanen SM, Ilonen J, Simell O, Knip M. "Short-term exclusive breastfeeding predisposes young children with increased genetic risk of Type I diabetes to progressive beta-cell autoimmunity." Diabetologia. 2001 Jan;44(1):63-9.
3. Vaarala O, Knip M, Paronen J, Hamalainen AM, Muona P, Vaatainen M, Ilonen J, Simell O, Akerblom HK. "Cow's milk formula feeding induces primary immunization to insulin in infants at genetic risk for type 1 diabetes." Diabetes. 1999 Jul;48(7):1389-94.
4. Paronen J, Knip M, Savilahti E, Virtanen SM, Ilonen J, Akerblom HK, Vaarala O. "Effect of cow's milk exposure and maternal type 1 diabetes on cellular and humoral immunization to dietary insulin in infants at generic risk of type 1 diabetes." Finnish Trial to Reduce IDDM in the Genetically at Risk Study Group. Diabetes. 2000 Oct,49 (10): 1657-65.
5. Monetini L, Cavallo MG, Stefanini L, Ferrazzoli F, Bizzarri C, Marietti G, Curro V, Cervoni M, Pozzilli P. "Bovine beta-casein antibodies in breast- and bottle-fed infants: their relevance in Type 1 diabetes." Diabetes Metab Res Rev. 2001 Jan-Feb;17(1):51-4.