Type 1 Causes

What causes diabetes? Researchers have identified several genes associated with the development of type 1 diabetes. While the causes are complex and not completely understood, the prevailing belief about the etiology, or cause, of type 1 diabetes is that while someone may have a genetic predisposition for developing the disease, it takes an environmental trigger or series of triggers (e.g., virus, toxin, drug) to set off the autoimmune process that destroys insulin-producing beta cells of the pancreas.

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% risk of developing the disease. The risk is higher if both a parent and sibling or an identical twin have type 1 diabetes. (The risk for type 1 in the general population without a family history is about 0.4%.) Although family history is important, 80% of people with type 1 diabetes do not have another relative with type 1 diabetes.  
• Autoimmune diseases. The presence of other autoimmune disorders, such as thyroid disease and celiac disease, raise the risk of type 1 diabetes.  
• Early cessation of breastfeeding and/or exposure to cow's milk. Some clinical research indicates that breastfeeding for at least three months decreases the risk of type 1 diabetes. Other studies suggest 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 Latinos. Worldwide, Finland and Sweden 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.

Reviewed by Jason C. Baker, M.D. (5/13)