Can a person have both type 1 and type 2 diabetes at the same time?
Generally speaking, we do not diagnose both disorders in the same individual. If people have type 1 diabetes, they are completely lacking effective circulating insulin. By definition, this is not the case in people with type 2 diabetes, so having the one disorder effectively rules out the other. However, people with type 1 diabetes may be prone to the same metabolic problems as those with type 2 diabetes. In other words, if people with type 1 diabetes gain weight, become sedentary, or are members of an ethnic group at high risk for type 2 diabetes, they may become insulin resistant and their diabetes will be more difficult to control. Higher doses of insulin will be required and they may develop the metabolic problems that tend to be associated with type 2 diabetes, such as cholesterol and related blood fat abnormalities, as well as high blood pressure. These will add to their risk of cardiovascular disease. Some people with apparent type 2 diabetes appear to have a partial form of type 1 diabetes, which has stopped short of complete destruction of their insulin-producing cells in the pancreas. This is known as LADA or latent autoimmune diabetes of the adult. They tend to require insulin treatment earlier in the course of their diabetes, but are not considered to have both diseases.