My friend Jay was diagnosed with type 1 diabetes at the age of 40. This is unusual; type 1 is usually diagnosed in children, and was once called juvenile onset diabetes. Patients such as Jay demonstrate that it can develop at any age.
Adults are much more likely to develop type 2 diabetes, which is characterized by insulin resistance of cells throughout the body. The pancreas is still able to produce insulin, and may actually produce higher than normal amounts. But the body is not able to use insulin effectively to control blood sugar, so the symptoms produce the appearance of too little insulin. At first Jay's doctor prescribed pills to enhance his ability to use insulin, assuming that he also had type 2 diabetes. They didn't work. Jay carefully monitored his diet and blood sugar, exercised, and lost weight, all without success. His pancreas had stopped producing insulin. The correct treatment for type 1 diabetes is insulin replacement. Jay now uses an injector, which is less painful than ordinary needles.
A study in Finland showed that type 1 diabetes can be predicted up to 20 years before symptoms develop. The researchers started with 3,475 non-diabetic subjects aged 3 to 18 years. They tested each subject for GAD antibodies and islet antigen-2 antibodies, which are markers of the autoimmune process that destroys the insulin-producing pancreas cells. Six years later, the researchers retested 2,375 of the subjects. All subjects were observed for 27 years (1980 to 2007). Eighteen developed type 1 diabetes during this observation period, and all of these were identified by a positive test for one or both antibodies.
Not everyone who had a positive antibody test went on to develop diabetes, but the correlation was very strong. Of the individuals who tested positive for one antibody, 60 percent developed diabetes within 0.9 to 20.3 years. Seven of the subjects tested positive for both antibodies, and 100 percent of them developed diabetes.
With such advanced warning, there is hope that the autoimmune process can be stopped before type 1 diabetes develops. One of the promising findings of the Finnish study was that some patients who had a positive test for one antibody in 1980 had a negative test six years later. Researchers attribute this result to a dynamic process, similar to the relapsing-remitting course of other autoimmune diseases. Further research is in progress to correct this process before too much damage is done.
Reference:
Knip M et al, “Prediction of type 1 diabetes in the general population”, Diabetes Care. 2010 June; 33(6): 1206-12.
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.