Type 1 or autoimmune diabetes has for some time been thought of as a disease of childhood and was previously called juvenile diabetes. But the myth that Type 1 diabetes is a childhood disease is a relatively new-on-the-scene myth. In 1934 Dr. Elliot Joslin noted that the incidence of diabetes in lean individuals was relatively constant in each decade of life, but that diabetes in the obese was related to older age. A book published in 1958 (“How to Live with Diabetes” by Henry Dolger, M.D. and Bernard Seeman) that states that “[Type 1] diabetes is almost three times more frequent among young adults than among youngsters.” Since the 1980s the autoimmune nature of Type 1a diabetes has been known, and antibody testing (glutamic acid decarboxylase antibodies (GADA), islet cell antibodies (ICA), and insulinoma-associated (IA-2) autoantibodies) has been the gold standard for the diagnosis of Type 1a diabetes. In numerous scientific studies, approximately 10% of people diagnosed with Type 2 diabetes were found to be antibody positive and in fact had Type 1a diabetes, sometimes called latent autoimmune diabetes in adults (LADA) or Type 1.5. A recent article in the July 2007 issue of "Diabetes Care" indicated that autoimmune gestational diabetes (new onset Type 1 diabetes) accounts for about 10% of all Caucasian women diagnosed with gestational diabetes. However, the medical community has been slow to abandon the myth of Type 1 diabetes as a childhood disease, and Type 1 diabetics diagnosed as adults are still treated as abnormalities and frequently given inappropriate treatment for the disease they have. All too often, they are diagnosed with Type 2 diabetes, which is a fundamentally different disease not only clinically but genetically, and the methods of treatment for the two diseases are also different. The misdiagnosis typically results in undertreatment, and causes needless suffering, the hastening of complications, and sometimes even death. In a recent survey conducted by Australia’s Type 1 Diabetes Network, one third of all Australians with Type 1 diabetes reported being initially misdiagnosed as having the more common Type 2 diabetes. In a recent dLife poll (dlife.com), 13% of respondents said that they initially had been misdiagnosed as having Type 2 diabetes when in fact they have Type 1 diabetes.

People with adult-onset Type 1 diabetes who initially were misdiagnosed as having Type 2 diabetes, strictly due to age not etiology, include Manny Hernandez (founder of TuDiabetes.org), Amy Tenderich (diabetesmine.com), professional surfer Rob Blase, author June Biermann, actress Elizabeth Perkins, and prima ballerina Zippora Karz. People who were correctly diagnosed as adults include Mary Tyler Moore (33), author Anne Rice, swimmer Gary Hall Jr. (24), pro football player Jay Cutler (25), and former acting US Surgeon General Ken Moritsugu (49).

It is well-known that the symptoms of Type 1 diabetes develop slightly more slowly in adults than in children. Unfortunately, because an adult with Type 1 diabetes typically has some functioning beta cells for some time after diagnosis, oral medications for Type 2 diabetes may to some degree control glucose levels right after diagnosis. However, the correct treatment for Type 1 diabetes, at whatever age it is diagnosed, is exogenous insulin as early as possible, to control glucose levels, prevent further destruction of residual beta cells, and reduce the possibility of diabetic complications. LADA researchers in Japan (Kobayashi et al, 2002) have conclusively demonstrated that better preservation of beta cell function occurs with exogenous insulin compared to sulfonylureas, and that sulfonylureas hasten beta cell destruction.

However, these are very clinical outcomes that fail to address the “human side” of misdiagnosis. Those of us who have Type 1 diabetes but were initially diagnosed with Type 2 diabetes often suffered needlessly while on oral medications for Type 2 diabetes until we received appropriate treatment for the disease that we have (exogenous insulin). The following example describes the human impact of misdiagnosis.

June Biermann, prolific author of books on diabetes including The Diabetic’s Sports and Exercise Book, was diagnosed with Type 2 diabetes in 1967 at age 45, even though she failed to meet the criteria associated with Type 2 diabetes. June was prescribed various oral medications for Type 2 diabetes, which did not adequately control her blood sugars, and after one year of much suffering and further weight loss (and several doctors), June was treated with exogenous insulin. The standard for that time was one injection per day of NPH insulin. Although for many years June referred to herself as a Type 1.5 diabetic, today she probably would be called a late-onset Type 1 diabetic. June says, “The medical profession wanted to believe that I did not exist and that the problem was with me, when in fact it was the medical profession that ignored Type 1 diabetes in adults” and that she “has always felt misunderstood and ignored, and that [she] was a freak to the medical profession.”

Why is there a tendency to misdiagnose adults who have Type 1 as Type 2 diabetics? I believe that there are several factors, the primary one being the emphasis by the diabetes medical community that Type 1 diabetes is a childhood disease. I also think that doctors want to keep people off of insulin injections as long as possible, not realizing that for Type 1 diabetics there are significant short- and long-term benefits to beginning exogenous insulin at diagnosis. The two principal organizations that address diabetes in the United States are the American Diabetes Association (ADA) and the Juvenile Diabetes Research Foundation (JDRF). A common theme in materials published by both organizations is using diabetic children to garner more sympathy, and therefore more funding; thus, adults with Type 1 tend to be ignored because they do not garner as much sympathy. The ADA’s emphasis is on Type 2 diabetes, and ADA puts a lot of emphasis on the rarity of Type 1 diabetes (if people with adult-onset Type 1 diabetes are appropriately included in the statistics for Type 1 diabetes, it is not so rare). ADA has published a position paper on Type 2 diabetes in children, even though Type 2 diabetes affects a significantly smaller number of children than the number of adults who acquire Type 1 diabetes. JDRF was founded in 1970 by parents of children with diabetes. JDRF appears to use children, again for sympathy, but also to distance JDRF’s mission from Type 2 diabetes, which often is a lifestyle-related, preventable disease that typically occurs in older adults. Thankfully, just recently JDRF has begun to acknowledge adult-onset Type 1 diabetes and reach out to adults with Type 1. Mary Tyler Moore, International Chair of JDRF, was diagnosed with Type 1 diabetes at age 33. Arnold Donald, President and CEO for JDRF in 2007 said, “Many people don't realize that you can develop type 1 diabetes, have your first onset, in your 20s and 30s or even 40s or later, and that there are a lot of adults who have it, who didn't have it expressed as a child. And so I would say that's probably the most misunderstood thing.”

If you are newly diagnosed, and unsure if you have Type 1 or Type 2 diabetes, you can request antibody testing (GADA, ICA, IA-2). Although many doctors say the test is too expensive and not necessary, the full suite of antibody testing is only $479 (full cost out-of-pocket), it is a definitive test that means a person correctly diagnosed can receive appropriate treatment, and any diabetic complication or hospital visit will greatly exceed that small cost. A positive antibody test confirms a diagnosis of Type 1 diabetes. Also, the C-peptide test, which is a measurement of the body’s natural production of insulin, can be a way to gauge whether you have Type 1 or Type 2 diabetes, although it is not a definitive test.

All people deserve appropriate medical care for the disease that they have. It is imperative that the true incidence of Type 1 diabetes in adults be known, and that the diabetes medical community recognizes us, so that we who acquire the disease as adults can live the best lives possible.