New Form of Diabetes Described by Researchers
Feb. 2, 2000 (Los Angeles) -- Investigators in Japan have identified a form of type 1 diabetes characterized by very abrupt onset, unlike the popular perception of diabetes as a disease that develops gradually.
However, this condition is not the "novel subtype" the authors claim it is, says Marc Rendell, MD, professor of medicine at Creighton University in Omaha, Neb., and director of the Creighton Diabetes Center. In an interview seeking independent comment, he tells WebMD, "I believe this is part of the overall spectrum of insulin-dependent diabetes."
To conduct their study, the authors, led by Akihisa Imagawa, MD, of Osaka University, studied 56 Japanese adults with type 1 (previously known as insulin-dependent) diabetes. Among those 56, they found 11 whose blood sugar was much higher than those of the other patients. Those patients also had low values of a compound known as HbA1C, a reflection of their average glucose level for the last two to three months, suggesting that the rise in blood sugar was relatively recent.
On the basis of these and related findings, the authors suggest that this could be a subtype of type 1 diabetes, called "type 1B." Today it is assumed that most cases of type 1 diabetes result from an autoimmune process in which the body treats the insulin-producing cells in the pancreas as foreign invaders and produces antibodies against them, thus leading to death of these cells. These patients, however, did not have these antibodies, implying that their form of the disease has some other cause.
There could be "a possible environmental influence, such as a virus or another factor," says Ake Lernmark, PhD, professor of medicine at the University of Washington in Seattle, and the author of an editorial that accompanies the study in The New England Journal of Medicine. He tells WebMD that no one knows yet what this environmental trigger might be, but notes that certain viruses, including rubella, mumps, and the Coxsackie virus, are all known to cause mild inflammation in the pancreas, which is the first step in the development of type 1 diabetes. It is possible that a similar, but still unidentified, virus may be causing the form the Japanese authors describe.
The study's greatest value lies in the reminder it provides that diabetes can have an abrupt onset, says Rendell. "This survey of a large number of patients clearly does not support a long-term autoimmune process as a universal path to insulin-dependent diabetes." On the other hand, he does not agree that these investigators have found a new subtype, and tells WebMD that doctors often see patients whose diabetes appears to have developed rapidly. He urges consumers to consult their doctors at the first sign of any diabetes symptoms, including excessive thirst, urination, unexplained weight loss, and fatigue.