New Form of Diabetes Described by Researchers
WebMD News Archive
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