From San Francisco, Calif., at a meeting of the American Diabetes Association
There are two forms of diabetes. Type I occurs when a person doesn't make enough insulin. Type II is associated with obesity and appears when the body doesn't respond to insulin. Researchers have long suspected that some people with type II diabetes, like those with type I, lose the cells that make insulin.
But that's been difficult to prove, even by autopsy. The insulin-producing cells, called beta cells, are part of the pancreas, which breaks down rapidly after a person dies. However, by reviewing the results of autopsies done within a few hours after the deaths of 124 people with and without type II diabetes, Peter C. Butler of the Mayo Clinic in Rochester, Minn., and his colleagues found signs of beta-cell depletion in both people with the disease and those with a condition known as impaired glucose tolerance, which often leads to it.
The researchers found that the weight of beta cells as a percentage of pancreas weight was 63 percent less in obese people with type II diabetes than in obese people without diabetes. Obese people with impaired glucose tolerance had about 40 percent less beta cell mass. Lean people with the disease had 41 percent less beta cell mass than did lean counterparts without diabetes. Since insulin therapy may protect beta cells, Butler says his results indicate that insulin should be given earlier and to more people with type II diabetes than it is today.
Division of Endocrinology and Diabetes
Keck School of Medicine
University of Southern California
Los Angeles, CA 90033