This might put an end to the "you got diabetes because you're fat" folks.
It appears it might be the other way round.
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Brain May Control Type 2 Diabetes Altering Single Gene in the Brain of Mice Cures Abnormal Sugar
Metabolism Seen in Type 2 Diabetes
By Jennifer Warner Reviewed By Brunilda Nazario, MD on Wednesday, November 12, 2003 WebMD
Medical News
Nov. 12, 2003 -- The key to curing type 2 diabetes may be in our heads, or at least in the heads of
mice. A new study shows that altering a single gene in the brains of obese mice bred to have type 2
diabetes helped them completely normalize blood sugar levels.
Researchers say that it's the first study to show that glucose control may be regulated by the
brain. If further research confirms these results, it could open a whole new approach to treating
type 2 diabetes.
People with type 2 diabetes are unable to regulate their blood sugar (glucose) levels normally
because their bodies have become resistant to insulin, which is the hormone responsible for
controlling glucose in the blood.
Researchers say that obesity is thought to lead to decreased insulin sensitivity and then to type 2
diabetes. But this study suggests that obesity and type 2 diabetes may both be caused by the same
genetic defect in the brain.
Brain Gene Provides Glucose Control
In the study, published in the November issue of Diabetes, researchers looked at the effect of
manipulating a gene in the brain known as POMC in mice bred to be obese with type 2 diabetes.
Previous studies have shown that POMC production is reduced in the brains of obese and diabetic
mice. People with mutations in this gene are also obese and diabetic. But because many genes are
implicated in obesity and diabetes, it's not clear which genes, if any, play a role in regulating
glucose levels.
The study showed that when the activity of POMC was increased through genetic engineering, the mice
reduced their food intake slightly and lost some weight.
"But the surprising part was that the effect on glucose regulation was not partial," says researcher
Charles V. Mobbs, PhD, assistant professor at the Fishberg Neurobiology of Aging Laboratories at the
Mount Sinai School of Medicine in New York City, in a news release. "Even though these mice remained
obese, their glucose levels were completely normal."
Those findings showed that the dramatic improvement in glucose control and regulation was not
related to the weight loss.
New Direction for Diabetes Research
Mobbs says these new results suggest this perception of a cause-and-effect relationship between
obesity and glucose control might sometimes be wrong.
"It appears that both conditions can be caused by the same defects, impairments in the production,
processing, or responsiveness to POMC gene products," says Mobbs.
Mobbs says it's still too soon to rule out a role of obesity in glucose regulation, but drugs that
mimic the effects of the POMC gene may eventually be useful for people who developed diabetes due to
aging or as the result of damage to the hypothalamus, which might affect the body's own POMC
synthesis.
He says drugs that mimic POMC are already being studied for the treatment of obesity, but it may
turn out that these drugs will be even more effective in treating type 2 diabetes.
But until those drugs are available, he says diet and exercise are the best way to control glucose
levels and type 2 diabetes.
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SOURCES: Mizuno, T. Diabetes, November 2003; vol 52: pp 2675-2682. News release, Mount Sinai School
of Medicine.
© 2003 WebMD Inc. All rights reserved.