Body's anticipation of a meal can be a diabetes risk factor

Mar 11, 2010

Alterations in our response to the taste or smell of food may be another culprit responsible for Type 2 diabetes, according to scientists at Duke University Medical Center who have identified the specific mechanism in human specimens and in mice.

When we anticipate or smell a meal, the parasympathetic nervous system triggers salivation and increases in response to the expectation that glucose will be entering the blood stream.

"We think this parasympathetic response is potentially important in type 2 ," said Vann Bennett, the James B. Duke professor in the departments of cell biology, biochemistry, and neurobiology and Howard Hughes Medical Institute investigator. "Our study showed there is a novel mutation in the gene encoding ankyrin-B, which increases the risk of type 2 diabetes. This happens through an impairment of the that is added by the parasympathetic nervous system."

The study was released online on Tuesday, March 16 in Science Signaling.

Bennett was the first scientist to delineate a molecule called ankyrin and for years has been studying its roles in the heart and brain, as well as other organ systems. Bennett and colleagues discovered the importance of ankyrin-B in the insulin response and the source of a mutation that could lead to diabetes.

In earlier experiments, the group found that that are ankyrin-B deficient display impaired insulin secretion in mice. Ankyrin-B-deficient mice had high blood sugar after eating a source of glucose, but not if the glucose bypassed the mouse's mouth. These findings indicated that ankyrin-B deficiency impaired the parasympathetic chain of events that enhance insulin secretion and had a measurable impact on blood sugar levels.

The scientists then asked whether mutations involving ankyrin-B loss of function were associated with diabetes in humans. They used the American Diabetes Association's GENNID genetic specimen collection from families with type 2 diabetes to genotype 524 people with diabetes disorders and 498 non-diabetic controls. They were searching for three ankyrin-B mutations that had previously been shown in heart muscle cells to create severe loss of function.

They found that one of these mutations of ankyrin-B (R1788W) was associated with type 2 diabetes in about 1 percent of Caucasian and Hispanic individuals. "Genomewide studies have failed to identify more than a small fraction of the genetic heritability in diabetes as well as in other complex diseases," Bennett said. "There are estimates that only 6 percent of the heritability of type 2 diabetes has been detected, by multiple genomewide studies."

Bennett said this implies there is a large reservoir of genes yet to be identified, that are risk factors in type 2 diabetes. "We are excited by our findings of a specific mutation with a known mechanism because of the potential for personalized treatment of diabetes," he said. "This particular mutation is likely to play a role in 1 percent of adults with diabetes. We hope our finding will lead to strategies to specifically benefit these individuals."

Explore further: West Africa's Ebola outbreak prompts changes in I.Coast cuisine

add to favorites email to friend print save as pdf

Related Stories

Study pinpoints role of insulin on glucagon levels

Apr 07, 2009

April 7, 2009 - Researchers at the Joslin Diabetes Center have shown for the first time that insulin plays a key role in suppressing levels of glucagon, a hormone involved in carbohydrate metabolism and regulating blood glucose ...

Impaired fat-burning gene worsens diabetes

Feb 07, 2008

Researchers at the Swedish medical university Karolinska Institutet have in collaboration with researchers from Finland, China, Japan and the US discovered new cellular mechanisms that lead to in insulin resistance in people ...

Cell 'anchors' required to prevent muscular dystrophy

Jan 13, 2009

A protein that was first identified for playing a key role in regulating normal heart rhythms also appears to be significant in helping muscle cells survive the forces of muscle contraction. The clue was a laboratory mouse ...

Fat cells send message that aids insulin secretion

Nov 06, 2007

The body's fat cells help the pancreas do its job of secreting insulin, according to research at Washington University School of Medicine in St. Louis. This previously unrecognized process ultimately could lead to new methods ...

Recommended for you

Two expats die of MERS in Saudi commercial hub

19 hours ago

Two foreigners died of MERS in the Saudi city of Jeddah, the health ministry said Saturday, as fears rise over the spreading respiratory virus in the kingdom's commercial hub.

UAE reports 12 new cases of MERS

19 hours ago

Health authorities in the United Arab Emirates have announced 12 new cases of infection by the MERS coronavirus, but insisted the patients would be cured within two weeks.

Filipino tests negative for Middle East virus

Apr 19, 2014

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

User comments : 0

More news stories

Cancer stem cells linked to drug resistance

Most drugs used to treat lung, breast and pancreatic cancers also promote drug-resistance and ultimately spur tumor growth. Researchers at the University of California, San Diego School of Medicine have discovered ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.