Anticipation is sometimes more fun than the actual event itself. This was shown in the case of vacations – as well as in eating. And in the case of the latter, looking forward to a meal can actually have some physiological consequences, e.g. on the blood sugar level, for example. In a study on lab animals, researchers at Duke University observed that anticipation of a meal, either by sight or by smell, activates the parasympathetic nervous system to perform biological processes such as saliva production and increased insulin production. Increased salivation is expected to aid in the mastication and digestion of food whereas increased insulin production is in preparation of the event that glucose will be entering the bloodstream. In other words, our body anticipates what we need and prepares for it in advance. The parasympathetic nervous system therefore plays an important role in sugar metabolism.
Disruption of insulin secretion creates havoc with glucose levels in the blood and for those suffering from diabetes, can have some serious consequences. Researchers found that a certain genetic mutation can lead to ankyrin-B deficiency that impairs the parasympathetic production of insulin.
According to lead researcher Dr. Vann Bennett, professor in the departments of cell biology, biochemistry, and neurobiology at Duke University:
“We think this parasympathetic response is potentially important in type 2 diabetes. 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 insulin secretion that is added by the parasympathetic nervous system.”
To confirm that this problem also occurs in humans, the researchers looked at genetic specimens of the American Diabetes Association’s GENNID collection from families with type 2 diabetes. They performed genotyping on 524 people with diabetes and 498 people without diabetes for comparison. They found that one of these mutations of ankyrin-B (R1788W) was associated with type 2 diabetes in about 1% of Caucasian and Hispanic individuals. You would think this is a very low percentage. However, according to Dr. Bennet
“Genomewide studies have failed to identify more than a small fraction of the genetic heritability in diabetes as well as in other complex diseases. There are estimates that only 6 percent of the heritability of type 2 diabetes has been detected, by multiple genomewide studies.”
There are still a lot of diabetes-associated genes out there that need to be identified. The gene mutation for ankyrin B deficiency seems to be relevant in 1% of patients with type 2 diabetes.