New research suggests that for some people, brain defaults make it more difficult to handle emotional stress which can lead to anxiety. Anxiety, in turn, may activate a metabolic pathway associated with diabetes and high blood glucose.
Rice University investigators believe the key is the brain’s ability to control anxiety when confronted with emotional stress.
That control lies with the brain’s executive functions, processes that handle attention, inhibition, working memory and cognitive flexibility, and are also involved in reasoning, problem-solving, and planning.
The new study, published in the journal Psychoneuroendocrinology, posits that a metabolic chain reaction begins with low inhibition, aka attention control, leaving a person vulnerable to tempting or distracting information, objects, thoughts, or activities.
Previous studies have shown that such vulnerability can lead to more frequent anxiety. Anxiety is known to activate a metabolic pathway responsible for the production of pro-inflammatory cytokines, signaling proteins that include interleukin-6 (IL-6).
Along with cognitive tests that measured attention control, the Rice study measured levels of both blood glucose and IL-6 in more than 800 adults. IL-6 is a protein the body produces to stimulate immune response and healing.
It is a biomarker of acute and chronic stress that also has been associated with a greater likelihood of diabetes and high blood glucose.
Investigators discovered that individuals with low inhibition were more likely to have diabetes than those with high inhibition due to the pathway from high anxiety to IL-6. The results were the same no matter how subjects performed on other cognitive tests, like those for memory and problem-solving.
Researchers have suspected a link between anxiety and poor health, including diabetes, for many years but none have detailed the biological pathway responsible, said lead author Kyle Murdock.
The new study is unique in that it takes a deeper look at how inflammation bridges anxiety and diabetes.
“The literature shows individuals with poor inhibition are more likely to experience stressful thoughts and have a harder time breaking their attention away from them,” Murdock said.
“That made me wonder if there’s a stress-induced pathway that could link inhibition with inflammation and the diseases we’re interested in, such as diabetes.
“Plenty of research shows that when individuals are stressed or anxious or depressed, inflammation goes up,” he said. “The novel part of our study was establishing the pathway from inhibition to anxiety to inflammation to diabetes.”
The data came from a Midlife Development in the United States study of 1,255 middle-aged adults whose cognitive abilities were tested two years apart. More than 800 of those also underwent blood tests to check IL-6 and glucose levels.
The Rice researchers found not only the positive link between inhibition and diabetes, but the absence of a link between other cognitive functions and the disease. They also determined that the pathway only went in one direction: Inflammation never appeared to affect inhibition.
Murdock said the researchers suspected a feedback loop could be at play in those with diabetes. “Individuals who are anxious are more likely to avoid treatment and use maladaptive strategies (like smoking or unhealthy diets) that enhance their blood glucose, which is problematic. It’s a snowball effect: The further they go, the worse it gets,” he said.
“We also know that extremely high blood glucose can impact cognition as well. We talked about how, if we’re going to treat these individuals appropriately, it won’t be by sitting them down in a room and saying, ‘Hey, you need to eat better,’ or ‘You need to use your insulin on time.'”
“Research shows that people who practice mindfulness do better on the inhibition tests over time,” Murdock said, suggesting that shifting one’s attention away from stressful thoughts may affect physiological responses.
“I’m a firm believer that mindfulness-based approaches to treatment are a great idea, for a lot of reasons,” Fagundes said. “That doesn’t mean medicines that promote inhibition, such as stimulants, shouldn’t be considered, but a combination of the two could be really helpful.”
Source: Rice University