With commentary by Kyle Murdock, PhD, postdoctoral research fellow in psychology, Rice University, and Christopher Fagundes, PhD, assistant professor of psychology, Rice University.
Having too much stress can lead to inflammation, and that can boost your risk of getting type 2 diabetes, as experts have long known.
Now, in a new study, researchers say they have uncovered some clues how that happens, the biological pathway that explains the process. It has roots in your brain's ability to control anxiety, they say.
"People who have the cognitive inability to deal with stress well are more likely to have type 2 diabetes, and the immune system seems to be one mechanism [driving the link]," says study researcher Christopher Fagundes, PhD, assistant professor of psychology at Rice University, Houston.
Put another way, "One's ability to control anxious thoughts is related to the risk of getting diabetes, and the immune system seems to be important [in explaining why]," says study researcher Kyle Murdock, PhD, a postdoctoral research fellow in psychology at Rice.
The study is in the September issue of Psychoneuroendocrinology.
The researchers evaluated more than 800 men and women, most of them not diagnosed with diabetes. They evaluated a variety of tests, including:
• A test of inhibition, or how well the participants could set aside a stressful thought, as well as other tests of thinking ability such as memory.
• A self-report of their mood and anxiety level in the past week, telling how often they felt high anxiety.
• A measure of an inflammatory marker known as interleukin-6. The body produces the protein IL-6 to promote immune response and healing; it is a marker of stress.
• The HbA1C test, which measures blood sugar control over the past three months.
Those with poor inhibition were more likely to have diabetes than those who were good at handling stress. The other cognitive skills were not linked to diabetes risk, the researchers found. The poor stress management skills, in turn, were linked to higher levels of IL-6 and higher blood glucose levels.
What do the researchers see as poor stress management? As one example, suppose you forgot to pay an important bill.
A person with good stress coping skills, Murdock says, ''would take care of what they need to take care of, and direct their attention to something else after taking care of it. A person with poor ability would think 'I can't believe I forgot to do that,' '' he says, and be stuck in the stress cycle even after correcting the problem.
The link between inflammation and poor stress coping skills did not go both ways, Murdock and Fagundes say. That is, high level of inflammation did not seem to affect inhibition skills, so that strengthens the validity of their finding.
Minisha Sood, MD, director of inpatient diabetes, Lenox Hill Hospital, New York, reviewed the findings and puts the new research into perspective this way: "The relationship between chronic stress and inflammation has been established previously," she says. In the new study, the researchers compare people who are anxious and stressed to those who are less anxious and stressed to determine how that ability may affect diabetes risk. Their bottom line: those with better stress coping skills had lower markers of inflammation, less anxiety, less diabetes risk.
Poor stress management is also bad news once a person gets a diabetes diagnosis, Sood says, because ''they are exactly the type of people who are less capable of dealing with diabetes self-management." They may not adhere to a medication schedule, for instance, or not follow a regular exercise plan.
The new research suggests that doctors need to pay attention to their patients' emotional and cognitive health, Dr. Sood says.
The Rice University researchers agree, suggesting that those who handle stress poorly should consider learning mindfulness therapy, which helps people learn to be more ''in the present'' rather than continuing to stress out over problems. Those who learn and practice mindfulness, Murdock says, do better, in time, on the inhibition tests, research suggests.
Cognitive behavior therapy, which helps people change behaviors, such as excessive worry, could also help, Murdock and Fagundes add. Yet another route to better stress management, Murdock and Fagundes say, is to consider anti-inflammatory medicine or stimulant medication, such as the type used to manage attention deficit hyperactivity disorder (ADHD). That may help people direct their attention to problems at hand, rather than circle back and worry about previous issues.