Insulin resistance may increase negative responses to stress

Insulin resistance may have effects that lead people to respond more to stress, a new study suggests.
US researchers think that insulin resistance may have effects on the brain’s emotional response that lead to greater negative feelings. Insulin resistance means that the body is less able to respond well to the blood sugar lowering hormone insulin. Insulin resistance is the main characteristic of type 2 diabetes and prediabetes.
The study involved 331 adults who had their reactions to various images tested. The study used eye-blink response (EBR) methods to assess negative responses and an electroencephalogram (EEG) device recorded to track brain activity.
The participants wore electrical sensors on the face, head and under the eyes to track involuntary responses. The research team were therefore able to monitor how each person reacted to the images by noting their blinking and flinching movements.
The results showed that participants with higher levels of insulin resistance showed a greater startle response to certain images.
Auriel Willette, an Iowa State University assistant professor of food science and human Nutrition, said: “People with higher levels of insulin resistance were more startled by negative pictures.
“By extensio, they may be more reactive to negative things in life. It is one piece of evidence to suggest that these metabolic problems are related to issues with how we perceive and deal with things that stress all of us out.”
The EEG was also used to measure brain activity when the participants were resting. The results showed the right side of the brain was more active in the those with either type 2 diabetes or prediabetes. Activity in the right side of the brain is more commonly associated with negative feelings or depression.
Participants with diabetes were also noted as having lower cognitive performance and less well-regulated cortisol levels (the stress hormone).
Lead author Tovah Wolf, a graduate student at the university, said: “For people with blood sugar problems, being more stressed and reactive can cause blood sugar to spike. If people with prediabetes and diabetes are trying to reverse or treat the disease, stressful events may hinder their goals.
“Frequent negative reactions to stressful events can lead to a lower quality of life and create a vicious cycle that makes it difficult to be healthy.”
The findings have been published in the Psychosomatic Medicine journal.