Americans who are obese and living with diabetes or prediabetes, feelings of sadness, anger and anxiety are often part of daily life.
In a new Iowa State University study, researchers suggest those negative feelings may stem from problems regulating blood sugar levels that influence emotional response in the brain.
The study found people with Type 2 diabetes and prediabetes were more likely to focus on and have a strong emotional response to threats and negative things.
It could affect quality of life and increases risk for depression.
The team analyzed data on startle response, brain activity, cortisol levels and cognitive assessment. Data for the study came from Midlife in the U.S. (MIDUS), a national study of health and well-being.
Gauging the startle response allowed the team to measure central nervous system activity using tiny electrodes placed below the eye.
Study participants viewed a series of negative, positive and neutral images intended to elicit an emotional response.
The electrodes captured the rate of flinch or startle, a contraction people cannot control, associated with each image.
The researchers suggest that people with higher levels of insulin resistance were more startled by negative pictures. By extension, 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 researchers say the evidence is even more compelling when combined with the results of EEG tests recording activity when the brain is at rest.
Study participants with prediabetes and Type 2 diabetes had more activity on the right side of the brain, which is associated with depression and negative emotions.
People with prediabetes and diabetes also recorded lower cortisol levels – a potential indicator of chronic stress – and cognitive test scores, providing additional support for the findings.
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 researchers say additional work is needed to determine if the link between insulin resistance and emotional response is causal, and explore options for potential interventions.
The research is published in the journal Psychosomatic Medicine.
Source: Iowa State University.