When something as routine as grocery shopping might lead to a deadly COVID-19 infection, stress is inevitable -- and that extra tension can make it harder for people with diabetes to manage their disease.
The reason? The stress hormone cortisol is linked to higher blood sugar levels, according to a new study.
Under stress, the body releases cortisol, which leads to an increase in blood sugar and a decrease in insulin (the hormone that helps process that sugar).
"This is all part of the fight-or-flight response. You need sugar if you want to run from, let's say, a bear. To prepare for that, your body needs to make energy, so it releases cortisol," explained study author Dr. Joshua Joseph. He's an endocrinologist at the Diabetes and Metabolism Research Center at The Ohio State Wexner Medical Center, in Columbus.
Cortisol levels naturally fluctuate. They're highest in the morning as you rise, and usually fall at night, Joseph said. But in people with diabetes, cortisol levels stayed steadier throughout the night, his team found.
The researchers noted that past studies have linked stress and depression to a steadier cortisol level.
The study included data from more than 2,000 participants, aged 45 to 84, who were followed over six years. The investigators found that people with diabetes who had steadier cortisol levels (indicating stress) tended also to have higher blood sugar (glucose) levels.
"Cortisol is driving glucose changes, and it does make diabetes much harder to control. Naturally, cortisol levels should be going lower in the evening. But people with stress have higher cortisol levels and blood sugar at night. Cortisol also makes you want to eat, and when you're stressed, you're not reaching for the carrots and broccoli -- you're reaching for high-carbohydrate, high-sugar foods," Joseph said.
Over time, higher blood sugar levels can lead to serious complications of diabetes, such as vision problems, heart disease and kidney disease. Joseph said it also appears that constant higher blood sugar levels might make people more susceptible to complications from a COVID-19 infection, though there aren't yet studies to prove it.
Dr. Akankasha Goyal, an endocrinologist at NYU Langone Health in New York City, reviewed the new study findings. She described cortisol as a "double whammy."
"It increases glucose production, and it decreases insulin from the pancreas," she said. "And, in patients with type 2 diabetes, at baseline, their bodies are unable to use insulin effectively and their glucose levels are higher."
Goyal said the study is proof of what many patients already knew: that stress can worsen blood sugar control. The findings may help motivate people to take steps to control their stress, she added.
"Stress relief is medication without side effects," Goyal said. "Exercise if you can. Walk, yoga, tai chi or lift some dumbbells. Do mindful activities, paint, read a book -- anything that slows down and quiets the mind."
Joseph and other researchers at Ohio State are recruiting diabetes patients for a study to see if mindfulness practices improve blood sugar management. People with diabetes need to focus on stress relief as part of managing their disease, he said.
"To ease stress, maintain healthy social support, get regular exercise, sleep seven to eight hours a night, practice mindfulness, meditation, yoga, listen to music and eat a healthy diet," Joseph suggested.
The study was published online July 13 in the journal Psychoneuroendocrinology.
For more about stress relief, visit the U.S. National Institute of Mental Health.