June 26 (UPI) -- Stress hormones and white blood cells can be good or bad -- they can join together to fight infection and heal injuries, but they also can lead to heart attacks.
Researchers at the University of Pittsburgh School of Medicine studied how white blood cells can rupture and hemorrhage in people with diabetes, because they are overactive, and cause inflammation in plaques in blood vessels.
Findings from the new study were published Tuesday in the journal Immunity.
"If the rupture occurs in the coronary artery, the person has a heart attack. If the rupture occurs in the carotid artery, it causes a stroke," Dr. Partha Dutta, an assistant professor of medicine at Pitt's School of Medicine, said in a press release.
There are more than 100 million adults in the United States living with diabetes or pre diabetes, reports the Centers for Disease Control and Prevention. Among this population, heart attack is a major risk and cause of death.
But the researchers found if patients were taking beta 2 blockers, they had fewer inflammatory cells -- which could limit their risk for heart attack.
"The findings suggest that diabetic patients could be treated with beta 2 blockers to reduce the number of inflammatory myeloid cells that cause plaque to rupture," Duta said. "If patients are on beta 2 blockers, the spleen will still be making the myeloid cells necessary to fight infection, but in smaller amounts."
The researchers studied stress factors in humans and mice with diabetes. When the fight-or-flight response was triggered, they saw an over-production of white blood cells, or leukocytes, being produced.
They found for the first time that stress hormones, or catecholamines, are made by a sub-group of white blood cells in the spleen. Researchers had previously only confirmed their production by the sympathetic nervous system.
But in the spleen, the stress hormones trigger granulocyte macrophage progenitor cells, which then form inflammatory myeloid cells. In the new study, these cells were found in the blood vessels.
In addition, the granulocyte macrophage progenitor cells had high levels of beta 2 receptors for stress hormones.
While the researchers caution that lowering white blood cell levels could be dangerous for patients more likely to develop infections, in the right patients -- and when the risk for other illness is properly weighed against preventing death -- they say beta 2 blockers could be effective at saving lives.