Researchers have discovered that when patients who have type 2 diabetes and asthma take a certain class of medication to control their blood sugar, their asthma symptoms also improved.
Not only could this help diabetes patients who may have less asthma control on asthma medicines, but it could potentially open up new treatment options for those who don't have diabetes.
The study showed that patients who are started taking these medications reported both less asthma exacerbation, with less need for oral steroids and fewer asthma-related symptoms over a six-month period, said study author Dr. Katherine Cahill, medical director of clinical asthma research at Vanderbilt University Medical Center, in Nashville, Tenn.
"What this means for us is that for patients who have type 2 diabetes and asthma, it suggests that the medications they're being treated with for their type 2 diabetes may have direct and beneficial effects on their asthma," Cahill said.
These medications are known as GLP-1 receptor agonists. They are a newer class of FDA-approved therapeutics used either with metformin to control blood sugar for type 2 diabetes patients or to induce weight loss in patients who have obesity.
According to the National Center for Biotechnology Information, GLP-1 receptor agonists currently approved in the United States include exenatide, liraglutide, lixisenatide, albiglutide, and dulaglutide.
Researchers from several hospitals -- Vanderbilt, Brigham and Women's Hospital and Harvard Medical School in Massachusetts, and University Hospital Zurich in Switzerland -- used electronic health record data of patients with asthma and type 2 diabetes who started taking GLP-1 receptor agonists between March 2018 and January 2020.
They found fewer asthma symptoms in the patients who took these medications instead of other diabetes drugs.
Researchers at Vanderbilt have also completed preclinical models, finding that these medications reduce allergic airway inflammation and viral-induced airway inflammation. Patients reported better breathing, less cough and shortness of breath.
"We know that obesity and metabolic dysfunction, which is often a precursor to overt type 2 diabetes, are common comorbidities of our patients with asthma and are known to worsen asthma control and increase risk for asthma flares and need for asthma medication," Cahill said.
Only an association was seen between taking GLP-1 receptor agonists and asthma improvements, and clinical trials will be necessary to confirm the results of the impact on people with asthma, both those with and without diabetes.
The findings were published recently in the American Journal of Respiratory and Critical Care. The U.S. National Institute of Allergy and Infectious Diseases funded the research.
There are a couple of reasons to be excited about future potential access to a completely new type of medication for asthma, Cahill said, including that these may work well for patients who are not responding well to standard therapies.
"Our patients with obesity and type 2 diabetes who have asthma are the ones who seem to respond most poorly to the conventional asthma medications that have been around for the last number of decades," Cahill said. "We think that this medication class would really target a patient population that even today struggles to get adequate control of their asthma."
About 8% of adults and 7% of children in the United States have asthma, according to the U.S. Centers for Disease Control and Prevention.
This leads to large amounts of money being spent each year for hospitalizations, emergency room visits and doctor visits for asthma that's not well controlled, said Dr. Andy Nish, a physician at Northeast Georgia Physicians Group Allergy and Asthma in Gainesville. Nish was not involved in the study.
"To have asthma well controlled is extremely important, first, and then to have control of symptoms, which keep people out of [the] emergency room and the hospital, urgent care, and the doctor's office is also important," he said.
Though in the past asthma medications were limited, there are now those that can control both inflammation and airway constriction, Nish said. However, certain patients don't respond well to any existing treatments, he said.
"There's still always room for medicines that have fewer side effects or are more efficacious, cost less to make, cost less to use, have less morbidity," Nish said. "It is a positive for this medicine that it's already being used for people who are overweight. And, so, it's not a far reach to say, OK, we can use this for people who have asthma that maybe aren't even overweight because, apparently, its side-effect profile is such that it's relatively benign."
The U.S. National Heart, Lung and Blood Institute has more on asthma.
SOURCES: Katherine Cahill, MD, medical director, clinical asthma research, Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tenn.; William "Andy" Nish, MD, physician, Northeast Georgia Physicians Group Allergy and Asthma, Gainesville; American Journal of Respiratory and Critical Care, April 1, 2021