Dr. Heather Edgell is an associate professor at York University, in Toronto, Canada, and director of the university’s Women’s Cardiovascular Health Laboratory. She recently won a Solve Ramsay Research Program grant to study how inspiratory muscle training improves physiological and cognitive functions in patients with Long Covid or ME/CFS.
Inspiratory muscle training involves using a handheld device that resists natural breathing; thus, exercising with the device strengthens the diaphragm (the muscle below the lungs that expands the lungs, drawing air in). This helps people consume oxygen more efficiently, lowers blood pressure and heart rate, and improves physical functions.
Since winning her Ramsay Award, Dr. Edgell has published four papers related to inspiratory muscle training for patients with Long Covid or ME/CFS (and over a dozen papers related to other research). She has also won over half a million dollars in other grants to bolster her Ramsay Grant seed funds.
Dr. Edgell’s team just published a paper in the journal Respiratory Physiology and Neurology about how inspiratory muscle training especially improves the autonomic nervous system in patients with Long Covid or ME/CFS. The autonomic nervous system controls functions of the body that happen automatically, without our needing to regulate them consciously. (For example, autonomic functions include breathing, heart rate, and blood pressure.)
Problems with the autonomic system may explain key symptoms of Long Covid and ME/CFS—exercise intolerance, fatigue, gastrointestinal problems, lightheadedness, orthostatic intolerance (dizziness when rising to stand), pain, poor cognition, poor sleep, sweatiness, and trouble breathing. Encouragingly, inspiratory muscle training improves such symptoms in patients with heart failure or pulmonary problems (and even in healthy people). For example, inspiratory muscle training significantly boosts functioning of the vagus nerve, a main nerve handling key autonomic operations.
Dr. Edgell’s team performed a clinical trial to compare autonomic functions and autonomic symptoms in 9 patients diagnosed with Long Covid, 12 patients diagnosed with mild or moderate ME/CFS (and never having COVID or Long Covid), and 12 healthy participants. The team also measured how much inspiratory muscle training reduced these symptoms and improved functions. They assessed symptoms like fatigue, pain, and sleep by using questionnaires; and they assessed autonomic function by measuring heart rate variability (when participants were resting) and heart rate, blood oxygen level, and blood pressure (after walking for six minutes).
Patients with Long Covid or ME/CFS had more serious autonomic symptoms—more fatigue, neurological and cognitive problems, trouble sleeping, variable heart rate and poorer pupil movement—than did healthy participants. And although none of the patients had especially severe cases of ME/CFS, the patients with ME/CFS were even worse off than the patients with Long Covid, having significantly more pain, gastrointestinal problems, immunological problems, and vasomotor problems. Patients with ME/CFS also had the greatest orthostatic intolerance and the most trouble walking.
For all participants (even the healthy ones), inspiratory muscle training significantly strengthened the diaphragm and improved heart rate variability, quality of sleep, resting heart rate, and walking. For patients with ME/CFS, training also significantly improved vasomotor function and reduced pain. Overall, these results suggest that inspiratory muscle training significantly lowers many autonomic symptoms in patients with Long Covid or ME/CFS.
Dr. Edgell’s study was especially noteworthy because of the great care the team took to protect patients. She explained, “We chose a type of training that did not increase effort with time, but rather decreased the time between breaths in consideration of the potential for post-exertional malaise (PEM). We were in communication with patients throughout the protocol to help with pacing and to make sure that patients were doing well. I highlight this as researchers need to act with care and understanding with any protocol that involves physical activity in these populations.”
Dr. Edgell hopes to next evaluate inspiratory muscle training in a larger and more informative study. By including more patients, for example, she may compare autonomic functions of patients who complete inspiratory muscle training with those of patients who do not. This would show whether patients need inspiratory muscle training to improve, or whether patients eventually improve by themselves (with no treatments). With more participants, the team could also see how inspiratory muscle training helps patients with different severities of Long Covid or ME/CFS, patients taking other treatments, and patients with other infection-associated chronic conditions.
Dr. Edgell expressed her sincere gratitude for the Solve donors who made her grant possible, noting, “I would have been entirely unable to complete this work without the Solve Ramsay Grant. I would like to thank the donors and patients for their support, and I truly hope that these studies will be helpful to the patients and their families by finding biomarkers for diagnosis and potential treatments to improve symptoms.”
