Women with long COVID may need rehab to improve physical activity
Women with long COVID experience heart-rate irregularities after physical exertion, which could constrain their exercise tolerance and their free-living physical activity, according to a study published in Experimental Physiology.
Since there is a greater prevalence of age-related physical disability among women than among men, these findings illustrate the need for targeted rehabilitation programs that manage persistent heart and lung problems in women with long COVID, the researchers said.
“Consistent with other universities during the spring of 2020, our usual research activities involving exercise training and postmenopausal women were temporarily halted amid the emerging pandemic,” author Stephen J. Carter, MS, PhD, assistant professor in the department of kinesiology at the Indiana University School of Public Health – Bloomington, told Healio.
“Since our lab has a history of studying the acute and chronic effects of exercise in women, we thought it sensible to pivot our research efforts accordingly. We felt this to be especially important, given that women are largely underrepresented in clinical work, and thus offering us a unique opportunity to explore the effects of SARS-CoV-2 on cardiopulmonary health,” Carter said.
The researchers recruited 45 women for the case-controlled study. According to the researchers, 29 women (age, 54 ± 10 years; BMI, 25.6 ± 5.4 kg/m2) had a positive laboratory test for mild to moderate SARS-CoV-2 infection 4 weeks before enrolling in the study or earlier, while the control group included 16 women (age, 58 ± 11 years; BMI, 26.7 ± 4.8 kg/m2) who never tested positive.
Also, 17 of the 29 participants who had tested positive experienced cough, shortness of breath, fatigue, joint or muscle aches, dermatitis or hair loss, or loss of taste or smell. Before enrolling in the study, one participant was hospitalized for less than 24 hours at the onset of illness due to chest and neck pain and/or pressure.
Each participant completed pulmonary function testing before and after a 6-minute walk test. They also rated their perceived exertion using a 100 mm visual analog scale ranging from “no exertion” to “maximal exertion.”
The participants with a history of SARS-CoV-2 infection had reduced total lung capacity (84% ± 8% vs. 93% ± 13%; P = .006), vital capacity (87% ± 10% vs. 93% ± 10%; P = .04), functional residual capacity (75% ± 16% vs. 88% ± 16%; P = .006) and residual volume (76% ± 18% vs. 93% ± 22%; P = .001) compared with controls.
There were no differences between the groups in how much distance they walked or in their perceived exertion, but the participants who had been infected saw an attenuated increase in heart rate (+52 ± 20 bpm vs. +65 ± 18 bpm; P = .029) compared to controls. Also, the SARS-CoV-2 participants saw a delay of 1 to 5 minutes in decreased heart rate during a 5-minute period of standing recovery after the walk (P < .05).
“We were surprised to observe abnormalities in heart rate responses to and recovery from a standard 6-minute walk test, especially since our cohort of women recovering from COVID-19 all met the criteria for mild to moderate symptom severity based on their initial illness characteristics,” Carter said.
Participants actively experiencing shortness of breath or joint or muscle aches during testing achieved a lower proportion of predicted 6-minute walk test distance compared with both controls and participants who had tested positive but were not experiencing such symptoms.
Additionally, the researchers found an association between more abnormal heart rate responses and a greater number of days experiencing shortness of breath at illness onset as well as poorer ability for gas exchange in the lungs.
“Such findings were surprising given the considerable time since participants initially contracted the SARS-CoV-2 virus to when we tested them — on average, 3 months — the primary implications being that certain individuals may still be experiencing physical impairment months following a diagnosis, and these impairments can act as a barrier to exercise tolerance and/or free-living physical activity,” Carter said.
By matching the control and experimental groups based on age and BMI, the researchers said, they had greater certainty that their findings could be attributed to long COVID and not to underlying differences related to aging or obesity.
“Based on our work, it is important that physicians not marginalize what patients may be experiencing,” Carter said. “Again, although our participants had mild to moderate SARS-CoV-2 symptoms, they were exhibiting clear irregularities that could undermine their ability to return to pre-COVID levels of exercise and physical activity. Physicians need to be attentive to such things and take record of how their patients may be recovering over time.”
The researchers noted recent reports suggesting that women may be more susceptible to lung-related limitations months into their recovery from SARS-CoV-2 infection. For example, they continued, the Mayo Clinic Proceedings indicate that women outnumber men 3:1 in seeking treatment for persistent COVID-19 symptoms.
“Our findings suggest targeted rehabilitation programs might be especially useful to women and other groups affected by persistent symptoms,” Carter said. “Future controlled trials should focus on testing feasibility and efficacy of certain interventions to promote physical recovery and minimize susceptibility for deteriorating physical condition in those with latent recovery.”