Chronic fatigue syndrome — medically unexplained fatigue lasting six months or more, preventing people from carrying out their normal activities, and often worsening after any exertion — is hard to treat. But new research could offer a lifeline. Chronic fatigue patients appear to be much more prone to disordered breathing than healthy controls, suggesting that chronic fatigue could cause respiratory issues which make patients’ symptoms worse. These findings might lead to new treatments reducing chronic fatigue symptoms by improving patients’ breathing.
Chronic fatigue syndrome leaves patients exhausted and struggling with brain fog — and it typically gets worse after mental or physical exercise, a phenomenon called post-exertional malaise. Now scientists investigating shortness of breath in chronic fatigue patients have discovered that they are highly likely to experience dysfunctional breathing, which could be caused by dysautonomia, abnormal control of innervation to blood vessels and muscles. Targeting treatments towards these breathing problems could potentially offer patients some relief from their symptoms.
“Nearly half of our chronic fatigue subjects had some disorder of breathing — a totally unappreciated issue, probably involved in making symptoms worse,” said Dr Benjamin Natelson of Icahn School of Medicine, senior author of the article in Frontiers in Medicine. “Identifying these abnormalities will lead researchers to new strategies to treat them, with the ultimate goal of reducing symptoms.”
Breathe easy
The scientists recruited 57 patients diagnosed with chronic fatigue syndrome and 25 control participants whose ages and activity levels matched the chronic fatigue cohort. Both groups took part in cardiopulmonary exercise tests over two days. The scientists measured their heart rate and blood pressure, how effectively they were taking in oxygen, the oxygen saturation of their blood, and how hard they had to breathe to get enough oxygen. They also tracked how fast participants breathed and the patterns of their breathing, to identify hyperventilation and dysfunctional breathing.
Dysfunctional breathing is usually associated with asthma patients, but it can arise from many different causes. Characteristics include deep sighing in the course of ordinary breathing, overly rapid breathing, forcing your exhale from your abdomen, breathing from your chest without using your diaphragm so your lungs are never properly full, and a loss of synchrony between your chest and abdomen, so the different muscles which help you breathe aren’t working together.
“While we know the symptoms generated by hyperventilation, we remain unsure what symptoms may be worse with dysfunctional breathing,” said Dr Donna Mancini of the Icahn School of Medicine, first author of the article. “But we are sure patients can have dysfunctional breathing without being aware of it. Dysfunctional breathing can occur in a resting state.”
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Catching your breath
The scientists found that participants with chronic fatigue were taking in approximately the same amount of oxygen when they breathed compared to the control participants — their peak VO2 maxes were comparable. However, 71% of the participants with chronic fatigue experienced breathing problems — either hyperventilation, dysfunctional breathing, or both.
Almost half of the participants with chronic fatigue were observed breathing erratically during the test, compared to only four of the control participants. A third of the chronic fatigue patients hyperventilated, compared to just one control participant. Nine chronic fatigue patients displayed dysfunctional breathing as well as hyperventilation. None of the control participants had this combination of breathing issues.
Both dysfunctional breathing and hyperventilation can cause symptoms similar to chronic fatigue, like dizziness, difficulty focusing, shortness of breath and exhaustion. Combining the two can also cause people to experience heart palpitations, chest pain, fatigue, and (unsurprisingly) anxiety. These breathing problems, the scientists suggest, could be exacerbating chronic fatigue symptoms or even directly contributing to post-exertional malaise.
“Possibly dysautonomia could trigger more rapid and irregular breathing,” said Mancini. “It is well known that chronic fatigue syndrome patients often have dysautonomia in the form of orthostatic intolerance, which means you feel worse when upright and not moving. This raises the heart rate and leads to hyperventilation.”
Pulmonary physiotherapy?
This could mean that tackling dysfunctional breathing would relieve some patients’ symptoms. The scientists intend to follow up on this research to learn more about how dysfunctional breathing and hyperventilation interact. Although more research will be needed before treatments can be rolled out, they already have ideas for possible therapies that could improve breathing function.
“Breathing exercises via yoga could potentially help, or gentle physical conditioning where breath control is important, as with swimming,” suggested Natelson. “Or biofeedback, with assessment of breathing while encouraging gentle continuous breath use. If a patient is hyperventilating, this can be seen by a device that measures exhaled CO2. If this value is low, then the patient can try to reduce the depth of breathing to raise it to more normal values.”
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