Altered hEDS breathing pattern linked to poor perception: Study
Patients may not sense how much air lungs can hold
An altered breathing pattern in hypermobile Ehlers–Danlos syndrome (hEDS) may be linked to difficulty sensing how much air fills the lungs with each breath and in controlling ventilation, especially when engaging in a cognitive task, a study suggests.
The study, “Impairment of lung volume perception and breathing control in hypermobile Ehlers-Danlos syndrome,” was published in Scientific Reports.
People with hEDS have hypermobile joints, or joints that move beyond the normal range of motion, causing frequent dislocations and pain. Their skin can be unusually stretchy, and they tend to bruise easily. They also often present with an altered breathing pattern that can result in shortness of breath, cough, and faster or deeper breaths. What exactly causes an altered breathing pattern in hEDS is unclear.
To understand if there may be problems in proprioception, or sensing how much air the lungs can hold, the researchers developed a device that measures how accurately people can estimate the volume of air filling their lungs.
The study, ProprioRespi (NCT05000151), involved 19 adults with hEDS and 19 healthy individuals. In each group, there were 18 women and one man, with a mean age of 33. Most patients (74%) had received their diagnosis less than a year before the study.
Judging air volume in a breath
Four of the patients had asthma, a condition in which inflammation of the airways can make it difficult to breathe. Ten reported “doing an activity requiring good breathing control,” such as “yoga, cycling, swimming, walking, horse riding, and dancing,” the researchers said.
Patients were asked to breathe in specific amounts of air after emptying their lungs. They practiced with the help of a device that showed them how much air they were breathing in real time. The device consisted of a mouthpiece, a flowmeter, and a flatscreen monitor for visual feedback.
They were then asked to reproduce specific target volumes, with a break of one to two minutes in between. After each try, the difference between how much air they actually breathed in and how much they were supposed to was calculated as a measure of how accurately they estimated the volume of air in their lungs.
People with hEDS were significantly less accurate than healthy individuals in perceiving the volume of air breathed in at 30%, but not at 50%, of their maximum lung capacity (210 vs. 140 mL). Here, a smaller value indicates greater accuracy.
The researchers also investigated whether the breathing pattern of people with hEDS changes when they’re engaged in a cognitive task. The Trail Making Test part B consisted of “connecting, as quickly and accurately as possible, in ascending order circles containing numbers and letters, alternating one number and one letter each time,” the investigators wrote.
At rest, patients took on average 3.1 more breaths per minute compared with healthy individuals (14.7 vs. 11.6).
When asked to do the cognitive task, patients adopted an “erratic” breathing pattern, the team noted, with apnea (repeated stops and starts in breathing), volume variations, and flow variations.
Changes in ventilation were based on spatial and temporal criteria, suggesting that the lack of full proprioception, or proper body awareness, may affect the way people with hEDS breathe, especially when doing a task that requires thinking.
“These data support the influence of the proprioceptive deficit on ventilatory control in hEDS,” the researchers wrote. “Future research should focus on this relationship between lung volume perception and ventilation.”
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