Respiratory load perception in overweight and asthmatic children
Victoria MacBean, Lorna Wheatley, Alan C Lunt, Gerrard F. Rafferty
Published in the journal Respiratory Physiology & Neurobiology, February 2017
This study examined differences in children’s awareness of breathing difficulty, specifically the influence of weight and asthma. With obesity on the rise in Western society and asthma being a common long-term medical condition, it is crucial to understand why obese, asthmatic children report more breathlessness than asthmatic children who are not overweight, even when there are no differences in the severity of their asthma. It has previously been suggested that overweight children may have an increased awareness of breathing effort.
This study compared various aspects of breathing across three groups of children: asthmatic children with healthy weight, overweight children with asthma and a control group of healthy weight children. The project involved the children breathing through a device which added resistance to breathing. Children were asked to rate how hard they felt it was to breathe, and the tests also measured the children’s breathing muscle activity to find out how hard the breathing muscles were working as the researchers purposefully increased the children’s effort to breathe.
The anticipated results were that healthy weight asthmatic children and healthy weight children would show similar results, that is that their breathing effort scores would steadily increase as they found it harder to breathe, with the breathing muscles working gradually harder. Meanwhile, the overweight asthmatic children would show a much steeper increase.
From the 27 children who were studied, the results showed that the overweight children gave higher effort scores throughout the tests, but that these increased at the same rate. There were no differences in the way the children’s breathing muscles responded to the tests. The reason for the higher overall effort scores in the overweight asthmatic children was that their muscles are already working harder than the other two groups before the experiment due to the changes that occur in the lung with increased weight. It was then concluded that overweight asthmatic children do not have differences in their awareness of breathing effort, but that their additional body mass means their muscles are already working harder.
This summary was produced by Sarah Ezzeddine, Year 13 student from Harris Academy Peckham and Neta Fibeesh, Year 13 student from JFS School, Harrow, as part of our departmental educational outreach programme.