title: Respiratory load perception in overweight and asthmatic children.
abstract: Overweight asthmatic children report greater symptoms than normal weight asthmatics, despite comparable airflow obstruction. This has been widely assumed to be due to heightened perception of respiratory effort. Three groups of children (healthy weight controls, healthy weight asthmatics, overweight asthmatics) rated perceived respiratory effort throughout an inspiratory resistive loading protocol. Parasternal intercostal electromyogram was used as an objective marker of respiratory load; this was expressed relative to tidal volume and reported as a ratio of the baseline value (neuroventilatory activity ratio (NVEAR)). Significant increases in perception scores (p<0.0001), and decreases in NVEAR (p<0.0001) were observed from lowest to highest resistive load. Higher BMI increased overall perception scores, with no influence of asthma or BMI-for-age percentile on the resistance-perception relationships. These data, indicating elevated overall respiratory effort in overweight asthmatic children but comparable responses to dynamic changes in load, suggest that the greater disease burden in overweight asthmatic children may be due to altered respiratory mechanics associated with increased body mass.
authors.affiliation: Division of Asthma, Allergy & Lung Biology, King's College London Department of Respiratory Medicine, Bessemer Road, London SE5 9PJ, United Kingdom. Electronic address: victoria.macbean@kcl.ac.uk.
authors.forename: Victoria
authors.initials: V
authors.lastname: MacBean
authors.affiliation: Chest Unit, King's College Hospital NHS Foundation Trust, Denmark Hill, London SE5 9RS, United Kingdom. Electronic address: lorna.wheatley@nhs.net.
authors.forename: Lorna
authors.initials: L
authors.lastname: Wheatley
authors.affiliation: Division of Asthma, Allergy & Lung Biology, King's College London Department of Respiratory Medicine, Bessemer Road, London SE5 9PJ, United Kingdom. Electronic address: alan.lunt@nhs.net.
authors.forename: Alan C
authors.initials: AC
authors.lastname: Lunt
authors.affiliation: Division of Asthma, Allergy & Lung Biology, King's College London Department of Respiratory Medicine, Bessemer Road, London SE5 9PJ, United Kingdom. Electronic address: gerrard.rafferty@kcl.ac.uk.
authors.forename: Gerrard F
authors.initials: GF
authors.lastname: Rafferty
mesh_terms: D000293:Adolescent; D000403:Airway Resistance / Q000502:physiology; D001249:Asthma / Q000150:complications*; D002648:Child; D004576:Electromyography; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D016014:Linear Models; D008297:Male; D050177:Overweight / Q000150:complications*; D010465:Perception / Q000502:physiology*; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics / Q000502:physiology*; D013990:Tidal Volume; D064232:Visual Analog Scale
keywords: Asthma; Breathlessness perception; Child; Obesity