title: Variability of the perception of dyspnea in healthy subjects assessed through inspiratory resistive loading.
abstract: OBJECTIVE
  Few studies have evaluated the variability of the perception of dyspnea in healthy subjects. The objective of this study was to evaluate the variability of the perception of dyspnea in healthy subjects during breathing against increasing inspiratory resistive loads, as well as to assess the association between the level of perception of dyspnea and the level of physical activity.
  
  
  METHODS
  This was a cross-sectional study involving healthy individuals 16 years of age or older. Subjects underwent inspiratory resistive loading testing, in which the level of perception of dyspnea was quantified with the modified Borg scale. We also determined body mass indices (BMIs), assessed maximal respiratory pressures, performed pulmonary function tests, applied the international physical activity questionnaire (IPAQ)-long form, and conducted six-minute walk tests (6 MWTs). The level of perception of dyspnea was classified as low (Borg score < 2), intermediate (Borg score, 2-5), or high (Borg score > 5).
  
  
  RESULTS
  We included 48 healthy subjects in the study. Forty-two subjects completed the test up to a load of 46.7 cmH2O/L/s. The level of perception of dyspnea was classified as low, intermediate, and high in 13, 19, and 10 subjects, respectively. The level of perception of dyspnea was not significantly associated with age, gender, BMI, IPAQ-long form score, maximal respiratory pressures, or pulmonary function test results.
  
  
  CONCLUSIONS
  The scores for perceived dyspnea induced by inspiratory resistive loading in healthy subjects presented wide variability. The perception of dyspnea was classified as low in 31% of the subjects, intermediate in 45%, and high in 24%. There was no association between the level of perception of dyspnea and the level of physical activity (IPAQ or six-minute walk distance).
authors.affiliation: Porto Alegre Hospital de Clínicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Bruna
authors.initials: B
authors.lastname: Ziegler
authors.affiliation: Porto Alegre Hospital de Clínicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Andréia Kist
authors.initials: AK
authors.lastname: Fernandes
authors.affiliation: Porto Alegre Hospital de Clínicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Paulo Roberto Stefani
authors.initials: PR
authors.lastname: Sanches
authors.affiliation: Porto Alegre Hospital de Clínicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Glauco Luís
authors.initials: GL
authors.lastname: Konzen
authors.affiliation: School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Paulo de Tarso Roth
authors.initials: Pde T
authors.lastname: Dalcin
mesh_terms: D000293:Adolescent; D000328:Adult; D015992:Body Mass Index; D001938:Brazil; D003430:Cross-Sectional Studies; D004417:Dyspnea / Q000209:etiology / Q000503:physiopathology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D001239:Inhalation / Q000502:physiology*; D007320:Inspiratory Capacity; D008297:Male; D008875:Middle Aged; D010465:Perception; D011446:Prospective Studies; D012129:Respiratory Function Tests; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
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