title: Determining respiratory system resistance and reactance by impulse oscillometry in obese individuals.
abstract: OBJECTIVE
  To evaluate peripheral respiratory system resistance and reactance (Rrs and Xrs, respectively) in obese individuals.
  
  
  METHODS
  We recruited 99 individuals, dividing them into four groups by body mass index (BMI): < 30.0 kg/m2 (control, n = 31); 30.0-39.9 kg/m2 (obesity, n = 13); 40.0-49.9 kg/m2 (severe obesity, n = 28); and ≥ 50.0 kg/m2 (morbid obesity, n = 13). Using impulse oscillometry, we measured total Rrs, central Rrs, and Xrs. Peripheral Rrs was calculated as the difference between total Rrs and central Rrs. All subjects also underwent spirometry.
  
  
  RESULTS
  Of the 99 individuals recruited, 14 were excluded because they failed to perform forced expiratory maneuvers correctly during spirometry. The individuals in the severe obesity and morbid obesity groups showed higher peripheral Rrs and lower Xrs in comparison with those in the two other groups.
  
  
  CONCLUSIONS
  Having a BMI ≥ 40 kg/m2 was associated with a significant increase in peripheral Rrs and with a decrease in Xrs.
authors.affiliation: Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: Cláudio Gonçalves de
authors.initials: CG
authors.lastname: Albuquerque
authors.affiliation: Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: Flávio Maciel Dias de
authors.initials: FM
authors.lastname: Andrade
authors.affiliation: Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: Marcus Aurélio de Almeida
authors.initials: MA
authors.lastname: Rocha
authors.affiliation: Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: Alina Farias França de
authors.initials: AF
authors.lastname: Oliveira
authors.affiliation: Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: Waldemar
authors.initials: W
authors.lastname: Ladosky
authors.affiliation: Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: Edgar Guimarães
authors.initials: EG
authors.lastname: Victor
authors.affiliation: Universidade Federal de Pernambuco, Recife, PE, Brasil.
authors.forename: José Ângelo
authors.initials: JÂ
authors.lastname: Rizzo
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D009991:Oscillometry / Q000379:methods; D012016:Reference Values; D012129:Respiratory Function Tests; D012143:Respiratory Physiological Phenomena; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D055815:Young Adult