title: Impact of surgically-induced weight loss on respiratory function: a prospective analysis.
abstract: BACKGROUND
  Morbid obesity (MO) causes several degrees of respiratory impairment that may resolve after weight reduction. The aims of the present study were to investigate the frequency of respiratory impairment in a selected cohort of morbidly obese patients with BMI 40-50 kg/m(2) with no respiratory symptoms and to evaluate the impact of surgically-induced weight loss on respiratory function.
  
  
  METHODS
  Prospective analysis of respiratory impairment was conducted before surgery and 1 year after surgery in a cohort of patients with MO who underwent vertical banded gastroplasty (VBG). 30 consecutive patients with MO who underwent VBG (14 open and 16 laparoscopic) in a 1-year period were studied. Respiratory function tests, arterial blood gases and hemoglobin were obtained in all patients before and 1 year after VBG.
  
  
  RESULTS
  Results were analyzed using the Wilcoxon signed-rank test and Spearman for variables without normal distribution. Mean age was 35+/-8 years; there were 3 males and 27 females. BMI was 44+/-4 kg/m(2) before surgery and 32+/-4 kg/m(2) at 1-year follow-up. By respiratory function tests, the diagnosis of obstructive disease was made before surgery in 4 patients and a restrictive disorder was identified in 4 additional patients. Evidence of pulmonary disease was absent in all patients 1 year after surgery. Forced vital capacity, inspiratory and expiratory forces, tidal volume, SaO(2), and PaCO(2) significantly improved after weight reduction.
  
  
  CONCLUSIONS
  Surgically-induced weight loss significantly improves pulmonary function.
authors.affiliation: Department of Surgery, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico.
authors.forename: Andrea
authors.initials: A
authors.lastname: Dávila-Cervantes
authors.forename: Guillermo
authors.initials: G
authors.lastname: Domínguez-Cherit
authors.forename: Delia
authors.initials: D
authors.lastname: Borunda
authors.forename: Rosa
authors.initials: R
authors.lastname: Gamino
authors.forename: Florencia
authors.initials: F
authors.lastname: Vargas-Vorackova
authors.forename: Jorge
authors.initials: J
authors.lastname: González-Barranco
authors.forename: Miguel F
authors.initials: MF
authors.lastname: Herrera
mesh_terms: D000328:Adult; D015992:Body Mass Index; D005260:Female; D005500:Follow-Up Studies; D015391:Gastroplasty / Q000379:methods*; D006801:Humans; D007040:Hypoventilation / Q000209:etiology / Q000503:physiopathology*; D010535:Laparoscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000175:diagnosis / Q000601:surgery*; D011336:Probability; D011446:Prospective Studies; D011659:Pulmonary Gas Exchange; D012129:Respiratory Function Tests; D018570:Risk Assessment; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000209:etiology / Q000503:physiopathology*; D013997:Time Factors; D016896:Treatment Outcome; D014797:Vital Capacity; D015431:Weight Loss