title: Does obstructive sleep apnea impair the cardiopulmonary response to exercise?
abstract: OBJECTIVE
  The aim of this study was to evaluate cardiopulmonary exercise performance in lean and obese patients with obstructive sleep apnea (OSA) compared with controls.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  The study was carried out in Sao Paulo Sleep Institute, Sao Paulo, Brazil.
  
  
  METHODS
  INDIVIDUALS WITH SIMILAR AGES WERE ALLOCATED INTO GROUPS: 22 to the lean OSA group, 36 to the lean control group, 31 to the obese OSA group, and 26 to the obese control group.
  
  
  METHODS
  The participants underwent a clinical evaluation, polysomnography, a maximum limited symptom cardiopulmonary exercise test, two-dimensional transthoracic echocardiography, and spirometry.
  
  
  RESULTS
  The apnea-hypopnea index, arousal index, lowest arterial oxygen saturation (SaO2) and time of SaO2 < 90% were different among the groups. There were differences in functional capacity based on the following variables: maximal oxygen uptake (VO2max), P < 0.01 and maximal carbon dioxide production (VCO2max), P < 0.01. The obese patients with OSA and obese controls presented significantly lower VO2max and VCO2max values. However, the respiratory exchange ratio (RER) and anaerobic threshold (AT) did not differ between groups. Peak diastolic blood pressure (BP) was higher among the obese patients with OSA but was not accompanied by changes in peak systolic BP and heart rate (HR). When multiple regression was performed, body mass index (P < 0.001) and male sex in conjunction with diabetes (P < 0.001) independently predicted VO2max (mL/kg/min).
  
  
  CONCLUSIONS
  The results of this study suggest that obesity alone and sex, when associated with diabetes but not OSA, influenced exercise cardiorespiratory function.
authors.affiliation: Sleep Medicine and Biology Discipline, Psychobiology Department, Universidade Federal de São Paulo, São Paulo, Brazil.
authors.forename: Camila F
authors.initials: CF
authors.lastname: Rizzi
authors.forename: Fatima
authors.initials: F
authors.lastname: Cintra
authors.forename: Luciane
authors.initials: L
authors.lastname: Mello-Fujita
authors.forename: Lais F
authors.initials: LF
authors.lastname: Rios
authors.forename: Elisangela T
authors.initials: ET
authors.lastname: Mendonca
authors.forename: Marcia C
authors.initials: MC
authors.lastname: Feres
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
authors.forename: Dalva
authors.initials: D
authors.lastname: Poyares
mesh_terms: D000328:Adult; D000368:Aged; D015308:Anaerobic Threshold / Q000502:physiology; D001794:Blood Pressure; D015992:Body Mass Index; D001938:Brazil; D016022:Case-Control Studies; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications; D010092:Oximetry / Q000379:methods; D017286:Polysomnography / Q000379:methods; D012123:Pulmonary Ventilation; D020181:Sleep Apnea, Obstructive / Q000150:complications / Q000503:physiopathology*; D013147:Spirometry / Q000379:methods
keywords: Exercise; functional capacity; obesity; obstructive sleep apnea
references.citation: Sleep Med. 2009 Mar;10(3):368-73
references.pmid: 18706855
references.citation: Med Sci Sports Exerc. 2003 Jul;35(7):1088-92
references.pmid: 12840627
references.citation: Appl Psychophysiol Biofeedback. 1998 Dec;23(4):207-17
references.pmid: 10457812
references.citation: Diabetologia. 2011 Jun;54(6):1427-36
references.pmid: 21424396
references.citation: Diabetol Metab Syndr. 2009 Sep 21;1(1):8
references.pmid: 19825145
references.citation: Am J Physiol Regul Integr Comp Physiol. 2011 Jul;301(1):R60-6
references.pmid: 21490367
references.citation: Circulation. 1990 Dec;82(6):2286-322
references.pmid: 2242557
references.citation: Respiration. 2004 Sep-Oct;71(5):499-504
references.pmid: 15467328
references.citation: JAMA. 2000 Dec 20;284(23):3015-21
references.pmid: 11122588
references.citation: J Clin Sleep Med. 2007 Dec 15;3(7):689-94
references.pmid: 18198801
references.citation: Eur Heart J. 2006 Jan;27(2):207-15
references.pmid: 16267074
references.citation: Chest. 2010 Jan;137(1):109-14
references.pmid: 19801583
references.citation: Rev Esp Cardiol. 2003 Jun;56(6):594-600
references.pmid: 12783735
references.citation: Sleep Med. 2007 Mar;8(2):160-8
references.pmid: 17275399
references.citation: Respiration. 2008;75(1):26-33
references.pmid: 17114876
references.citation: Am J Cardiol. 2004 Mar 1;93(5):588-93
references.pmid: 14996584
references.citation: Chest. 1992 Mar;101(3):674-9
references.pmid: 1541131
references.citation: Respir Physiol Neurobiol. 2011 Dec 15;179(2-3):287-93
references.pmid: 21930252
references.citation: Sleep. 2008 Jan;31(1):104-10
references.pmid: 18220083
references.citation: Chest. 2005 Jun;127(6):2197-203
references.pmid: 15947337
references.citation: Med Sci Sports Exerc. 2010 Aug;42(8):1454-9
references.pmid: 20139786
references.citation: Proc Am Thorac Soc. 2008 Feb 15;5(2):136-43
references.pmid: 18250205
references.citation: J Physiol Pharmacol. 2007 Nov;58 Suppl 5(Pt 2):563-74
references.pmid: 18204170
references.citation: Chest. 2008 Sep;134(3):539-545
references.pmid: 18779193
references.citation: Am J Respir Crit Care Med. 2003 Jan 15;167(2):211-77
references.pmid: 12524257
references.citation: Proc Soc Exp Biol Med. 1991 Jan;196(1):61-8
references.pmid: 1984243
references.citation: Am J Respir Crit Care Med. 1995 Sep;152(3):1107-36
references.pmid: 7663792
references.citation: Sleep. 1992 Apr;15(2):173-84
references.pmid: 11032543
references.citation: Respir Physiol Neurobiol. 2006 Jan 25;150(1):27-34
references.pmid: 16448931
references.citation: Tuberk Toraks. 2005;53(1):10-9
references.pmid: 15765282
references.citation: Sleep. 1999 Aug 1;22(5):667-89
references.pmid: 10450601
references.citation: J Clin Sleep Med. 2008 Feb 15;4(1):19-25
references.pmid: 18350958
references.citation: Can J Appl Physiol. 2000 Feb;25(1):35-54
references.pmid: 10683599