title: Impaired oxygen on-kinetics in persons with human immunodeficiency virus are not due to highly active antiretroviral therapy.
abstract: OBJECTIVE
  To determine the effects of human immunodeficiency virus (HIV) and highly active antiretroviral therapy (HAART) on oxygen on-kinetics in HIV-positive persons.
  
  
  METHODS
  Quasi-experimental cross-sectional.
  
  
  METHODS
  Infectious disease clinic and exercise laboratory.
  
  
  METHODS
  Referred participants (N=39) included 13 HIV-positive participants taking HAART, 13 HIV-positive participants not taking HAART, and 13 noninfected controls.
  
  
  METHODS
  Participants performed 1 submaximal exercise treadmill test below the ventilatory threshold, 1 above the ventilatory threshold, and 1 maximal treadmill exercise test to exhaustion.
  
  
  METHODS
  Change in oxygen consumption (Delta.VO2) and oxidative response index (Delta.VO2/mean response time).
  
  
  RESULTS
  Delta.VO2 was significantly lower in both HIV-positive participants taking (946.5+/-68.1mL) and not taking (871.6+/-119.6mL) HAART than in controls (1265.3+/-99.8mL) during submaximal exercise above the ventilatory threshold. The oxidative response index was also significantly lower (P<.05) in HIV-positive participants both taking (15.0+/-1.3mL/s) and not taking (15.1+/-1.7mL/s) HAART than in controls (20.8+/-2.1mL/s) during exercise above the ventilatory threshold.
  
  
  CONCLUSIONS
  Oxygen on-kinetics during submaximal exercise above the ventilatory threshold was impaired in HIV-positive participants compared with a control group, and it appeared that the attenuated oxygen on-kinetic response was primarily caused by HIV infection rather than HAART.
authors.affiliation: Department of Physical Therapy, University of Maryland School of Medicine, Baltimore, MD, USA. tcade@im.wustl.edu
authors.forename: W Todd
authors.initials: WT
authors.lastname: Cade
authors.forename: Lori E
authors.initials: LE
authors.lastname: Fantry
authors.forename: Sharmila R
authors.initials: SR
authors.lastname: Nabar
authors.forename: Donald K
authors.initials: DK
authors.lastname: Shaw
authors.forename: Randall E
authors.initials: RE
authors.lastname: Keyser
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000502:physiology; D023241:Antiretroviral Therapy, Highly Active; D002302:Cardiac Output / Q000502:physiology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*