title: The Effects of Sex on Cardiopulmonary Responses to Acute Normobaric Hypoxia.
abstract: Boos, Christopher John, Adrian Mellor, John Paul O'Hara, Costas Tsakirides, and David Richard Woods. The effects of sex on cardiopulmonary responses to acute normobaric hypoxia. High Alt Med Biol. 17:108-115, 2016.-
  
  
  BACKGROUND
  Acute hypoxia leads to a number of recognized changes in cardiopulmonary function, including acute increase in pulmonary artery systolic pressure. However, the comparative responses between men and women have been barely explored.
  
  
  METHODS
  Fourteen young healthy adult Caucasian subjects were studied at sea-level rest and then after >150-minute exposure to acute normobaric hypoxia (NH) equivalent to 4800 m and again at sea-level rest at 2 hours post-NH exposure. Cardiac function, using transthoracic echocardiography, physiological variables, and Lake Louise Scores for acute mountain sickness (AMS) were collected.
  
  
  RESULTS
  All subjects completed the study, and there was an equal balance of men (n = 7) and women (n = 7) who were well matched for age (25.9 ± 3.2 vs. 27.3 ± 4.4; p = 0.51). NH exposure led to a significant increase in AMS scores and heart rate, as well as a fall in oxygen saturation, systolic blood pressure, and stroke volume. Stroke volumes and cardiac output were overall significantly higher in men than in women, and acute NH heart rate was higher in women (80.3 ± 10.2 vs. 69.7 ± 10.7/min; p < 0.05). NH led to a significant fall in the estimated left ventricular filling pressure (E/E'), an increase in the septal A' and S' and septal and lateral isovolumic contractile velocities (ICVs), and a fall in the E'A'S' ratio. The mitral E, lateral ICV, and E' velocities were all higher in men. Acute NH led to a significant increase in right ventricular systolic pressure and pulmonary vascular resistance. There was no interaction between NH exposure and sex for any parameters measured.
  
  
  CONCLUSIONS
  Despite several baseline differences between men and women, the cardiopulmonary effects of acute NH are consistent between men and women.
authors.affiliation: 1 Department of Cardiology, Poole Hospital NHS Foundation Trust , Poole, United Kingdom .|2 Department of Postgraduate Medical Education, Bournemouth University , Poole, United Kingdom .
authors.forename: Christopher John
authors.initials: CJ
authors.lastname: Boos
authors.affiliation: 3 James Cook University Hospital , Middlesbrough, United Kingdom .|4 Defence Medical Services , Lichfield, United Kingdom .|5 Institute for Sport, Physical Activity and Leisure, Leeds Beckett University , Leeds, United Kingdom .
authors.forename: Adrian
authors.initials: A
authors.lastname: Mellor
authors.affiliation: 5 Institute for Sport, Physical Activity and Leisure, Leeds Beckett University , Leeds, United Kingdom .
authors.forename: John Paul
authors.initials: JP
authors.lastname: O'Hara
authors.affiliation: 5 Institute for Sport, Physical Activity and Leisure, Leeds Beckett University , Leeds, United Kingdom .
authors.forename: Costas
authors.initials: C
authors.lastname: Tsakirides
authors.affiliation: 3 James Cook University Hospital , Middlesbrough, United Kingdom .|4 Defence Medical Services , Lichfield, United Kingdom .|5 Institute for Sport, Physical Activity and Leisure, Leeds Beckett University , Leeds, United Kingdom .|6 Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary , Newcastle, United Kingdom .|7 University of Newcastle , Newcastle upon Tyne, United Kingdom .
authors.forename: David Richard
authors.initials: DR
authors.lastname: Woods
mesh_terms: D000064:Acclimatization / Q000502:physiology; D000208:Acute Disease; D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000503:physiopathology*; D001274:Atmospheric Pressure; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D064368:Healthy Volunteers; D006339:Heart Rate / Q000502:physiology; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology; D012737:Sex Factors; D013318:Stroke Volume / Q000502:physiology; D014655:Vascular Resistance / Q000502:physiology; D016278:Ventricular Function, Right / Q000502:physiology; D055815:Young Adult
keywords: cardiac function; echocardiography; high altitude; normobaric hypoxia; sex; tissue Doppler imaging