title: Transcutaneous flow related variables measured in vivo: the effects of gender.
abstract: BACKGROUND
  The identification of potential sources of error is a crucial step for any new assessment technique. This is the case for transcutaneous variables, such as flow and arterial gases, which have been applied as functional indicators of various aspects of human health. Regarding gender, a particular subject-related determinant, it is often claimed that women present higher transcutaneous oxygen pressure (tcpO2) values than men. However, the statistical significance of this finding is still uncertain.
  
  
  METHODS
  The haemodynamical-vascular response to a local reactive hyperaemia procedure (the tourniquet cuff manoeuvre) was studied in two previously selected group of volunteers (n = 16; 8 women and 8 men). The effect of gender was assessed under standardised experimental conditions, using the transcutaneous flow-related variables tcpO2-tcpCO2 and Laser-doppler Flowmetry (LDF).
  
  
  RESULTS
  Regarding tcpO2, statistically significant differences between genders were not found, although higher values were consistently found for the gases in the female group. Regarding LDF, high statistically significant differences (p < 0.005) were found, with the men's group presenting the highest values and variability. Other derived parameters used to characterise the vascular response following the cuff-deflation (t-peak) were similar in both groups.
  
  
  CONCLUSIONS
  The relative influence of gender was not clearly demonstrated using these experimental conditions. However the gender-related LDF differences suggest that further investigation should be done on this issue. Perhaps in the presence of certain pathological disparities involving peripheral vascular regulation, other relationships may be found between these variables.
authors.affiliation: UCTF-Laboratory of Experimental Physiology, Faculdade de Farmácia da Universidade de Lisboa, AvForcas Armadas, Lisboa, Portugal. lrodrigues@ff.ul.pt
authors.forename: L M
authors.initials: LM
authors.lastname: Rodrigues
authors.forename: P C
authors.initials: PC
authors.lastname: Pinto
authors.forename: A
authors.initials: A
authors.lastname: Leal
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D001783:Blood Flow Velocity / Q000502:physiology; D001785:Blood Gas Monitoring, Transcutaneous / Q000592:standards; D005260:Female; D018056:Hemorheology / Q000379:methods / Q000592:standards*; D006801:Humans; D006940:Hyperemia / Q000175:diagnosis / Q000503:physiopathology*; D017078:Laser-Doppler Flowmetry / Q000379:methods; D008297:Male; D008833:Microcirculation / Q000502:physiology; D012016:Reference Values; D012039:Regional Blood Flow / Q000502:physiology; D012737:Sex Factors; D012867:Skin / Q000098:blood supply*