title: Pulmonary vascular function and exercise capacity in black sub-Saharan Africans.
abstract: Sex and age affect the pulmonary circulation. Whether there may be racial differences in pulmonary vascular function is unknown. Thirty white European Caucasian subjects (15 women) and age and body-size matched 30 black sub-Saharan African subjects (15 women) underwent a cardiopulmonary exercise test and exercise stress echocardiography with measurements of pulmonary artery pressure (PAP) and cardiac output (CO). A pulmonary vascular distensibility coefficient α was mathematically determined from the natural curvilinearity of multipoint mean PAP (mPAP)-CO plots. Maximum oxygen uptake (V̇o2max) and workload were higher in the whites, while maximum respiratory exchange ratio and ventilatory equivalents for CO2 were the same. Pulmonary hemodynamics were not different at rest. Exercise was associated with a higher maximum total pulmonary vascular resistance, steeper mPAP-CO relationships, and lower α-coefficients in the blacks. These differences were entirely driven by higher slopes of mPAP-CO relationships (2.5 ± 0.7 vs. 1.4 ± 0.7 mmHg·l(-1)·min; P < 0.001) and lower α-coefficients (0.85 ± 0.33 vs. 1.35 ± 0.51%/mmHg; P < 0.01) in black men compared with white men. There were no differences in any of the hemodynamic variables between black and white women. In men only, the slopes of mPAP-CO relationships were inversely correlated to V̇o2max (P < 0.01). Thus the pulmonary circulation is intrinsically less distensible in black sub-Saharan African men compared with white Caucasian Europeans men, and this is associated with a lower exercise capacity. This study did not identify racial differences in pulmonary vascular function in women.
authors.affiliation: Laboratory of Physiopathology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium; Laboratory of Exercise Physiology, Faculty of Motor Sciences, Université Libre de Bruxelles, Brussels, Belgium;
authors.forename: Bamodi
authors.initials: B
authors.lastname: Simaga
authors.affiliation: Laboratory of Physiopathology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium; Laboratory of Exercise Physiology, Faculty of Motor Sciences, Université Libre de Bruxelles, Brussels, Belgium;
authors.forename: Marco
authors.initials: M
authors.lastname: Vicenzi
authors.affiliation: Laboratory of Exercise Physiology, Faculty of Motor Sciences, Université Libre de Bruxelles, Brussels, Belgium;
authors.forename: Vitalie
authors.initials: V
authors.lastname: Faoro
authors.affiliation: Departement of Cardiology, Erasmus University Hospital, Brussels, Belgium; and.
authors.forename: Sergio
authors.initials: S
authors.lastname: Caravita
authors.affiliation: Departement of Cardiology, Erasmus University Hospital, Brussels, Belgium; and.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Di Marco
authors.affiliation: Laboratory of Exercise Physiology, Faculty of Motor Sciences, Université Libre de Bruxelles, Brussels, Belgium;
authors.forename: Kevin
authors.initials: K
authors.lastname: Forton
authors.affiliation: Laboratory of Exercise Physiology, Faculty of Motor Sciences, Université Libre de Bruxelles, Brussels, Belgium; Departement of Cardiology, Erasmus University Hospital, Brussels, Belgium; and.
authors.forename: Gael
authors.initials: G
authors.lastname: Deboeck
authors.affiliation: Departement of Kinesiology, University of Toledo, Toledo, Ohio.
authors.forename: Sophie
authors.initials: S
authors.lastname: Lalande
authors.affiliation: Laboratory of Physiopathology, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium; Laboratory of Exercise Physiology, Faculty of Motor Sciences, Université Libre de Bruxelles, Brussels, Belgium; rnaeije@ulb.ac.be.
authors.forename: Robert
authors.initials: R
authors.lastname: Naeije
mesh_terms: D000328:Adult; D017954:Africa South of the Sahara; D001794:Blood Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test / Q000379:methods; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D006976:Hypertension, Pulmonary / Q000503:physiopathology; D008168:Lung / Q000502:physiology*; D008297:Male; D011651:Pulmonary Artery / Q000502:physiology*; D011652:Pulmonary Circulation / Q000502:physiology*; D012143:Respiratory Physiological Phenomena; D012146:Rest / Q000502:physiology; D014655:Vascular Resistance
keywords: cardiopulmonary exercise test; echocardiography; exercise; maximum oxygen uptake; pulmonary vascular compliance; pulmonary vascular resistance; race