title: Acute effect of a single bout of aerobic exercise on vascular and baroreflex function of young males with a family history of hypertension.
abstract: The effect of one single bout of aerobic exercise on the vascular and baroreceptor function of individuals with a family history of hypertension was investigated. Forty young males, mean age 21 years, comprising offspring with (FH(+); n=20) and without (FH(-); n=20) a family history of hypertension participated in this study. Acute exercise was performed on a stationary bike for 20 min at 60% of maximal oxygen uptake. Peak forearm blood flow (FBF) was assessed using plethysmography and was determined as the highest blood flow after 5 min of reactive hyperaemia. Cardiopulmonary baroreceptor (CPBR) sensitivity was measured using lower-body negative pressure (LBNP) for 5 min at -20 mm Hg. CPBR was determined by calculating change of stroke volume and forearm vascular resistance (FVR) at baseline and during LBNP. Carotid baroreceptor (CBR) sensitivity was assessed using neck suction at -20, -40, -60 and -80 mm Hg pressures and was determined from RR interval divided by systolic blood pressure. Augmentation index (AIx), a measure of wave reflection, was assessed using applanation tonometry, and was calculated as the ratio of augmented pressure and pulse pressure. The peak FBF at pre-exercise was lower in FH(+) than in FH(-) subjects. Twenty minutes of acute cycle exercise resulted in significantly increased peak FBF by 22% in FH(+) and by 11% in FH(-) subjects, whereas peak FVR of both groups decreased by 17% and 11%, respectively. No change occurred in CPBR, CBR or AIx. It is concluded that 20 min of acute cycle exercise normalised baseline FBF and forearm vasodilation during hyperaemia in FH(+) subjects.
authors.affiliation: School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia. y.boutcher@unsw.edu.au
authors.forename: Y N
authors.initials: YN
authors.lastname: Boutcher
authors.forename: J P
authors.initials: JP
authors.lastname: Hopp
authors.forename: S H
authors.initials: SH
authors.lastname: Boutcher
mesh_terms: D000293:Adolescent; D000328:Adult; D001158:Arteries / Q000502:physiology*; D017704:Baroreflex / Q000502:physiology*; D015444:Exercise; D005542:Forearm / Q000098:blood supply; D006801:Humans; D006973:Hypertension / Q000235:genetics* / Q000503:physiopathology; D008150:Lower Body Negative Pressure; D008297:Male; D012039:Regional Blood Flow; D014655:Vascular Resistance