title: Metaboreflex activation delays heart rate recovery after aerobic exercise in never-treated hypertensive men.
abstract: Recent evidence indicates that metaboreflex regulates heart rate recovery after exercise (HRR). An increased metaboreflex activity during the post-exercise period might help to explain the reduced HRR observed in hypertensive subjects. Using lower limb circulatory occlusion, the present study showed that metaboreflex activation during the post-exercise period delayed HRR in never-treated hypertensive men compared to normotensives. These findings may be relevant for understanding the physiological mechanisms associated with autonomic dysfunction in hypertensive men.
  
  
  
  Muscle metaboreflex influences heart rate (HR) regulation after aerobic exercise. Therefore, increased metaboreflex sensitivity may help to explain the delayed HR recovery (HRR) reported in hypertension. The present study assessed and compared the effect of metaboreflex activation after exercise on HRR, cardiac baroreflex sensitivity (cBRS) and heart rate variability (HRV) in normotensive (NT) and hypertensive (HT) men. Twenty-three never-treated HT and 25 NT men randomly underwent two-cycle ergometer exercise sessions (30 min, 70% V̇O2 peak ) followed by 5 min of inactive recovery performed with (occlusion) or without (control) leg circulatory occlusion (bilateral thigh cuffs inflated to a suprasystolic pressure). HRR was assessed via HR reduction after 30, 60 and 300 s of recovery (HRR30s, HRR60s and HRR300s), as well as by the analysis of short- and long-term time constants of HRR. cBRS was assessed by sequence technique and HRV by the root mean square residual and the root mean square of successive differences between adjacent RR intervals on subsequent 30 s segments. Data were analysed using two- and three-way ANOVA. HRR60s and cBRS were significant and similarly reduced in both groups in the occlusion compared to the control session (combined values: 20 ± 10 vs. 26 ± 9 beats min-1and 2.1 ± 1.2 vs. 3.2 ± 2.4 ms mmHg-1, respectively, P < 0.05). HRR300s and HRV were also reduced in the occlusion session, although these reductions were significantly greater in HT compared to NT (-16 ± 11 vs. -8 ± 15 beats min-1for HRR300s, P < 0.05). The results support the role of metaboreflex in HRR and suggest that increased metaboreflex sensitivity may partially explain the delayed HRR observed in HT men.
authors.affiliation: Exercise Hemodynamic Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Tiago
authors.initials: T
authors.lastname: Peçanha
authors.affiliation: Exercise Hemodynamic Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Leandro Campos
authors.initials: LC
authors.lastname: de Brito
authors.affiliation: Exercise Hemodynamic Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Rafael Yokoyama
authors.initials: RY
authors.lastname: Fecchio
authors.affiliation: Exercise Hemodynamic Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Patricia Nascimento
authors.initials: PN
authors.lastname: de Sousa
authors.affiliation: Exercise Hemodynamic Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Natan Daniel
authors.initials: ND
authors.lastname: da Silva Junior
authors.affiliation: Hypertension Unit, General Hospital, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Andrea Pio
authors.initials: AP
authors.lastname: de Abreu
authors.affiliation: Hypertension Unit, General Hospital, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Giovanio Vieira
authors.initials: GV
authors.lastname: da Silva
authors.affiliation: Hypertension Unit, General Hospital, University of São Paulo, São Paulo, São Paulo, Brazil.
authors.forename: Décio
authors.initials: D
authors.lastname: Mion-Junior
authors.affiliation: Exercise Hemodynamic Laboratory, School of Physical Education and Sport, University of São Paulo, São Paulo, São Paulo, Brazil. cforjaz@usp.br.
authors.forename: Cláudia Lúcia de Moraes
authors.initials: CL
authors.lastname: Forjaz
mesh_terms: D000328:Adult; D015444:Exercise; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism / Q000502:physiology*; D010101:Oxygen Consumption; D012018:Reflex; D012039:Regional Blood Flow
keywords: baroreflex sensitivity; exercise pressor reflex; hypertension