Exercise training restores baroreflex sensitivity in never-treated hypertensive patients

Author(s)

Laterza, Mateus C. ; Matos, Luciana D. N. J. de ; Trombetta, Ivani C. ; Braga, Ana M. W. ; Roveda, Fabiana ; Alves, Maria J. N. N. ; Krieger, Eduardo M. ^[7] ; Negrão, Carlos E. ^[8] ; Rondon, Maria U. P. B.

• Document type: Journal article
• Source: Hypertension; v. 49, n. 6, p. 1298-1306, June 2007.
• Field of knowledge: Health Sciences - Medicine

Abstract

The effects of exercise training on baroreflex control of sympathetic nerve activity in human hypertension are unknown. We hypothesized that exercise training would improve baroreflex control of muscle sympathetic nerve activity (MSNA) and heart rate (HR) in patients with hypertension and that exercise training would reduce MSNA and blood pressure (BP) in hypertensive patients. Twenty never-treated hypertensive patients were randomly divided into 2 groups: exercise-trained (n=11; age: 46±2 years) and untrained (n=9; age: 42±2 years) patients. An age-matched normotensive exercise-trained group (n=12; age: 42±2 years) was also studied. Baroreflex control of MSNA (microneurography) and HR (ECG) was assessed by stepwise intravenous infusions of phenylephrine and sodium nitroprusside and analyzed by linear regression. BP was monitored on a beat-to-beat basis. Exercise training consisted of three 60-minute exercise sessions per week for 4 months. Under baseline conditions (before training), BP and MSNA were similar between hypertensive groups but significantly increased when compared with the normotensive group. Baroreflex control of MSNA and HR was similar between hypertensive groups but significantly decreased when compared with the normotensive group. In hypertensive patients, exercise training significantly reduced BP (P<0.01) and MSNA (P<0.01) levels and significantly increased baroreflex control of MSNA and HR during increases (P<0.01 and P<0.03, respectively) and decreases (P<0.01 and P<0.03, respectively) in BP. The baseline (preintervention) difference in baroreflex sensitivity between hypertensive patients and normotensive individuals was no longer observed after exercise training. No significant changes were found in untrained hypertensive patients. In conclusion, exercise training restores the baroreflex control of MSNA and HR in hypertensive patients. In addition, exercise training normalizes MSNA and decreases BP levels in these patients. (AU)

• FAPESP's process: 01/00009-0 - An integrated approach for the dissection of primary hypertension: molecular and functional characterization of the cardiovascular system
• Grantee: Eduardo Moacyr Krieger
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 05/59740-7 - Physical exercise and autonomic control in cardiovascular physiopathology
• Grantee: Carlos Eduardo Negrão
• Support Opportunities: Research Projects - Thematic Grants