Ambulatory blood pressure, sympathetic activity, and left ventricular structure and function in middle-aged normotensive men with exaggerated blood pressure response to exercise.
BACKGROUND
It is claimed that exaggerated blood pressure (BP) reactivity to behavioral stress may play a role in hypertension. This study aimed to clarify whether exaggerated BP reactivity during physical exercise is associated with any other abnormalities in ambulatory BP, autonomic nervous control, and target organ damage among middle-aged normotensive men.


METHODS
A total of 54 sedentary men (39+/-4 years old) with normal BP were enrolled in this study. Twenty-seven with exaggerated BP reactivity to exercise (ER) were compared with 27 age-matched controls with normal BP reactivity (NR). The subjects underwent 24-hour ambulatory BP monitoring, short-term Finapres recordings, a bicycle ergometry test, and M-mode and pulsed-Doppler echocardiography.


RESULTS
The ambulatory BP measurements were significantly higher in the ER group than in the NR group averaged over a 24-hour period, during daytime and nighttime. Power spectral analysis from continuous Finapres data revealed increased systolic BP variability in the low frequency band in the ER group. During graded exercise, the ER group showed remarkable elevations in systolic and diastolic BP compared to the NR group without a difference in heart rate increments. Although the plasma epinephrine showed similar levels, yet the exercise-induced increase in plasma norepinephrine in the ER group was significantly greater than in the NR group. In echocardiographic dimensions, left ventricular internal diameter and mass index were not different, whereas the ER group presented significantly greater posterior wall thickness. Doppler functional data showed significant increase in the late to early flow velocity ratio in the ER group.


CONCLUSIONS
Even in the absence of hypertension, exaggerated BP reactivity to physical exercise suggests greater BP elevation during daily activity as well as enhanced sympathetic nervous tonus, which may be considered a risk factor promoting hypertension, and these hemodynamic and neurohumoral behaviors are associated with a tendency to develop target organ abnormalities in the heart.
Miyai
Nobuyuki
N
Department of Hygiene, School of Medicine, Wakayama Medial University, 811-1 Kimiidera, Wakayama, Japan. miyain@wakayama-med.ac.jp
Arita
Mikio
M
Morioka
Ikuharu
I
Takeda
Shintaro
S
Miyashita
Kazuhisa
K
D000328:Adult; D001794:Blood Pressure; D003430:Cross-Sectional Studies; D004452:Echocardiography; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006352:Heart Ventricles / Q000033:anatomy & histology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013564:Sympathetic Nervous System / Q000502:physiology*; D016276:Ventricular Function