BACKGROUND: The relationship between peripheral circulation and blood pressure (BP) response to maximal exercise is an intriguing and not yet well defined topic. AIMS: Aims of the present study were to investigate in well trained young healthy males the possible relationships between the endothelial or the smooth muscle component of the peripheral circulation and 1) the BP response to physical exercise on treadmill 2) the body mass composition. SUBJECTS AND METHODS: Fifteen subjects (18-36 years), regularly performing physical activity 3 times weekly underwent the following examinations: body composition by bioelectrical impedance analysis; measurement of the forearm blood flow (FBF) at rest and during post-ischemic hyperemia by strain-gauge plethysmography at the upper arm; measurement of brachial artery diameter (BAD) at rest and after 4-min ischemia by echography; BP response to maximal exercise on treadmill with the determination of maximal oxygen consumption and the measurement of lactic acid serum concentration. RESULTS: BAD was significantly increased during post-ischemic hyperemia up to the 4th minute of observation with a peak at 60 s (+8.5%); FBF increased at 30 s after ischemia (+210%) and returned to baseline levels at the 2nd minute. In the linear correlation analysis, systolic BP increase at the end of the maximal exercise was significantly and inversely related to the increase in FBF (r=-0.663, p<0.01) and to the early FMD (r=0.503, p<0.05). In the multiple regression analysis, however, only FBF independently affected SBP increase during exercise (t=-3.268, p<0.02). Systolic BP increase at the end of the maximal exercise was significantly related to the increase in FBF but not to that of BAD. Among parameters of body composition, fat-free mass was closely related to changes only in BAD. CONCLUSIONS: These data indicate that FBF, which depends on the smooth muscle component of the peripheral circulation, is closely related to BP response to exercise while the endothelial function, which has been determined as changes in BAD, is related to the fat-free mass of the body, possibly through the peripheral insulin sensitivity.
BACKGROUND: The relationship between peripheral circulation and blood pressure (BP) response to maximal exercise is an intriguing and not yet well defined topic. AIMS: Aims of the present study were to investigate in well trained young healthy males the possible relationships between the endothelial or the smooth muscle component of the peripheral circulation and 1) the BP response to physical exercise on treadmill 2) the body mass composition. SUBJECTS AND METHODS: Fifteen subjects (18-36 years), regularly performing physical activity 3 times weekly underwent the following examinations: body composition by bioelectrical impedance analysis; measurement of the forearm blood flow (FBF) at rest and during post-ischemic hyperemia by strain-gauge plethysmography at the upper arm; measurement of brachial artery diameter (BAD) at rest and after 4-min ischemia by echography; BP response to maximal exercise on treadmill with the determination of maximal oxygen consumption and the measurement of lactic acid serum concentration. RESULTS: BAD was significantly increased during post-ischemic hyperemia up to the 4th minute of observation with a peak at 60 s (+8.5%); FBF increased at 30 s after ischemia (+210%) and returned to baseline levels at the 2nd minute. In the linear correlation analysis, systolic BP increase at the end of the maximal exercise was significantly and inversely related to the increase in FBF (r=-0.663, p<0.01) and to the early FMD (r=0.503, p<0.05). In the multiple regression analysis, however, only FBF independently affected SBP increase during exercise (t=-3.268, p<0.02). Systolic BP increase at the end of the maximal exercise was significantly related to the increase in FBF but not to that of BAD. Among parameters of body composition, fat-free mass was closely related to changes only in BAD. CONCLUSIONS: These data indicate that FBF, which depends on the smooth muscle component of the peripheral circulation, is closely related to BP response to exercise while the endothelial function, which has been determined as changes in BAD, is related to the fat-free mass of the body, possibly through the peripheral insulin sensitivity.