Abstract 535: Effects of Short-term Exercise-Training on Aortic Stiffness and Central Blood Pressure in Young-to-Middle Aged Pre- or Grade I Hypertensives.

Abstract

Aim: To assess the effects of 6-weeks of exercise-training and a period of detraining on aortic stiffness and central aortic blood pressure (BP) in young-to-middle-aged pre- and grade I hypertensives. Methods: Thirty-five sedentary or recreationally active men and women (30-57years) with untreated pre- or stage I hypertension completed 6-weeks of continuous moderate intensity (Mod Ex)(n=20) or high intensity interval (High Ex)(n=15) exercise-training (at least 3 days/week, on a stationary bike and/or treadmill) and a 3-week detraining period. Carotidfemoral pulse wave velocity (PWV), aortic augmentation index (AIx), central aortic BP (SphygmoCor) and brachial BP were determined before and after exercise-training and after 3-weeks of detraining. Results: Peak oxygen consumption increased from 26.5 to 28.7ml.kg-1.min-1 and from 27.0 to 29.3ml.kg-1.min-1 after 6-weeks of Mod or High Ex respectively (p<0.05). Mod Ex decreased brachial systolic (SBP) and diastolic BP from 141±9/93±7mmHg to 132±10/83±13mmHg (p<0.05) and these values returned to hypertensive/prehypertensive levels after detraining (146±8/92±10mmHg). Neither PWV (baseline: 4.79±0.96m/sec; after 6-weeks training: 4.99±1.00m/sec), AIx (Baseline: 25.5±10.0%; after 6-weeks training: 22.1±11.6%), nor aortic pulse pressure were modified by Mod Ex. Although aortic SBP decreased after 6-weeks of Mod Ex (p<0.05) and returned to baseline values after 3-weeks of detraining, these changes were accounted for by decreases in mean arterial pressure. High Ex did not modify brachial or aortic BP, PWV or AIx. Conclusions: In young-to-middle-aged pre- or grade I hypertensives, although short-term moderate intensity exercise-training may decrease aortic BP, these effects are not attributed to alterations in the properties of the aorta.