Abstract 462: Effect of Adding Beet Root Juice to Exercise on Physical Performance and Cardiovascular Measures in Old Hypertensive Subjects

Abstract

Hypertension and diminished blood flow to muscles and brain are common problems for the elderly that may lead to impaired cognition and physical performance and poor cardiovascular outcomes. Exercise improves blood pressure and brain blood flow. Thus, any intervention that can improve exercise effects in hypertensive individuals may have beneficial effects. High nitrate containing beetroot juice (BRJ) has been demonstrated to increase exercise tolerance and improve blood flow to working muscles. In this study we examined the effect of adding BRJ to an exercise regimen on exercise performance and cardiovascular measures in old subjects. Participant (n=26; mean age=65 yrs, range 57-77) with controlled hypertension (on 2 or more medications) were assigned to either exercise with BRJ+nitrate (BRJ+) (n=13, 6F) or BRJ-nitrate placebo drink (Placebo) (n=13, 7F). The exercise intervention was a 6-week treadmill walking program of self-paced. Participants walked 3 times per week for a maximum of 50 minutes per session. Participants also consumed 140 ml BRJ+ nitrate or BRJ-nitrate daily for 6 weeks. There were no differences between groups in mean VO 2 max at the beginning of study (placebo = 19.4 ± 0.5 ml O 2 /kg/min; BRJ = 19.4 ± 0.5 ml O 2 /kg/min) and change VO 2 max by the end of the intervention (increase of 1.15 ml O 2 /kg/min in placebo vs 0.9 ml O 2 /kg/min in BRJ+). There were no differences between groups in 24 hour ambulatory mean arterial pressure (MAP) or heart rate at the beginning of study. Heart rate and MAP showed similar reductions in both groups (4 beats/min for heart rate and 5 mm Hg for MAP). Similarly total arterial compliance was improved in both groups (placebo from 15.1 ± 3.7 ml/mm Hg to 18.3 ± 4.8, p = 0.02; BRJ+ from 18.3 ± 5.0 to 20.5 ± 3.9 ml/mm Hg; p = 0.04). There was no additional benefit of BRJ+ in the cardiovascular measures above that seen with exercise alone. In summary, in this cohort of controlled hypertensive elderly, addition of BRJ with nitrate to exercise has no additional benefits on physical performance or cardiovascular function. Further studies are warranted in different cohorts such as drug naïve or uncontrolled hypertensive to further characterize any possible benefits of BRJ. Support from WFU Translational Science Center