Acute and short-term beetroot juice nitrate-rich ingestion enhances cardiovascular responses following aerobic exercise in postmenopausal women with arterial hypertension: A triple-blinded randomized controlled trial.

BACKGROUND

The increase in blood pressure (BP) levels in the postmenopausal period can be partly explained by the decrease in nitric oxide synthases (NOS).

OBJECTIVE

To investigate the acute and one-week effects of beetroot juice nitrate-rich (BRJ-NO3-rich) ingestion on cardiovascular and autonomic performance in response to submaximal aerobic exercise in postmenopausal women with systemic arterial hypertension (SAH) who are physically inactive.

METHODS

Fourteen postmenopausal women with SAH [mean (SD) age: 59(4) y; BMI (kg/m2): 29.2(3.1)] completed submaximal aerobic exercise bouts after an acute and a one-week intervention with BRJ in a placebo-controlled, randomized, triple-blind, crossover design. Participants ingested either BRJ (800 mg of NO3-) or placebo acutely and drank either BRJ (400 mg of NO3-) or placebo every day for the next six days. After two and ½ hours, they performed a session of aerobic submaximal aerobic exercise, and their systolic BP (SBP) and diastolic BP (DBP), flow-mediated dilation (FMD), heart rate (HR) recovery, and HR variability were measured.

RESULTS

In the post-exercise recovery period, SBP dropped significantly in the BRJ-NO3-rich group (-9.28 mmHg [95%CI: -1.68 to -16.88] ES: -0.65, p = 0.019) compared to placebo after acute ingestion. The FMD values increased after acute BRJ-NO3-rich on post-exercise (3.18 % [0.36 to 5.99] ES: 0.87, p = 0.031). After the one-week intervention, FMD values were higher in the BRJ-NO3-rich group before (4.5 % [1.62 to 7.37] ES: 1.21, p = 0.005) and post-exercise measurements (4.2 % [1.52 to 6.87] ES: 1.22, p = 0.004) vs. placebo. HRV indices with remarkable parasympathetic modulation to heart recovered faster on the BRJ-NO3-rich group than placebo group. No between-group differences were identified in values of HR post-exercise recovery in the 30s, 60s, 120s, 180s, and 300s.

CONCLUSIONS

Acute and short-term BRJ-NO3-rich ingestion may enhance cardiovascular and autonomic behavior in response to aerobic exercise in postmenopausal women diagnosed with SAH.

CLINICAL TRIAL REGISTRY NUMBER: https://clinicaltrials.gov/ct2/show/NCT05384340.