Dietary nitrate supplementation and exercise tolerance in patients with heart failure with reduced ejection fraction.

Study answer

What this study found

Plasma nitrite concentration increased with nitrate-rich supplementation to about 240 ± 48 nM vs 56 ± 8 nM with placebo (P ≤ 0.05). Time to exercise intolerance did not differ significantly (placebo 495 ± 53 s vs nitrate 489 ± 58 s; P > 0.05). No significant differences were observed in arterial blood pressure, central hemodynamics (stroke volume, heart rate, cardiac output), pulmonary O2 uptake kinetics, skeletal muscle oxygenation, or blood lactate during rest-to-low- and rest-to-high-intensity transitions. Dietary nitrate via beetroot juice did not improve cardiorespiratory function or…

Study & population

Double-blind, randomized crossover design.

Intervention

Beetroot juice regimen: two 70-ml bottles daily for 9 consecutive days; nitrate-rich juice contained approximately 6.45 mmol nitrate per bottle; morning bottle consumed ~2 hours before testing and the afternoon bottle later in the day; placebo beverage was nitrate-depleted beetroot juice; bottles identical in…

Key limitation

Small, all-male sample (n=10) at a single center; short duration per arm (9 days); crossover design with potential carryover despite washout; limited generalizability to women or more severe disease; results may not apply to HF with preserved ejection fraction or non-ischemic etiologies.

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Original abstract