Background: Dietary nitrate has been shown to increase nitrate/nitrite levels in multiple populations, with potential blood pressure lowering effects. However, there are few reports among hypertensives.
Aims: We aimed to assess the effect of daily nitrate in subjects with controlled hypertension vs. uncontrolled hypertension.
Methods: On day 0, hypertensives wore an ambulatory BP monitor (ABPM) for 24 h and fasting blood was taken. Subjects then consumed concentrated beetroot juice (12.9 mmol nitrate) for 14 consecutive days. On day 14 subjects consumed their last nitrate dose after fasting blood was drawn and again had an ABPM for 24 h.
Results: According to baseline ABPM, 11 subjects had controlled BP while 8 had uncontrolled BP. There were similar, significant increases in serum nitrate/nitrite in both groups. We observed little change in BP variables among controlled hypertensives. However, there were reductions in BP variables in uncontrolled hypertensives where decreases in nighttime DBP (-6 ± 4.8 mmHg), arterial stiffness (-0.08 ± 0.03 ambulatory arterial stiffness index) and LDL (-0.36 ± 0.42 mmol/L) reached significance (p = 003, 0.05 and 0.046, respectively).
Conclusions: Our results support the existing data suggesting an anti-hypertensive effect of nitrate-containing beetroot juice, but only among those with uncontrolled hypertension.
Keywords: Blood pressure; Dietary nitrate; Hypertension; Nitric oxide; Nitrite.