Effects of Ascorbic Acid on Ambulatory Blood Pressure in Elderly Patients with Refractory Hypertension

Abstract

The increased production of reactive oxygen species plays a role in the etiology of hypertension, but the effects of antioxidants on blood pressure are controversial. However, antioxidants possibly lower blood pressure in elderly patients with hypertension, because vascular aging is also closely related to oxidative stress. Effects of chronic treatment with ascorbic acid (CAS 50-81-7; 600 mg/day for 6 months) on blood pressure and levels of C-reactive protein, 8-isoprostane, and malondialdehyde-modified low-density lipoproteins were examined in elderly patients (n = 12, six males/six females, age 78.3 +/- 5.0 years, mean +/- SD [range, 67 to 84 years]; elderly group) and adult patients (n = 12, five males/seven females, age 54.6 +/- 6.7 years [range, 39 to 621; adult group) with refractory hypertension. Chronic treatment with ascorbic acid markedly reduced systolic blood pressure and pulse pressure in ambulatory blood pressure monitoring in the elderly group (from 154.9 +/- 21.6 to 134.8 +/- 19.7 mmHg, p < 0.001; and from 79.1 +/- 22.1 to 63.4 +/- 18.7, p < 0.05; respectively), which was accompanied by an increase in the serum levels of ascorbic acid and decreases in the levels of C-reactive protein, 8-isoprostane, and malondialdehyde-modified low-density lipoproteins. In contrast, ascorbic acid did not affect blood pressure in the adult group. These results suggest that ascorbic acid is useful for controlling blood pressure in elderly patients with refractory hypertension.

Dietary Supplements and Hypertension: Potential Benefits and Precautions

“…Additionally, Sato and colleagues demonstrated a statistically significant reduction in SBP in elderly patients (65 years and older) with drug refractory hypertension compared with younger adults (younger than 65 years) who failed to show a significant BP reduction. After receiving 200 mg of ascorbic acid 3 times daily for 6 months, the mean 24‐hour ambulatory SBP decreased by approximately 20 mm Hg 24 . These findings are of interest, although the limited data prevents global recommendations on the efficacy of vitamin C in the treatment of hypertension.…”

Nutraceuticals and Blood Pressure Control: Results from Clinical Trials and Meta-Analyses

“…In elderly patients with refractory hypertension already on maximum pharmacologic therapy, 600 mg of vitamin C daily lowered the BP by 20 ± 8/16 ± 5 mmHg [47].…”

The role of nutrition and nutraceutical supplements in the treatment of hypertension

“…A serum level of 100 μmol/L is recommended [1,70,71] . The SBP and 24 ABM show the most significant reductions with chronic oral administration of Vitamin C [200][201][202][203][204][205] . Block et al [206] in an elegant depletion-repletion study of vitamin C demonstrated an inverse correlation of plasma ascorbate levels, SBP and DBP.…”

“…Dietary intake of vitamin C and plasma ascorbate concentration in humans is inversely correlated to SBP, DBP and heart rate [196][197][198][199][200][201][202][203][204][205][206][207][208][209][210] . An evaluation of published clinical trials indicate that vitamin C dosing at 250 mg twice daily will significantly lower SBP 5-7 mmHg and diastolic BP 2-4 mmHg over 8 wk [196][197][198][199][200][201][202][203][204][205][206][207][208][209][210] . Vitamin C will induce a sodium water diuresis, improve arterial compliance, improve endothelial function, increase nitric oxide and PGI2, decrease adrenal steroid production, improve sympathovagal balance, increase RBC Na/K ATPase, increase SOD, improve aortic elasticity and compliance, improve flow mediated vasodilation, decrease pulse wave velocity and augmentation index, increase cyclic GMP, activate potassium channels, reduce cytosolic calcium and reduce serum aldehydes [208] .…”

“…Vitamin C enhances the efficacy of amlodipine, decreases the binding affinity of the AT 1 receptor for angiotensin Ⅱ by disrupting the ATR1 disulfide bridges and enhances the anti-hypertensive effects of medications in the elderly Houston M. Hypertension, nutrition, nutritional supplements, cardiovascular disease with refractory hypertension [1,70,71,[200][201][202][203][204][205] . In elderly patients with refractory hypertension already on maximum pharmacologic therapy, 600 mg of vitamin C daily lowered the BP by 20/16 mmHg [205] . The lower the initial ascorbate serum level, the better is the BP response.…”