Type of Thesis
Age is the primary risk factor for cardiovascular disease (CVD). Adverse changes to arteries, including the development of vascular endothelial dysfunction, mediate the age-related increase in risk of CVD. Endothelial dysfunction is a consequence of insufficient nitric oxide (NO) bioavailability, secondary to increased oxidative stress. Inorganic nitrite supplementation is a novel strategy to improve NO bioavailability. Accordingly, a recent pilot study in our laboratory, showed that 12 weeks of sodium nitrite supplementation improved endothelial function measured as brachial artery flowmediated dilation (FMD) in healthy middle-aged and older (MA/O) adults. Here, we sought to confirm our pilot study findings by conducting a larger randomized, placebocontrolled, double-blind, parallel group study with 12 weeks of sodium nitrite (80mg/day) vs. placebo in MA/O adults (n=49, 68±1 yr) with impaired endothelial function (baseline brachial artery FMD <6%). Sodium nitrite increased plasma nitrite levels acutely (10- fold, p<0.05 vs. placebo) and chronically (p<0.05) and was safe and well tolerated. Vascular endothelial function, as measured by brachial artery FMD, was increased by 28% as compared to baseline (3.9±1.2 to 5.0±1.8%, p<0.05), but unchanged with placebo (3.8±1.4 to 4.0±1.5%, p>0.05). Endothelial cell expression of nitrotyrosine, a marker of oxidative stress, was decreased by 54% after sodium nitrite supplementation (p=0.034), but unchanged with placebo; endothelial cell markers of antioxidant status (manganese superoxide dismutase), inflammation (nuclear factor kappa B), and endothelial NO synthase were unaffected, as were participant characteristics and circulating factors (all p>0.05). These data suggest sodium nitrite supplementation improves endothelial function in healthy MA/O adults, possibly by reducing oxidative stress.
Woodward, Kayla, "Sodium Nitrite Supplemenation Improves Vascular Endothelial Function in Healthy Middle-Aged and Older Adults" (2019). Undergraduate Honors Theses. 1782.
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