Nitric Oxide Levels Predict Endothelial Health

In a recent study, researchers examined the hypothesis that plasma nitrite levels are reduced in humans with less than optimal endothelial function and that the decrease is correlated with increasing numbers of factors involved in suboptimal cardiovascular health. Past studies have shown that reduced nitric oxide availability is a hallmark of endothelial function concerns that occur in the early stages of suboptimal cardiovascular health.

Researchers measured the plasma nitrite concentrations in humans. They found that the baseline levels of plasma nitrite decreased progressively with increasing numbers of factors for suboptimal cardiovascular health. The study authors also used ultrasound to measure intima media thickness (a measurement of the thickness of artery walls) and flow-mediated dilation (FMD), a measurement of blood flow that assesses endothelial function. The results indicated that plasma nitrite and flow-mediated dilation levels were lower, whereas intima media thickness was greater in individuals with less than optimal endothelial function compared to healthy volunteers. Healthy nitrite levels were significantly associated with healthy flow-mediated dilation; less optimal nitrite levels were associated with effects on intima media thickness.

The researchers concluded that plasma nitrite levels can be reliably measured in humans, are an indicator of endothelial function, and correlate with factors known to be involved in suboptimal cardiovascular health.

Reference:

Kleinbongard P, Dejam A, Lauer T, Jax T, Kerber S, Gharini P, Balzer J, Zotz RB, Scharf RE, Willers R, Schechter AN, Feelisch M, Kelm M. Plasma nitrite concentrations reflect the degree of endothelial dysfunction in humans. Free Radic Biol Med. 2006 Jan 15;40(2):295-302.