Hypertension in Africa Research Team (HART), North-West University, Potchefstroom, South Africa.
MRC Research Unit for Hypertension and Cardiovascular Disease, North-West University, Potchefstroom, South Africa.
Amino Acids. 2020 Apr;52(4):639-648. doi: 10.1007/s00726-020-02842-3. Epub 2020 Apr 18.
Nitric oxide plays an important role in maintaining endothelial function, while increased oxidative stress may lead to nitric oxide inactivation and cardiovascular disease. If nitric oxide biosynthesis/bioavailability is already suppressed early in life, it may potentially predispose an individual to the early development of cardiovascular disease. We therefore aimed to identify differences in nitric oxide-related markers (urinary nitrate, nitrite and the nitrate-to-nitrite ratio (UR)) between young black and white individuals, and whether these markers are associated with blood pressure and carotid intima media thickness. We included black and white healthy boys (n = 80; aged 6-8 years) and men (n = 510; 20-30 years) and measured blood pressure and carotid intima media thickness, along with urinary biochemical markers including nitrate and nitrite. The black boys and men had lower nitrate and UR (all p ≤ 0.003) than their white counterparts. In single and multiple regression analyses, we found an inverse association of diastolic blood pressure in the black boys (adj. R = 0.27; β = -0.32; p = 0.030), and systolic blood pressure in black men (adj. R = 0.07; β = -0.13; p = 0.036) with nitrate. Carotid intima media thickness associated inversely with UR in the black men (adj. R = 0.02; β = -0.14; p = 0.023), but not in the boys. Lower urinary nitrate in black boys and young men was associated negatively with blood pressure, suggesting that potentially lower nitric oxide bioavailability in young black individuals may contribute to hypertension development in later life.
一氧化氮在维持内皮功能方面发挥着重要作用，而氧化应激的增加可能导致一氧化氮失活和心血管疾病。如果一氧化氮的生物合成/生物利用度在生命早期已经受到抑制，它可能使个体易患心血管疾病的早期发展。因此，我们旨在确定年轻的黑人和白人之间与一氧化氮相关的标志物（尿硝酸盐、亚硝酸盐和硝酸盐与亚硝酸盐的比值（UR））的差异，以及这些标志物是否与血压和颈动脉内膜中层厚度有关。我们纳入了黑人健康男孩（n=80；年龄 6-8 岁）和白人男性（n=510；20-30 岁），测量了血压和颈动脉内膜中层厚度，以及包括硝酸盐和亚硝酸盐在内的尿生化标志物。黑人男孩和男性的硝酸盐和 UR 水平均低于其白人同龄人（均 p≤0.003）。在单因素和多因素回归分析中，我们发现黑人男孩的舒张压（adj. R=0.27；β=-0.32；p=0.030）和黑人男性的收缩压（adj. R=0.07；β=-0.13；p=0.036）与硝酸盐呈负相关。颈动脉内膜中层厚度与黑人男性的 UR 呈负相关（adj. R=0.02；β=-0.14；p=0.023），但与男孩无关。黑人男孩和年轻男性的尿硝酸盐水平较低与血压呈负相关，这表明年轻黑人个体中潜在较低的一氧化氮生物利用度可能导致其晚年高血压的发生。
