a Department of Cardiovascular Medicine , Affiliated Hospital of Yan'an University , Yan'an , Shaanxi , China.
b Department of Cardiovascular Medicine , First Affiliated Hospital of Medical College, Xi'an Jiaotong University , Xi'an , Shaanxi , China.
Clin Exp Hypertens. 2017;39(8):769-773. doi: 10.1080/10641963.2017.1334793. Epub 2017 Jul 6.
The mechanism by which high-salt and low-potassium diet contributes to hypertension remains poorly understood. Plasma homocysteine (Hcys) is recognized as a primary mediator of blood pressure (BP) response to some diets. Therefore, the present study tried to investigate whether plasma Hcys and BP could be regulated by salt loading in normotensive salt-sensitive (SS) persons, and further explored whether potassium supplementation could reverse the effect. We enrolled 47 normotensive subjects, aged 29-65 years. The protocol included 7 days on a low-salt diet (3g/day, NaCl), 7 days on a high-salt diet (18g/day), and then a high-salt diet with potassium supplementation (4.5g/day) for 7 days. After high-salt intake, BP was significantly increased and potassium supplementation lowered it in the SS group. Plasma Hcys were higher in SS subjects than in salt-resistant (SR) subjects after salt loading (34.4 ± 17.0 μmol/L versus 19.16 ± 6.4 μmol/L, P < 0.01). Plasma Hcys in SS subjects was increased on a high-salt diet than on a low-salt diet (34.4 ± 17.0 μmol/L versus 16.5 ± 8.3 μmol/L, P < 0.01), but plasma Hcys was ameliorated by potassium supplementation (34.4 ± 17.0 μmol/L versus 20.9 ± 10.4 μmol/L, P < 0.01). In SS subjects, the change of mean arterial blood pressure (MBP) correlated significantly and positively with the alteration of plasma Hcys during low-salt to high-salt intake and high-salt to high-salt with potassium supplementation (r = 0.75, P < 0.001; r = 0.74, P < 0.001, respectively). Our results indicate that Hcys may partly mediate the impact of high-salt intake and potassium supplementation on BP in SS subjects.
高盐低钾饮食导致高血压的机制仍不清楚。血浆同型半胱氨酸（Hcys）被认为是一些饮食引起血压（BP）反应的主要介质。因此，本研究试图探讨在正常血压盐敏感（SS）人群中，盐负荷是否可以调节血浆 Hcys 和 BP，以及钾补充是否可以逆转这种作用。我们招募了 47 名年龄在 29-65 岁的正常血压受试者。方案包括 7 天低盐饮食（3g/天，NaCl），7 天高盐饮食（18g/天），然后高盐饮食加钾补充（4.5g/天）7 天。高盐摄入后，BP 在 SS 组明显升高，钾补充降低了它。盐负荷后，SS 组血浆 Hcys 高于盐抵抗（SR）组（34.4±17.0μmol/L 比 19.16±6.4μmol/L，P＜0.01）。SS 组高盐饮食时血浆 Hcys 高于低盐饮食时（34.4±17.0μmol/L 比 16.5±8.3μmol/L，P＜0.01），但钾补充改善了血浆 Hcys（34.4±17.0μmol/L 比 20.9±10.4μmol/L，P＜0.01）。在 SS 组中，平均动脉压（MBP）的变化与低盐至高盐摄入期间和高盐加钾补充期间血浆 Hcys 的变化呈显著正相关（r=0.75，P＜0.001；r=0.74，P＜0.001）。我们的结果表明，Hcys 可能部分介导了 SS 人群中高盐摄入和钾补充对 BP 的影响。
