慢性盐负荷及补钾对盐敏感者氧化应激及内皮功能的影响

Effect of slow salt loading and potassium supplement on oxidative stress and endothelial function in patients with salt-sensitive hypertension

目的通过慢性盐负荷及补钾试验,探索其对盐敏感者氧化应激和内皮功能的影响,探讨盐敏感高血压有效的预防措施。方法在陕西农村选择正常血压或1级高血压患者60人,进行基线调查和饮食干预研究。每个阶段的第2天和最后3 d测量体重和血压。测定各阶段尿钠、钾排泄量、血浆一氧化氮、丙二醛、尿一氧化氮含量,采用t检验统计学处理。结果无论盐敏感者还是盐不敏感者,低盐比基线血、尿一氧化氮升高,丙二醛、24 h尿微量清蛋白降低差异有统计学意义(P<0.05或P<0.01);高盐比低盐血、尿一氧化氮降低,丙二醛降低,差异有统计学意义(P<0.05或P<0.01);高盐比低盐血、尿一氧化氮降低,丙二醛升高(P<0.05或P<0.01);补钾后血、尿一氧化氮升高,丙二醛、24 h尿微量清蛋白降低,且盐敏感者比盐不敏感者变化更为显著。结论氧化应激在盐敏感者内皮功能损害中起着重要的作用。补钾具有保护作用,可改善高盐引起的肾脏损害。

Objective To analyze the effect of slow salt loading and potassium supplementation on oxidative stress and endothelial function in patients with salt-sensitive hypertension,and explore effective preventive measures.Methods Sixty subjects who had borderline or phase I hypertension were selected from rural area of Shaanxi province.They were investigated at baseline and after intervention of dietary.On the second day and the last three days of each salt diet,participants were measured for weight,blood pressure,urinary sodium and potassium,plasma nitric oxide（NO）,malondialdehyde（MDA）,urinary nitric oxide and 24 hour urinary microalbumin.Results In both the salt-sensitive hypertension（SSH）and non-salt-sensitive hypertension（NSSH）groups,the NO of plasma and urinary increased;while concentration of MDA and 24 hour urinary microalbumin decreased after salt restriction.The NO of plasma and urinary also decreased;while MDA and 24 hour urinary microalbumin increased after salt loading.At potassium supplementation stage,the NO concentration of plasma and urinary increased;while the concentration of MDA and 24 hour urinary microalbumin decreased again.The differences in the SSH group were more obvious than those in the NSS group.Conclusion Oxidative stress had an important effect on endothelial dysfunction.Potassium supplementation would prevent kidney damage,which was resulted from high salt.