代用盐影响原发性高血压患者家庭自测血压的双盲随机对照试验

Effects of salt substitution on blood pressure using home measurements in essential hypertensive patients:a double-blinded randomized controlled trial

目的利用家庭自测血压评价代用盐对高血压患者的长期降压效果。方法采用双盲随机对照试验方法。高血压患者220例被随机分到试验组（代用盐组，n=110）和对照组（普通盐组，n=110），分别于基线、干预3、6、12月测量家庭血压；在基线、干预3、12月检测血钠、血钾、肌酐和尿素氮；在基线、干预6、12月检测晨尿尿钠、尿钾。结果97％的研究对象完成试验。基线时，普通盐组家庭血压水平为（141．4±14．8）／（84．1±9．6）mmHg，代用盐组为（139．9±14．4）／（81．9±8．5）mmHg，两组比较差异无统计学意义（P〉0．05）。干预3、6、12月时，代用盐组收缩压低于普通盐组[分别为（133．7±12．6）比（138．3±14．1），（138．7±12．8）比（142．7±13．3），（133．3±13．3）比（138．2±13．6）mmHg，均P〈0．05]。两组比较，各次随访舒张压差异无统计学意义（均P〉0．05）。干预6月和12月时，代用盐组尿钠、尿钠钾比值低于普通盐组[尿钠：113．1（74．2～147．O）比126．0（81．9～166．1）mmol／L（P〈0．05）和122．5（83．9～160．3）比124．2（80．2～160．6）mmol／L（P〉0．05）；尿钠钾比值：2．9（2．1～4．0）比4．4（3．O～6．1）和2．5（1．7～4．3）比4．0（2．6～6．4），均P〈0．05]，尿钾高于普通盐组[36．9（26．7～54．6）比29．8（20．3～43．5）和40．5（24．7～70．5）比28．6（17．8～55．6）mmol／L，均P〈0．05]。干预3月和12月时，代用盐组和普通盐组血钠、血钾、肌酐和尿素氮差异无统计学意义（均P〉0．05）。结论代用盐可以降低高血压患者家庭自测收缩压。

Objective To evaluate the long-term antihypertensive effects of salt substitution in hypertensive patients by home blood pressure measurement. Methods A double blinded randomized controlled trial was conducted. A total of 220 hypertensive patients were enrolled in this study and were randomly divided into experimental group （ the salt substitution group, n= 110 ） and control group （ the regular salt group, n= 110 ） during one year. Home blood pressure was measured at baseline, 3, 6 and 12 months. Blood was sampled at baseline, 3 months and 12 months to measure serum creatinine, urea nitrogen, sodium and potassium for the safety evaluation. Spot morning urine samples were collected to measure urine sodium and potassium, at baseline, 6 and 12 months. Results A total of 97% subjects completed the trial. Home systolic and diastolic blood pressure of the the regular salt group and salt substitution group[（141.4±14.8） vs （139.9±14.4） and （84.1±9.6） vs （81.9±8.5）mm Hg, all P〈0.05] were not significantly different at baseline. Compared with the regular salt group, the salt substitute group had lower home systolic blood pressures at 3, 6 and 12 months [（133.7±12.6） vs （138.3±14.1}, （138.7± 12.8） vs （142.7±13.3}, （133.3±13.3） vs （138.2± 13.6）mm Hg, all P〈0.05], respectively. There was not significantly different between the two groups for home diastolic blood pressure at any time point （all P〉0.05）. Compared with the regular salt group, the salt substitute group showed lower urine sodium and urine sodium-to-potassium ratio at 6 and 12 months [113.1（74.2-147.0） vs 126.0（81.9--166.1}（P〈0.05）, 122.5 （83.9--160.3） vs 124.2 （80.2--160.6} mmoI/L（P〈0.05} ,and 2.9（2.1--4. 0） vs 4.4（3.0--6.1}, 2.5（1.7--4.3） vs 4.0（2.6--6.4）, all P〈0. 053, and higher urine potassium at 6 and 12 months [＇36.9（26.7--54.6） vs 29.8 （20.3--43.5） and 40.5 （24.7--70.5}vs 28.6（17.8--55.6） mmol/L, all P〈0. 053, respectively. Serum sodium, potassium, creatinine and urea nitrogen were not significantly different between the two groups at 3 and 12 months （all P〉 0.05 ）. Conclusion These findings demonstrated that a salt substitute containing low-sodium, high-potassium, and high- magnesium could reduce home systolic blood pressure.