He Feng J, Markandu Nirmala D, Coltart Rosemary, Barron Jeffrey, MacGregor Graham A
Blood Pressure Unit, St. George's Hospital Medical School, London, United Kingdom.
Hypertension. 2005 Apr;45(4):571-4. doi: 10.1161/01.HYP.0000158264.36590.19. Epub 2005 Feb 21.
Randomized trials have shown that increasing potassium intake lowers blood pressure. However, most previous trials used potassium chloride, whereas potassium in fruits and vegetables is not a chloride salt. It is unclear whether a nonchloride salt of potassium has a greater or lesser effect on blood pressure compared with potassium chloride. We performed a randomized crossover trial comparing potassium chloride with potassium citrate (96 mmol/d, each for 1 week) in 14 hypertensive individuals. At baseline, blood pressure was 151+/-16/93+/-7 mm Hg with a 24-hour urinary potassium of 81+/-24 mmol. During the randomized crossover part of the study, blood pressure was 140+/-12/88+/-7 mm Hg with potassium chloride (24-hour urinary potassium: 164+/-36 mmol) and 138+/-12/88+/-6 mm Hg with potassium citrate (24-hour urinary potassium: 160+/-33 mmol). These blood pressures were significantly lower compared with that at baseline; however, there was no significant difference in blood pressure between potassium chloride and potassium citrate, mean difference (95% confidence interval): 1.6 (-2.3 to 5.6) mm Hg for systolic and 0.6 (-2.4 to 3.7) mm Hg for diastolic. Our results, in conjunction with the evidence from many previous trials that potassium chloride has a significant blood pressure-lowering effect, suggest that potassium citrate has a similar effect on blood pressure as potassium chloride. These results support other evidence for an increase in potassium intake and indicate that potassium does not need to be given in the form of chloride to lower blood pressure. Increasing the consumption of foods high in potassium is likely to have the same effect on blood pressure as potassium chloride.
随机试验表明，增加钾摄入量可降低血压。然而，此前大多数试验使用的是氯化钾，而水果和蔬菜中的钾并非氯盐。与氯化钾相比，钾的非氯盐对血压的影响是更大还是更小尚不清楚。我们进行了一项随机交叉试验，在14名高血压患者中比较氯化钾与柠檬酸钾（每日96毫摩尔，各服用1周）的效果。基线时，血压为151±16/93±7毫米汞柱，24小时尿钾为81±24毫摩尔。在研究的随机交叉部分，服用氯化钾时血压为140±12/88±7毫米汞柱（24小时尿钾：164±36毫摩尔），服用柠檬酸钾时血压为138±12/88±6毫米汞柱（24小时尿钾：160±33毫摩尔）。这些血压与基线时相比显著降低；然而，氯化钾和柠檬酸钾之间的血压无显著差异，收缩压平均差异（95%置信区间）：1.6（-2.3至5.6）毫米汞柱，舒张压平均差异：0.6（-2.4至3.7）毫米汞柱。我们的结果，结合此前许多试验表明氯化钾有显著降压作用的证据，提示柠檬酸钾对血压的影响与氯化钾相似。这些结果支持了增加钾摄入量的其他证据，并表明降低血压并不需要以氯盐的形式补充钾。增加高钾食物的摄入量可能对血压产生与氯化钾相同的效果。
