He Feng J, Marciniak Maciej, Visagie Elisabeth, Markandu Nirmala D, Anand Vidya, Dalton R Neil, MacGregor Graham A
Blood Pressure Unit, Cardiac & Vascular Sciences, St. George's, University of London, Cranmer Terrace, London, UK.
Hypertension. 2009 Sep;54(3):482-8. doi: 10.1161/HYPERTENSIONAHA.109.133223. Epub 2009 Jul 20.
A reduction in salt intake lowers blood pressure. However, most previous trials were in whites with few in blacks and Asians. Salt reduction may also reduce other cardiovascular risk factors (eg, urinary albumin excretion, arterial stiffness). However, few well-controlled trials have studied these effects. We carried out a randomized double-blind crossover trial of salt restriction with slow sodium or placebo, each for 6 weeks, in 71 whites, 69 blacks, and 29 Asians with untreated mildly raised blood pressure. From slow sodium to placebo, urinary sodium was reduced from 165+/-58 (+/-SD) to 110+/-49 mmol/24 hours (9.7 to 6.5 g/d salt). With this reduction in salt intake, there was a significant decrease in blood pressure from 146+/-13/91+/-8 to 141+/-12/88+/-9 mm Hg (P<0.001), urinary albumin from 10.2 (IQR: 6.8 to 18.9) to 9.1 (6.6 to 14.0) mg/24 hours (P<0.001), albumin/creatinine ratio from 0.81 (0.47 to 1.43) to 0.66 (0.44 to 1.22) mg/mmol (P<0.001), and carotid-femoral pulse wave velocity from 11.5+/-2.3 to 11.1+/-1.9 m/s (P<0.01). Subgroup analysis showed that the reductions in blood pressure and urinary albumin/creatinine ratio were significant in all groups, and the decrease in pulse wave velocity was significant in blacks only. These results demonstrate that a modest reduction in salt intake, approximately the amount of the current public health recommendations, causes significant falls in blood pressure in all 3 ethnic groups. Furthermore, it reduces urinary albumin and improves large artery compliance. Although both could be attributable to the falls in blood pressure, they may carry additional benefits on reducing cardiovascular disease above that obtained from the blood pressure falls alone.
减少盐的摄入量可降低血压。然而，此前大多数试验的对象是白人，针对黑人和亚洲人的试验较少。减少盐的摄入量还可能降低其他心血管危险因素（如尿白蛋白排泄、动脉僵硬度）。然而，很少有严格对照试验研究这些影响。我们对71名白人、69名黑人和29名未治疗的轻度血压升高的亚洲人进行了一项随机双盲交叉试验，用慢效钠或安慰剂进行盐限制，各为期6周。从慢效钠改为安慰剂后，尿钠从165±58（±标准差）降至110±49 mmol/24小时（盐从9.7克/天降至6.5克/天）。随着盐摄入量的减少，血压从146±13/91±8显著降至141±12/88±9 mmHg（P<0.001），尿白蛋白从10.2（四分位间距：6.8至18.9）降至9.1（6.6至14.0）mg/24小时（P<0.001），白蛋白/肌酐比值从0.81（0.47至1.43）降至0.66（0.44至1.22）mg/mmol（P<0.001），颈股脉搏波速度从11.5±2.3降至11.1±1.9 m/s（P<0.01）。亚组分析表明，所有组的血压和尿白蛋白/肌酐比值均显著降低，仅黑人的脉搏波速度降低显著。这些结果表明，适度减少盐的摄入量，大约为当前公共卫生建议的量，可使所有三个种族的血压显著下降。此外，它还能降低尿白蛋白并改善大动脉顺应性。虽然这两者都可能归因于血压下降，但它们在降低心血管疾病方面可能带来超出仅由血压下降所获得的额外益处。
