A pooled analysis of four large prospective studies revealed that compared with moderate sodium intake, high sodium intake is associated with an increased risk of cardiovascular events and death in hypertensive populations (no association in normotensive population), while the association of low sodium intake with increased risk of cardiovascular events and death is observed in those with or without hypertension. Another prospective cohort study of patients with chronic kidney disease (CKD) in the US concluded that higher urinary sodium excretion was associated with increased risk of cardiovascular disease (CVD). In comparison to the U-shaped association in the pooled analysis, restricted cubic spline analyses of the association between sodium excretion and composite CVD provided no evidence of a nonlinear association and indicated a significant linear association. A positive association between sodium intake and blood pressure is well established. Blood pressure of patients with CKD is more sensitive to high sodium intake than persons with normal kidney function due to a diminished capacity to excrete sodium. Although mixed results have been reported on the nature of the association between dietary sodium and CVD, the data suggest that lowering sodium intake is targeted at populations with hypertension and CKD who consume high sodium diets. Source: http://www.thelancet.com/; http://jama.jamanetwork.com/
四个大型前瞻性研究的汇总分析表明，与适量摄入钠相比，高钠摄入量与高血压人群心血管事件和死亡的风险增加相关（正常血压人群则无相关），而低钠摄入量与心血管事件和死亡风险增加的关联可见于有或无高血压者。美国另一个前瞻性慢性肾脏病研究得出的结论是较高的尿钠排泄量与心血管病的风险增加有关。相较于前述汇总分析的U形相关，钠排泄与复合心血管病之间并无非线性相关的证据，而呈显著线性相关。钠摄入量与血压呈正相关是公认的。由于钠排泄能力减弱，慢性肾脏病者的血压对高钠摄入比正常肾功能的人更敏感。虽然关于钠摄入和心血管病之间相关性的研究报告并不一致，上述数据表明，降低钠的摄入量应针对患有高血压和慢性肾脏病的高钠饮食群体。来源：http://www.thelancet.com/; http://jama.jamanetwork.com/