Department of Laboratory Medicine, University of California, San Francisco, California.
Department of Physiology, College of Osteopathic Medicine, Michigan State University, East Lansing, Michigan.
Am J Physiol Heart Circ Physiol. 2021 May 1;320(5):H1903-H1918. doi: 10.1152/ajpheart.00980.2020. Epub 2021 Apr 2.
On average, black individuals are widely believed to be more sensitive than white individuals to blood pressure (BP) effects of changes in salt intake. However, few studies have directly compared the BP effects of changing salt intake in black versus white individuals. In this narrative review, we analyze those studies and note that when potassium intake substantially exceeds the recently recommended US dietary goal of 87 mmol/day, black adults do not appear more sensitive than white adults to BP effects of short-term or long-term increases in salt intake (from an intake ≤50 mmol/day up to 150 mmol/day or more). However, with lower potassium intakes, racial differences in salt sensitivity are observed. Mechanistic studies suggest that racial differences in salt sensitivity are related to differences in vascular resistance responses to changes in salt intake mediated by vasodilator and vasoconstrictor pathways. With respect to cause and prevention of racial disparities in salt sensitivity, it is noteworthy that ) on average, black individuals consume less potassium than white individuals and ) consuming supplemental potassium bicarbonate, or potassium rich foods can prevent racial disparities in salt sensitivity. However, the new US dietary guidelines reduced the dietary potassium goal well below the amount associated with preventing racial disparities in salt sensitivity. These observations should motivate research on the impact of the new dietary potassium guidelines on racial disparities in salt sensitivity, the risks and benefits of potassium-containing salt substitutes or supplements, and methods for increasing consumption of foods rich in nutrients that protect against salt-induced hypertension.
一般认为，黑人个体对盐摄入量变化引起的血压（BP）变化比白人个体更为敏感。然而，很少有研究直接比较黑人和白人个体盐摄入量变化对血压的影响。在这篇叙述性综述中，我们分析了这些研究，并指出当钾摄入量大大超过最近推荐的美国膳食目标 87mmol/天，黑人成年人对短期或长期盐摄入量增加（从摄入量≤50mmol/天增加到 150mmol/天或更多）的血压影响并不比白人成年人更敏感。然而，在较低的钾摄入量下，观察到盐敏感性的种族差异。机制研究表明，盐敏感性的种族差异与血管阻力对盐摄入量变化的反应有关，这种反应是由血管舒张和血管收缩途径介导的。关于盐敏感性种族差异的原因和预防，值得注意的是）平均而言，黑人个体的钾摄入量低于白人个体，以及）补充碳酸氢钾或富含钾的食物可以预防盐敏感性的种族差异。然而，新的美国膳食指南将膳食钾目标大大降低到与预防盐敏感性的种族差异相关的水平以下。这些观察结果应促使人们研究新的膳食钾指南对盐敏感性的种族差异的影响、含钾盐替代品或补充剂的风险和益处，以及增加富含可预防盐诱导性高血压的营养素的食物的消费的方法。
