Division of Cardiovascular Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
Vanderbilt Translational and Clinical Cardiovascular Research Center, Vanderbilt University Medical Center, Nashville, Tennessee.
JAMA. 2023 Dec 19;330(23):2258-2266. doi: 10.1001/jama.2023.23651.
Dietary sodium recommendations are debated partly due to variable blood pressure (BP) response to sodium intake. Furthermore, the BP effect of dietary sodium among individuals taking antihypertensive medications is understudied.
To examine the distribution of within-individual BP response to dietary sodium, the difference in BP between individuals allocated to consume a high- or low-sodium diet first, and whether these varied according to baseline BP and antihypertensive medication use.
DESIGN, SETTING, AND PARTICIPANTS: Prospectively allocated diet order with crossover in community-based participants enrolled between April 2021 and February 2023 in 2 US cities. A total of 213 individuals aged 50 to 75 years, including those with normotension (25%), controlled hypertension (20%), uncontrolled hypertension (31%), and untreated hypertension (25%), attended a baseline visit while consuming their usual diet, then completed 1-week high- and low-sodium diets.
High-sodium (approximately 2200 mg sodium added daily to usual diet) and low-sodium (approximately 500 mg daily total) diets.
Average 24-hour ambulatory systolic and diastolic BP, mean arterial pressure, and pulse pressure.
Among the 213 participants who completed both high- and low-sodium diet visits, the median age was 61 years, 65% were female and 64% were Black. While consuming usual, high-sodium, and low-sodium diets, participants' median systolic BP measures were 125, 126, and 119 mm Hg, respectively. The median within-individual change in mean arterial pressure between high- and low-sodium diets was 4 mm Hg (IQR, 0-8 mm Hg; P < .001), which did not significantly differ by hypertension status. Compared with the high-sodium diet, the low-sodium diet induced a decline in mean arterial pressure in 73.4% of individuals. The commonly used threshold of a 5 mm Hg or greater decline in mean arterial pressure between a high-sodium and a low-sodium diet classified 46% of individuals as "salt sensitive." At the end of the first dietary intervention week, the mean systolic BP difference between individuals allocated to a high-sodium vs a low-sodium diet was 8 mm Hg (95% CI, 4-11 mm Hg; P < .001), which was mostly similar across subgroups of age, sex, race, hypertension, baseline BP, diabetes, and body mass index. Adverse events were mild, reported by 9.9% and 8.0% of individuals while consuming the high- and low-sodium diets, respectively.
Dietary sodium reduction significantly lowered BP in the majority of middle-aged to elderly adults. The decline in BP from a high- to low-sodium diet was independent of hypertension status and antihypertensive medication use, was generally consistent across subgroups, and did not result in excess adverse events.
ClinicalTrials.gov Identifier: NCT04258332.
部分由于钠摄入量对血压（BP）反应的差异，膳食钠推荐存在争议。此外，服用抗高血压药物的个体中膳食钠的血压效应研究较少。
检查个体对膳食钠的血压反应分布，首先摄入高钠或低钠饮食的个体之间的血压差异，以及这些差异是否根据基线血压和抗高血压药物的使用而有所不同。
设计、地点和参与者：2021 年 4 月至 2023 年 2 月期间，在美国两个城市的社区参与者中进行前瞻性分配的饮食顺序和交叉。共有 213 名年龄在 50 至 75 岁之间的个体，包括血压正常（25%）、控制良好的高血压（20%）、未控制的高血压（31%）和未经治疗的高血压（25%），参加了基线访问，同时食用他们的常规饮食，然后完成了 1 周的高钠和低钠饮食。
高钠（每天向常规饮食中添加约 2200 毫克钠）和低钠（每天总摄入量约 500 毫克）饮食。
24 小时动态收缩压和舒张压、平均动脉压和脉搏压的平均值。
在完成高钠和低钠饮食访问的 213 名参与者中，中位年龄为 61 岁，65%为女性，64%为黑人。在食用常规、高钠和低钠饮食时，参与者的中位收缩压分别为 125、126 和 119 毫米汞柱。高钠和低钠饮食之间平均动脉压的中位个体内变化为 4 毫米汞柱（IQR，0-8 毫米汞柱；P<0.001），与高血压状态无关。与高钠饮食相比，低钠饮食使 73.4%的个体的平均动脉压下降。常用的平均动脉压在高钠和低钠饮食之间下降 5 毫米汞柱或更多的阈值将 46%的个体归类为“盐敏感”。在第一饮食干预周结束时，分配到高钠饮食与低钠饮食的个体之间的平均收缩压差异为 8 毫米汞柱（95%CI，4-11 毫米汞柱；P<0.001），在年龄、性别、种族、高血压、基线血压、糖尿病和体重指数等亚组中基本相似。不良事件轻微，分别有 9.9%和 8.0%的个体在食用高钠和低钠饮食时报告。
减少膳食钠摄入量可显著降低大多数中年至老年成年人的血压。从高钠到低钠饮食的血压下降与高血压状态和抗高血压药物的使用无关，在大多数亚组中基本一致，并且不会导致不良事件增加。
ClinicalTrials.gov 标识符：NCT04258332。
