Gaziano Thomas, Kapaon David, du Toit Jacques D, Crowther Nigel J, Wade Alisha N, Fabian June, Riumallo-Herl Carlos, Roberts-Toler F Carla, Gómez-Olivé Xavier, Tollman Stephen
Cardiovascular Medicine Division, Brigham & Women's Hospital, Boston, Massachusetts.
Harvard T. H. Chan School of Public Health, Boston, Massachusetts.
JAMA Cardiol. 2025 Apr 1;10(4):335-342. doi: 10.1001/jamacardio.2024.5410.
Reductions in dietary salt are associated with blood pressure reductions; however, national governments that have passed laws to reduce sodium intake have not measured these laws' impact.
To determine if South African regulations restricting sodium content in processed foods were associated with reductions in sodium consumption and blood pressure.
DESIGN, SETTING, AND PARTICIPANTS: The HAALSI (Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa) study is a population-based cohort study among adults aged 40 years or older randomly selected from individuals living in rural Mpumalanga Province in South Africa. This study incorporated 3 waves of data (2014/2015, 2018/2019, and 2021/2022) from the HAALSI study to examine how 24-hour urine sodium (24HrNa) excretion changed among a population-based cohort following mandatory sodium regulations. Spot urine samples were collected across 3 waves, and data analysis was performed from 2023 to 2024.
South African regulations introduced in 2013 that reduced levels for the maximum amount of sodium in milligrams per 100 mg of food product by 25% to 80% across 13 processed food categories by 2019.
24HrNa was estimated using the INTERSALT equation, and generalized estimating equations were used to assess changes in sodium excretion and blood pressure.
Among 5059 adults 40 years or older, mean (SD) age was 62.43 years (13.01), and 2713 participants (53.6%) were female. Overall mean (SD) estimated 24HrNa excretion at baseline was 3.08 g (0.78). There was an overall reduction in mean 24HrNa excretion of 0.22 g (95% CI, -0.27 to -0.17; P < .001) between the first 2 waves and a mean reduction of 0.23 g (95% CI, -0.28 to -0.18; P < .001) between the first and third waves. The reductions were larger when analysis was restricted to those with samples in all 3 waves (-0.26 g for both waves 2 and 3 compared to wave 1). Every gram of sodium reduction was associated with a -1.30 mm Hg reduction (95% CI, 0.65-1.96; P = .00) in systolic blood pressure. The proportion of the study population that achieved ideal sodium consumption (<2 g per day) increased from 7% to 17%.
In this cohort study, following South African regulations limiting sodium in 13 categories of processed foods, there was a significant reduction in 24HrNa excretion among this rural South African population, which was sustained with reductions in blood pressure consistent with levels of sodium excreted. These results support the potential health effects anticipated by effective implementation of population-based salt reformulation policies.
减少膳食盐摄入量与降低血压相关；然而，已通过法律来减少钠摄入量的各国政府尚未衡量这些法律的影响。
确定南非限制加工食品中钠含量的法规是否与钠消耗量和血压的降低相关。
设计、背景和参与者：HAALSI（非洲的健康与老龄化：南非一个深入社区的纵向研究）研究是一项基于人群的队列研究，研究对象为年龄在40岁及以上的成年人，他们是从南非姆普马兰加省农村地区的居民中随机选取的。本研究纳入了HAALSI研究的3轮数据（2014/2015年、2018/2019年和2021/2022年），以研究在实施强制性钠法规后，一个基于人群的队列中24小时尿钠（24HrNa）排泄量是如何变化的。在3轮研究中均采集了即时尿样，并于2023年至2024年进行了数据分析。
2013年出台的南非法规，到2019年，13类加工食品中每100毫克食品的钠最大含量水平降低了25%至80%。
使用INTERSALT方程估算24HrNa，并使用广义估计方程评估钠排泄量和血压的变化。
在5059名40岁及以上的成年人中，平均（标准差）年龄为62.43岁（13.01），2713名参与者（53.6%）为女性。基线时总体平均（标准差）估计24HrNa排泄量为3.08克（0.78）。在前两轮之间，平均24HrNa排泄量总体减少了0.22克（95%置信区间，-0.27至-0.17；P < .001），在第一轮和第三轮之间平均减少了0.23克（95%置信区间，-0.28至-0.18；P < .001）。当分析仅限于在所有3轮中均有样本的人群时，减少幅度更大（与第1轮相比，第2轮和第3轮均减少0.26克）。每减少1克钠，收缩压降低-1.30毫米汞柱（95%置信区间，0.65 - 1.96；P = .00）。达到理想钠消耗量（每天<2克）的研究人群比例从7%增至17%。
在这项队列研究中，遵循南非对13类加工食品中钠的限制法规后，该南非农村人群的24HrNa排泄量显著减少，且血压降低与钠排泄量水平一致并持续存在。这些结果支持了有效实施基于人群的盐配方改革政策所预期的潜在健康影响。
