Cost-effectiveness of a Household Salt Substitution Intervention: Findings From 20,995 Participants of the Salt Substitute and Stroke Study (SSaSS)

Effect of sodium-reduced potassium-enriched salt substitutes on stomach cancer: the Salt Substitute and Stroke Study (SSaSS)

BACKGROUND

There is an association between increased dietary sodium intake and the risk of stomach cancer. Lowering dietary sodium intake with sodium-reduced potassium-enriched salt substitutes may reduce this risk. To evaluate the effects of sodium-reduced potassium-enriched salt substitutes on the risk of stomach cancer and other types of cancer.

METHODS

The primary analyses of the Salt Substitute and Stroke Study (SSaSS) defined the effects of sodium-reduced potassium-enriched salt substitutes compared to regular salt on the risk of stroke. This post-hoc investigation explored effects on stomach and other cancers. SSaSS was an open-label, cluster randomised controlled trial done in 600 Chinese villages among 20,996 participants. Villages were assigned at random in a 1:1 ratio to receive sodium-reduced potassium-enriched salt substitutes or continue regular salt use. Fatal and hospitalised cancer events were identified through direct face-to-face follow-up and record linkage, with adjudication of fatal, but not non-fatal events.

RESULTS

During a mean follow-up of 4.7 years, there were 1040 cancer events (507 fatal, 533 non-fatal) recorded. There were 212 stomach cancers, 725 other cancers, and 103 cancers with an unknown primary site. There was a trend toward but not a significant effect of randomised treatment on total stomach cancer (rate ratio (RR) 0.77, 95% confidence interval (CI) 0.54 to 1.08). The RR for adjudicated fatal stomach cancer was 0.66 (95% CI 0.44 to 1.00) compared to 0.88 (95% CI 0.56 to 1.37) for unadjudicated non-fatal stomach cancer. There was no detectable effect on total cancer at any site (RR 0.94, 95% CI 0.81 to 1.08), adjudicated fatal cancer at any site (RR 0.85, 95% CI 0.69 to 1.05), or unadjudicated non-fatal cancer at any site (RR 1.04, 95% CI 0.88 to 1.23).

CONCLUSIONS

There was no effect of sodium-reduced potassium-enriched salt substitutes on stomach cancer or other cancer types detected. Trends toward protection against fatal and non-fatal stomach cancer align with the observational epidemiology and warrant further investigation.

TRIAL REGISTRATION

This trial was registered in ClinicalTrials.gov as NCT02092090.

Nutrition and Hypertension Researches in 2023: focus on salt intake and blood pressure

Hypertension is a major global health issue that contributes significantly to cardiovascular morbidity and mortality. The management and prevention of hypertension often involve nutritional and dietary modifications, which are considered effective non-pharmacological strategies. In 2023, the Hypertension Research published several papers highlighting nutrition and hypertension. In addition, multiple studies published in leading journals explored the relationship between salt intake and blood pressure (BP) in 2023. In this mini-review, we summarize the key findings of nutritional studies published in the Hypertension Research in 2023. This mini-review also highlights significant findings from the latest research on salt intake and its impact on BP. The new findings from nutritional studies will provide deeper insights on planning dietary strategies for the management of hypertension.

Salt Substitution and Recurrent Stroke and Death: A Randomized Clinical Trial

Importance

The direct effect of consumption of salt substitutes on recurrent stroke and mortality among patients with stroke remains unclear.

Objective

To evaluate the effects of salt substitutes vs regular salt on the incidence of recurrent stroke and mortality among patients with stroke.

Design, Setting, and Participants

The Salt Substitute and Stroke Study (SSaSS), an open-label, cluster randomized clinical trial, was conducted in 600 northern Chinese villages (clusters). Patients who self-reported a hospital diagnosis of stroke were included in this prespecified subgroup analysis. Data were analyzed from November 2023 to August 2024.

Interventions

Participants were assigned to use either a salt substitute, consisting of 75% sodium chloride and 25% potassium chloride by mass, or regular salt.

Main Outcomes and Measures

The primary outcome was recurrent stroke.

Results

After excluding 5746 persons without a baseline history of stroke, 15 249 patients with stroke (mean [SD] age, 64.1 [8.8] years; 6999 [45.9%] female; 8250 male [54.1%]) were included. Over a median (IQR) follow-up of 61.2 (60.9-61.6) months, the mean difference in systolic blood pressure was -2.05 mm Hg (95% CI, -3.03 to -1.08 mm Hg). A total of 2735 recurrent stroke events (691 fatal and 2044 nonfatal) and 3242 deaths were recorded. Recurrent stroke was significantly lower in the salt substitute vs regular salt group (rate ratio [RR], 0.86; 95% CI, 0.77-0.95; P = .005), with larger effects on hemorrhagic stroke (relative reduction, 30%; P = .002). Death rates were also significantly lower (RR, 0.88; 95% CI, 0.82-0.96; P = .003), with larger effects on stroke-related deaths (relative reduction 21%; P = .01). No significant difference was observed for hyperkalemia (RR, 1.01; 95% CI, 0.74-1.38; P = .96).

Conclusions and Relevance

Results of this cluster trial demonstrate that salt substitution was safe, along with reduced risks of stroke recurrence and death, which underscores large health gains from scaling up this low-cost intervention among patients with stroke.

Trial Registration

ClinicalTrials.gov Identifier: NCT02092090.

Role of dietary potassium and salt substitution in the prevention and management of hypertension

Cardiovascular diseases (CVD) continue to be the leading cause of deaths and disability worldwide and the major contributor is hypertension. Despite all the improvements in detecting hypertension together with technological advances and affordable, efficacious and relatively free of adverse effects anti-hypertensive agents, we continue to struggle to prevent the onset of hypertension and to control blood pressure (BP) to acceptable targets. The poor control of hypertension is commonly due to non-adherence to medications. Another reason is the failure to adopt diet and lifestyle changes. Reduction of dietary salt intake is important for lowering BP but the role of potassium intake is also important. Globally the intake of sodium is double that of the recommended 2 gm per day (equivalent to 5 gm of sodium chloride/salt) and half that of the daily recommended intake of potassium of 3500 mg/day, giving a sodium-to-potassium ratio of >1, when ideally it should be <1. Many studies have shown that a higher potassium intake is associated with lower BPs, particularly when coupled concurrently with a lower sodium intake giving a lower sodium to potassium ratio. Most hypertension guidelines, while recommending reduction of salt intake to a set target, do not specifically recommend a target for potassium intake nor potassium supplementation. Here we review the role of potassium and salt substitution with potassium in the management of hypertension. Hence, the focus of dietary changes to lower BP and improve BP control should not be on reduction of salt intake alone but more importantly should include an increase in potassium intake.

Relationship between daily eating habits and occurrence of stroke in the O City Cohort I survey: a 26-year follow-up of residents in rural Japan

Objective

This study aimed to elucidate the relationship between daily eating habits and stroke risk factors in O City, Ehime Prefecture, Japan, using stroke registry data collected over a 26-year follow-up period based on standardized national criteria.

Materials and Methods

Overall, 1,793 middle-aged Japanese participants (446 men and 1,347 women) who completed a 33-item Food Frequency Questionnaire (FFQ) and had no history of stroke were matched to those from O City in a stroke registry from 1996 to 2022. Stroke diagnosis for each person was used to determine whether this was their first documented stroke, and we classified strokes as either a cerebral infarction (CI) or a hemorrhagic stroke (HS), the latter which included an intracerebral hemorrhage (ICH) or a subarachnoid hemorrhage (SAH). A Cox proportional hazard regression model was used to examine the association between habitual dietary intake and the occurrence of stroke, using the following covariates: age, body mass index, elevated blood pressure/hypertension, dyslipidemia, prediabetes/diabetes, alcohol consumption, and smoking.

Results

During the 26 years of follow-up, 45 men (10.1%) and 76 women (5.6%) had stroke. The CI rate was 70.2% (n=85; 38 men, 47 women). The HS rate was 29.8% (n=36; 7 men and 29 women); of these patients, 26 and 10 had ICH and SAH, respectively. In men, orange intake showed a significant inverse correlation with CI. In women, fresh fish intake showed a significant inverse correlation with CI, while yogurt intake showed a significant inverse correlation with HS.

Conclusion

Our results indicated that fresh fish intake was significantly associated with the prevention of CI among women in a Japanese cohort survey.

Impact of sodium intake on blood pressure, mortality and major cardiovascular events: an umbrella review of systematic reviews and meta-analyses

A plethora of systematic reviews with meta-analyses (SRMAs) evaluating sodium intake on cardiovascular health have been published. However, the quality of the SRMAs, that report absolute estimates of effect for major cardiovascular events and the corresponding certainty of the evidence has not been explicitly summarized. We conducted an umbrella review to assess the strength and validity of associations between lower sodium intake and cardiovascular outcomes. We used a modified, more stringent, version of the AMSTAR 2 instrument and the GRADE approach to assess SRMA methodological quality and evidence certainty, respectively. Across three cardiovascular risk strata, we computed the absolute risk reduction (ARR) for binary outcomes. We included 56 SRMAs. In various cardiovascular risk populations, moderate to high certainty evidence suggested that lower sodium intake reduced systolic blood pressure (BP) by -8.69 to -2.00 mmHg, and had concordant but smaller effects on diastolic BP. Salt substitutes conferred a small but important reduction in all-cause and cardiovascular mortality [ARR 12 fewer per 1000; 9 fewer per 1000; respectively], and had little to no effect on the risk of stroke [ARR 1 fewer per 1000]. Moderate to high certainty evidence suggested that lower sodium intake is probably beneficial for the prevention of major cardiovascular events, especially in low cardiovascular risk populations.

Cost-Effectiveness of Salt Substitution and Antihypertensive Drug Treatment in Chinese Prehypertensive Adults

BACKGROUND

Recent guidelines recommend antihypertensive drug treatment for prehypertensive individuals with blood pressure between 130/80 and 139/89 mm Hg. This study evaluates the cost-effectiveness of 3 interventions in Chinese prehypertensive adults: salt substitution, antihypertensive drug treatment, and their combination.

METHODS

We developed a Markov cohort model to estimate cardiovascular disease (CVD) events, costs, and quality-adjusted life years (QALYs) over a lifetime. Data from the China Kadoorie Biobank informed the simulation. Costs and utilities were drawn from published sources. We evaluated the cost-effectiveness of salt substitution alone, antihypertensive drug treatment alone, and a combination of the 2, focusing on the overall prehypertensive population, those at high CVD risk, and different starting ages (40, 50, 60, and 70 years). Incremental cost-effectiveness ratios (ICERs) were calculated per QALY gained.

RESULTS

Salt substitution at age 40 years is the only cost-effective strategy for prehypertensive individuals, with an ICER of $6413.62/QALY. For those at high CVD risk, the combination intervention starting at age 40 years is most cost-effective, with an ICER of $2913.30/QALY. Interventions initiated at younger ages yielded greater CVD reductions and lower ICERs. For example, a combined intervention at age 40 years reduces CVD events by 5.3% with an ICER of $2913.30/QALY, compared with 4.9% and $32 635.33/QALY at age 70 years. These results were consistent across sensitivity analyses.

CONCLUSIONS

In China, replacing usual salt with a salt substitute is more cost-effective than treating prehypertensive individuals over the age of 40 years with antihypertensive drugs. Furthermore, starting intervention at a younger age in prehypertensive adults can result in even greater cost savings.

Association between bike-sharing systems and the blood pressure of local citizens: a cross-sectional study in China

Introduction

Globally, hypertension stands as the foremost preventable risk factor for cardiovascular disease and premature death. However, scalable approach to lowering blood pressure (BP) at the population level remains lacking. We investigated whether shared bikes, a sustainable method of transportation gaining increasing popularity across the world, can serve as a supplemental instrument to combat the increasing prevalence of hypertension.

Methods

Based on 8 107 363 physical examination visits to one of the largest medical examination centres in China during the period of June 2016 to August 2017, we perfermed a staggered difference-in-differences (DiD) analysis that exploited the roll-out of bike-sharing systems across different cities. The main outcome was the blood pressure among adult participants who were likely to adopt shared bikes (age <45), measured by (1) systolic blood pressure (SBP), (2) diastolic blood pressure (DBP) and (3) a binary indicator of hypertension status (SBP≥130 or DBP≥80 mm Hg).

Results

Blood pressure showed a decreasing trend after a bike-sharing platform entered the local city. After 6 months post an entry event, SBP reduced by 0.67 mm Hg (β (SE), -0.672 (0.245); 95% CI, -1.154 to -0.191); the prevalence of hypertension reduced by 1.4 percentage points (β (SE), -0.014 (0.007); 95% CI, -0.027 to -0.000); the reduction in DBP was statistically insignificant (β (SE), -0.193 (0.193); 95% CI, -0.572 to 0.187). Participants less likely to adopt shared bikes (age ≥45) showed no significant response. The number of visits and the age of participants were also unaffected by the entry events. Reduction in blood pressure was more pronounced in male, younger and non-obese participants.

Conclusion

The findings of this study suggest that bike-sharing systems in China may be associated with lowered blood pressure, and thus may serve as a supplemental instrument to combat the increasing prevalence of hypertension, especially among young adults.

Long-Term Effects of a Comprehensive Intervention Strategy for Salt Reduction in China: Scale-Up of a Cluster Randomized Controlled Trial

BACKGROUND

Salt intake in China was high and a series of salt reduction measures were accordingly carried out recently. Our study aimed to assess the long-term effect of a scale-up community randomized controlled trial (RCT); Methods: Individuals between the ages of 18 and 75, from six provinces in China, were recruited and randomized into control (n = 1347) and intervention (n = 1346) groups. A one-year salt reduction intervention was first implemented in the intervention group, followed by a two-year scale-up intervention in both groups. The 24 h urine sample, anthropometric measurement, and knowledge, attitude, and practice (KAP) of salt reduction, as well as lifestyle information, were collected at baseline, after one-year RCT (mid-term evaluation, n = 2456), and two-year scale-up intervention (terminal evaluation, n = 2267); Results: Both control (351.82 mg/24 h, p < 0.001) and intervention (192.84 mg/24 h, p = 0.006) groups showed a decrease in 24 h urinary sodium excretion from baseline to terminal evaluation. Except for an increase in 24 h urinary potassium excretion (85.03 mg/24 h, p = 0.004) and a decrease in systolic blood pressure (SBP) (2.95 mm Hg, p < 0.001) in the intervention group at the mid-term assessment, no statistically significant differences in other indicators were found between two groups. The KAP of salt reduction in two groups was gradually improved; Conclusions: After one-year RCT and two-year scale-up, all participants showed a decreasing trend in 24 h urinary sodium excretion and an increase in salt reduction KAP. The community salt reduction intervention package has the potential for broader application across other regions in China.

Usage of table salt and risk of all-cause and cardiovascular disease mortality among patients with diabetes: a national population-based cohort study

BACKGROUND

A lower dietary sodium intake has been associated with a reduced risk of cardiovascular disease (CVD) mortality in the general population. However, the evidence is less clear in diabetic patients. The study aims to investigate whether the usage of table salt is associated with all-cause and CVD mortality among individuals with diabetes.

METHODS

In this prospective cohort study, participants with diabetes from the U.S. National Health and Nutritional Examination Survey (NHANES) 2003-2018 were included. Weighted linear regression models were employed to assess the association between the usage of table salt and dietary sodium intake. Weighted Cox proportional hazards regression models were used to assess the association between the usage of table salt and all-cause and CVD mortality.

RESULTS

This cohort study included data from 6,258 participants in analysis. During 44,035 person-years of follow-up, 1,504 deaths from all-causes and 427 from CVD were documented. Not using table salt was significantly associated with lower dietary sodium intake, with a β of -192.60 (95% CI, -297.01 to -88.18) mg. A higher risk of all-cause and CVD mortality was observed in the group of participants not using table salt among patients with diabetes. Compared with participants using table salt, the hazard ratios for all-cause mortality were 1.18 (95% CI, 1.03 to 1.35), and for CVD were 1.48 (95 CI, 1.16 to 1.90) for participants not using table salt. The subgroup analysis revealed a significantly stronger link between the usage of table salt and all-cause mortality in participants with CVD (P for interaction = 0.004).

CONCLUSIONS

This study indicated that not using table salt was associated with a lower dietary sodium intake, and an increased risk of all-cause and CVD mortality among individuals with diabetes. Interventional studies are needed to determine more beneficial relevant approaches to dietary management in diabetes care.

Health Claims, Product Features and Instructions for Use on the Labels of Potassium-enriched Salt Products: A Content Analysis

Background

Potassium-enriched salt is a proven dietary intervention for reducing risk of stroke, cardiovascular disease, and premature mortality when used instead of regular table salt. Potassium-enriched salt products are available globally, but the on-pack health claims, product features, and instructions for use are diverse.

Objectives

The objective of this study was to summarize the label features of potassium-enriched salt products available worldwide.

Methods

A content analysis was conducted on the labels of potassium-enriched salt products available for sale in May 2023. Potassium-enriched salt products were identified through a systematic search of literature, major online shopping websites, and Google using similar keywords such as "salt substitute" or "low sodium salt." Information on product labels was coded relating to health claims, product features, and instructions for use, and were quantitatively summarized.

Results

A total of 117 potential potassium-enriched salt products were identified, with 83 included in the final analysis after excluding products containing no sodium (n = 15), no potassium (n = 5), or that were duplicates (n = 14). There were 23 (28%) products with on-pack claims for health benefits and 36 (43%) with health warnings. Twenty-five (30%) of product labels included descriptions of other product features such as taste and potassium content, and 36 (43%) had instructions for use.

Conclusions

There was large variability in the label features of potassium-enriched salt products identified in this study. Most product labels made no health-related statements, but among those that did, warnings occurred more frequently than statements of health benefits. The diversity in labeling may cause confusion among consumers, and standardized, evidence-based labeling should be developed.

Global burden and cross-country inequalities in stroke and subtypes attributable to diet from 1990 to 2019

DATA SOURCES

The Global Burden of Diseases, Injuries, and Risk Factors study (GBD) 2019.

BACKGROUND

To describe burden, and to explore cross-country inequalities according to socio-demographic index (SDI) for stroke and subtypes attributable to diet.

METHODS

Death and years lived with disability (YLDs) data and corresponding estimated annual percentage changes (EAPCs) were estimated by year, age, gender, location and SDI. Pearson correlation analysis was performed to evaluate the connections between age-standardized rates (ASRs) of death, YLDs, their EAPCs and SDI. We used ARIMA model to predict the trend. Slope index of inequality (SII) and relative concentration index (RCI) were utilized to quantify the distributive inequalities in the burden of stroke.

RESULTS

A total of 1.74 million deaths (56.17% male) and 5.52 million YLDs (55.27% female) attributable to diet were included in the analysis in 2019.Between 1990 and 2019, the number of global stroke deaths and YLDs related to poor diet increased by 25.96% and 74.76% while ASRs for death and YLDs decreased by 42.29% and 11.34% respectively. The disease burden generally increased with age. The trends varied among stroke subtypes, with ischemic stroke (IS) being the primary cause of YLDs and intracerebral hemorrhage (ICH) being the leading cause of death. Mortality is inversely proportional to SDI (R = -0.45, p < 0.001). In terms of YLDs, countries with different SDIs exhibited no significant difference (p = 0.15), but the SII changed from 38.35 in 1990 to 45.18 in 2019 and the RCI showed 18.27 in 1990 and 24.98 in 2019 for stroke. The highest ASRs for death and YLDs appeared in Mongolia and Vanuatu while the lowest of them appeared in Israel and Belize, respectively. High sodium diets, high red meat consumption, and low fruit diets were the top three contributors to stroke YLDs in 2019.

DISCUSSION

The burden of diet-related stroke and subtypes varied significantly concerning year, age, gender, location and SDI. Countries with higher SDIs exhibited a disproportionately greater burden of stroke and its subtypes in terms of YLDs, and these disparities were found to intensify over time. To reduce disease burden, it is critical to enforce improved dietary practices, with a special emphasis on mortality drop in lower SDI countries and incidence decline in higher SDI countries.

Cost-effectiveness analysis of low-sodium potassium-rich salt substitutes in Indonesia: an equity modelling study

Background

Evidence suggests low-sodium potassium-rich salt substitutes (LSSS) are effective in reducing blood pressure (BP). However, the health and economic impacts of LSSS in Indonesia are currently unknown.

Methods

We developed a proportional multistate lifetable Markov model to assess a government-led strategy implementing the use of LSSS compared to current regular salt consumption. BP data were derived from the Indonesian Basic Health Research Survey (RISKESDAS 2018), while epidemiological data were from the Global Burden of Disease 2019 study. We estimated implementation costs and the impact of changes in BP on disease events and healthcare costs, and incremental cost-effectiveness ratios. Outcomes were simulated over different time horizons for the 2019 Indonesian population overall, and by income quintiles. Probabilistic sensitivity analysis was done to capture uncertainty.

Findings

Over the first 10 years, LSSS could prevent 1.5 million non-fatal cardiovascular disease (CVD) events (8.3%-19.4% reduction) and 643,000 incident chronic kidney disease (CKD) cases (8.2% reduction), while averting over 200,000 CVD and CKD deaths (0.2%-5.2% reduction). This translated to over 24.6 million health-adjusted life years (HALYs) gained over the lifetime of the population, and reduced CVD-related health inequalities (concentration index, -0.075, 95% CI: -0.088 to -0.062). Implementation cost (US$ 1.2 billion [IDR 17.2 trillion] total; US$ 4.5 [IDR 63,665] per capita, as of July 2019) was outweighed by the net health expenditure savings (∼US$ 2 billion [IDR 27.7 trillion] total; US$ 7.3 [IDR 103,300] per capita) in the first 10 years. LSSS were cost-saving over the lifetime, and very cost-effective even with a high LSSS price.

Interpretation

Scaling the use of LSSS nationally could be a cost-saving strategy to prevent substantial cardiovascular and kidney disease burden in Indonesia.

Funding

Griffith University Postdoctoral Fellowship.

Association between Salt-Related Knowledge, Attitudes, and Behaviours and 24 h Urinary Salt Excretion in Nepal

This study examined the association between salt-related knowledge, attitudes, and behaviors (KAB) and salt excretion using the 24-hour (24 h) urinary collection method. Data were utilized from the Community-Based Management of Non-Communicable Diseases in Nepal (COBIN) Salt Survey, a community-based cross-sectional study conducted among a sub-sample of COBIN cohort in Pokhara Metropolitan City, Western Nepal, from July to December 2018, among adults aged 25-70 years. A total of 451 adults participated in the study, and a single 24 h urine sample was collected from each participant. The mean [(standard deviation (SD)] age of the participants was 49.6 (9.82) years, and the majority were female (65%). The mean urinary salt excretion was 13.28 (SD: 4.72) g/day, with 98% of participants consuming ≥5 g of salt/day. Although 83% of participants knew the risks of high salt intake and 87% believed it was important to reduce their intake, only 10% reported doing so. Salt-related attitude i.e., self-perceived salt intake was significantly associated with urinary salt excretion, adding extra salt to food, consuming processed foods, and taking actions to salt control. Participants who perceived themselves as consuming high salt had higher urinary salt excretion [(14.42 g/day; 95% confidence interval (95% CI): 13.45, 15.39, p = 0.03)], were more likely to add extra [(Odds ratio (OR) = 3.59; 95% CI: 2.03, 6.33, p < 0.001)], and consume processed foods more often (OR = 1.90; 95% CI: 1.06, 3.40, p < 0.05) compared to those who self-perceived consuming a normal amount of salt. Conversely, participants who perceived themselves as consuming low salt were more likely to take actions to control salt intake (OR = 4.22; 95% CI: 1.90, 9.37, p < 0.001) compared to their counterparts who perceived consuming a normal amount of salt. There existed a gap between salt-related knowledge, attitudes, and actual behaviors, resulting in a high salt intake among the Nepalese population. Nepal urgently requires tailored national salt reduction programs that comprise both policy and community-level interventions to achieve a 30% reduction in mean population salt intake by 2025. Further validation studies are needed to assess the effectiveness of community-based intervention in Nepal.

The Guidelines for use and promotion of low sodium salt in China

AIM

Both excessive intake of sodium and inadequate intake of potassium are associated with blood pressure elevation and subsequent increase in the risk of cardiovascular disease, which accounts for the largest number of deaths in China and worldwide. Low sodium salt, a mixture of mainly sodium chloride and potassium chloride, has shown its great potential as a promising population strategy for sodium intake reduction through multiple large-scale, multicenter, randomized controlled trials among populations including patients with cardiovascular disease, individuals with and without hypertension, older and younger adults, and men and women in China and other countries. This Guidelines aims to provide expert recommendations for promotion and use of low sodium salt in China, based on the current available scientific evidence regarding the effectiveness, safety, cost-effectiveness, and acceptability of low sodium salts in various population groups and different application scenarios. The suggestions to key stakeholders are also made.

METHODS

A working group, an expert review committee and an advisory committee were established to be responsible for formulating the guidelines' scope and key questions to be addressed, for searching, synthesizing, and evaluating research evidence, proposing and reviewing the recommendations. The consensus on the final recommendations was reached using the GRADE grid method.

RESULTS

The working group summarized current available evidence of salt substitution regarding its effectiveness, safety, cost-effectiveness, acceptability, availability, suitability, etc. The Guidelines provided six recommendations advising different populations how to use low sodium salt, four recommendations on the application of low sodium salts in different scenarios, and five suggestions for key stakeholders to promote salt substitution.

CONCLUSION

The first evidence-based guidelines on promotion and use of low sodium salts covers all key questions in relevance and would play a critical role in prevention and control of hypertension and cardiovascular disease in China and worldwide.

Secondary Analysis of the Salt Substitute and Stroke Study (SSaSS): Effects of Potassium-Enriched Salt on Cardiac Outcomes

BACKGROUND

The SSaSS (Salt Substitute and Stroke Study) has shown that use of a potassium-enriched salt lowers the risk of stroke, total cardiovascular events, and premature death. The effects on cause-specific cardiac outcomes are reported here.

METHODS

SSaSS was an unblinded, cluster-randomised trial assessing the effects of potassium-enriched salt compared with regular salt among 20 995 Chinese adults with established stroke and older age and uncontrolled hypertension. Post hoc efficacy analyses were performed using an intention-to-treat method and a hierarchical Poisson regression model adjusting for clustering to obtain rate ratios and 95% CIs. We assessed acute coronary syndrome, heart failure, arrhythmia, and sudden death.

RESULTS

Over a mean 4.74 years follow-up, there were 695 acute coronary syndrome events, 454 heart failure events, 230 arrhythmia events, and 1133 sudden deaths recorded. The rates of events were lower in potassium-enriched salt group for all outcomes but CIs were wide for most: acute coronary syndrome (6.32 versus 7.65 events per 1000 person-years; rate ratio, 0.80 [95% CI, 0.65-0.99]); heart failure (9.14 versus 11.32 events per 1000 person-years; rate ratio, 0.88 [95% CI, 0.60-1.28]); arrhythmia (4.43 versus 6.20 events per 1000 person-years; rate ratio, 0.59 [95% CI, 0.35-0.98]); and sudden death (11.01 versus 11.76 events per 1000 person-years; rate ratio, 0.94 [95% CI, 0.82-1.07]; all P>0.05 with adjustment for multiple comparisons).

CONCLUSIONS

These results suggest that use of potassium-enriched salt is more likely to prevent than cause cardiac disease but the post hoc nature of these analyses precludes definitive conclusions.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02092090.

Long-Term Effect of Salt Substitution for Cardiovascular Outcomes : A Systematic Review and Meta-analysis

BACKGROUND

Salt substitution is a simple yet increasingly promising strategy to improve cardiovascular outcomes.

PURPOSE

To evaluate the long-term effects of salt substitution on cardiovascular outcomes.

DATA SOURCES

PubMed, EMBASE, Cochrane CENTRAL, and CINAHL searched from inception to 23 August 2023. Trial registries, citation analysis, and hand-search were also done.

STUDY SELECTION

Randomized controlled trials (RCTs) comparing provision of or advice to use a salt substitute with no intervention or use of regular salt among adults for 6 months or longer in total study duration.

DATA EXTRACTION

Two authors independently screened articles, extracted data, and assessed risk of bias. Primary outcomes include mortality, major cardiovascular events (MACE), and adverse events at 6 months or greater. Secondary and post hoc outcomes include blood pressure, cause-specific mortality, and urinary excretion at 6 months or greater. Random-effects meta-analyses were done and certainty of effect estimates were assessed using GRADE (Grading of Recommendations Assessment, Development and Evaluation).

DATA SYNTHESIS

Of the 16 included RCTs, 8 reported on primary outcomes. Most (n = 7 of 8) were done in China or Taiwan, 3 were done in residential facilities, and 7 included populations of older age (average 62 years) and/or with higher-than-average cardiovascular risk. In this population, salt substitute may reduce risk for all-cause mortality (6 RCTs; 27 710 participants; rate ratio [RR], 0.88 [95% CI, 0.82 to 0.93]; low certainty) and cardiovascular mortality (4 RCTs; 25 050 participants; RR, 0.83 [CI, 0.73 to 0.95]; low certainty). Salt substitute may result in a slight reduction in MACE (3 RCTs; 23 215 participants; RR, 0.85 [CI, 0.71 to 1.00]; very low certainty), with very low-certainty evidence of serious adverse events (6 RCTs; 27 995 participants; risk ratio, 1.04 [CI, 0.87 to 1.25]).

LIMITATIONS

The evidence base is dominated by a single, large RCT. Most RCTs were from China or Taiwan and involved participants with higher-than-average cardiovascular risk; therefore, generalizability to other populations is very limited.

CONCLUSION

Salt substitution may reduce all-cause or cardiovascular mortality, but the evidence for reducing cardiovascular events and for not increasing serious adverse events is uncertain, particularly for a Western population. The certainty of evidence is higher among populations at higher cardiovascular risk and/or following a Chinese diet.

PRIMARY FUNDING SOURCE

National Health and Medical Research Council. (PROSPERO: CRD42022327566).

The potential for current sodium and potassium production to support a global switch to the use of potassium-enriched salt: a desktop research study

OBJECTIVE

Switching regular salt (sodium chloride) to salt enriched with potassium chloride (25 % potassium chloride, 75 % sodium chloride) has been shown to reduce blood pressure and the risk of cardiovascular diseases. We sought to define the potential for the current production of sodium chloride and potassium chloride to support a global switch to the use of potassium-enriched salt.

DESIGN

We summarised data from geological surveys, government reports and trade organisations describing the global production and supply of sodium chloride and potash (the primary source of potassium chloride) and compared this to potential requirements for potassium-enriched salt.

SETTING

Global.

PARTICIPANTS

Not applicable.

RESULTS

Approximately 280 million tonnes of sodium chloride were produced in 2020 with China and the USA the main producers. Global production of potash from which potassium chloride is extracted was about forty-four million tonnes with Canada, Belarus, Russia and China providing 77 % of the world's supply. There were forty-eight countries in which potassium-enriched salt is currently marketed with seventy-nine different brands identified. Allowing for loss of salt between manufacture and consumption, a full global switch from regular salt to potassium-enriched salt would require about 9·7 million tonnes of sodium chloride to be replaced with 9·7 million tonnes of potassium chloride annually.

CONCLUSIONS

Significant upscaling of the production of potassium chloride and the capacity of companies able to manufacture potassium-enriched salt, as well as a robust business case for the switch to potassium chloride, would be required.

Cost-Effectiveness of Salt Substitute and Salt Supply Restriction in Eldercare Facilities: The DECIDE-Salt Cluster Randomized Clinical Trial

Importance

Salt substitution has been reported to be a cost-saving sodium reduction strategy that has not yet been replicated in different contexts.

Objective

To estimate the cost-effectiveness of sodium reduction strategies within the DECIDE-Salt trial.

Design, Setting, and Participants

The DECIDE-Salt trial cluster randomized in a 1:1:1:1 ratio 48 eldercare facilities in China into 4 groups for evaluation of 2 sodium reduction strategies for 2 years: 1 with both strategies, 2 with either strategy, and 1 with neither strategy. The trial was conducted from September 25, 2017, through October 24, 2020.

Interventions

The 2 intervention strategies were replacing regular salt with salt substitute and progressively restricting salt supply to kitchens.

Main Outcomes and Measures

The main outcomes included per-participant costs of intervention implementation and medical treatments for hypertension and major adverse cardiovascular events (MACEs) against mean reductions in systolic blood pressure, hypertension prevalence, MACE incidence, and mortality. The incremental cost-utility ratio was then assessed as the additional mean cost per quality-adjusted life-year gained. Analyses were conducted separately for each strategy, comparing groups assigned and not assigned the test strategy. Disease outcomes followed the intention-to-treat principle and adopted different models as appropriate. One-way and probabilistic sensitivity analyses were conducted to explore uncertainty, and data analyses were performed between August 13, 2022, and April 5, 2023.

Results

A total of 1612 participants (1230 males [76.3%]) with a mean (SD) age of 71.0 (9.5) years were enrolled. Replacing regular salt with salt substitute reduced mean systolic blood pressure by 7.14 (95% CI, 3.79-10.48) mm Hg, hypertension prevalence by 5.09 (95% CI, 0.37-9.80) percentage points, and cumulative MACEs by 2.27 (95% CI, 0.09-4.45) percentage points. At the end of the 2-year intervention, the mean cost was $25.95 less for the salt substitute group than the regular salt group due to substantial savings in health care costs for MACEs (mean [SD], $72.88 [$9.11] vs $111.18 [$13.90], respectively). Sensitivity analysis showed robust cost savings. By contrast, the salt restriction strategy did not show significant results. If the salt substitution strategy were rolled out to all eldercare facilities in China, 48 101 MACEs and 107 857 hypertension cases were estimated to be averted and $54 982 278 saved in the first 2 years.

Conclusions and Relevance

The findings of this cluster randomized clinical trial indicate that salt substitution may be a cost-saving strategy for hypertension control and cardiovascular disease prevention for residents of eldercare facilities in China. The substantial health benefit savings in preventing MACEs and moderate operating costs offer strong evidence to support the Chinese government and other countries in planning or implementing sodium intake reduction and salt substitute campaigns.

Trial Registration

ClinicalTrials.gov Identifier: NCT03290716.

Switching the World's Salt Supply-Learning from Iodization to Achieve Potassium Enrichment

Sodium is an essential dietary component, but excess sodium intake can lead to high blood pressure and an increased risk of cardiovascular disease. Many national and international bodies, including the World Health Organization, have advocated for population-wide sodium reduction interventions. Most have been unsuccessful due to inadequate sodium reduction by food industry and difficulties in persuading consumers to add less salt to food. Recent research highlights potassium-enriched salt as a new, feasible, acceptable, and scalable approach to reducing the harms caused by excess sodium and inadequate potassium consumption. Modeling shows that a global switch from regular salt to potassium-enriched salt has the potential to avert millions of strokes, heart attacks, and premature deaths worldwide each year. There will be many challenges in switching the world's salt supply to potassium-enriched salt, but the success of universal salt iodization shows that making a global change to the manufacture and use of salt is a tractable proposition. This in-depth review of universal salt iodization identified the importance of a multisectoral effort with strong global leadership, the support of multilateral organizations, engagement with the salt industry, empowered incountry teams, strong participation of national governments, understanding the salt supply chain, and a strategic advocacy and communication plan. Key challenges to the implementation of the iodization program were costs to government, industry, and consumers, industry concerns about consumer acceptability, variance in the size and capabilities of salt producers, inconsistent quality control, ineffective regulation, and trade-related regulatory issues. Many of the opportunities and challenges to universal salt iodization will likely also be applicable to switching the global salt supply to iodized and potassium-enriched salt.

India's tryst with salt: Dandi march to low sodium salts

Salt plays a critical role in India's past as well as its present, from Dandi March to its role as a vehicle for micronutrient fortification. However, excess salt intake is a risk factor for high blood pressure and cardiovascular diseases (CVDs). Indians consume double the World Health Organization recommended daily salt (<5 g). India has committed to a 30 per cent reduction in sodium intake by 2025. Evidence based strategies for population sodium intake reduction require a moderate reduction in salt in - home cooked foods, packaged foods and outside-home foods. Reducing the sodium content in packaged food includes policy driven interventions such as front-of-package warning labels, food reformulation, marketing restrictions and taxation on high sodium foods. For foods outside of the home, setting standards for foods purchased and served by schemes like mid-day meals can have a moderate impact. For home cooked foods (the major source of sodium), strategies include advocacy for reducing salt intake. In addition to mass media campaigns for awareness generation, substituting regular salt with low sodium salt (LSS) has the potential to reduce salt intake even in the absence of a major shift in consumer behaviour. LSS substitution effectively lowers blood pressure and thus reduces the risk of CVDs. Further research is required on the effect of LSS substitutes on patients with chronic kidney disease. India needs an integrated approach to sodium reduction that uses evidence based strategies and can be implemented sustainably at scale. This will be possible only through scientific research, governmental leadership and a responsive evidence-to-action approach through a multi-stakeholder coalition.

Global cardiovascular diseases burden attributable to high sodium intake from 1990 to 2019

Sodium intake shows a positive correlation with blood pressure, resulting in an increased risk for cardiovascular diseases (CVD). Salt reduction is a key step toward the WHO's goal of 25% reduction in mortality from non-communicable diseases (NCDs) by 2025. This study aims to assess the current condition and temporal changes of the global CVD burden due to high sodium intake (HSI). We extracted data from the Global Burden of Disease (GBD) study 2019. The numbers and age-standardized rates of mortality and disability-adjusted life-years (DALYs), stratified by location, sex, and socio-demographic Index (SDI), were used to assess the high sodium intake attributable CVD burden from 1990 to 2019. The relationship between the DALYs rates and related factors was evaluated by stepwise multiple linear regression analysis. Globally, in 2019, the deaths and DALYs of HSI-related CVD were 1.72 million and 40.54 million, respectively, increasing by 41.08% and 33.06% from 1990. Meanwhile, the corresponding mortality and DALYs rates dropped by 35.1% and 35.2%, respectively. The high-middle and middle SDI quintiles bore almost two-thirds of CVD burden caused by HSI. And the leading cause of HSI attributable CVD burden was ischemic heart disease. Universal health coverage (UHC) was associated with the DALYs rates after adjustment. From 1990 to 2019, the global CVD burden attributable to HSI has declined with spatiotemporal and sexual heterogeneity. However, it remains a major public health challenge because of the increasing absolute numbers. Improving UHC serves as an effective strategy to reduce the HSI-related CVD burden.

Temporal trends in inequalities of the burden of cardiovascular disease across 186 countries and territories

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality globally. The extent to which CVD affects the population's health varies across countries. Moreover, quantitative estimates of the trend of inequalities in CVD burden remain unclear. The objective of our study was to assess the socioeconomic inequalities and temporal trends of CVD burden across 186 countries and territories from 2000 to 2019.

METHODS

We extracted data from the Global Burden of Disease, Injuries, and Risk Factors Study (GBD) 2019, and conducted a cross-national time-series analysis. Age-standardized disability-adjusted life-year (DALY) rates were used to measure the burden of CVDs, and gross national income (GNI) per capita was used to approximate the socioeconomic development. Concentration curves and concentration indexes (CIs) were generated to evaluate the cross-national socioeconomic inequality of CVD burden. A joinpoint regression analysis was used to quantify the changes in trends in socioeconomic inequality of CVD burden from 2000 to 2019.

RESULTS

The age-standardized DALY rates of CVDs decreased in 170 (91%) of 186 countries from 2000 to 2019. The concentration curves of the age-standardized DALY rates of CVDs were above the equality line from 2000 to 2019, indicating a disproportional distribution of CVD burden in low-income countries. The CIs declined from - 0.091 (95% CI: -0.128 to - 0.054) in 2000 to - 0.151 (95% CI: -0.190 to - 0.112) in 2019, indicating worsened pro-poor inequality distributions of CVD burden worldwide. A four-phase trend of changes in the CIs of age-standardized DALY rates for CVD was observed from 2000 to 2019, with an average annual percentage change (AAPC) of - 2.7% (95% CI: -3.0 to - 2.4). Decreasing trends in CIs were observed in all CVD subcategories but endocarditis, with AAPC ranging from - 6.6% (95% CI: -7.3 to - 5.9) for ischemic heart disease to - 0.2% (95% CI: -0.4 to - 0.1) for hypertensive heart disease.

CONCLUSIONS

Globally, the burden of CVD has decreased in more than 90% of countries over the past two decades, accompanied by an increasing trend of cross-country inequalities. Moreover, the overall burden of CVD continues to fall primarily on low-income countries.

China stroke surveillance report 2021

Since 2015, stroke has become the leading cause of death and disability in China, posing a significant threat to the health of its citizens as a major chronic non-communicable disease. According to the China Stroke High-risk Population Screening and Intervention Program, an estimated 17.8 million [95% confidence interval (CI) 17.6-18.0 million] adults in China had experienced a stroke in 2020, with 3.4 million (95% CI 3.3-3.5 million) experiencing their first-ever stroke and another 2.3 million (95% CI 2.2-2.4 million) dying as a result. Additionally, approximately 12.5% (95% CI 12.4-12.5%) of stroke survivors were left disabled, as defined by a modified Rankin Scale score greater than 1, equating to 2.2 million (95% CI 2.1-2.2 million) stroke-related disabilities in 2020. As the population ages and the prevalence of risk factors like diabetes, hypertension, and hyperlipidemia continues to rise and remains poorly controlled, the burden of stroke in China is also increasing. A large national epidemiological survey initiated by the China Hypertension League in 2017 showed that the prevalence of hypertension was 24.7%; the awareness, treatment, and control rates in hypertensive patients were: 60.1%, 42.5%, and 25.4%, respectively. A nationally representative sample of the Chinese mainland population showed that the weighted prevalence of total diabetes diagnosed by the American Diabetes Association criteria was 12.8%, suggesting there are 120 million adults with diabetes in China, and the awareness, treatment, and control rates in diabetic patients were: 43.3%, 49.0%, and 49.4%, respectively. The "Sixth National Health Service Statistical Survey Report in 2018" showed that the proportion of the obese population in China was 37.4%, an increase of 7.2 points from 2013. Data from 1599 hospitals in the Hospital Quality Monitoring System and Bigdata Observatory Platform for Stroke of China (BOSC) showed that a total of 3,418,432 stroke cases [mean age ± standard error (SE) was (65.700 ± 0.006) years, and 59.1% were male] were admitted during 2020. Of those, over 80% (81.9%) were ischemic stroke (IS), 14.9% were intracerebral hemorrhage (ICH) strokes, and 3.1% were subarachnoid hemorrhage (SAH) strokes. The mean ± SE of hospitalization expenditures was Chinese Yuan (CNY) (16,975.6 ± 16.3), ranging from (13,310.1 ± 12.8) in IS to (81,369.8 ± 260.7) in SAH, and out-of-pocket expenses were (5788.9 ± 8.6), ranging from (4449.0 ± 6.6) in IS to (30,778.2 ± 156.8) in SAH. It was estimated that the medical cost of hospitalization for stroke in 2020 was CNY 58.0 billion, of which the patient pays approximately CNY 19.8 billion. In-hospital death/discharge against medical advice rate was 9.2% (95% CI 9.2-9.2%), ranging from 6.4% (95% CI 6.4-6.5%) for IS to 21.8% for ICH (95% CI 21.8-21.9%). From 2019 to 2020, the information about 188,648 patients with acute IS receiving intravenous thrombolytic therapy (IVT), 49,845 patients receiving mechanical thrombectomy (MT), and 14,087 patients receiving bridging (IVT + MT) were collected through BOSC. The incidence of intracranial hemorrhage during treatment was 3.2% (95% CI 3.2-3.3%), 7.7% (95% CI 7.5-8.0%), and 12.9% (95% CI 12.3-13.4%), respectively. And in-hospital death/discharge against medical advice rate was 8.9% (95% CI 8.8-9.0%), 16.5% (95% CI 16.2-16.9%), and 16.8% (95% CI 16.2-17.4%), respectively. A prospective nationwide hospital-based study was conducted at 231 stroke base hospitals (Level III) from 31 provinces in China through BOSC from January 2019 to December 2020 and 136,282 stroke patients were included and finished 12-month follow-up. Of those, over 86.9% were IS, 10.8% were ICH strokes, and 2.3% were SAH strokes. The disability rate [% (95% CI)] in survivors of stroke at 3-month and 12-month was 14.8% (95% CI 14.6-15.0%) and 14.0% (95% CI 13.8-14.2%), respectively. The mortality rate [% (95% CI)] of stroke at 3-month and 12-month was 4.2% (95% CI 4.1-4.3%) and 8.5% (95% CI 8.4-8.6%), respectively. The recurrence rate [% (95% CI)] of stroke at 3-month and 12-month was 3.6% (95% CI 3.5-3.7%) and 5.6% (95% CI 5.4-5.7%), respectively. The Healthy China 2030 Stroke Action Plan was launched as part of this review, and the above data provide valuable guidelines for future stroke prevention and treatment efforts in China.

Awareness and Use of Low-Sodium Salt Substitutes and Its Impact on 24-h Urinary Sodium and Potassium Excretion in China-A Cross-Sectional Study

The use of low-sodium salt substitute (LSSS) has the potential to reduce sodium and increase potassium intake. LSSS has been available in the Chinese market for years. However, its real-world use and impact on sodium/potassium intake is unclear. Baseline data of 4000 adult individuals who participated in three similarly designed randomized controlled trials were pooled together for this analysis. Self-reported awareness and use of LSSS were collected using a standardized questionnaire, and the participants' 24-h urinary sodium and potassium excretion was used to estimate their dietary intake. Mixed-effects models were developed to assess the relationship between LSSS and 24-h urinary sodium and potassium excretion. 32.0% of the participants reported awareness of LSSS and 11.7% reported its current use. After adjusting for location, sex, age, and education, compared with the group of participants unaware of LSSS, participants who were aware of but not using LSSS and those who were using LSSS had a lower 24-h urinary sodium excretion by -356.1 (95% CI: -503.9, -205.9) mg/d and -490.6 (95% CI: -679.2, -293.7) mg/d, respectively (p < 0.001). No significant difference was found for 24-h urinary potassium excretion or sodium-to-potassium ratio among the three groups (p > 0.05). In conclusion, the findings of low usage of LSSS and the reduced urinary sodium excretion associated with the awareness and use of LSSS provide further support for the prometon of LSSS as a key salt reduction strategy in China.

Advances in pathogenesis and treatment of essential hypertension

Hypertension is a significant risk factor for cardiovascular and cerebrovascular diseases and the leading cause of premature death worldwide. However, the pathogenesis of the hypertension, especially essential hypertension, is complex and requires in-depth studies. Recently, new findings about essential hypertension have emerged, and these may provide important theoretical bases and therapeutic tools to break through the existing bottleneck of essential hypertension. In this review, we demonstrated important advances in the different pathogenesis areas of essential hypertension, and highlighted new treatments proposed in these areas, hoping to provide insight for the prevention and treatment of the essential hypertension.

Advancing Health Research Impact through a Systemic Multi-Sectoral Approach: A Protocol for Introducing Reduced-Sodium Salts and Salty Condiments in Vietnam

Better alignment between health research organisations with the needs (and interests) of key stakeholders in the health policy and research system is critical to improving research impact. The George Institute for Global Health's 'Healthier Societies' program focuses on harnessing the power of governments, markets, and communities to improve population level health equity outcomes and maximise research impact. This protocol outlines a systemic multi-sectoral approach to advance health research impact globally applied to a project to reduce population salt intake in Vietnam by introducing reduced-sodium salts and salty condiments. We defined a systemic multi-sectoral approach to be a strategy that involves engaging with government, market and communities in a deliberate and joined-up way to solve a problem in which they all have a role to play. The project objectives are to: (i) produce reduced-sodium fish sauce products and test consumer acceptability; (ii) investigate the market feasibility of introducing reduced-sodium foods (salt, bot canh and fish sauce) into the Vietnamese market; (iii) estimate the cost-effectiveness of three different government strategies to support the implementation of reduced-sodium products; and (iv) develop an advocacy roadmap to maximise potential research impact. Methods will include standard quality and safety assessments, consumer sensory testing for the locally produced reduced-sodium fish sauces, market feasibility assessment (including collating market data and semi-structured interviews with stakeholders), cost-effectiveness modelling (Markov cohort model), multi-sector stakeholder engagement, and the development of a coordinated advocacy strategy using the Kotter Plus framework. Health research organisations are increasingly seeking ways to achieve greater impact with their research. Through the application of a systemic multi-sectoral approach with governments, markets and communities, this protocol provides an example of how health research projects can achieve such impact.