Salt substitution and salt-supply restriction for lowering blood pressure in elderly care facilities: a cluster-randomized trial

The association between urinary sodium and the risk of dementia: Evidence from a population-based cohort study

BACKGROUND

Sodium intake reduction is crucial for cardiovascular health, however, its lasting impact on dementia remains unclear.

METHODS

We included 458,577 UK Biobank participants without dementia at baseline. We estimated 24-h urinary sodium (E24hUNa) using spot urinary parameters and obtained the incidence of all-cause dementia, Alzheimer's disease, and vascular dementia from multiple sources.

RESULTS

The mean E24hUNa was 3.0 g (1st-99th percentile: 1.5 g-5.1 g). Over a mean follow-up of 13.6 years, 7886 (1.7 %) participants developed all-cause dementia, including 3763 (0.8 %) Alzheimer's disease and 1851 (0.4 %) vascular dementia. In the restricted cubic spline model, we identify a potential cutoff of 3.13 g for E24hUNa, below which each 1 g decrease in E24hUNa was associated with 21 % (95 % confidence interval [CI] 1.11-1.34) higher all-cause dementia risk and 35 % (95 % CI 1.11-1.63) higher vascular dementia risk (P-value <0.001 for non-linearity). The hazard ratios were 1.15 (95 % CI, 1.07-1.24) for all-cause dementia and 1.21 (95 % CI 1.04-1.40) for vascular dementia among individuals with E24hUNa below 3.13 g compared to those with E24hUNa higher than 3.13 g.

LIMITATIONS

One of the major limitations is the estimation of 24-h urinary sodium with spot urine samples.

CONCLUSIONS

An E24hUNa level below 3.13 g, equivalent to 3.37 g daily sodium intake, is associated with increased risks of all-cause and vascular dementia. This exploratory study suggests a potential lower limit below which the risk of dementia increases with a lower sodium level. Future studies are necessary to validate our findings.

Selected highlights in the updated treatment of hypertension

Hypertension remains the leading international risk factor for cardiovascular disease and premature death but, despite effective treatments, hypertension remains significantly underdiagnosed and undertreated. In the present review paper, we provide a selected update on recent developments of interest in the management of hypertension. We focus on summarizing four topics that we believe are worth highlighting to a clinical audience: (1) the evidence and strong motivation for new lower systolic BP treatment targets; (2) new studies reporting on the efficacy of renal denervation in the management of hypertension; (3) interesting new data to inform the great salt debate; and (4), perhaps most importantly, pioneering new work highlighting the huge potential of multi-disciplinary care in the management of hypertension.

Effect of salt substitute and antihypertensive medications among high cardiovascular risk patients: A sub-study of Salt Substitute and Stroke Study (SSaSS)

The relationship between the differential protective effect of salt substitute between hypertensive and normotensive individuals and the use of cardiovascular medications remains unclear. This study involved 4211 individuals with a history of stroke or hypertension who participated in the Salt Substitute and Stroke Study (SSaSS) from 120 villages in Shanxi Province. The aim of this study was to investigate the differences in major adverse cardiovascular events and blood pressure changes between the salt substitute and the regular salt group in the subgroups of participants taking different antihypertensive medications. Mixed models were employed and adjusted for the cluster effect (village) and potential confounding variables. During the average follow-up period of 4.66 years, a significantly protective effect of salt substitute on reducing the risk of cardiovascular events was observed in the participants who taking antihypertensive medications (rate ratio: 0.81, 95% CI: 0.68 to 0.95. p = 0.011), whereas no significant effect in participants not taking antihypertensive medications (rate ratio: 0.91, 95% CI: 0.62 to 1.32, p = 0.612). Significant effects to lower systolic blood pressure of the salt substitutes were observed in the participants who took different antihypertensive medications. This study emphasized that the use of salt substitutes might enhance the efficacy of anti-hypertensive medications in lowering blood pressure and reducing the risk of adverse cardiovascular events.

Remission to normal blood pressure in older adults with hypertension who did not receive antihypertensive medication: analysis of data from two longitudinal cohorts

Background

How often hypertensive patients could achieve remission to normal blood pressure (BP) (i.e., <140/90 mmHg) in the absence of antihypertensive drugs, which is important for the management of hypertension, remains largely unknown. This observational study aimed to investigate the change of BP in older adults with hypertension who did not take antihypertensive drugs and preliminarily examine whether the remission from hypertension to normal BP observed in this setting was associated with lower risk of cardiovascular disease (CVD).

Methods

2760 participants aged 33-99 years (median 60 years, interquartile 54-68 years) from the Health and Retirement Study (wave 2006 to wave 2018) and the English Longitudinal Study of Ageing (wave 1998 to wave 2016), who had no major CVD, were hypertensive, and were not on antihypertensive drugs at the time of baseline BP measurement, and had at least one follow-up BP measurement before which no antihypertensive drugs were taken, were included for analysis. The main outcome was the proportion of patients who achieved remission of hypertension at the last wave of measurement.

Findings

During a median follow-up of six years, 52% of the participants showed a reduction of ≥6 mmHg in systolic BP and 60% a reduction of ≥3 mmHg in diastolic BP. 1171 participants (42%, 95% CI: 41-44%) achieved remission at the last measurement, and by that time 67%, 43%, and 29% of them had maintained the normotensive state for around 4, 8, and 12 years, respectively. Various supplementary analyses that aimed to examine the impact of chance and bias yielded similar results. Preliminary analyses showed that being non-smokers at baseline, achieving a normal body mass index during follow-up, and quitting alcohol drinking during follow-up, among others, were associated with the remission of hypertension. Compared with the participants who remained hypertensive, those who achieved remission had a lower CVD risk (adjusted hazard ratio 0.66, 95% CI: 0.47-0.92).

Interpretation

In many of this study population, hypertension could be reversed without the intervention of drug treatment in the first few years after diagnosis. This finding may have implications for more individualized management of hypertension. Further studies to identify the factors or algorithms predictive of such hypertension remission are warranted.

Funding

The Chinese University of Hong Kong (7106452; 7105959),Shenzhen Science and Technology Program (KQTD20190929172835662), Strategic Priority Research Program of Chinese Academy of Sciences (XDB 38040200), National Institute on Aging (R01AG017644; NIA U01AG009740).

The Relationship between Low-Sodium Salt Intake and Both Blood Pressure Level and Hypertension in Chinese Residents

Compared to common salt, low-sodium salt can reduce blood pressure to varying degrees. However, the exact dosage relationship remains unclear. We aimed to investigate the dose-response relationships between low-sodium salt intake and systolic blood pressure (SBP) and diastolic blood pressure (DBP), as well as the risk of hypertension, and to determine the optimal range for low-sodium salt intake. We investigated the basic characteristics and dietary profile of 350 individuals who consumed low-sodium salt. The samples were divided into three groups according to the 33.3rd and 66.6th percentiles of low-sodium salt intake in condiments (Q1: <4.72 g/d, Q2: ≥4.72 g/d, and <6.88 g/d, and Q3: ≥6.88 g/d). The restricted cubic spline results indicated that low-sodium salt intake decreased linearly with SBP and DBP, while low-sodium intake demonstrated a non-linear, L-shaped relationship with the risk of hypertension, with a safe range of 5.81 g to 7.66 g. The multiple linear regression analysis revealed that compared with group Q1, the DBP in group Q2 decreased by 2.843 mmHg (95%CI: -5.552, -0.133), and the SBP in group Q3 decreased by 4.997 mmHg (95%CI: -9.136, -0.858). Exploratory subgroup analyses indicated that low-sodium salt intake had a significant impact on reducing SBP in males, DBP in females, SBP in rural populations, and DBP in urban populations. The intake of low-sodium salt adheres to the principle of moderation, with 5.81-7.66 g potentially serving as a pivotal threshold.

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.

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).

Potassium-Enriched Salt Substitutes: A Review of Recommendations in Clinical Management Guidelines

Excess dietary sodium intake and insufficient dietary potassium intake are both well-established risk factors for hypertension. Despite some successful initiatives, efforts to control hypertension by improving dietary intake have largely failed because the changes required are mostly too hard to implement. Consistent recent data from randomized controlled trials show that potassium-enriched, sodium-reduced salt substitutes are an effective option for improving consumption levels and reducing blood pressure and the rates of cardiovascular events and deaths. Yet, salt substitutes are inconsistently recommended and rarely used. We sought to define the extent to which evidence about the likely benefits and harms of potassium-enriched salt substitutes has been incorporated into clinical management by systematically searching guidelines for the management of hypertension or chronic kidney disease. We found incomplete and inconsistent recommendations about the use of potassium-enriched salt substitutes in the 32 hypertension and 14 kidney guidelines that we reviewed. Discussion among the authors identified the possibility of updating clinical guidelines to provide consistent advice about the use of potassium-enriched salt for hypertension control. Draft wording was chosen to commence debate and progress consensus building: strong recommendation for patients with hypertension-potassium-enriched salt with a composition of 75% sodium chloride and 25% potassium chloride should be recommended to all patients with hypertension, unless they have advanced kidney disease, are using a potassium supplement, are using a potassium-sparing diuretic, or have another contraindication. We strongly encourage clinical guideline bodies to review their recommendations about the use of potassium-enriched salt substitutes at the earliest opportunity.

Modifying Dietary Sodium and Potassium Intake: An End to the 'Salt Wars'?

Excessive salt intake raises blood pressure, but the implications of this observation for human health have remained contentious. It has also been recognized for many years that potassium intake may mitigate the effects of salt intake on blood pressure and possibly on outcomes such as stroke. Recent large randomized intervention trials have provided strong support for the benefits of replacing salt (NaCl) with salt substitute (75% NaCl, 25% KCl) on hard outcomes, including stroke. During the same period of time, major advances have been made in understanding how the body senses and tastes salt, and how these sensations drive intake. Additionally, new insights into the complex interactions between systems that control sodium and potassium excretion by the kidneys, and the brain have highlighted the existence of a potassium switch in the kidney distal nephron. This switch seems to contribute importantly to the blood pressure-lowering effects of potassium intake. In recognition of these evolving data, the United States Food and Drug Administration is moving to permit potassium-containing salt substitutes in food manufacturing. Given that previous attempts to reduce salt consumption have not been successful, this new approach has a chance of improving health and ending the 'Salt Wars'.

Sodium as an Important Regulator of Immunometabolism

Salt sensitivity concerns blood pressure alterations after a change in salt intake (sodium chloride). The heart is a pump, and vessels are tubes; sodium can affect both. A high salt intake increases cardiac output, promotes vascular dysfunction and capillary rarefaction, and chronically leads to increased systemic vascular resistance. More recent findings suggest that sodium also acts as an important second messenger regulating energy metabolism and cellular functions. Besides endothelial cells and fibroblasts, sodium also affects innate and adaptive immunometabolism, immune cell function, and influences certain microbes and microbiota-derived metabolites. We propose the idea that the definition of salt sensitivity should be expanded beyond high blood pressure to cellular and molecular salt sensitivity.

Effect of a Salt Substitute on Incidence of Hypertension and Hypotension Among Normotensive Adults

BACKGROUND

Reports on the effects of salt substitution among individuals with normal blood pressure are scarce and controversial.

OBJECTIVES

This study sought to assess the effects of a salt substitute (62.5% NaCl, 25% KCl, and 12.5% flavorings) on incidence of hypertension and hypotension among older adults with normal blood pressure.

METHOD

A post hoc analysis was conducted among older adults with normal blood pressure participating in DECIDE-Salt, a large, multicenter, cluster-randomized trial in 48 elderly care facilities for 2 years. We used the frailty survival model to compare risk of incident hypertension and the generalized linear mixed model to compare risk of hypotension episodes.

RESULTS

Compared with usual salt group (n = 298), the salt substitute group (n = 313) had a lower hypertension incidence (11.7 vs 24.3 per 100 person-years; adjusted HR: 0.60; 95% CI: 0.39 to 0.92; P = 0.02) but did not increase incidence of hypotension episodes (9.0 vs 9.7 per 100 person-years; P = 0.76). Mean systolic/diastolic blood pressure did not increase from the baseline to the end of intervention in the salt substitute group (mean changes: -0.3 ± 11.9/0.2 ± 7.1 mm Hg) but increased in the usual salt group (7.0 ± 14.3/2.1 ± 7.5 mm Hg), resulting in a net reduction of -8.0 mm Hg (95% CI: -12.4 to -3.7 mm Hg) in systolic and -2.0 mm Hg (95% CI: -4.1 to 0.1 mm Hg) in diastolic blood pressure between intervention groups.

CONCLUSIONS

In Chinese older adults with normal blood pressure, replacing usual salt with a salt substitute may reduce the incidence of hypertension without increasing hypotension episodes. This suggests a desirable strategy for population-wide prevention and control of hypertension and cardiovascular disease, deserving further consideration in future studies. (Diet Exercise and Cardiovascular Health [DECIDE]-Salt Reduction Strategies for the Elderly in Nursing Homes in China [DECIDE-Salt]; NCT03290716).

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.

Potassium and Hypertension: A State-of-the-Art Review

Hypertension is the single most important and modifiable risk factor for cardiovascular morbidity and mortality worldwide. Non pharmacologic interventions, in particular dietary modifications have been established to decrease blood pressure (BP) and hypertension related adverse cardiovascular events. Among those dietary modifications, sodium intake restriction dominates guidelines from professional organizations and has garnered the greatest attention from the mainstream media. Despite guidelines and media exhortations, dietary sodium intake globally has not noticeably changed over recent decades. Meanwhile, increasing dietary potassium intake has remained on the sidelines, despite similar BP-lowering effects. New research reveals a potential mechanism of action, with the elucidation of its effect on natriuresis via the potassium switch effect. Additionally, potassium-substituted salt has been shown to not only reduce BP, but also reduce the risk for stroke and cardiovascular mortality. With these data, we argue that the focus on dietary modification should shift from a sodium-focused to a sodium- and potassium-focused approach with an emphasis on intervention strategies which can easily be implemented into clinical practice.

Salt restriction for treatment of hypertension - current state and future directions

PURPOSE OF REVIEW

Given the adverse effects of excess dietary sodium chloride (also known as table salt) on blood pressure (BP) and cardiovascular disease (CVD), restriction of dietary sodium is recommended by numerous guidelines. The strictest of these recommend no more than 1.5 g/day of dietary sodium among hypertensive persons. However, average dietary sodium intake in the population is closer to 5 g/day and there is debate about whether too much sodium restriction may be associated with increased CVD risk. Herein, we aim to provide a balanced update on this topic.

RECENT FINDINGS

In 2021, the Salt Substitute and Stroke Study (SSaSS) demonstrated a significant reduction in BP, CVD, and death among Chinese adults randomized to a low sodium salt-substitute supplemented with potassium. This trial largely puts to rest any remaining debate about the benefits of dietary sodium restriction among persons with excess baseline intake (dietary sodium intake fell from approximately 5 down to 4 g/day in the active arm of SSaSS). However, whether achieving and maintaining a dietary sodium of less than1.5 g/day is feasible in real-world settings and whether this low an intake is harmful remain open questions.

SUMMARY

Aiming for sodium intakes of 2--3 g/day in the general population and as low as 2 g/day in persons with hypertension or CVD seems most reasonable, but there is some uncertainty around lower targets.

Potassium intake: the Cinderella electrolyte

Dietary guidelines recommend intake targets for some essential minerals, based on observational and experimental evidence relating mineral intake levels to health outcomes. For prevention of cardiovascular disease, reducing sodium intake and increasing potassium intake are the principal tools. While reducing sodium intake has received greatest public health priority, emerging evidence suggests that increasing potassium intake may be a more important target for cardiovascular prevention. Increased potassium intake reduces blood pressure and mitigates the hypertensive effects of excess sodium intake, and the recent large Phase III SSaSS trial reported that increasing potassium intake (and reducing sodium intake) in populations with low potassium intake and high sodium intake, through salt substitution (25% KCl, 75%NaCl), reduces the risk of stroke in patients at increased cardiovascular risk. As key sources of potassium intake include fruit, vegetables, nuts, and legumes, higher potassium intake may be associated with healthy dietary patterns. The current review makes the case that increasing potassium intake might represent a more advantageous dietary strategy for prevention of cardiovascular disease. Future research should focus on addressing the independent effect of potassium supplementation in populations with low or moderate potassium intake, and determine effective strategies to increase potassium intake from diet.

Measuring Sodium from Discretionary Salt: Comparison of Methods

(1) Background: The best method to assess discretionary salt intake in population surveys has not been established. (2) Methods: This secondary analysis compared three different methods of measuring sodium intake from discretionary salt in a convenience sample of 109 adults in New Zealand. Participants replaced their household salt with lithium-tagged salt provided by researchers over eight days. Baseline 24 h urine was collected, and two further 24 h urine and 24 h dietary recalls were collected between days six and eight. Discretionary salt was estimated from the lithium-tagged salt, focused questions in the 24 h dietary recall, and the 'subtraction method' (a combination of 24 h urine and 24 h dietary recall measures). (3) Results: Around one-third of estimates from the 'subtraction method' were negative and therefore unrealistic. The mean difference between 24 h dietary recall and lithium-tagged salt estimates for sodium from discretionary salt mean were 457 mg sodium/day and 65 mg/day for mean and median, respectively. (4) Conclusions: It is possible to obtain a reasonable estimate of discretionary salt intake from careful questioning regarding salt used in cooking, in recipes, and at the table during a 24 h recall process to inform population salt reduction strategies.

Association of serum potassium level with dietary potassium intake in Chinese older adults: a multicentre, cross-sectional survey

OBJECTIVES

Evidence linking dietary potassium and serum potassium is virtually scarce and inconclusive. The aim of the study was to investigate the association between serum potassium level and potassium intake measured by 24-hour urine. We also explored whether the association differed across health conditions.

DESIGN

A cross-sectional study conducted from September 2017 to March 2018.

SETTING

48 residential elderly care facilities in northern China.

PARTICIPANTS

Participants aged 55 years and older and with both serum potassium and 24-hour urinary potassium measured were classified as having a low (apparently healthy), moderate (with ≥1 health condition but normal renal function) and high (with ≥1 health condition and abnormal renal function) risk of hyperkalaemia.

EXPOSURE

Potassium intake is measured by 24-hour urinary potassium.

OUTCOMES

Serum potassium in association with potassium intake after adjustment for age, sex, region and accounting for the cluster effect.

RESULTS

Of 962 eligible participants (mean age 69.1 years, 86.8% men), 17.3% were at low risk, 48.4% at moderate risk and 34.3% at high risk of hyperkalaemia. Serum potassium was weakly associated with 24-hour urinary potassium among individuals with moderate (adjusted β=0.0040/L; p=0.017) and high (adjusted β=0.0078/L; p=0.003) but not low (adjusted β=0.0018/L; p=0.311) risk of hyperkalaemia.

CONCLUSIONS

A weak association between dietary potassium intake and serum potassium level existed only among individuals with impaired renal function or other health conditions but not among apparently healthy individuals. The results imply that increasing dietary potassium intake may slightly increase the risk of hyperkalaemia but may also decrease the risk of hypokalaemia in unhealthy individuals, both of which have important health concerns.

TRIAL REGISTRATION NUMBER

NCT03290716; Post-results.

National Initiatives on Salt Substitutes: Scoping Review

BACKGROUND

Salt substitutes are edible salts that contain less sodium chloride owing to its partial substitution with other minerals, which serve as an important and effective intervention and public health strategy targeting hypertension and its secondary diseases, despite a small degree of controversy.

OBJECTIVE

This study aimed to identify the current salt substitute initiatives in various nations and intergovernmental organizations (IGOs) worldwide and summarize their types and characteristics.

METHODS

A scoping review was performed based on Arksey and O'Malley's framework and the latest guidance from the Joanna Briggs Institute. Searches were conducted on Google; government websites on food, health, and other related topics; PubMed; Web of Science; and Google Scholar from January 2022 to May 2022. Initiatives related to salt substitutes that were included in the study focused on the involvement of governments or IGOs through the publication of standards, actions, collaborations, funding, and so on. Data were extracted into Microsoft Excel (version 2019; Microsoft Corp) based on predefined items and analyzed using narrative synthesis and frequency count methods.

RESULTS

A total of 35 initiatives from 11 countries (of which 9 are high-income countries) and 3 IGOs were identified. We classified all salt substitute initiatives into 5 types, namely benefit-risk assessments and cautions; plans and actions; regulations and standards; labels; and food reformulation, cooperation with the food industry, and media. More than half (18/35, 51%) of the salt substitute initiatives were launched within the past 5 years. Except for regulations and standards, salt substitute initiatives are, in general, part of the salt reduction framework. No nation or IGO has yet reported on the monitoring and implications of the use of salt substitutes.

CONCLUSIONS

Despite the limited number of salt substitute initiatives worldwide at present, a review on the different types and characteristics of such initiatives could be helpful in providing a reference for policy makers and stakeholders. Given the great potential of salt substitutes in improving hypertension and stroke, we call on more nations to pay attention to these substitutes and propose salt substitute initiatives in line with their national conditions.

Experience with 2 years' intervention to progressively reduce salt supply to kitchens in elderly care facilities-challenges and further research: post hoc analysis of the DECIDE-Salt randomized clinical trial

BACKGROUND

Progressive reduction of sodium intake is an attractive approach for addressing excessive salt intake, but evidence for this strategy in real practice is limited. We aimed to determine the feasibility, effectiveness, and safety of a progressive sodium intake reduction intervention in real-world setting.

METHODS

We randomized 48 residential elderly care facilities in China, with 1612 participants aged 55 years and older, to either progressive reduction (PR, 24 facilities) or no reduction (NR, 24 facilities) of the supply of study salt to the kitchens of these facilities for 2 years. The primary efficacy outcome was systolic blood pressure (SBP) at any scheduled follow-up visit. Secondary efficacy outcomes included diastolic blood pressure (DBP) at any scheduled follow-up visit, and major adverse cardiovascular events (comprising non-fatal stroke, non-fatal myocardial infarction, hospitalized non-fatal heart failure, or vascular death) and total mortality. The perception of food saltiness, the addition of out-of-study salt in meals, and 24-h urinary sodium excretion were used as process indicators.

RESULTS

Pre-specified analysis per randomization found no effect of the intervention on the 2-year overall mean systolic and diastolic blood pressure (SBP, DBP) and any other outcomes. However, post hoc analysis showed that the intervention effect on blood pressure varied over multiple follow-up visits (p for interaction < 0.046) and presented favorable differences at the 24-month visit (SBP =  - 3.0 mmHg, 95%CI =  - 5.6, - 0.5; p = 0.020; DBP =  - 2.0 mmHg, 95%CI - 3.4, - 0.63; p = 0.004). The effect on 24-h sodium was non-significant (- 8.4 mmol, 95%CI =  - 21.8 to 4.9, p = 0.216), though fewer participants with NR than with PR reported food tasting bland (odds ratio 0.46; 95%CI 0.29 to 0.73; p = 0.001). Reporting of bland food taste and other process measures indicated that intervention delivery and adherence were not fully achieved as designed.

CONCLUSIONS

The experience of this real-world study demonstrated that achieving acceptability and sustainability of the progressive sodium intake reduction strategy among older adults was challenging, but it has shown potential for effectiveness in these and potentially other residential settings if the lessons of DECIDE-Salt are applied in further studies.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03290716).

Potassium homeostasis - Physiology and pharmacology in a clinical context

Membrane voltage controls the function of excitable cells and is mainly a consequence of the ratio between the extra- and intracellular potassium concentration. Potassium homeostasis is safeguarded by balancing the extra-/intracellular distribution and systemic elimination of potassium to the dietary potassium intake. These processes adjust the plasma potassium concentration between 3.5 and 4.5 mmol/L. Several genetic and acquired diseases but also pharmacological interventions cause dyskalemias that are associated with increased morbidity and mortality. The thresholds at which serum K+ not only associates but also causes increased mortality are hotly debated. We discuss physiologic, pathophysiologic, and pharmacologic aspects of potassium regulation and provide informative case vignettes. Our aim is to help clinicians, epidemiologists, and pharmacologists to understand the complexity of the potassium homeostasis in health and disease and to initiate appropriate treatment strategies in dyskalemic patients.

Salt Substitutes-An Important Tool to Increase Potassium and Reduce Sodium Intakes?

Potassium is an essential mineral and is the main cation in intracellular fluid [...].

Initiatives to Reduce the Content of Sodium in Food Products and Meals and Improve the Population's Health

Table salt is the main source of sodium (Na) in the human diet. Excessive supply of Na in a diet is strongly linked to many non-communicable human diseases, such as hypertension, obesity and stomach cancer. The World Health Organization recommends that daily intake of salt in adult diets should be kept below 5 g/person/day, which corresponds to 2 g Na/person/day. However, on average, adults consume about 9-10 g/person/day, and children and young people about 7-8 g/person/day. Initiatives to reduce salt intake include modifications of food composition in collaboration with the food industry, education of consumers, salt marking on foodstuff labels and taxation of salt. A need also exists to educate society so that they choose low-sodium products. In view of the food technology and amount of salt intake, the most important and the easiest change to make is to reduce the content of salt in baked goods. This paper analyses the results of surveys regarding strategies to reduce salt content in food products and considers multifaceted initiatives to reduce salt intake as a possible efficient method of improving the population's health status.