Effects of salt substitute on home blood pressure differs according to age and degree of blood pressure in hypertensive patients and their families

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.

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).

Sex differences in blood pressure regulation and hypertension: renal, hemodynamic, and hormonal mechanisms

The teleology of sex differences has been argued since at least as early as Aristotle's controversial Generation of Animals more than 300 years BC, which reflects the sex bias of the time to contemporary readers. Although the question "why are the sexes different" remains a topic of debate in the present day in metaphysics, the recent emphasis on sex comparison in research studies has led to the question "how are the sexes different" being addressed in health science through numerous observational studies in both health and disease susceptibility, including blood pressure regulation and hypertension. These efforts have resulted in better understanding of differences in males and females at the molecular level that partially explain their differences in vascular function and renal sodium handling and hence blood pressure and the consequential cardiovascular and kidney disease risks in hypertension. This review focuses on clinical studies comparing differences between men and women in blood pressure over the life span and response to dietary sodium and highlights experimental models investigating sexual dimorphism in the renin-angiotensin-aldosterone, vascular, sympathetic nervous, and immune systems, endothelin, the major renal sodium transporters/exchangers/channels, and the impact of sex hormones on these systems in blood pressure homeostasis. Understanding the mechanisms governing sex differences in blood pressure regulation could guide novel therapeutic approaches in a sex-specific manner to lower cardiovascular risks in hypertension and advance personalized medicine.

[Can salt substitution or reduction replace pharmaceuticals for arterial hypertension?]

Nonpharmacological treatment is still an important supplement to the pharmacological treatment of hypertension. Thereby, either an elevated blood pressure can be lowered further or, alternatively, the use of antihypertensive drugs can be reduced. In the context of nonpharmacological treatment of hypertension, sodium restriction plays an important role. Sodium intake can either be reduced by lowering excessive dietary salt consumption or by the use of table salts with reduced sodium content. Lower dietary sodium consumption lowers blood pressure. This was controversial for a long time; however, now more and more observational and interventional studies have confirmed this fact. Nevertheless, some studies have shown an association of low salt consumption with increased mortality. This observation is explained by the so-called reverse epidemiology. This means that diseases with increased mortality, such as consuming diseases or severe heart diseases are associated with lowered food intake and as a consequence, with lower sodium intake. In addition to sodium restriction, the use of so-called salt substitutes with lower sodium content is also effective in lowering blood pressure. In most of the salt substitutes examined so far sodium chloride is partly replaced by potassium chloride. Numerous investigations show that these salt substitutes lower blood pressure. From a statistical point of view side effects such as hyperkalemia are very rare; however, hyperkalemia is potentially life-threatening. Therefore, the broader use of these salt substitutes is principally helpful but these salts should only be used after medical consultation. Especially renal insufficiency and the use of certain drugs, such as potassium-sparing diuretics and blockers of the renin-angiotensin system increase the risk of hyperkalemia.

Effects of salt substitutes on clinical outcomes: a systematic review and meta-analysis

OBJECTIVES

The Salt Substitute and Stroke Study (SSaSS) recently reported blood pressure-mediated benefits of a potassium-enriched salt substitute on cardiovascular outcomes and death. This study assessed the effects of salt substitutes on a breadth of outcomes to quantify the consistency of the findings and understand the likely generalisability of the SSaSS results.

METHODS

We searched PubMed, Embase and the Cochrane Library up to 31 August 2021. Parallel group, step-wedge or cluster randomised controlled trials reporting the effect of salt substitute on blood pressure or clinical outcomes were included. Meta-analyses and metaregressions were used to define the consistency of findings across trials, geographies and patient groups.

RESULTS

There were 21 trials and 31 949 participants included, with 19 reporting effects on blood pressure and 5 reporting effects on clinical outcomes. Overall reduction of systolic blood pressure (SBP) was -4.61 mm Hg (95% CI -6.07 to -3.14) and of diastolic blood pressure (DBP) was -1.61 mm Hg (95% CI -2.42 to -0.79). Reductions in blood pressure appeared to be consistent across geographical regions and population subgroups defined by age, sex, history of hypertension, body mass index, baseline blood pressure, baseline 24-hour urinary sodium and baseline 24-hour urinary potassium (all p homogeneity >0.05). Metaregression showed that each 10% lower proportion of sodium choloride in the salt substitute was associated with a -1.53 mm Hg (95% CI -3.02 to -0.03, p=0.045) greater reduction in SBP and a -0.95 mm Hg (95% CI -1.78 to -0.12, p=0.025) greater reduction in DBP. There were clear protective effects of salt substitute on total mortality (risk ratio (RR) 0.89, 95% CI 0.85 to 0.94), cardiovascular mortality (RR 0.87, 95% CI 0. 81 to 0.94) and cardiovascular events (RR 0.89, 95% CI 0.85 to 0.94).

CONCLUSIONS

The beneficial effects of salt substitutes on blood pressure across geographies and populations were consistent. Blood pressure-mediated protective effects on clinical outcomes are likely to be generalisable across population subgroups and to countries worldwide.

TRIAL REGISTRATION NUMBER

CRD42020161077.

Replacing salt with low-sodium salt substitutes (LSSS) for cardiovascular health in adults, children and pregnant women

BACKGROUND

Elevated blood pressure, or hypertension, is the leading cause of preventable deaths globally. Diets high in sodium (predominantly sodium chloride) and low in potassium contribute to elevated blood pressure. The WHO recommends decreasing mean population sodium intake through effective and safe strategies to reduce hypertension and its associated disease burden. Incorporating low-sodium salt substitutes (LSSS) into population strategies has increasingly been recognised as a possible sodium reduction strategy, particularly in populations where a substantial proportion of overall sodium intake comes from discretionary salt. The LSSS contain lower concentrations of sodium through its displacement with potassium predominantly, or other minerals. Potassium-containing LSSS can potentially simultaneously decrease sodium intake and increase potassium intake.  Benefits of LSSS include their potential blood pressure-lowering effect and relatively low cost. However, there are concerns about potential adverse effects of LSSS, such as hyperkalaemia, particularly in people at risk, for example, those with chronic kidney disease (CKD) or taking medications that impair potassium excretion.

OBJECTIVES

To assess the effects and safety of replacing salt with LSSS to reduce sodium intake on cardiovascular health in adults, pregnant women and children.

SEARCH METHODS

We searched MEDLINE (PubMed), Embase (Ovid), Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science Core Collection (Clarivate Analytics), Cumulative Index to Nursing and Allied Health Literature (CINAHL, EBSCOhost), ClinicalTrials.gov and WHO International Clinical Trials Registry Platform (ICTRP) up to 18 August 2021, and screened reference lists of included trials and relevant systematic reviews. No language or publication restrictions were applied.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and prospective analytical cohort studies in participants of any age in the general population, from any setting in any country. This included participants with non-communicable diseases and those taking medications that impair potassium excretion. Studies had to compare any type and method of implementation of LSSS with the use of regular salt, or no active intervention, at an individual, household or community level, for any duration.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles, abstracts and full-text articles to determine eligibility; and extracted data, assessed risk of bias (RoB) using the Cochrane RoB tool, and assessed the certainty of the evidence using GRADE. We stratified analyses by adults, children (≤ 18 years) and pregnant women. Primary effectiveness outcomes were change in diastolic and systolic blood pressure (DBP and SBP), hypertension and blood pressure control; cardiovascular events and cardiovascular mortality were additionally assessed as primary effectiveness outcomes in adults. Primary safety outcomes were change in blood potassium, hyperkalaemia and hypokalaemia.

MAIN RESULTS

We included 26 RCTs, 16 randomising individual participants and 10 randomising clusters (families, households or villages). A total of 34,961 adult participants and 92 children were randomised to either LSSS or regular salt, with the smallest trial including 10 and the largest including 20,995 participants. No studies in pregnant women were identified. Studies included only participants with hypertension (11/26), normal blood pressure (1/26), pre-hypertension (1/26), or participants with and without hypertension (11/26). This was unknown in the remaining studies. The largest study included only participants with an elevated risk of stroke at baseline. Seven studies included adult participants possibly at risk of hyperkalaemia. All 26 trials specifically excluded participants in whom an increased potassium intake is known to be potentially harmful. The majority of trials were conducted in rural or suburban settings, with more than half (14/26) conducted in low- and middle-income countries. The proportion of sodium chloride replacement in the LSSS interventions varied from approximately 3% to 77%. The majority of trials (23/26) investigated LSSS where potassium-containing salts were used to substitute sodium. In most trials, LSSS implementation was discretionary (22/26). Trial duration ranged from two months to nearly five years.  We assessed the overall risk of bias as high in six trials and unclear in 12 trials. LSSS compared to regular salt in adults: LSSS compared to regular salt probably reduce DBP on average (mean difference (MD) -2.43 mmHg, 95% confidence interval (CI) -3.50 to -1.36; 20,830 participants, 19 RCTs, moderate-certainty evidence) and SBP (MD -4.76 mmHg, 95% CI -6.01 to -3.50; 21,414 participants, 20 RCTs, moderate-certainty evidence) slightly.  On average, LSSS probably reduce non-fatal stroke (absolute effect (AE) 20 fewer/100,000 person-years, 95% CI -40 to 2; 21,250 participants, 3 RCTs, moderate-certainty evidence), non-fatal acute coronary syndrome (AE 150 fewer/100,000 person-years, 95% CI -250 to -30; 20,995 participants, 1 RCT, moderate-certainty evidence) and cardiovascular mortality (AE 180 fewer/100,000 person-years, 95% CI -310 to 0; 23,200 participants, 3 RCTs, moderate-certainty evidence) slightly, and probably increase blood potassium slightly (MD 0.12 mmol/L, 95% CI 0.07 to 0.18; 784 participants, 6 RCTs, moderate-certainty evidence), compared to regular salt.  LSSS may result in little to no difference, on average, in hypertension (AE 17 fewer/1000, 95% CI -58 to 17; 2566 participants, 1 RCT, low-certainty evidence) and hyperkalaemia (AE 4 more/100,000, 95% CI -47 to 121; 22,849 participants, 5 RCTs, moderate-certainty evidence) compared to regular salt. The evidence is very uncertain about the effects of LSSS on blood pressure control, various cardiovascular events, stroke mortality, hypokalaemia, and other adverse events (very-low certainty evidence). LSSS compared to regular salt in children: The evidence is very uncertain about the effects of LSSS on DBP and SBP in children. We found no evidence about the effects of LSSS on hypertension, blood pressure control, blood potassium, hyperkalaemia and hypokalaemia in children.

AUTHORS' CONCLUSIONS

When compared to regular salt, LSSS probably reduce blood pressure, non-fatal cardiovascular events and cardiovascular mortality slightly in adults. However, LSSS also probably increase blood potassium slightly in adults. These small effects may be important when LSSS interventions are implemented at the population level. Evidence is limited for adults without elevated blood pressure, and there is a lack of evidence in pregnant women and people in whom an increased potassium intake is known to be potentially harmful, limiting conclusions on the safety of LSSS in the general population. We also cannot draw firm conclusions about effects of non-discretionary LSSS implementations. The evidence is very uncertain about the effects of LSSS on blood pressure in children.

Effects of Cuisine-Based Chinese Heart-Healthy Diet in Lowering Blood Pressure Among Adults in China: Multicenter, Single-Blind, Randomized, Parallel Controlled Feeding Trial

BACKGROUND

More than one-fifth of the world's population consumes Chinese cuisines regularly, but no evidence-based healthy diets fitting the Chinese food culture are available for implementation.

METHODS

A multicenter, patient- and outcome assessor-blind, randomized feeding trial was conducted among 265 participants with 130 to 159 mm Hg baseline systolic blood pressure (SBP) for 4 major Chinese cuisines (Shangdong, Huaiyang, Cantonese, Szechuan). After a 7-day run-in period on a control diet matching the usual local diets, participants were randomized to continue with the control diet or the cuisine-based Chinese heart-healthy diet for another 28 days. The primary outcome was SBP, and secondary outcomes included diastolic blood pressure and food preference score. Linear regression models were used to estimate the intervention effects and adjustments for the center. The incremental cost per 1 mm Hg reduction in SBP was also calculated.

RESULTS

A total of 265 participants were randomized (135 on the Chinese heart-healthy diet and 130 on the control diet), with 52% women, mean age of 56.5±9.8 years, and mean SBP and diastolic blood pressure of 139.4±8.3 and 88.1±8.0 mm Hg, respectively, at baseline. The change in SBP and diastolic blood pressure from baseline to the end of the study in the control group was -5.0 (95% CI, -6.5 to -3.5) mm Hg and -2.8 (95% CI, -3.7 to -1.9) mm Hg, respectively. The net difference of change between the 2 groups in SBP and diastolic blood pressure were -10.0 (95% CI, -12.1 to -7.9) mm Hg and -3.8 (95% CI, -5.0 to -2.5) mm Hg, respectively. The effect size did not differ among cuisines (P for interaction=0.173). The mean food preference score was 9.5 (with 10 the best preferred) at baseline, and the net change during intervention was 0.1 (95% CI, -0.1 to 0.2; P=0.558). The incremental cost-effectiveness ratio per 1 mm Hg SBP reduction was CNY 0.4 (USD 0.06) per day. No difference in the number of adverse events was found between the 2 groups (P=0.259), and none of the adverse events was associated with the intervention.

CONCLUSIONS

The Chinese heart-healthy diet is effective, palatable, and cost-effective in reducing blood pressure in Chinese adults with high blood pressure, with a clinically significant effect applicable across major Chinese cuisine cultures.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT03882645.

A randomized, double-blind clinical trial to evaluate the blood pressure lowing effect of low-sodium salt substitution on middle-aged and elderly hypertensive patients with different plasma renin concentrations

This study aimed to evaluate the blood pressure (BP) lowing effect of low‐sodium (LS) salt substitution and how the effect influenced by plasma renin concentration (PRC) on middle‐aged and elderly hypertensive patients. Three hundred fifty‐two hypertensives were randomized at a 1:1 ratio into a LS group and a normal salt (NS) group. We compared intergroup changes observed in office blood pressure measurement (OBPM) and home blood pressure measurement (HBPM). Then, all patients in LS group were divided into tertiles according to baseline PRC, aldosterone concentration, and aldosterone/renin ratio (ARR), and changes in OBPM and HBPM were compared across the three tertile subgroups. Follow‐up surveys were completed by 322 patients. The intergroup net reduction in systolic OBPM, systolic HBPM, and diastolic HBPM was −6.6, −4.6, and −2.3 mmHg, respectively (all P < .05), and −1.8 mmHg in diastolic OBPM (P = .068). There was a more significant reduction in OBPM and HBPM among the low baseline PRC subgroup than among the high PRC subgroup. There were no significant differences in the changes in OBPM and HBPM between the three subgroups when grouped according to baseline aldosterone concentration. The reduction in OBPM and HBPM in the high tertile of ARR was larger than that in the low tertile subgroup. LS salt substitution is effective in reducing systolic OBPM, systolic HBPM, and diastolic HBPM in middle‐aged and elderly hypertensive patients. LS salt substitution may offer a non‐pharmaceutical therapy for hypertensive patients. Baseline PRC may be a marker to predict BP response after salt restriction.

Preliminary Experiment on the Effect of 18% Substitute Salt on Home Blood Pressure Variability in Hypertensives

At present, the effect of substitute salt in reducing sodium intake and blood pressure is relatively clear. The present study is a phase I clinical trial involving 43 hypertensives in which the effect of 18% sodium substitute salt on the home blood pressure variability (BPV) was observed for 8 weeks with weekly follow-up. Finally, 4 patients were lost, and 39 patients completed the intervention and were included in the analysis. Daily home blood pressure and weekly adverse events were collected. The systolic blood pressure (SBP) in the morning (-10.0 mmHg, 95% CI: -16.5 to -3.5, P = 0.003), SBP at night (-10.2 mmHg, 95% CI: -16.1 to -4.3, P = 0.001), and diastolic blood pressure (DBP) at night (-4.0 mmHg, 95% CI: -7.1 to -0.8, P = 0.014) decreased significantly. Also, there was no statistically significant change in morning (F = 1.137, P = 0.352) and night diastolic (F = 0.344, P = 0.481) BPV and morning systolic BPV (F = 0.663, P = 0.930) over time during the intervention period, except for that night systolic BPV had a downward trend (F = 2.778, P = 0.016) and had decreased 2.04 mmHg (95% CI: 0.84 to 3.23, P = 0.001) after intervention. The use of 18% of the substitute salt did not increase BPV during the intervention and even may decrease it, which indicates its control effects on blood pressure. This study is the first one to observe the effect of 18% sodium substitute salt on the home blood pressure variability, providing a basis for further experiments.

Comparative analysis of visit and home blood pressure in a pilot trial on the effect of 18% sodium substitute salt on blood pressure

Aim to compare the home blood pressure monitoring (HBPM) and visit blood pressure monitoring in a clinical phase I single-arm pilot trial. The 18% sodium substitute salt was used in 43 hypertensives for 8 weeks, and visited once a week, while weekly visit blood (VBP) pressure, daily home blood pressure (HBP) and urine test results before and after intervention were collected. 43 hypertensive patients were recruited, 4 were lost. And enrolled 39 patients for analysis. The VBP were lower than morning HBP and night HBP (P < 0.05). And VBP was good correlated with morning BP (SBP: r = 0.692, P < 0.001, DBP: r = 0.789, P < 0.001) and night BP (SBP: r = 0.571, P < 0.001, DBP: r = 0.738, P < 0.001). The results of mixed linear model analysis showed that patients' visit SBP (- 11.4 mmHg, 95% CI: - 17.0 to - 5.7, P < 0.001), morning home SBP (- 10.0 mmHg, 95% CI: - 16.4 to - 3.6, P = 0.003) and night home SBP (- 10.2 mmHg, 95% CI: - 15.8 to - 4.6, P = 0.001) decreased significantly, after intervention. Both HBP and VBP showed that 18% substitute salt intervention could decrease the blood pressure of hypertensives. Medication led to VBP lower than HBP, but the two still had a good correlation.Trial registration: NCT03226327. Registered 21 July 2017-Retrospectively registered, http://www.clinicaltrials.gov .

The association between dietary sodium intake, adiposity and sugar-sweetened beverages in children and adults: a systematic review and meta-analysis

Higher intakes of Na may contribute to weight gain. The primary aim of this systematic review and meta-analysis was to examine the relationship between dietary Na intake and measures of adiposity in children and adults. Given the previous link between Na intake and the consumption of sugar-sweetened beverages (SSB), which are a known risk factor for obesity, a secondary aim examining the relationship between Na intake and SSB consumption was assessed. A systematic literature search identified cross-sectional and longitudinal studies and randomised controlled trials (RCT) which reduced dietary Na (≥3 months). Meta-analysis was performed for outcomes with ≥3 studies. Cross-sectionally higher Na intakes were associated with overweight/obesity in adults (five studies; n 11 067; OR 1·74; 95 % CI 1·43, 2·13) and in children (three studies; n 3625, OR 3·29; 95 % CI 2·25, 4·80), and abdominal obesity (five studies; n 19 744; OR 2·04; 95 % CI 1·72, 2·42) in adults. Overall, associations remained in sensitivity analyses which adjusted for energy. Findings from longitudinal studies were inconsistent. RCT in adults indicated a trend for lower body weight on reduced-Na compared with control diets (fifteen studies; n 5274; -0·29 kg; 95 % CI -0·59, 0·01; P = 0·06); however, it is unclear if energy intakes were also altered on reduced-Na diets. Among children higher Na intakes were associated with higher intake of SSB (four studies, n 10 329, b = 22, 16 and 26 g/d); no studies were retrieved for adults. Overall, there was a lack of high-quality studies retrieved. While cross-sectional evidence indicates Na intake was positively associated with adiposity, these findings have not been clearly confirmed by longitudinal studies or RCT.

The hypotensive effect of salt substitutes in stage 2 hypertension: a systematic review and meta-analysis

Background

Hypertension (HTN) is a ubiquitous risk factor for numerous non-communicable diseases, including cardiovascular disease and stroke. There are currently no wholly effective pharmacological therapies for subjects with HTN. However, salt substitutes have emerged as a potential therapy for the treatment of HTN. The aim of the present study was to assess the effect of salt substitutes on reducing systolic blood pressure (SBP) and diastolic BP (DBP), following a meta-analysis of randomized controlled trials.

Methods

Studies were found via systematic searches of the Pubmed/Medline, Scopus, Ovid, Google Scholar and Cochrane library. Ten studies, comprised of 11 trials and 1119 participants, were included in the meta-analysis.

Results

Pooled weighted mean differences showed significant reductions of SBP (WMD − 8.87 mmHg; 95% CI − 11.19, − 6.55, p < 0.001) and DBP (WMD − 4.04 mmHg; 95% CI − 5.70, − 2.39) with no statistically significant heterogeneity between the 11 included comparisons of SBPs and DBPs. The stratified analysis of trials based on the mean age of participants showed a significant reduction in the mean difference of SBP in both adults (< 65 years old) and elderly (≥65 years old). However, the DBP-lowering effect of salt substitutes was only observed in adult patients (WMD − 4.22 mmHg; 95% CI − 7.85, − 0.58), but not in the elderly subjects.

Conclusions

These findings suggest that salt-substitution strategies could be used for lowering SBP and DBP in patients with stage 2 HTN; providing a nutritional platform for the treatment, amelioration, and prevention of HTN.