Highlights
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High blood pressure (BP) is a leading cause of death, and there is clear evidence that reducing dietary sodium intake and increasing dietary potassium intake can reduce BP. Sodium consumption in China is high 4 and salt substitution is a proven non-pharmaceutical intervention for BP reduction in China. Studies of salt substitutes among older populations, who are at greatest risk and have the most benefit, are few. Additionally, there have been concerns about the risk of hyperkalemia , but safety data is limited. Modeling studies projecting the effects of salt substitution in China have indicated large potential benefits for cardiovascular disease (CVD) and death, but data from large trials were lacking until recently.
Progressive reduction in the use of salt for food preparation and seasoning is a recommended strategy to reduce sodium consumption in the diet. Small, gradual decreases in the sodium content of foods could accumulate into large decreases, even if consumers do not notice them. Furthermore, sustained reduction in salt intake may result in an adaptive change in taste preference for a low-salt diet. Some small, short-term trials have shown that a quarter decrease in the sodium content of bread can go unnoticed with a gradual reduction. However, solid evidence of the effectiveness and feasibility of this strategy from large-scale long-term studies remains lacking.
The Diet, Exercise, and Cardiovascular Health (DECIDE)–Salt Reduction Strategies for Seniors in Residential Facilities (DECIDE-Salt) study aimed to use a factorial design to determine the effectiveness and safety of two sodium reduction intervention strategies. Practical and scalable in parallel, targeting older adults living collectively in residential aged care facilities: (1) replacing regular salt with a salt substitute and (2) making a gradual reduction in the amount of salt/salt substitute salt supplied to facility kitchens.
Summary
There is a paucity of high-quality evidence on the effectiveness and safety of salt reduction strategies, particularly for older people, who benefit the most but are at higher risk of adverse effects. Here, we conducted a clinical trial in which 48 residential elderly care facilities in China (1612 participants, including 1230 men and 382 women, aged 55 years or older) were cluster-randomized using a 2 × 2 factorial design. for the provision of salt substitutes (62.5% NaCl and 25% KCl) versus usual salt and a progressively restricted supply of salt or salt substitute versus usual for 2 years.
Salt substitute compared to regular salt reduced systolic blood pressure (-7.1 mmHg, 95% confidence interval (CI) -10.5 to -3.8), meeting the primary outcome of the trial , while restricted delivery compared to usual delivery of salt or salt substitute had no effect on systolic blood pressure.
The salt substitute also reduced diastolic blood pressure (-1.9 mmHg, 95% CI -3.6 to -0.2) and resulted in fewer cardiovascular events (hazard ratio (HR) 0.60, 95% CI 0.38-0.96), but had no effect on overall mortality (HR 0.84, 95% CI 0.63-1.13).
From a safety point of view , salt substitute increased mean serum potassium and led to more frequent biochemical hyperkalemia, but was not associated with adverse clinical outcomes.
In contrast, salt restriction had no effect on any study outcomes.
The results of this trial indicate that the use of salt substitutes, but not efforts to restrict salt supply, can achieve a reduction in blood pressure and provide health benefits to residents of nursing homes. older in China.
Figure 1 Effect on blood pressure : a, b, the effects of salt substitute versus usual salt (a) and progressively restricted salt or salt substitute versus continuous usual salt (b) on blood pressure are shown. SBP (top) and DBP (bottom). Data show mean and 95% CI values at baseline and at each follow-up visit. Mean differences and 95% CIs in SBP and DBP between comparison groups are based on BP measurements at four follow-up visits and were calculated using a linear mixed model with repeated measurements, taking into account the effects grouping and adjusting the initial values. The P value was two-sided and was not adjusted for multiple comparison. P values < 0.001 are reported as P < 0.001, rather than the actual exact P values.
Figure 2 Effects on CV events : a, b, Effects of salt substitute versus usual salt (a) and progressively restricted salt or salt substitute versus usual continuation (b) on cardiovascular events (top) and total mortality (bottom). HR, 95% CI, and P values were calculated from the Cox frailty model. The P value was two-sided and was not adjusted for multiple comparison.
Final message In conclusion, salt substitute reduced BP and cardiovascular events in an elderly resident population. The frequency of biochemical hyperkalemia increased but without adverse clinical results. The DECIDE trial shows a net benefit from the use of salt substitutes consistent with data from previous salt replacement trials showing a BP-lowering effect in various populations, and results from the recent SSaSS trial showing a BP-lowering effect. of CVD prevention. Studies strongly and consistently support the more widespread use of salt substitutes for CVD prevention. However, efforts to restrict salt supply did not achieve the planned BP reduction goal in our study, requiring further analysis to better understand the feasibility and implementation of this intervention. |
