Late-Breaking Science: Which sodium-reduction strategy has an effect on BP?
29 Aug 2021
Late-Breaking Science presented at ESC Congress
A Late-Breaking Science presentation today from Professor Yangfeng Wu (Peking University, Beijing, China) looks at the results of the real-world DECIDE-Salt trial, which compared the efficacy and safety of different dietary-sodium reduction strategies over 2 years.
Individuals aged ≥55 years living in residential care facilities in urban communities and rural villages in China were cluster randomised (1:1:1:1) using a factorial design to 1) use of usual salt vs. salt substitute and 2) progressive restriction of dietary salt/substitute supply to facility kitchens vs. usual supply. The primary outcome was systolic blood pressure (BP), with secondary outcomes including diastolic BP and major cardiovascular (CV) events.
The study included 1,612 individuals from 48 residential care facilities whose mean baseline BP was 138.6/81.4 mmHg.
The use of salt substitute led to reductions in mean systolic BP (−7.14 mmHg; 95% confidence interval [CI] −10.49 to −3.79; p<0.0001) and mean diastolic BP (−1.91 mmHg; 95% CI −3.58 to −0.24; p=0.0251) compared with usual salt. Notably, there was also a 40% reduction in the risk of major CV events (hazard ratio [HR] 0.60; 95% CI 0.38 to 0.96; p=0.0318).
Salt substitute was associated with an increase in mean serum potassium and in the incidence of biochemical hyperkalaemia compared with usual salt (relative risk [RR] 2.67; 95% CI 1.18 to 6.05; p=0.0189), with no deaths attributed to hyperkalaemia. The risk of hypokalaemia was lower with salt substitute compared with usual salt (RR 0.23; 95% CI 0.06 to 0.89; p=0.0334). There was no difference between salt substitute and usual salt in the risk of all-cause death (HR 0.84; 95% CI 0.63 to 1.13; p=0.2451).
When progressive restriction of salt/substitute supply was compared with usual supply, no differences were observed for any of the outcomes. Mean 24-hour urinary sodium excretion in participants with progressive restriction of salt/substitute supply was not significantly reduced (−5.7 mmol; 95% CI -24.7 to 13.3; p=0.5551) compared with usual supply.
The results suggest that salt substitutes can reduce BP and CV risk and that biochemical hyperkalaemia does not pose a clinical risk. The DECIDE-Salt efforts to restrict supply of salt/salt substitute to facility kitchens did not meaningfully reduce sodium intake, and hence had no impact on BP or CV events.
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See also the Hot Line, Salt Substitute and Stroke Study: