Partial substitution of dietary salt with potassium-enriched salt may reduce stroke, death: Study

The study, published in the journal Hypertension, found that the incomplete replacement of dietary salt with potassium-enriched substitute led to reduced risk for major cardiovascular (CV) events, stroke, and death in Chinese adults. These are the results from the post hoc analysis of the Salt Substitute and Stroke Study (SSaSS).

The Salt Substitute and Stroke Study (SSaSS) has recently shown the definitive effects of a potassium-enriched salt on death and cardiovascular outcomes.

Interventions that increase dietary potassium reduce dietary sodium, or both have significant potential for cardiovascular protection and lowering blood pressure (BP). An average intake of 4 g/day is indicated by worldwide estimates, which is twice the maximum intake recommended by the World Health Organization, i.e. 2g per day. Also, in many countries, the average daily potassium intake is lower than the recommended level of WHO, which is 3.5 g/day (90 mmol/day).

SSaSS was a cluster-randomized, open-label trial in which 20,995 adults were enrolled. Enrolled adults were aged 60 years and older with high BP living in rural China with a history of stroke (mean age 65 years, 59.3% with uncontrolled high BP; 72.6% with a history of stroke). Participants were randomly assigned to either regular salt or a salt substitute comprising 25% potassium chloride and 70% sodium chloride.

For the study, the researchers collected baseline and annual 24-hour urine samples from a subgroup of SSaSS participants throughout the 5-year follow-up. They calculated the corresponding projected sodium intake differences between groups and compared them with the observed difference. Between the two groups, the mean difference in 24-hour potassium excretion was used for estimating the quantity of potassium-enriched salt consumed in the intervention group.

The study revealed the following findings:

· The potassium-enriched salt group had a mean increase in 24-hour urinary potassium excretion of 0.80 g/d compared to the regular salt group, which equates to the consumption of 8.8 g/d of potassium-enriched salt.

· The projected difference in 24-hour urinary sodium excretion was −0.79 g/d based on 8.8 g/d potassium-enriched salt consumption. This compares to an observed difference of −0.35 g/d and indicates that 72% of baseline regular salt intake was replaced by potassium-enriched salt.

"The smaller than anticipated between-group difference in sodium excretion could be likely due to the joint use of regular salt and potassium-enriched salt in the intervention group," the researchers wrote. "Our findings indicate that even an incomplete replacement of regular salt with potassium-enriched salt can deliver significant health gains."

Reference:

Yin X, Paige E, Tian M, Li Q, Huang L, Yu J, Rodgers A, Elliott P, Wu Y, Neal B. The Proportion of Dietary Salt Replaced With Potassium-Enriched Salt in the SSaSS: Implications for Scale-Up. Hypertension. 2023 Jan 11. doi: 10.1161/HYPERTENSIONAHA.122.20115. Epub ahead of print. PMID: 36628969.