Effects of a reduced-sodium added-potassium salt substitute on blood pressure in rural Indian hypertensive patients: a randomized, double-blind, controlled trial
Restriction on salt intake is one of the important approaches included in medical nutrition therapy to reduce hypertension. There is no clear evidence to support whether salt substitutes reduce blood pressure (BP) among Indian hypertensive patients. Jie Yu and colleagues conducted research under the title “Effects of a reduced-sodium added-potassium salt substitute on blood pressure in rural Indian hypertensive patients: a randomized, double-blind, controlled trial” published in the American Society of Nutrition. The summary of the study is given below:
Objective:
To investigate the acceptability, usage, and BP effects in hypertensive patients with reduced sodium and added-potassium salt substitute.
Method:
502 participants with hypertension from 7 villages in rural India were included in the study. They were randomly assigned to include either regular salt which is 100% sodium chloride or the salt substitute which is a combination of 70% sodium chloride/30% potassium chloride blend. They were also advised to replace all home salt use. The main outcome was the change in systolic BP (SBP) from baseline to 3 mo comparing both the groups. Secondary outcomes included the difference in diastolic BP (DBP), 24-h urinary biomarkers, and self-reported use by patients, and self-satisfaction with the studied salt provided.
Findings:
The study reports that a reduced sodium intake by adding a potassium salt substitute to replace regular salt for daily use reduced SBP by 4.6 mmHg and DBP by 1.1 mmHg. This reduction is believed to decrease the overall risk of CVD by ≥10%. Investigators suggest that favorable taste as reported by participants and low-cost can make this substitute an acceptable and effective dietary intervention in hypertensive individuals. This study highlights the safety profile of the salt substitute among hypertensive patients as no adverse events were reported, no serious CKD, and no use of potassium-sparing medications.
Limitations:
This was a short-term study and the effect of a salt substitute might differ with long-duration intervention. Authors acknowledge that the study findings may not be generalizable to other Indian hypertensive populations, such as those living in urban centers with different dietary sources of sodium. The study excluded hypertensive patients with kidney disease, and hence, future studies should be conducted for the same. Although investigators did not find clinical evidence of adverse events including risks associated with hyperkalemia, they acknowledge that undetected hyperkalemia was present and cannot be ruled out. Lastly, investigators did not collect 24-h urine biomarkers at 1 month due to participant burden, and thus they failed to track the trajectory of changes in urinary sodium and potassium over time.
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