Salt substitution: a low-cost strategy for blood pressure control among rural Chinese. A randomized, controlled trial.
OBJECTIVE
Dietary sodium and potassium consumption is associated with blood pressure levels. The objective of this study was to define a practical and low-cost method for the control of blood pressure by modification of these dietary cations in rural Chinese.


METHODS
This study was a double-blind, randomized, controlled trial designed to establish the long-term effects of a reduced-sodium, high-potassium salt substitute (65% sodium chloride, 25% potassium chloride, 10% magnesium sulphate) compared to normal salt (100% sodium chloride) on blood pressure among high-risk individuals. Following a 4-week run-in period on salt substitute, participants were randomly assigned to replace their household salt with either the study salt substitute or normal salt for a 12-month period.


RESULTS
The mean age of the 608 randomized participants was 60 years and 56% of them were female. Sixty-four percent had a history of vascular disease and 61% were taking one or more blood pressure-lowering drugs at entry. Mean baseline blood pressure was 159/93 mmHg (SD 26/14). The mean overall difference in systolic blood pressure between randomized groups was 3.7 mmHg (95% confidence interval 1.6-5.9, P < 0.001). There was strong evidence that the magnitude of this reduction increased over time (P = 0.001) with the maximum net reduction of 5.4 mmHg (2.3-8.5) achieved at 12 months. There were no detectable effects on diastolic blood pressure.


CONCLUSIONS
Salt substitution produced a substantial and sustained systolic blood pressure reduction in this population, and should be actively promoted as a low-cost alternate or adjunct to drug therapy for people consuming significant quantities of salt.
D000368:Aged; D001794:Blood Pressure / Q000187:drug effects; D002681:China; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006973:Hypertension / Q000178:diet therapy* / Q000503:physiopathology / Q000517:prevention & control; D008278:Magnesium Sulfate / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D011189:Potassium Chloride / Q000008:administration & dosage / Q000009:adverse effects; D012307:Risk Factors; D012424:Rural Population; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage* / Q000009:adverse effects
D017673:Sodium Chloride, Dietary; D011189:Potassium Chloride; D008278:Magnesium Sulfate