RESUMO
OBJECTIVE: To investigate the effects of potassium and calcium supplementation in table salt on reduction of arterial blood pressure and sodium metabolism in adolescents with higher blood pressure. METHODS: A single blind placebo-controlled trial was carried out for two years in 220 adolescents with higher blood pressure, aged 18 - 22 years, who were randomly divided into supplementary group (n = 110) and control group (n = 110). Each of the subjects in the supplementary group and their family members was given 10 mmol of potassium and 10 mmol of calcium mixed in their table salt daily for 24 months. RESULTS: Night urinary sodium and potassium excretion increased (urinary Na(+), P < 0.05; urinary K(+), P < 0.01) and blood pressure lowered by 5.3 mm Hg/1.8 mm Hg in average from the baseline in the supplementary group two years after potassium and calcium supplementation, as compared with that in the control group increased by (1.3/1.7) mm Hg. CONCLUSIONS: Adequate supplement of potassium and calcium in daily table salt intake was an effective way to prevent form hypertension and could promote their urinary sodium excretion and reduction of arterial blood pressure in adolescents with higher blood pressure.
