Potassium-rich and sodium-poor salt reduces blood pressure in hospitalized patients.

To investigate whether a K-rich/Na-poor salt is able to reduce blood pressure, 10 mildly hypertensive inpatients (six males) aged 28-53 years, with supine diastolic blood pressure (DBP) greater than 95 mmHg after 5 days of hospitalization, on a standard diet containing about 20 mmol Na plus 4 g common salt (CS) were randomly given, in double-blind conditions, 2 g twice daily of either CS (five patients) or K-rich/Na-poor salt (five patients) to add to food for a further 8 days. Mean blood pressure was significantly (P less than 0.01) reduced to a similar extent in both groups in the first 4 days, and declined significantly (P less than 0.01) only in the K/Na group in the following 8 days, reaching values significantly (P less than 0.01) lower than those of the CS group. The heart rate did not change significantly while body weight decreased to a similar extent in both groups. Urinary sodium excretion was similarly and significantly (P less than 0.01) reduced in both groups in the first 4 days (CS 100.8 +/- 7.9 and K/Na 100.2 +/- 11.0 mmol/24 h, and remained unchanged in the CS group (109.9 +/- 4.3 mmol/24 h) but declined significantly (P less than 0.05) by about 50% in the K/Na group (62.9 +/- 3.6 mmol/24 h) in the following 8 days. Plasma renin activity (PRA) and plasma noradrenaline did not differ significantly between the two groups, nor among the days of treatment, but the mean blood pressure response to mental stress was reduced significantly (P less than 0.4) in the Na/K group compared with the CS group.(ABSTRACT TRUNCATED AT 250 WORDS)