Potassium supplementation reduces clinic and ambulatory blood pressure in elderly hypertensive patients.
OBJECTIVE
To determine the effects of potassium chloride 60 mmol/day supplementation on clinic and 24-h ambulatory blood pressure values in elderly untreated hypertensive patients.


METHODS
A double-blind randomized placebo-controlled crossover study lasting 8 weeks, following a 4-week run-in period.


METHODS
Outpatient clinic in a district general hospital.


METHODS
Eighteen untreated elderly hypertensive patients (mean age 75 years, range 66-79) with a systolic blood pressure of > or = 160 mmHg and/or a diastolic blood pressure of > or = 95 mmHg were recruited from the clinics of local general practitioners and from the current hospital outpatient department. Patients had not received any antihypertensive medication for at least 4 weeks before entry into the study.


METHODS
Before entry into the study, the daily dietary electrolyte intake of each individual was established and this was maintained during the run-in and intervention periods. Following a 4-week run-in period patients received potassium supplements or matching placebo, each for 4 weeks.


METHODS
The within-patient changes in clinic and 24-h ambulatory blood pressures at the end of each intervention period.


RESULTS
After 4 weeks potassium supplementation compared with placebo there was a significant fall in supine clinic blood pressure, standing and 24-h ambulatory systolic blood pressure. There was no significant change in clinic standing diastolic blood pressure, 24-h ambulatory diastolic blood pressure or pulse rate. Plasma renin activity increased and body weight fell after potassium supplementation. Twenty-four-hour urinary potassium rose significantly, whereas urinary sodium excretion was unchanged.


CONCLUSIONS
A 60-mmol daily supplement of potassium chloride reduces clinic and 24-h ambulatory blood pressure in elderly hypertensive patients.
Fotherby
M D
MD
University Department of Medicine for the Elderly, Leicester General Hospital, UK.
Potter
J F
JF
D000368:Aged; D001794:Blood Pressure / Q000187:drug effects*; D001795:Blood Pressure Determination / Q000379:methods; D015924:Blood Pressure Monitors; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy*; D008297:Male; D011188:Potassium / Q000494:pharmacology / Q000627:therapeutic use*
D011188:Potassium