Conclusion:
Increased potassium intake should be considered as a recommendation for prevention and treatment of hypertension. A low potassium intake may play an important role in the genesis of high blood pressure.

STUDY

1. Meta-analysis selected 33 randomized controlled trials (2000 participants) in which potassium supplementation was the only difference between the intervention and control conditions.

RESULTS

1. K supplementation ranged from 48 mmol to 200 mmol (2 to 7 g) per day— mainly in the form of KCl. The mean increase in K excretion was 2 gm/day (53 mmol) .
2. Potassium supplementation was associated with a significant reduction in mean BP—by 3.1/- 2.0 mm Hg.
3. Effects of treatment appeared to be enhanced in studies in which participants were concurrently exposed to a high intake of sodium.
4. The oral supplements appeared to be well tolerated in all studies.

DISCUSSION

1. The INTERSALT study1 estimated that each mmol (39 mg) increase in K excretion is related to a 0.045/0.029 reduction in BP. Thus, a 53 mmol increase in K excretion, given these coefficients, would be expected to show a 2.4/1.5 lower level of BP.
2. A causal relationship between K supplementation and reduced BP is suggested by the strength of the association, narrow 95% confidence intervals, temporal sequences, dose response, replication of the relationship in varying studies and study designs, and biologic plausibility.
3. The average effect size in reduction of BP was of sufficient magnitude to suggest that K supplementation may have a role in treatment of patients with hypertension.
4. The ratio of sodium/potassium excretion has appeared to be more closely related to changes in BP than either urinary sodium or urinary potassium alone.

CONCLUSION
"Our results support the premise that low potassium intake may play an important role in the genesis of high blood pressure. Increased potassium intake should be considered as a recommendation for prevention and treatment of hypertension, especially in those who are unable to reduce their intake of sodium."
JAMA May 28, 1997; 277: 1624-32 Original investigation from Johns Hopkins Univ. School of Hygiene and Public Health, Baltimore, MD
1. "Intersalt: an International Study of Electrolyte Excretion and Blood Pressure" BMJ 1988; 297: 319-328

Comment:
I recall the serious adverse of some KCl tablets reported a number of years ago. Some enteric-coated tablets dissolved locally in the small intestine, causing strictures.
Reduced dietary Na intake and increased K intake are important life-style measures.
The Joint National Committee VI (November 1997) suggests that high potassium intake may protect against developing hypertension as well as improve BP control in patients with hypertension. It recommends intake be in the form of foods. Caution in individuals susceptible to hyperkalemia— renal insufficiency and and those receiving ACE inhibition. RTJ