1. Home>
2. Specialties>
3. General Medicine>
4. Summary and Comment

Serum and Dietary Potassium and Risk for Stroke

Among people who didn't use diuretics, a low dietary intake of potassium was associated with significantly increased stroke risk.

In several observational studies, low serum or low dietary potassium was associated with increased mortality from stroke. In this report from the prospective U.S. Cardiovascular Health Study, researchers examined associations between potassium and overall incidence of stroke among 5600 people (age, 65 or older) without histories of stroke. After baseline evaluations that included measurement of serum potassium levels and dietary assessments, subjects were followed for up to 8 years.

During follow-up, 473 strokes occurred. A baseline serum potassium level of 4.0 mEq/L or lower was associated with significantly increased risk for stroke among diuretic users (relative risk, 2.5 compared with higher serum levels), but not among diuretic nonusers. For dietary potassium, the results were somewhat different: A low dietary intake of potassium was associated with significantly increased risk for stroke among diuretic nonusers (RR, 1.76 for lowest vs. highest quintile of intake), but not among diuretic users. These analyses were adjusted for age, blood pressure, and other variables.

Comment: Potassium might influence stroke risk through several mechanisms that involve vascular biology, according to an editorialist. Dietary potassium seems to be the most important marker among nonusers of diuretics. In contrast, serum potassium appears to be more important among diuretic users; perhaps modest variations in dietary potassium are rendered inconsequential by diuretic use. In any case, these results are provocative, but we still need evidence that increased dietary potassium (or other maneuvers that raise serum potassium levels) reduces stroke risk.

— Allan S. Brett, MD

Published in Journal Watch General Medicine September 3, 2002

Citation(s):

Green DM et al. Serum potassium level and dietary potassium intake as risk factors for stroke. Neurology 2002 Aug 13; 59:314-20.

• Original article (Subscription may be required)
• Medline abstract (Free)

Levine SR and Coull BM. Potassium depletion as a risk factor for stroke: Will a banana a day keep your stroke away? Neurology 2002 Aug 13; 59:302-3.

• Original article (Subscription may be required)
• Medline abstract (Free)