Potassium intake, stroke, and cardiovascular disease a meta-analysis of prospective studies.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of prospective observational cohort studies.
PubMed 21371638 · doi:10.1016/j.jacc.2010.09.070
What was done
A systematic review and meta-analysis of prospective adult cohort studies (1966 to December 2009) evaluated the relationship between habitual potassium intake and cardiovascular outcomes over at least 4 years of follow-up. Relative risks (RRs) and 95% confidence intervals were extracted and pooled using random-effects models weighted by inverse variance. The meta-analysis included 11 prospective studies providing 15 cohort samples with 247,510 participants followed for 5 to 19 years, capturing 7,066 strokes, 3,058 coronary heart disease (CHD) events, and 2,497 total cardiovascular disease (CVD) events. Baseline potassium was measured by food frequency questionnaires (n = 6), 24-hour urinary excretion (n = 3), or 24-hour dietary recall (n = 2).
What was found
A 1.64-g (42 mmol) per day higher potassium intake was associated with a 21% lower risk of stroke (RR: 0.79; 95% CI: 0.68 to 0.90; p = 0.0007). In primary analyses, associations with CHD and total CVD showed non-significant trends, but achieved statistical significance after excluding a single cohort in sensitivity analyses (CHD RR: 0.93; 95% CI: 0.87 to 0.99; p = 0.03; total CVD RR: 0.74; 95% CI: 0.60 to 0.91; p = 0.0037).
Why it matters
This study pools large-scale prospective observational data showing a substantial inverse association between dietary potassium and incident stroke. It provides quantitative backing for public health recommendations encouraging consumption of potassium-rich foods.
Limits
The included studies were observational cohorts, leaving potential for residual confounding by overall diet quality or lifestyle factors. Measurement methods for potassium varied across studies and relied largely on self-reported dietary recalls or single baseline assessments. Significant findings for CHD and total CVD were not robust in main pooled models and required post-hoc sensitivity exclusions.
Cited by
- supports Increasing dietary potassium intake has been shown to reduce the risk of stroke.