Serum potassium and risk of cardiovascular disease - The Framingham Heart Study

Background: Published studies of the association between serum potassium concentration and risk for cardiovascular disease in community-based populations have reported conflicting results. We sought to determine the association between serum potassium concentration and cardiovascular disease risk in the Framingham Heart Study. Methods: A total of 3151 participants (mean age, 43 years; 48% men) in the Framingham Heart Study who were free of cardiovascular disease and not taking medications affecting potassium homeostasis had serum potassium levels measured (1979-1983). Proportional hazards models were used to determine the association of serum potassium concentration at baseline with the incidence of cardiovascular disease at follow-up. Results: During mean follow-up of 16 years, 313 cardiovascular disease events occurred, including 46 cardiovascular disease-related deaths. After adjustment for age, serum potassium level was marginally associated with risk of cardiovascular disease (hazard ratio [HR] per I mg/dL increment, 1.03; 95% confidence interval [CI], 1.00-1.05; P=.02). However, after further adjustment for multiple confounders, serum potassium level was not significantly associated with cardiovascular disease risk (HR, 1.00; 95% Cl, 0.98-1.03). There were no significant associations between serum potassium level and cardiovascular disease-related death in either age- and sex-adjusted models (HR, 1.06; 95% Cl, 0.99-1.12) or multivariable-adjusted models (HR, 1.04; 95% CI, 0.97-1.11). Conclusion. In our community-based sample of individuals free of cardiovascular disease and not taking medications that affect potassium homeostasis, serum potassium level was not associated with risk of cardiovascular disease.