Serum potassium is not associated with blood pressure tracking in the Framingham Heart Study

Background: Abnormal potassium homeostasis accompanies many secondary forms of hypertension as well as uncommon inherited, monogenic forms of hypertension. We hypothesized that serum potassium may be associated with longitudinal tracking of blood pressure (BP) and development of hypertension. Methods: A total of 2358 participants (1292 women, 1066 men) in the Framingham Heart Study who were free of hypertension, were not taking drugs affecting potassium homeostasis, and had serum potassium measured in 1979 to 1983 were followed for longitudinal tracking of BP and development of hypertension at examination 4 years later. Progression of BP stage was defined as an increment of one or more BP category, as defined by the sixth report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-VI), between baseline and follow-up examinations. Results: At baseline, there were no differences in systolic or diastolic BP across serum potassium quartiles. Over 4 years of follow up, 37% (457 women, 412 men) of subjects progressed by one or more JNC-VI BP category. In a logistic regression model adjusting for multiple confounders, serum potassium quartile was not associated with risk of BP progression. During follow-up, 14% (162 women, 175 men) of subjects progressed to hypertension. After adjustment for multiple confounders, there was no significant association between serum potassium quartile and risk for progression to hypertension. Conclusions: In our community-based study sample, serum potassium was not associated with current BP, longitudinal BP tracking, or progression to hypertension.