Does dietary potassium lower blood pressure and protect against coronary heart disease and death? Findings from the Scottish Heart Health Study?
We related 24-hour sodium and potassium excretion cross-sectionally to blood pressure and longitudinally to coronary events and deaths during follow-up in a representative sample of the Scottish population. A random sampling of men and women aged 40-59 in 1984 to 1987 produced 11,629 men and women who provided questionnaire results, examination and biochemical findings, and follow-up data, the majority of whom provided a 24-hour urine collection. The main outcome measures were blood pressure, myocardial infarction or coronary deaths during follow-up, and death from all causes. Risks of endpoints were calculated by fifths of the 24-hour sodium and potassium excretion. Blood pressure was very weakly related to sodium excretion and marginally better related to potassium, at least for systolic blood pressure in men, although age, body mass index, alcohol consumption, and pulse rate were better related than either electrolyte. Potassium excretion was very significantly related to risk of death from all causes, having a protective role, whereas its role in coronary events was weaker and that of sodium excretion weak and even paradoxical. These results are unifactorial, without correction other than for age and sex. Our findings need corroboration from elsewhere and more detailed analysis with more events from longer follow-up.
Tunstall-Pedoe
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Cardiovascular Epidemiology Unit, The University of Dundee, Ninewells Hospital and Medical School, Scotland. h.tunstallpedoe@dundee.ac.uk
D000328:Adult; D017677:Age Distribution; D001794:Blood Pressure / Q000187:drug effects; D003327:Coronary Disease / Q000401:mortality* / Q000517:prevention & control*; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000378:metabolism / Q000652:urine*; D017419:Potassium, Dietary / Q000008:administration & dosage* / Q000652:urine; D012044:Regression Analysis; D012307:Risk Factors; D012606:Scotland / Q000453:epidemiology; D017678:Sex Distribution; D012964:Sodium / Q000378:metabolism / Q000652:urine*; D011795:Surveys and Questionnaires; D016019:Survival Analysis
D017419:Potassium, Dietary; D012964:Sodium; D011188:Potassium