Sodium and potassium intake and risk of cardiovascular events and all-cause mortality: the Rotterdam Study.
BACKGROUND
Dietary electrolytes influence blood pressure, but their effect on clinical outcomes remains to be established. We examined sodium and potassium intake in relation to cardiovascular disease (CVD) and mortality in an unselected older population.


METHODS
A case-cohort analysis was performed in the Rotterdam Study among subjects aged 55 years and over, who were followed for 5 years. Baseline urinary samples were analyzed for sodium and potassium in 795 subjects who died, 206 with an incident myocardial infarction and 181 subjects with an incident stroke, and in 1,448 randomly selected subjects. For potassium, dietary data were additionally obtained by food-frequency questionnaire for 78% of the cohort.


RESULTS
There was no consistent association of urinary sodium, potassium, or sodium/potassium ratio with CVD and all-cause mortality over the range of intakes observed in this population. Dietary potassium estimated by food frequency questionnaire, however, was associated with a lower risk of all-cause mortality in subjects initially free of CVD and hypertension (RR = 0.71 per standard deviation increase; 95% confidence interval: 0.51-1.00). We observed a significant positive association between urinary sodium/potassium ratio and all-cause mortality, but only in overweight subjects who were initially free of CVD and hypertension (RR = 1.19 (1.02-1.39) per unit).


CONCLUSIONS
The effect of sodium and potassium intake on CVD morbidity and mortality in Western societies remains to be established.
Geleijnse
Johanna M
JM
Division of Human Nutrition, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands. marianne.geleijnse@wur.nl
Witteman
Jacqueline C M
JC
Stijnen
Theo
T
Kloos
Margot W
MW
Hofman
Albert
A
Grobbee
Diederick E
DE
D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality / Q000503:physiopathology*; D002423:Cause of Death; D015331:Cohort Studies; D004032:Diet; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology; D009426:Netherlands / Q000453:epidemiology; D017063:Outcome Assessment, Health Care; D011188:Potassium / Q000008:administration & dosage* / Q000494:pharmacology / Q000652:urine; D018570:Risk Assessment; D012964:Sodium / Q000008:administration & dosage* / Q000494:pharmacology / Q000652:urine; D020521:Stroke / Q000453:epidemiology; D011795:Surveys and Questionnaires
D012964:Sodium; D011188:Potassium