Long-term potassium intake and associated renal and cardiovascular outcomes in the clinical setting

High potassium intake has been suggested to lower the risk for renal and cardiovascular outcome, but data are conflicting. This may be explained by the use of different methods for potassium intake assessment across studies. Also, most data are limited to the general population. We investigated the optimal potassium intake, as measured with multiple 24-h urine samples, in patients with a clinical indication for 24-h urine collection, for prevention of cardiorenal disease.

We performed a retrospective cohort study in 541 outpatient subjects with an estimated glomerular filtration rate >60 mL/min/1.73 m² who had sampled a 24-h urine collection between 1998 and 1999, and had at least 1 additional collection during a 17-year follow-up. We assessed incidence of renal (i.e. renal replacement therapy, 60% decline in estimated glomerular filtration rate or death) and cardiovascular disease (i.e. cardiovascular event or death).

Average age of subjects was 47 years. Estimated mean potassium intake was 74 mmol/day and remained similar during follow-up. The highest tertile of estimated potassium intake was associated with a significant 76% reduction in renal outcome, and 73% decrease of cerebrovascular events, while no effect for overall cardiovascular outcome was found. A 20-mmol increase in potassium intake during follow-up was associated with a 24% reduction in renal outcome.

Our data demonstrate that high estimated potassium intake is associated with improved renal outcome and less cerebrovascular events in outpatient subjects with preserved kidney function.