Dietary Potassium Intake and Blood Pressure in CKD

In the general population, increased dietary intake of potassium is associated with lower blood pressure. There are few data available on the effect of increased dietary potassium on blood pressure among patients with chronic kidney disease (CKD).

Sharon Turban, MD, and colleagues, conducted a randomized feeding trial with a 2-period crossover design to compare the effects of diets containing 100 mmol potassium per day and diets containing 40 mmol potassium per day in adults with stage 3 CKD and treated or untreated systolic blood pressure 120 to 159 mm Hg and diastolic blood pressure <100 mm Hg. Results of the trial were reported online in Nutrients [].

The primary outcome of interest was 24-hour ambulatory systolic blood pressure.

There was no significant effect with the higher versus the lower potassium diet on 24-hour systolic blood pressure ­(–2.12 mm Hg; P=.16) or on 24-hour diastolic blood pressure (–0.70 mm Hg; P=.44). Corresponding differences in clinic blood pressure were –4.21 mm Hg (P=.054) and –0.08 mm Hg (P=.94), respectively.

Among patients on the higher potassium diet, mean serum potassium increased by 0.21 mmol/L (P=.003) compared with the lower potassium diet. Two participants had confirmed hyperkalemia, defined as serum potassium ≥5.5 mmol/L.

In conclusion, the authors said, “A higher dietary intake of potassium did not lower 24-hour systolic blood pressure, while clinic systolic blood pressure reduction was of borderline statistical significance. Additional trials are warranted to understand the health effects of increased potassium intake in individuals with CKD.”