Randomized Trial on the Effects of Dietary Potassium on Blood Pressure and Serum Potassium Levels in Adults with Chronic Kidney Disease

• Main Authors: Sharon Turban, Stephen P. Juraschek, Edgar R. Miller, Cheryl A. M. Anderson, Karen White, Jeanne Charleston, Lawrence J. Appel
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Nutrients
• Subjects: potassium; blood pressure; hypertension; chronic kidney disease; hyperkalemia
• Online Access: https://www.mdpi.com/2072-6643/13/8/2678

In the general population, an increased potassium (K) intake lowers blood pressure (BP). The effects of K have not been well-studied in individuals with chronic kidney disease (CKD). This randomized feeding trial with a 2-period crossover design compared the effects of diets containing 100 and 40 mmol K/day on BP in 29 adults with stage 3 CKD and treated or untreated systolic BP (SBP) 120–159 mmHg and diastolic BP (DBP) <100 mmHg. The primary outcome was 24 h ambulatory systolic BP. The higher-versus lower-K diet had no significant effect on 24 h SBP (−2.12 mm Hg; <i>p</i> = 0.16) and DBP (−0.70 mm Hg; <i>p</i> = 0.44). Corresponding differences in clinic BP were −4.21 mm Hg for SBP (<i>p</i> = 0.054) and −0.08 mm Hg for DBP (<i>p</i> = 0.94). On the higher-K diet, mean serum K increased by 0.21 mmol/L (<i>p</i> = 0.003) compared to the lower-K diet; two participants had confirmed hyperkalemia (serum K ≥ 5.5 mmol/L). In conclusion, a higher dietary intake of K did not lower 24 h SBP, while clinic SBP reduction was of borderline statistical significance. Additional trials are warranted to understand the health effects of increased K intake in individuals with CKD.