Liberal Fruit and Vegetable Intake in Patients With Advanced Chronic Kidney Disease With or Without Sodium Zirconium Cyclosilicate

Objectives: Higher dietary potassium intake is associated with lower blood pressure, better kidney outcomes and improved survival. However, the risk of hyperkalemia limits implementation of healthy potassium-rich diets in patients with chronic kidney disease (CKD). Novel potassium binders such as sodium zirconium cyclosilicate (SZC) may enable a more liberal intake of potassium-rich diets and thereby enable their cardiorenal benefits. Methods: This randomized, crossover, noninferiority clinical trial included 16 CKD patients receiving renin–angiotensin–aldosterone system (RAAS) inhibitors. Participants followed, in a randomized order, a potassium-rich diet for 6 weeks (adding 40 mmol potassium/day via extra fruits, vegetables, and nuts) or their regular diet. Hyperkalemia (>5.5 mmol/L) was managed with SZC, while continuing the diet. The primary endpoint was serum potassium after 6 weeks, with a noninferiority margin of 0.5 mmol/L. Results: At 6 weeks, there was no significant difference in serum potassium between the control and potassium-enriched diet phases (between-group difference 0.03 mmol/L, 95% confidence interval −0.32 to 0.27; P = .850). In contrast, 24-hour urinary potassium excretion increased significantly during the potassium-enriched diet (between-group difference 24.7 mmol/24h, 95% confidence interval 8.0 to 41.3; P = .005). Two patients developed hyperkalemia (5.9 and 6.1 mmol/L) and were treated with SZC, after which the diet was continued without recurrence. Conclusions: A potassium-rich diet was consistent with noninferior serum potassium levels compared with a regular diet at 6 weeks in patients with advanced CKD receiving RAAS inhibition. Hyperkalemia occurred in a minority of patients, and was effectively managed with SZC, allowing continuation of both the diet and RAAS inhibition. These findings suggest that a potassium-rich diet may be feasible in selected patients with advanced CKD, with careful monitoring and use of SZC when needed.