Effects of Short-Term Potassium Chloride Supplementation in Patients with CKD

Abstract

BackgroundObservational studies suggest that adequate dietary potassium intake (90–120 mmol/day) may be renoprotective, but the effects of increasing dietary potassium and the risk of hyperkalemia are unknown.MethodsThis is a prespecified analysis of the run-in phase of a clinical trial in which 191 patients (age 68±11 years, 74% males, 86% European ancestry, eGFR 31±9 ml/min per 1.73 m2, 83% renin-angiotensin system inhibitors, 38% diabetes) were treated with 40 mmol potassium chloride (KCl) per day for 2 weeks.ResultsKCl supplementation significantly increased urinary potassium excretion (72±24 to 107±29 mmol/day), plasma potassium (4.3±0.5 to 4.7±0.6 mmol/L), and plasma aldosterone (281 [198–431] to 351 [241–494] ng/L), but had no significant effect on urinary sodium excretion, plasma renin, BP, eGFR, or albuminuria. Furthermore, KCl supplementation increased plasma chloride (104±3 to 105±4 mmol/L) and reduced plasma bicarbonate (24.5±3.4 to 23.7±3.5 mmol/L) and urine pH (all P<0.001), but did not change urinary ammonium excretion. In total, 21 participants (11%) developed hyperkalemia (plasma potassium 5.9±0.4 mmol/L). They were older and had higher baseline plasma potassium.ConclusionsIn patients with CKD stage G3b–4, increasing dietary potassium intake to recommended levels with potassium chloride supplementation raises plasma potassium by 0.4 mmol/L. This may result in hyperkalemia in older patients or those with higher baseline plasma potassium. Longer-term studies should address whether cardiorenal protection outweighs the risk of hyperkalemia.Clinical trial number:NCT03253172

Kir4.2 mediates proximal potassium effects on glutaminase activity and kidney injury

“…This hypothesis is currently being tested in a clinical trial in which patients with CKD stages 3 and 4 are being supplemented with KCl to determine effects on disease progression. 24 , 25 Future studies should determine what level of K + intake is optimal not only for patients at various stages of CKD but also for the general population to maintain cardiovascular health and preserve kidney function.…”

The Highs and Lows of Potassium Intake in CKD—Does One Size Fit All?

“…The BP-lowering effects of higher potassium intake that underlie stroke protection may also offer kidney protection. Although Gritter et al 6 did not observe effects on BP over 2 weeks in this run-in phase, it will be important to determine if there are longer-term effects throughout the duration of their main trial.…”

“…Recently, Hoorn and colleagues 5 initiated a clinical trial (NCT03253172) to test the hypothesis that potassium supplementation slows rates of CKD progression on the basis of eGFR. In this issue of JASN , Gritter et al 6 report findings from the run-in phase of this clinical trial, “Effects of Short-Term Potassium Chloride Supplementation in Patients with Chronic Kidney Disease.” Specifically, the authors describe effects of treating 191 patients with CKD stage 3b–4 (mean eGFR 31 ml/min per 1.73 m 2 ; 83% used renin-angiotensin inhibitors) with 40 mmol potassium chloride (KCl) daily (roughly equivalent to the potassium in four bananas) for 2 weeks. This dose was chosen to raise potassium intake to “recommended values of 90–120 mmol per day.” 7 The investigators found that KCl supplementation raised plasma potassium, chloride, and aldosterone, along with urine potassium, but did not change urine sodium excretion or office BP.…”

Short-term blood pressure variability and outcomes in non-dialysis chronic kidney disease

“…We may be the first to find a relationship between blood potassium levels and BPV that is not yet supported by the literature. However, studies on the effects of potassium intake levels on BPV as well as the cardiovascular system suggest that a certain level of potassium intake (90–120 mmol/day) may be a protective factor for blood pressure and cardiovascular events in patients with CKD ( 27 ). However, this may also have the risk of hyperkalemia.…”