Potassium Dysregulation in Patients with CKD - Time to Focus on Low Potassium Intake and Hypokalemia

Sep 30, 2026

Potassium dysregulation in chronic kidney disease (CKD) has traditionally centered on hyperkalemia, but accumulating evidence shows hypokalemia occurs at least as often and is linked to higher all-cause and cardiovascular mortality, faster renal disease progression, and earlier need for kidney replacement therapy. A focused review summarizes low potassium intake and hypokalemia across epidemiologic cohorts, meta-analyses, and CKD/ESKD studies, describing U-shaped risk patterns and emphasizing potential clinical misdirection in dietary potassium restriction guidance. The article discusses implications for optimizing serum potassium targets to preserve beneficial RAASi and MRA therapies.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages8

Reading Time20 min

AccessFree to download

Potassium Dysregulation in CKD

Potassium Intake

Relationship between Serum Potassium and Outcomes

Serum Potassium and Cardiovascular Events

Potassium Dysregulation in Patients with CKD Time to Focus on Low Potassium Intake and Hypokalemia Christopher Wilcox , 1 Anand Vaidya ,2 and Bertram Pitt 3 Hyperkalemia has long been the focus of potassium (K 1) dysregulation in patients with CKD. However, although the risks of hyperkalemia are well known and clearly important, there is growing evidence that hypokalemia occurs at least as frequently in those with CKD and is associated with an increase in all-cause or cardiovascular mortality as well as a faster progression of renal disease and earlier requirement for KRT. This is a brief review of low K 1 intake and hypokalemia inpatients with CKD. Kidney360 6: 1810–1817, 2025. doi: [https://doi.org/10.34067/KID.0000000903](https://doi.org/10.34067/KID.0000000903) Potassium Intake The Prospective Urban Rural Epidemiological study of 101,945 participants reported a steep increase in death or cardiovascular (CV) events at a potassium (K 1) intake below 2.12 g/d.1 A meta-analysis of 31,873 participants reported a U-shaped relationship between the risk of developing diabetes mellitus and K 1 intake, but the increase at low K 1 intake exceeded that at high K 1 intake.2 A meta-analysis of K 1 intake in CKD reported that the average K 1 intake was low and that a high K 1 intake protected against CKD progression or death in early-stage CKD. Remarkably, four studies in CKD reported no increase in serum potassium concentration (Sk) with increased dietary K 1 intake.3 Thus, the adverse effects of a low K 1 intake in early CKD can usually be addressed with an increase in dietary K 1 without inducing hyperkalemia. Indeed, low dietary K 1 intake is not usually the cause of hypokalemia unless it complicates general protein calorie malnutrition.4,5 Relationship between Sk and Outcomes The Chinese Multi-Provincial Cohort Study of 5220 elderly participants found a U-shaped relationship between total mortality and Sk ,3.5 or .5.0 mmol/L6 which was conﬁrmed for hypertensive patients from Denmark7 and elderly patients from Taiwan, where risk was increased signiﬁcantly only for a low Sk ,3.5–3.8 mmol/L.8 A meta-analysis of 31 cohort studies of 227,645 patients with cardiovascular disease (CVD) found a U-shaped relationship between mortality and Sk with an ideal Sk for the lowest risk of 4.2 mmol/L.9 Thus, both hypokalemia and hyperkalemia convey an increased risk of death or CV events in the general population. Among 1714 elderly patients with CKD 4–5, 15% had an Sk ,4.0 mmol/L but only 7% had an Sk .5.5 mmol/L. The ideal Sk was 4.9 mmol/L.10 Likewise, among 1117 incident patients with ESKD, 10% had an Sk ,4.0 mmol/L but only 8% had an Sk .6.0 mmol/L. Mortality was increased signiﬁcant only for hypokalemia with an ideal Sk of 5.0 mmol/L.11 Hypokalemia was more frequent than hyperkalemia among 678 patients with CKD and/or ESKD who developed cardiac arrhythmias.12 Hypokalemia carried a 31% increase in all-cause mortality over 4 years inpatients with CKD and congestive heart failure (HF) .13 The FIDELITY trials of ﬁnerenone in 13,022 patients with CKD and type 2 diabetes mellitus reported a greater incidence for hypokalemia (13.4 for Sk ,3.5 mmol/L) than for hyperkalemia (10% for Sk .5.5 mmol/L) with a signiﬁcant 16% increase in CV events and arrhythmias at Sk ,4.0 mmol/L compared with 4.0–4.5 mmol/L. The authors concluded that hypokalemia in CKD and type 2 diabetes mellitus was remarkably frequent and that the risk of adverse CV events increases at Sk ,4.0 mmol/L.14 Thus, the advice given frequently to patients with CKD to restrict K 1 intake and thereby to select a diet low in fruit, vegetables, grains, legumes, and nuts which can prevent CVD may be misplaced.15 Indeed, most patients with CKD should beneﬁt from an increase in K 1 intake that is associated with other beneﬁts such as a reduction in kidney stone disease16 and osteoporosis.17 1Division of Nephrology and Hypertension, Georgetown University, Washington, DC 2Divisi

FAQs

Why has CKD potassium dysregulation traditionally focused on hyperkalemia, and what does the review argue instead?

The review notes that hyperkalemia risks are well known and have been the main focus. It argues that evidence increasingly shows hypokalemia is at least as frequent in CKD and is associated with worse mortality and faster renal decline.

How does potassium intake relate to serum potassium changes and hypokalemia risk in early CKD?

The review reports that adverse effects of low potassium intake in early CKD can often be addressed by increasing dietary potassium without inducing hyperkalemia, and low intake is typically not the cause of hypokalemia unless it complicates protein-calorie malnutrition.

What is the relationship between serum potassium levels and outcomes described in the review?

Cohort data and meta-analyses cited in the review describe U-shaped associations between serum potassium and mortality, with both low and high levels increasing risk. It highlights that risk for mortality is increased particularly at lower serum potassium ranges in CKD populations.

What clinical implication does the review propose regarding potassium restriction and therapies in CKD?

Because lowering dietary potassium may lead clinicians to reduce exposure to mineralocorticoid receptor antagonists and RAAS inhibitors—therapies that can be beneficial—the review suggests tolerating somewhat higher serum potassium may be better when it allows continuation of these treatments, though this has not yet been investigated.

Sep 30, 2026

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