RAASi Therapy Attenuates the Association between 24-h Urinary Potassium Excretion and Dietary Potassium Intake in CKD Patients

Nutrients. 2023 May 24;15(11):2454. doi: 10.3390/nu15112454.

Abstract

The aim of this study was to evaluate urinary potassium (K) excretion as a reliable marker of dietary K intake, in a cohort of CKD patients with or without Renin-Angiotensin-Aldosterone System (RAAS) inhibitor therapy. One hundred and thirty-eight consecutive out-patients (51 f and 87 m) aged 60 ± 13 years and affected by CKD stage 3-4, who were metabolically and nutritionally stable, entered the study between November 2021 and October 2022. No difference was observed between patients with (n = 85) or without (n = 53) RAAS inhibitor therapy, regarding dietary intakes, blood biochemistry, and 24-h urine excretion parameters. Considering all patients, urinary K showed a weak relationship with eGFR (r = 0.243, p < 0.01), and with dietary K intake (r = 0.184, p < 0.05). Serum K was not associated with dietary K intake, but an inverse relationship was observed with eGFR (r = -0.269, p < 0.01). When patients were examined depending on whether they were receiving RAAS inhibitor therapy, the weak inverse relationship between serum K and eGFR was maintained in both groups. Conversely, urinary K excretion remained positively associated with dietary K intake only in the no RAAS inhibitor group. In conclusion, 24-h urine K excretion may be used as a surrogate of K intake, but RAAS inhibitor therapy reduces the association between 24-h urine K excretion and dietary K intake in CKD patients.

Keywords: CKD; RAAS inhibitors; diet; potassium; urine potassium.

MeSH terms

  • Aldosterone
  • Angiotensin-Converting Enzyme Inhibitors / pharmacology
  • Angiotensin-Converting Enzyme Inhibitors / therapeutic use
  • Antihypertensive Agents / pharmacology
  • Humans
  • Potassium*
  • Potassium, Dietary / pharmacology
  • Renal Insufficiency, Chronic*
  • Renin-Angiotensin System

Substances

  • Potassium
  • Potassium, Dietary
  • Angiotensin-Converting Enzyme Inhibitors
  • Aldosterone
  • Antihypertensive Agents

Grants and funding

This research received no external funding.