Non-inferiority of sodium zirconium cyclosilicate versus potassium-restricted diet in achieving normokalaemia in patients with type 2 diabetes mellitus: protocol for a multicentre, open-label, randomised controlled, two-arm clinical trial (SILVERSTAR study)

BMJ Open. 2025 Mar 3;15(3):e089564. doi: 10.1136/bmjopen-2024-089564.

Abstract

Background: To effectively manage the progression of diabetic kidney disease, it is essential to address the associated hyperkalaemia while concurrently using renin-angiotensin-aldosterone system inhibitors and mineralocorticoid receptor antagonists. In this study, we aim to evaluate the effects of administering sodium zirconium cyclosilicate (SZC) to patients with type 2 diabetes mellitus (T2DM) complicated by hyperkalaemia.

Methods and analysis: A total of 80 patients with type 2 diabetes and hyperkalaemia will be included in the study and randomly stratified into two groups.After consent, both groups will enter an initiation phase, receiving 10 g of SZC, three times per day for 2 days. SZC administration (5 g once daily) will subsequently commence in group A, while dietary therapy will be initiated in group B by implementing a potassium-restricted diet. The primary endpoint of the study is the proportion of normokalaemic (3.5 mEq/L≤serum potassium (sK)<5.0 mEq/L) participants at visit 7. The secondary endpoints are: (a) the proportion of normokalaemic participants (3.5 mEq/L≤sK<5.0 mEq/L) at visit 4 and (b) serum potassium levels at visit 7.

Ethics and dissemination: Written informed consent will be obtained from all participants prior to commencing the study. This study has been approved by the Kyoto Prefectural University of Medicine Clinical Research Review Board. All data obtained from this study will be published in a peer-reviewed journal.

Trial registration number: jRCTs051230067.

Keywords: Chronic renal failure; Diabetes Mellitus, Type 2; Randomised Controlled Trial.

Publication types

  • Clinical Trial Protocol

MeSH terms

  • Adult
  • Aged
  • Diabetes Mellitus, Type 2* / blood
  • Diabetes Mellitus, Type 2* / complications
  • Diabetes Mellitus, Type 2* / diet therapy
  • Diabetic Nephropathies
  • Equivalence Trials as Topic
  • Female
  • Humans
  • Hyperkalemia* / complications
  • Hyperkalemia* / diet therapy
  • Hyperkalemia* / drug therapy
  • Hyperkalemia* / etiology
  • Male
  • Middle Aged
  • Multicenter Studies as Topic
  • Potassium* / blood
  • Potassium, Dietary* / administration & dosage
  • Randomized Controlled Trials as Topic
  • Silicates* / administration & dosage
  • Silicates* / therapeutic use

Substances

  • Silicates
  • sodium zirconium cyclosilicate
  • Potassium
  • Potassium, Dietary