Acute Effects of SGLT2 Inhibitor on Kidney Allograft Oxygen Tension

Background:

Kidney transplantation is the best treatment of end-stage renal disease (ESRD), although median allograft survival is only 15 years. In non-transplant diabetic and non-diabetic patient's sodium-glucose co-transporter type 2 inhibitors (SGLT2i) protect kidney function, possibly by reducing the proximal tubule transport workload with subsequent improvement of renal oxygenation and relieve hypoxia.

Hypothesis:

SGLT2i in kidney transplant recipients (KTR) will improve kidney allograft cortex oxygenation.

Research Objective:

We aim to test the acute effect of SGLT2i on kidney allograft oxygen tension.

Design:

A randomized, double-blind, placebo-controlled, crossover intervention study. Designed according to the CONSORT statement

Methods:

A single dose of oral SGLT2i (50 mg Jardiance) and placebo in random order, separated by at least 2 week washout period, the experiment will be repeated with the opposite treatment.

Kidney cortex oxygenation and blood flow in different compartments of the kidney allograft will be estimated by blood-oxygen-dependent level magnetic resonance imaging (BOLD-MRI). Patients will be evaluated by routine clinical examination and routine biochemical measures for transplant patients.

Primary endpoint:

• Kidney allograft cortical and medullary oxygen tension, estimated by BOLD-MRI based renal T2* relaxation rate.

Secondary endpoint:

• Renal cortical and medullary perfusion ml/100 g/min
• Renal artery blood flow ml/min
• Blood glucose mmol/L
• Systolic blood pressure (SysBP) and diastolic blood pressure (DiaBP) mmHg
• Heart rate (HR), beats min-1

Study population:

8 Non-diabetic kidney transplant recipients > 6 months post-transplant and stable eGFR >20 ml/min will be recruited from Odense University Hospital (OUH) kidney transplant outpatient clinic.

Inclusion criteria

• Male or female patients, age ≥ 18 years.
• Non-diabetic kidney transplant recipients
• > 6 months post-transplant
• Stable eGFR> 20 ml/min (defined as eGFR 20 ml/min ± 5 ml/min variation in the last 3 months)
• Immunosuppressive: Tacrolimus (Adport) and Mycophenolatmofetil (Myfenax/Cellcept/Mycophenolatmofetil)
• Capable of lying in a MR-scanner
• Capable of providing a signed informed consent and comply with study requirements.

• Negativ pregnancy test

Exclusion criteria

• Diabetic kidney disease type 1 or 2 (World Health Organization (WHO) criteria)

• Hemoglobin A1c ≥ 48 mmol/mol
• Fasting venous plasma glucose ≥ 7,0 mmol/l or
• 2-hours venous plasma glucose ≥ 11,1 mmol/l after oral glucose tolerance test (OGTT).
• Renal allograft failure (eGFR< 20 ml/min)
• Alanine aminotransferase (ALAT) > 3 x upper normal limit
• Bilirubin > 2 x upper normal limit
• Prednisone treatment
• Pregnancy
• Breastfeeding
• Exclusion criteria for MRI o Claustrophobia/physical not able to lie in MR-s