Semaglutide and empagliflozin each independently reduced kidney cortical ADC on MRI and decreased total kidney volume in patients with type 2 diabetes, but their combination did not show additive effects on ADC.
3-5% kidney volume reductionAll active treatments (semaglutide, empagliflozin, combination) decreased total kidney volume in T2D patients
What the researchers found
Semaglutide and empagliflozin each reduced kidney cortical ADC and total kidney volume, but their combination did not show additive ADC effects; changes were independent of GFR, albuminuria, and inflammation.
Why it matters
Understanding how kidney-protective drugs work at the tissue level could optimize combination therapy strategies. The unexpected finding that combination therapy didn't enhance kidney MRI changes challenges assumptions about additive benefits.
The numbers in context
32-week randomized trial; diffusion-weighted MRI and total kidney volume measured; semaglutide vs. empagliflozin vs. combination.
How the study worked
Post hoc analysis of a 32-week randomized trial. 80 patients with T2D and high CV risk randomized to 4 groups (n=20 each): placebo, empagliflozin, semaglutide, or combination. Kidney ADC and total kidney volume measured by MRI.
Who was studied
Type 2 diabetes patients in a 32-week randomized trial with kidney MRI assessment
What this study cannot tell us
Small sample (20 per group). Post hoc analysis. ADC interpretation is debated — may not specifically reflect fibrosis. 32-week duration may be insufficient. Combination group had sequential rather than simultaneous drug initiation. ADC changes did not correlate with clinical endpoints.
How to read the evidence
Moderate evidence — randomized trial substudy with novel imaging endpoint, but small sample size and post hoc analysis limit conclusions.
When this study was published
Published in 2024. Uses advanced MRI techniques to investigate drug mechanisms in diabetic kidney disease.
The bigger picture
Advanced imaging is beginning to reveal the kidney-level effects of metabolic drugs that previously could only be measured by blood and urine markers. This represents a new frontier in understanding renoprotection — and the surprising combination results suggest the drugs may work through overlapping rather than complementary kidney pathways.
Questions still open
- Why does the semaglutide-empagliflozin combination not show additive kidney MRI changes?
- Does cortical ADC change reflect actual kidney fibrosis or other microstructural processes?
- Should DWI-MRI become a routine tool for monitoring kidney drug effects in diabetes?
Common questions
Can MRI scans show how diabetes drugs protect the kidneys?
Is it better to take both drugs together for kidney protection?
Read the original research
Effects of semaglutide, empagliflozin and their combination on renal diffusion-weighted MRI and total kidney volume in patients with type 2 diabetes: a post hoc analysis from a 32 week randomised trial.
Diabetologia, 67(10), 2175-2187
Citation
Vernstrøm, Liv; Gullaksen, Søren; Sørensen, Steffen S; Ringgaard, Steffen; Laustsen, Christoffer; Birn, Henrik; Funck, Kristian L; Laugesen, Esben; Poulsen, Per L. (2024). Effects of semaglutide, empagliflozin and their combination on renal diffusion-weighted MRI and total kidney volume in patients with type 2 diabetes: a post hoc analysis from a 32 week randomised trial.. Diabetologia, 67(10), 2175-2187. https://doi.org/10.1007/s00125-024-06228-y