The effects of semaglutide, empagliflozin and their combination on the kidney sodium signal from magnetic resonance imaging: A prespecified, secondary analysis from a randomized, clinical trial

Aims: To evaluate the effect of treatment with semaglutide and empagliflozin on the cortico-medullary sodium gradient (MCR; medulla/cortex ratio), urine sodium/creatinine ratio (UNACR), and estimated plasma volume (ePV) and to compare the MCR between persons with and without type 2 diabetes. Methods: Using the 23Na magnetic resonance imaging (23Na-MRI) technique, we investigated the effects of 32 weeks of treatment with semaglutide, empagliflozin or their combination on MCR in 65 participants with type 2 diabetes and high risk of cardiovascular disease. The participants were recruited from a randomized, controlled interventional trial and further characterized by UNACR and ePV. In addition, in a cross-sectional design, we compared MCR by 23Na-MRI in 12 persons with type 2 diabetes and 17 matched controls. Data from the interventional trial were analyzed using a single, multivariate linear mixed model strategy for repeated measurements. Data from the cross-sectional study were analyzed by fitting a linear regression model adjusted for age and sex. Results: Compared to placebo, semaglutide, but not empagliflozin, significantly decreased the MCR (-9 %, 95%CI (-18, -0.06)%, p = 0.035 and -0.05 %, 95%CI(-0.15, 0.05)%, p = 0.319, respectively). The UNACR decreased in the semaglutide group( -35 %, 95 % CI( -52, -14) %, p = 0.003) but not in the empagliflozin group (7 %, 95 % CI( -21, 44)%, p = 0.657), whereas the ePV decreased in the combination group. The MCR was not different between persons with and without type 2 diabetes. Conclusion: 23Na magnetic resonance imaging can identify drug induced changes in the MCR in persons with type 2 diabetes, and 32 weeks of semaglutide decreases the MCR in such persons. There is no difference in the MCR between persons with and without type 2 diabetes. Trial number and registry: EUDRACT 2019-000781-38, clinicaltrialsregister.eu.