Effects of canagliflozin on kidney resistive index and oxygenation in patients with type 2 diabetes: findings obtained with ultrasonography and blood oxygenation level-dependent MRI.

BACKGROUND

Details regarding kidney-protective mechanisms of sodium-glucose cotransporter 2 (SGLT2) inhibitors remain unclear. High kidney resistive index (RI), evaluated by Doppler ultrasonography, and low T2* value, evaluated by blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) are risk factors for chronic kidney disease progression. In our previous study, canagliflozin (Cana) improved kidney oxygenation. In this post-hoc analysis, the effects of Cana on RI, as well as the correlation between changes in RI and T2* values, were evaluated.

METHODS

Thirteen patients with type 2 diabetes (T2D) were analyzed. RI was determined at screening and on Day 5 (D5) following administration of Cana, while BOLD MRI was performed on D0, D1 (administration day), and D5. Cortical T2* values were evaluated using twelve-layer concentric object (TLCO) and region of interest (ROI) methods. Changes in RI and T2* values from D0 to D1 or D5 are expressed as ΔRI, ΔT2* (D1-D0), and Δ T2* (D5-D0), respectively.

RESULTS

Cana significantly decreased RI, while ROI findings showed increased T2* (D0: 54.5 [50.8-55.5] vs D1: 56.2 [52.7-56.4], p = 0.003, r = 0.77; D0 vs D5: 54.5 [53.0-57.2], p = 0.080, r = 0.49). A significant negative correlation between ΔRI and ΔT2* (D1-D0) was shown by both TLCO (ρ = -0.621, p = 0.024) and ROI (ρ = -0.557, p = 0.048).

CONCLUSION

Short-term Cana treatment improved RI and kidney oxygenation in patients with T2D. The inverse correlation found between changes in RI and T2* values suggest a mechanistic link between hemodynamic changes and improved oxygenation by SGLT2 inhibitors.