Kidney Week

Abstract: TH-PO1087

Effect of SGLT2 Inhibitor-Associated Glucosuria on Calculated and Estimated Urine Osmolality

Session Information

• Pathology and Lab Medicine
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Pathology and Lab Medicine

• 1700 Pathology and Lab Medicine

Authors

• Hopf, Karen, Centro Medico Nacional 20 de Noviembre, Mexico City, CDMX, Mexico

Karen Hopf, MD

• Salazar Hurtado, Jorge David, Centro Medico Nacional 20 de Noviembre, Mexico City, CDMX, Mexico

Jorge David Salazar Hurtado, MD

• Magaña, José Alejandro, Centro Medico Nacional 20 de Noviembre, Mexico City, CDMX, Mexico

José Alejandro Magaña, MD

• De La Torre, Juana Citlali, Centro Medico Nacional 20 de Noviembre, Mexico City, CDMX, Mexico

Juana Citlali De La Torre, DM

• Islas Serrano, Juan, Centro Medico Nacional 20 de Noviembre, Mexico City, CDMX, Mexico

Juan Islas Serrano, MD

• Alamilla-Sanchez, Mario, Centro Medico Nacional 20 de Noviembre, Mexico City, CDMX, Mexico

Mario Alamilla-Sanchez, MD, MSc

Background

Urinary osmolality is essential for evaluating dysnatremias, acid–base disorders, and disturbances of water balance. SGLT2 inhibitor–associated glycosuria may affect the accuracy of these surrogate methods. We evaluated the effect of glycosuria on calculated and estimated urinary osmolality compared with measured osmolality.

Methods

Case-control study in hospitalized adults at a referral center in Mexico City. Measured urinary osmolality by osmometry (mUOsm) was compared with calculated (cUOsm) and estimated (eUOsm) values derived from routine urinary parameters. Patients receiving dapagliflozin were compared with controls without exposure to SGLT2 inhibitors.

Results

30 patients were included: 15 receiving dapagliflozin and 15 controls. Variables were expressed as median [IQR], and nonparametric tests were used. In the dapagliflozin group, mUOsm was 527 [361–680] mOsm/kg, compared with cUOsm of 345.4 [240.2–478.3] mOsm/kg and eUOSm of 450 [300–450] mOsm/kg. In controls, measured, calculated, and estimated osmolality were 379 [297–526], 320.6 [303.0–428.8], and 450 [450–600] mOsm/kg, respectively. Disagreement with mUOsm was greater with dapagliflozin: calculated–measured difference −129.6 vs −38.2 mOsm/kg (p=0.004), and absolute error 129.6 vs 52.0 mOsm/kg (p=0.021). Estimated osmolality by specific gravity showed the largest absolute error in the dapagliflozin group: 190 [137–227] mOsm/kg.

Conclusion

Dapagliflozin-associated glycosuria modifies the performance of surrogate methods for urinary osmolality. Although conventional cUOsm showed the best overall performance compared to mUOsm, its error increases in the presence of glycosuria. cUOsm showed the lowest absolute error, whereas estimation based on urinary specific gravity showed high variability and should be interpreted with caution.