Sodium-glucose co-transporter 2 (SGLT-2) inhibitors are widely used for glycemic management and cardiorenal risk reduction in type 2 diabetes mellitus (T2DM). A retrospective study published in Acta Diabetologica evaluated the incidence of erythrocytosis associated with SGLT-2 inhibitor therapy and examined clinical factors associated with hemoglobin (Hb) and hematocrit (Hct) changes during treatment.

The analysis included patients who initiated SGLT-2 inhibitor therapy between January 2020 and January 2021. Hemoglobin and hematocrit levels were monitored for a median follow-up duration of 16 months after treatment initiation. A total of 385 patients without baseline polycythemia were included in the primary analysis.

Findings

• Polycythemia developed in 15.1% (n = 58) of patients receiving SGLT-2 inhibitors.
• Mean hemoglobin levels increased by 0.97 ± 0.94 g/dL during follow-up.
• Male sex and smoking were identified as significant risk factors for erythrocytosis, while insulin use and iron deficiency were associated with lower risk.
• A negative correlation was observed between baseline Hb levels and the degree of Hb increase during treatment.
• Patients with lower baseline Hb levels showed greater increases in Hb and Hct following SGLT-2 inhibitor initiation.
• Among patients excluded because of baseline polycythemia (n = 18), no significant Hb changes were observed during follow-up.

The analysis showed that SGLT-2 inhibitor therapy was associated with increased Hb and Hct levels in patients without baseline polycythemia. Larger hematologic changes among patients with lower baseline Hb levels may warrant further evaluation, while the absence of significant Hb increases in patients with pre-existing polycythemia provides additional safety-related observations.