erythrocytosis

Background Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have become a cornerstone in the management of type 2 diabetes mellitus (T2DM) because of their established cardiovascular and renal benefits. In addition to improving glycemic control, these agents are associated with increases in hemoglobin and hematocrit levels. While mild hematological changes are commonly observed, clinically significant erythrocytosis remains underrecognized and may prompt investigation for myeloproliferative or secondary causes.(1-2 ) Case Presentations We describe three male patients with T2DM who developed erythrocytosis while receiving dapagliflozin or empagliflozin. All patients were overweight active smokers and demonstrated elevated hemoglobin and hematocrit levels, preserved renal function, normal oxygen saturation, elevated or upper-normal erythropoietin concentrations, and negative JAK2 mutation testing. No patient demonstrated splenomegaly, hyperviscosity symptoms, or thrombotic complications. One patient developed erythrocytosis within six months of dapagliflozin initiation, whereas two patients developed erythrocytosis during long-term SGLT2 inhibitor therapy. Dose reduction in the latter two cases resulted in stabilization or reduction of hemoglobin levels without treatment discontinuation. Conclusion SGLT2 inhibitor-associated erythrocytosis is an increasingly recognized clinical entity that may mimic primary or secondary hematologic disorders. Careful evaluation and individualized management may allow continuation of therapy while preserving its established cardiometabolic benefits.