Hemoglobin stability in patients with anemia, CKD, and type 2 diabetes: an analysis of the TREAT (trial to reduce cardiovascular events with aranesp therapy) placebo arm

Background: Sparse data are available about the natural history of hemoglobin (Hb) level trends in contemporary patients with anemia, chronic kidney disease (CKD), and type 2 diabetes mellitus. We intended to describe Hb level trends over time with no or minimal administration of erythropoiesis- stimulating agents. Study Design: Prospective clinical trial cohort. Setting & Participants: 2,019 individuals with type 2 diabetes, moderate anemia, and CKD from the placebo arm of the Trial to Reduce Cardiovascular Events With Aranesp Therapy (TREAT) followed up for 2.3 years with an average of 32 monthly Hb level determinations per patient. Darbepoetin alfa was administered only if Hb level decreased to <9 g/dL. Outcomes & Measurements: Number of protocol-directed doses of darbepoetin alfa received due to an Hb level decrease to <9 g/dL. Results: 1,106 (55%) placebo patients consistently maintained an Hb level ≥9 g/dL and received no protocol-directed darbepoetin alfa. The other patients received 1 (16%), 2-4 (16%), or 5 or more (13%) doses of darbepoetin alfa. Those who received no darbepoetin alfa doses had higher baseline Hb levels, higher estimated glomerular filtration rates (eGFRs), less proteinuria, and lower ferritin and transferrin saturation values. On average, Hb levels were stable or increased in all groups. Compared with individuals who received no darbepoetin alfa, those who received 5 or more doses were more likely to receive intravenous iron therapy and blood transfusions and progress to renal replacement therapy, but were not at higher risk of death. The strongest predictors of requiring 5 or more doses of darbepoetin alfa were lower baseline Hb level, lower eGFR, and higher proteinuria level. Limitations: Post hoc analysis of a clinical trial of a specific population with diabetes, anemia, and non-dialysis-dependent CKD. Conclusions: In the TREAT placebo arm, Hb levels were stable with no or minimal protocol-directed darbepoetin alfa during 2.3 years of follow-up. Most patients with moderate anemia, non-dialysis- dependent CKD, and type 2 diabetes are able to maintain a stable Hb level without implementing long-term erythropoiesis-stimulating agent therapy.