[TREAT or not to treat: anemia in type 2 diabetes and chronic kidney disease at stages 3 and 4]

Anemia is associated with an increased risk of cardiovascular and renal events among patients with type 2 diabetes and chronic kidney disease (CKD). Although erythropoiesis-stimulating agents (ESA) can effectively increase hemoglobin (Hb) levels, their effect on clinical outcomes has not been demonstrated in CKD patients. The TREAT study is the first randomized, double-blind, placebo-controlled trial with the aim to evaluate the effect of a Hb level of 13 g/dL on the risk of death, cardiovascular events and progression to end-stage renal disease (ESRD) in type 2 diabetes with stage 3 to 4 CKD. Four thousand and thirty-eight patients were included. Death, cardiovascular events and progression to ESRD were not different between the two groups. Stroke occurred in 101 patients assigned to DA and 53 patients assigned to placebo (p<0.001), and red-cell transfusions were administered in 14.8% patients in the DA group and in 24.5% patients assigned to placebo (p<0.001). There was a modest improvement in patient-reported fatigue in the DA group. Studies performed in CKD patients who were not undergoing dialysis failed to show a benefit of the use of ESA to target a Hb level of 13 g/dl or more, on the risk of death, cardiovascular morbidity and progression to ESRD. Post hoc analysis of randomized studies suggest that the increase cardiovascular risk induced by targeting a high Hb level is more related to the resistance state of patients who failed to increase their Hb level under high ESA doses and by the rate of change in Hb concentration over time. After the release of the TREAT study, the recommendations of a Hb level of 10 to 12 g/dl in CKD patients seems adequate. This target needs to be tailored for each patient taking into account the comorbidity, age and physical activity.