Influence of erythropoiesis-stimulating agents on glycated hemoglobin in nondiabetic kidney diseases at the start of dialysis

Background: Although glycated hemoglobin (HbA₁(C)) is a practical tool to assess long-term glucose control in the general population, it may underestimate glycemic control in chronic kidney disease (CKD) patients - especially those undergoing treatment with erythropoiesis-stimulating agents (ESA). We evaluated the association of HbA₁(C) with other parameters of glucose homeostasis and tested its association with ESA use and mortality in nondiabetic incident dialysis patients.

Methods: We studied 270 nondiabetic CKD stage 5 patients referred to initiate dialysis therapy [median age: 54 years (43-63), 154 males]. Patients were followed for up to 5 years for survival analysis.

Results: HbA₁(C) was positively correlated with age (Rho = 0.13; p = 0.031), C-reactive protein (Rho = 0.14; p = 0.024), total cholesterol (Rho = 0.19; p = 0.001), triglycerides (Rho = 0.21; p < 0.001) and glucose (Rho = 0.21; p = 0.001), but it was negatively correlated with HDL-cholesterol (Rho = -0.22; p < 0.001) and ESA dose (Rho = -0.27; p < 0.001). Across increasing HbA₁(C) tertiles, increased glucose levels and reduced use of ESA and dose of ESA were observed (p < 0.001), but there were no differences in insulin and HOMA index. In a stepwise multivariate linear regression analysis, ESA dose was negatively associated with logHbA₁(C). HbA₁(C) did not predict mortality.

Conclusion: In nondiabetic CKD stage 5 patients, HbA₁(C) levels were associated with ESA dose. HbA₁(C) was not independently associated with surrogate markers of insulin resistance or mortality.