Variability of glycated hemoglobin levels in the first year post renal transplantation in patients without diabetes

Abstract

BackgroundGlycated hemoglobin (HbA1c) is an alternative test used for the diagnosis and monitoring of diabetes in kidney transplant recipients. Immunosuppressive drugs are the most important risk factors related with changes in the glucose metabolism after transplant. It is still unknown if they impact on the variability of HbA1c. We assessed the variability of HbA1c levels in a group of renal transplant recipients without diabetes during the first year after transplant. MethodsWe estimated the variability of HbA1c in a group of 95 Brazilian kidney transplant recipients. Three EDTA whole blood samples were collected from each patient, one every four months for twelve months, totalizing 285 blood specimens. HbA1c values were measured by HPLC (Bio-Rad Variant™ II Turbo analyzer). Estimations were calculated according to Fraser and Harris method. ResultsThere was no difference in HbA1c mean levels between men and women. Within-subject and between-subject biological variations were 4.42% and 7.05%, respectively. The reference change value calculated for HbA1c was 16.15% and the index of individuality was 0.63. ConclusionsKidney transplant patients without diabetes presented higher HbA1c within-subject variation than individuals without diabetes from the general population. This should be considered when interpreting HbA1c results in the diagnosis and management of diabetes after kidney transplantation.