Measurement of Hba1C in patients with chronic renal failure

Background: Carbamylated hemoglobin (carbHb) is reported to interfere with measurement and interpretation of HbA1c in diabetic patients with chronic renal failure (CRF). There is also concern that HbA1c may give low results in these patients due to shortened erythrocyte survival. Methods: We evaluated the effect of carbHb on HbA1c measurements and compared HbA1c with glycated albumin (GA) in patients with and without renal disease to test if CRF causes clinically significant bias in HbA1c results by using 11 assay methods. Subjects included those with and without renal failure and diabetes. Each subject's estimated glomerular filtration rate (eGFR) was used to determine the presence and degree of the renal disease. A multiple regression model was used to determine if the relationship between HbA1c results obtained from each test method and the comparative method was significantly (p7% at 6 or 9% HbA1c. The relationship between HbA1c and glycated albumin (GA) in patients with and without renal failure was also compared. Results: Some methods showed small but statistically significant effects of eGFR; none of these differences were clinically significant. If GA is assumed to better reflect glycemic control, then HbA1c was approximately 1.5% HbA1c lower in patients with renal failure. Conclusions: Although most methods can measure HbA1c accurately in patients with renal failure, healthcare providers must interpret these test results cautiously in these patients due to the propensity for shortened erythrocyte survival in renal failure. © 2013 Elsevier B.V.