The Variability of One-Year Averaged Glycosylated Hemoglobin (HgbA1c) and Association with Pre-Dialysis Glucose in Patients on Maintenance Hemodialysis.

We hypothesized that glycosylated hemoglobin (HghA1c) that is averaged for a period of 1 year is relatively stable within hemodialysis (HD) patients and maintains a good correlation with the yearlong averaged random pre-dialysis blood glucose. HD patients in the database of a large dialysis organization with a diagnosis of diabetes and ≥3 HgbA1c results during 2002 who were present from Jan. 1, 2003 to Jan. 1, 2004 formed the study cohort. All available HgbA1c values and pre-dialysis blood glucose measurements were included in computing the averages. There were 18, 867 patients with mean age 63.9 ± 12 years, 52% female, 51% white and 39% black, 90% type 2 diabetes, with mean HgbA1c 6.8 ± 1.5% (median 6.5%) and mean glucose 169 ± 68 mg/dL (median 156 mg/dL). The distribution of the standard deviations (SD) of the HgbA1c in individual patients is shown below. Eighteen percent of patients had HghA1c SD > 1%. The association with random pre-dialysis blood glucose averaged over 1 year is R=0.68 (p < 0.001). The HgbA1c appears stable over the course of the year for most patients with median HgbA1c SD at 0.5%. The prognostic significance of high vs. low HgbA1c variability remains to be determined. [ABSTRACT FROM AUTHOR]