Glycated Albumin Is a Better Glycemic Indicator than Glycated Hemoglobin Values in Hemodialysis Patients with Diabetes

Abstract

The significance of glycated albumin (GA), compared with casual plasma glucose (PG) and glycated hemoglobin (HbA 1c ), was evaluated as an indicator of the glycemic control state in hemodialysis (HD) patients with diabetes. The mean PG, GA, and HbA 1c levels were 164.5 ؎ 55.7 mg/dl, 22.5 ؎ 7.5%, and 5.85 ؎ 1.26%, respectively, in HD patients with diabetes (n ‫؍‬ 538), which were increased by 51.5, 31.6, and 17.7%, respectively, compared with HD patients without diabetes (n ‫؍‬ 828). HbA 1c levels were significantly lower than simultaneous PG and GA values in those patients in comparison with the relationship among the three parameters in patients who had diabetes without renal dysfunction (n ‫؍‬ 365), as reflected by the significantly more shallow slope of regression line between HbA 1c and PG or GA. A significant negative correlation was found between GA and serum albumin (r ‫؍‬ ؊0.131, P ‫؍‬ 0.002) in HD patients with diabetes, whereas HbA 1c correlated positively and negatively with hemoglobin (r ‫؍‬ 0.090, P ‫؍‬ 0.036) and weekly dose of erythropoietin injection (r ‫؍‬ ؊0.159, P < 0.001), respectively. Although PG and GA did not differ significantly between HD patients with diabetes and with and without erythropoietin injection, HbA 1c levels were significantly higher in patients without erythropoietin. Categorization of glycemic control into arbitrary quartile by HbA 1c level led to better glycemic control in a significantly higher proportions of HD patients with diabetes than those assessed by GA. Multiple regression analysis demonstrated that the weekly dose of erythropoietin, in addition to PG, emerged as an independent factor associated with HbA 1c in HD patients with diabetes, although PG but not albumin was an independent factor associated with GA. In summary, it is suggested that GA provides a significantly better measure to estimate glycemic control in HD patients with diabetes and that the assessment of glycemic control by HbA 1c in these patients might lead to underestimation likely as a result of the increasing proportion of young erythrocyte by the use of erythropoietin.

Introduction of glycated albumin measurement for all blood donors and the prevalence of a high glycated albumin level in Japan

“…First, the reference range for GA was determined as three times the reference range for HbA 1c in the present study. Although this was based on the results from several previous reports 8 , the actual conversion coefficient between GA and HbA 1c might be smaller than 3.0. A slight change in the GA level for categorizing prediabetes/diabetes would seriously affect the projected number of such persons.…”

“…The reference range for GA on which diabetes is categorized has not yet been officially determined, therefore reports from several studies that dealt with the correlation between HbA 1c and GA were referenced. It was found that most studies concentrated on an average ratio of 3:1 for the GA:HbA 1c ratio 8 . The JRCS therefore adopted a tentative value for the reference range for GA that was three times the reference range for HbA 1c (Japan Diabetes Society value) 9 .…”

Pitfalls in Hemoglobin A1c Measurement: When Results may be Misleading

“…30,46,47 Plasma 1,5-anhydroglucitol (1,5-AG) is a naturally occurring dietary polyol that has been proposed as a measure of glycemic control. Renal reabsorption of 1,5-AG is competitively inhibited by glucose.…”

The dipeptidyl peptidase-4 (DPP-4) inhibitor vildagliptin improves glycemic control in type 2 diabetic patients undergoing hemodialysis

“…Anemia, which results from a short erythrocyte lifespan, theoretically suppresses HbA1c levels. Therefore, some studies have suggested that the HbA1c level is not the optimal index for assessing glycemic control in diabetic dialysis patients and those with advanced chronic kidney disease who receive erythropoietin [17][18][19]. By increasing the proportion of young erythrocytes in the blood, both anemia and erythropoietin can falsely lower the HbA1c level, leading to a false negative diagnosis of hyperglycemia.…”