title: The ratio of glycated albumin to hemoglobin A1c measured in IFCC units accurately represents the glycation gap.
abstract: The glycation gap (G-gap: difference between measured hemoglobin A1c [A1C] and the value predicted by its regression on the fructosamine level) is stable and associated with diabetic complications. Measuring A1C level in International Federation of Clinical Chemistry (IFCC) units (A1C-SI; mmol/mol) and National Glycohemoglobin Standardization Program units (A1C-NGSP; %) and using glycated albumin (GA) level instead of fructosamine level for calculating the G-gap, we investigated whether the G-gap is better represented by GA/A1C ratio if expressed in SI units (GA/A1C-SI ratio) rather than in NGSP units (GA/A1C-% ratio). We examined 749 Japanese children with type 1 diabetes using simultaneous GA and A1C measurements. Of these, 369 patients were examined more than five times to assess the consistency of the G-gap and the GA/A1C ratio within individuals. The relationship of GA/A1C-% ratio to the corresponding A1C-NGSP was stronger than that of GA/A1C-SI ratio to A1C-IFCC. At enrollment, the inverse relationship between the GA/A1C-SI ratio and G-gap was highly significant (R(2) = 0.95) compared with that between the GA/A1C-% ratio and G-gap (R(2) = 0.69). A highly significant inverse relationship was also observed between the mean GA/A1C-SI ratio and the mean G-gaps obtained individually over time (R(2) = 0.95) compared with that using the corresponding A1C-NGSP (R(2) = 0.67). We conclude that the G-gap is better represented by the GA/A1C-SI ratio. We propose the use of mean GA/A1C-SI ratios easily obtained individually over time as reference values in Japanese children with type 1 diabetes (6.75 ± 0.60 [means ± SD]).
authors.affiliation: Department of Pediatrics, Saitama Medial University, Saitama 350-0495, Japan.
authors.forename: Junya
authors.initials: J
authors.lastname: Akatsuka
authors.forename: Mie
authors.initials: M
authors.lastname: Mochizuki
authors.forename: Ikuma
authors.initials: I
authors.lastname: Musha
authors.forename: Akira
authors.initials: A
authors.lastname: Ohtake
authors.forename: Kisho
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Toru
authors.initials: T
authors.lastname: Kikuchi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kikuchi
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kawamura
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Urakami
authors.forename: Shigetaka
authors.initials: S
authors.lastname: Sugihara
authors.forename: Tadao
authors.initials: T
authors.lastname: Hoshino
authors.forename: Shin
authors.initials: S
authors.lastname: Amemiya
mesh_terms: D000293:Adolescent; D000465:Algorithms; D002648:Child; D015331:Cohort Studies; D003131:Combined Modality Therapy; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000178:diet therapy / Q000188:drug therapy / Q000378:metabolism; D003927:Diet, Diabetic; D005260:Female; D019270:Fructosamine / Q000097:blood*; D006442:Glycated Hemoglobin / Q000032:analysis*; D017127:Glycation End Products, Advanced; D006031:Glycosylation / Q000187:drug effects; D006801:Humans; D006943:Hyperglycemia / Q000517:prevention & control*; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use; D007394:International System of Units; D007564:Japan; D008297:Male; D012709:Serum Albumin / Q000032:analysis*; D000075462:Serum Albumin, Human; D000093423:Glycated Serum Albumin
chemical_list: D019270:Fructosamine; D006442:Glycated Hemoglobin; D017127:Glycation End Products, Advanced; D007004:Hypoglycemic Agents; D007328:Insulin; D012709:Serum Albumin; D000075462:Serum Albumin, Human; D000093423:Glycated Serum Albumin; C422455:ALB protein, human; C517652:hemoglobin A1c protein, human