title: Inverse association between glycated albumin and insulin secretory function may explain higher levels of glycated albumin in subjects with longer duration of diabetes.
abstract: BACKGROUND
  Glycated albumin (GA) has been increasingly used as a reliable index for short-term glycemic monitoring, and is inversely associated with β-cell function. Because the pathophysiologic nature of type 2 diabetes (T2D) is characterized by progressive decline in insulin secretion, the aim was to determine whether GA levels were affected by diabetes duration in subjects with T2D.
  
  
  METHODS
  To minimize the effect of glucose variability on GA, subjects with stably maintained HbA1c levels of <0.5% fluctuation across 6 months of measurements were included. Patients with newly diagnosed T2D (n = 1059) and with duration>1 year (n = 781) were recruited and categorized as New-T2D and Old-T2D, respectively. Biochemical, glycemic, and C-peptide parameters were measured.
  
  
  RESULTS
  GA levels were significantly elevated in HbA1c-matched Old-T2D subjects compared to New-T2D subjects. Duration of diabetes was positively correlated with GA, whereas a negative relationship was found with C-peptide increment (ΔC-peptide). Among insulin secretory indices, dynamic parameters such as ΔC-peptide were inversely related to GA (r = -0.42, p<0.001). Multiple linear regression analyses showed that duration of diabetes was associated with GA (standardized β coefficient [STDβ] = 0.05, p<0.001), but not with HbA1c (STDβ = 0.04, p<0.095). This association disappeared after additional adjustment with ΔC-peptide (STDβ = 0.02, p = 0.372), suggesting that β-cell function might be a linking factor of close relationship between duration of diabetes and GA values.
  
  
  CONCLUSIONS
  The present study showed that GA levels were significantly increased in subjects with longer duration T2D and with decreased insulin secretory function. Additional caution should be taken when interpreting GA values to assess glycemic control status in these individuals.
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea; Severance Hospital, Seoul, South Korea.
authors.forename: Yong-ho
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Severance Hospital, Seoul, South Korea.
authors.forename: Mi Hyang
authors.initials: MH
authors.lastname: Kown
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea; Severance Hospital, Seoul, South Korea; Severance Executive Healthcare Clinic, Yonsei University Health System, Seoul, South Korea.
authors.forename: Kwang Joon
authors.initials: KJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea; Severance Hospital, Seoul, South Korea.
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Lee
authors.affiliation: Department of Biochemistry and Molecular Biology, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Daham
authors.initials: D
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea; Severance Hospital, Seoul, South Korea.
authors.forename: Byung-Wan
authors.initials: BW
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea; Severance Hospital, Seoul, South Korea.
authors.forename: Eun Seok
authors.initials: ES
authors.lastname: Kang
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea; Severance Hospital, Seoul, South Korea.
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Cha
authors.affiliation: Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea; Severance Hospital, Seoul, South Korea.
authors.forename: Hyun Chul
authors.initials: HC
authors.lastname: Lee
mesh_terms: D002096:C-Peptide / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000097:blood*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D017127:Glycation End Products, Advanced; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D012709:Serum Albumin / Q000378:metabolism*; D013997:Time Factors; D000093423:Glycated Serum Albumin
chemical_list: D002096:C-Peptide; D006442:Glycated Hemoglobin; D017127:Glycation End Products, Advanced; D007328:Insulin; D012709:Serum Albumin; D000093423:Glycated Serum Albumin