title: Correlation of Glypican-4 Level with Basal Active Glucagon-Like Peptide 1 Level in Patients with Type 2 Diabetes Mellitus.
abstract: BACKGROUND
  Previous studies have reported that glypican-4 (GPC4) regulates insulin signaling by interacting with insulin receptor and through adipocyte differentiation. However, GPC4 has not been studied with regard to its effects on clinical factors in patients with type 2 diabetes mellitus (T2DM). We aimed to identify factors associated with GPC4 level in T2DM.
  
  
  METHODS
  Between January 2010 and December 2013, we selected 152 subjects with T2DM and collected serum and plasma into tubes pretreated with aprotinin and dipeptidyl peptidase-4 inhibitor to preserve active gastric inhibitory polypeptide (GIP) and glucagon-like peptide 1 (GLP-1). GPC4, active GLP-1, active GIP, and other factors were measured in these plasma samples. We performed a linear regression analysis to identify factors associated with GPC4 level.
  
  
  RESULTS
  The subjects had a mean age of 58.1 years, were mildly obese (mean body mass index [BMI], 26.1 kg/m²), had T2DM of long-duration (mean, 101.3 months), glycated hemoglobin 7.5%, low insulin secretion, and low insulin resistance (mean homeostatic model assessment of insulin resistance [HOMA-IR], 1.2). Their mean GPC4 was 2.0±0.2 ng/mL. In multivariate analysis, GPC4 was independently associated with age (β=0.224, P=0.009), and levels of active GLP-1 (β=0.171, P=0.049) and aspartate aminotransferase (AST; β=-0.176, P=0.043) after being adjusted for other clinical factors.
  
  
  CONCLUSIONS
  GPC4 was independently associated with age, active GLP-1, and AST in T2DM patients, but was not associated with HOMA-IR and BMI, which are well known factors related to GPC4. Further study is needed to identify the mechanisms of the association between GPC4 and basal active GLP-1 levels.
authors.affiliation: Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea. salee@jejunu.ac.kr.
authors.forename: Sang Ah
authors.identifier: http://orcid.org/0000-0002-9797-8050
authors.initials: SA
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea.
authors.forename: Gwanpyo
authors.initials: G
authors.lastname: Koh
authors.affiliation: Department of Anesthesiology, Jeju National University School of Medicine, Jeju, Korea.
authors.forename: Suk Ju
authors.initials: SJ
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea.
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Yoo
authors.affiliation: Department of Internal Medicine, Jeju National University School of Medicine, Jeju, Korea.
authors.forename: Sang Ouk
authors.initials: SO
authors.lastname: Chin
keywords: Active glucagon-like peptide 1; Diabetes mellitus; Glypicans