title: Circulating apelin is increased in patients with type 1 or type 2 diabetes and is associated with better glycaemic control.
abstract: BACKGROUND
  Apelin is an adipokine expressed in several tissues and it appears to be involved in energy metabolism.
  
  
  OBJECTIVE
  The aim of this study was to determine serum apelin levels in a large cohort of patients with type 1 and type 2 diabetes and control subjects and to correlate the results with glycaemic control.
  
  
  METHODS
  One hundred and thirty patients with type 1 diabetes, 98 patients with type 2 diabetes and 162 controls were enrolled in the study. Apelin levels were measured by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Serum apelin levels were significantly higher in type 1 and type 2 diabetic patients than in controls (P < 0·0001). Serum apelin levels were higher in type 1 than in type 2 diabetic patients (P = 0·02). In multivariate analysis, serum apelin levels were higher in patients with type 1 diabetes and in patients with type 2 diabetes versus controls. We found a negative correlation between glycosylated haemoglobin and serum apelin levels in all diabetic patients (r = -0·17, P = 0·008) and in patients with type 2 diabetes (r = -0·24 P = 0·01). No correlation was found in type 1 diabetic patients.
  
  
  CONCLUSIONS
  Our study showed that apelin concentrations were increased in diabetic patients. This rise, which was greater in type 1 than in type 2 diabetic patients, suggests that obesity is not the main determinant of plasma apelin levels. The negative correlation with glycosylated haemoglobin in patients with type 2 diabetes could indicate that apelin plays a role in glycaemic balance and even insulin sensitivity.
authors.affiliation: Services de diabétologie et endocrinologie Université de Bourgogne, Dijon Cedex, France.
authors.forename: Marana
authors.initials: M
authors.lastname: Habchi
authors.forename: Laurence
authors.initials: L
authors.lastname: Duvillard
authors.forename: Vanessa
authors.initials: V
authors.lastname: Cottet
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Brindisi
authors.forename: Benjamin
authors.initials: B
authors.lastname: Bouillet
authors.forename: Maud
authors.initials: M
authors.lastname: Beacco
authors.forename: Elodie
authors.initials: E
authors.lastname: Crevisy
authors.forename: Perrine
authors.initials: P
authors.lastname: Buffier
authors.forename: Sabine
authors.initials: S
authors.lastname: Baillot-Rudoni
authors.forename: Bruno
authors.initials: B
authors.lastname: Verges
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Petit
mesh_terms: D000328:Adult; D000368:Aged; D000073861:Apelin; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000097:blood* / Q000628:therapy; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000628:therapy; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D007333:Insulin Resistance; D036341:Intercellular Signaling Peptides and Proteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015854:Up-Regulation
chemical_list: D000073861:Apelin; D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; D036341:Intercellular Signaling Peptides and Proteins; C115436:APLN protein, human; C517652:hemoglobin A1c protein, human