title: Plasma amino acid profiles are associated with insulin, C-peptide and adiponectin levels in type 2 diabetic patients.
abstract: OBJECTIVE
  Plasma-free amino acid (PFAA) profiles have been associated with a future risk of developing diabetes or cardiovascular disease in nondiabetic subjects. These PFAA alterations might predominantly result from the metabolic shift caused by insulin resistance and visceral fat deposition. The variety of PFAA profiles within diabetic subjects is not well researched. In this study, we focused on type 2 diabetic subjects and examined the association between PFAA profiles and insulin- and glucose-related variables.
  
  
  METHODS
  Fifty-one Japanese subjects diagnosed with type 2 diabetes were recruited from an outpatient clinic. The plasma concentrations of 21 amino acids; glucose-related markers including glucose, hemoglobin A1c (HbA1c), glycoalbumin and 1,5-anhydroglucitol; insulin-related markers including insulin, C-peptide, and the homeostasis model assessment of insulin resistance; and adipocytokines including adiponectin and leptin were determined. The association of PFAA and other metabolic profiles were analyzed, and stratified analyses of the PFAAs and clinical characteristics were performed according to the fasting plasma insulin and HbA1c levels. In addition, the PFAA indices that correlate to visceral fat obesity were evaluated.
  
  
  RESULTS
  Although strong correlations between PFAAs and glucose-related markers were not observed, several amino acids (branched-chain amino acids, tryptophan, alanine, tyrosine, glutamate and proline) and PFAA indices that evaluate visceral obesity were highly correlated with insulin-related markers and adiponectin (P<0.001). In the group of diabetic patients with hyperinsulinemia, the amino acid levels were significantly increased, which generally demonstrated good concordance with insulin-related markers and adiponectin levels.
  
  
  CONCLUSIONS
  The PFAA profiles in diabetic patients were strongly associated with hyperinsulinemia and hypoadiponectinemia, which might become risk evaluation factors for the development of cardiovascular diseases.
authors.affiliation: Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
authors.affiliation: Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Jinzu
authors.affiliation: Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nagao
authors.affiliation: Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Noguchi
authors.affiliation: R&D Planning Department, Ajinomoto Co., Inc., Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Shimba
authors.affiliation: Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Miyano
authors.affiliation: Link and Communication Co., Inc., Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Iseki Internal Medicine, Tokyo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Iseki