title: Plasma soluble leptin receptor levels are associated with pancreatic β-cell dysfunction in patients with type 2 diabetes.
abstract: OBJECTIVE
  A soluble form of the leptin receptor (soluble Ob-R) in the circulation regulates leptin's bioactivity, and is inversely associated with body adiposity and circulating leptin levels. However, no study has examined the clinical impact of soluble Ob-R on glucose metabolism in diabetes. The present study aimed to investigate the association of plasma soluble Ob-R levels with insulin resistance and pancreatic β-cell function in patients with type 2 diabetes.
  
  
  METHODS
  A total of 289 Japanese patients with type 2 diabetes were included in the present study. Fasting plasma soluble Ob-R levels and plasma leptin levels were measured by enzyme-linked immunosorbent assay. Insulin resistance and pancreatic β-cell function were estimated by homeostasis model assessment of insulin resistance, homeostasis model assessment of β-cell function and fasting C-peptide index.
  
  
  RESULTS
  The median plasma soluble Ob-R level and plasma leptin level were 3.4 ng/mL and 23.6 ng/mL, respectively. Plasma soluble Ob-R levels were negatively correlated with homeostasis model assessment of insulin resistance, homeostasis model assessment of β-cell function and the C-peptide index, whereas plasma leptin levels were positively correlated with each index in univariate analyses. Multivariate analyses including plasma soluble Ob-R levels, plasma leptin levels and use of sulfonylureas, along with age, sex, body mass index and other covariates, showed that soluble Ob-R levels were independently and negatively associated with homeostasis model assessment of β-cell function and the C-peptide index, but not significantly associated with homeostasis model assessment of insulin resistance.
  
  
  CONCLUSIONS
  Plasma soluble Ob-R levels are independently associated with pancreatic β-cell function, but not with insulin resistance, in patients with type 2 diabetes. The present study implicates the role of soluble Ob-R in pancreatic β-cell dysfunction in type 2 diabetes.
authors.affiliation: Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Tomoaki
authors.identifier: http://orcid.org/0000-0002-2329-8191
authors.initials: T
authors.lastname: Morioka
authors.affiliation: Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Emoto
authors.affiliation: Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yamazaki
authors.affiliation: Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Kurajoh
authors.affiliation: Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Koka
authors.initials: K
authors.lastname: Motoyama
authors.affiliation: Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Katsuhito
authors.initials: K
authors.lastname: Mori
authors.affiliation: Premier Preventive Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Fukumoto
authors.affiliation: Vascular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Shioi
authors.affiliation: Vascular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Shoji
authors.affiliation: Departments of Metabolism, Endocrinology and Molecular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Inaba
mesh_terms: D000368:Aged; D001786:Blood Glucose; D002096:C-Peptide / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D050417:Insulin-Secreting Cells / Q000378:metabolism*; D020738:Leptin / Q000097:blood; D008297:Male; D008875:Middle Aged; D054411:Receptors, Leptin / Q000097:blood*
chemical_list: D001786:Blood Glucose; D002096:C-Peptide; D020738:Leptin; D054411:Receptors, Leptin
keywords: Leptin; Soluble leptin receptor; β-Cell function