title: Serum galectin-3 is elevated in obesity and negatively correlates with glycosylated hemoglobin in type 2 diabetes.
abstract: BACKGROUND
  Adipocytes synthesize galectin-3 whose deficiency protects from inflammation associated with metabolic diseases. We aimed to study circulating galectin-3 in obesity and type 2 diabetes (T2D).
  
  
  METHODS
  Galectin-3 was measured by ELISA in the serum of male normal-weight and overweight controls and T2D patients and in T2D patients of both sexes. Because visceral fat contributes to systemic inflammation, galectin-3 was analyzed in paired samples of human and rodent sc and visceral adipose tissue. Visceral adipose tissue adipokines are released to the portal vein, and galectin-3 was analyzed in portal, hepatic, and systemic venous serum (PVS, HVS, and SVS, respectively) of patients with liver cirrhosis and in patients who underwent surgery for nonhepatic diseases. The effect of metformin on adipocyte galectin-3 was analyzed by immunoblot.
  
  
  RESULTS
  Circulating galectin-3 was similarly elevated in T2D and obesity compared with normal-weight individuals and revealed a body mass index-dependent positive correlation with leptin, resistin, IL-6, and age. In T2D patients, galectin-3 was increased in serum of patients with elevated C-reactive protein and negatively correlated with glycated hemoglobin. Metformin treatment was associated with lower systemic galectin-3. Reduced galectin-3 in metformin-incubated human adipocytes indicated that low galectin-3 may be a direct effect of this drug. Galectin-3 was higher in PVS compared with HVS and SVS, suggesting that the splanchnic region is a major site of galectin-3 synthesis. Low galectin-3 in HVS compared with PVS demonstrated hepatic removal.
  
  
  CONCLUSIONS
  Systemic galectin-3 is elevated in obesity and negatively correlates with glycated hemoglobin in T2D patients, pointing to a modifying function of galectin-3 in human metabolic diseases.
authors.affiliation: Department of Internal Medicine I, Regensburg University Hospital, D-93042 Regensburg, Germany.
authors.forename: Johanna
authors.initials: J
authors.lastname: Weigert
authors.forename: Markus
authors.initials: M
authors.lastname: Neumeier
authors.forename: Josef
authors.initials: J
authors.lastname: Wanninger
authors.forename: Sabrina
authors.initials: S
authors.lastname: Bauer
authors.forename: Stefan
authors.initials: S
authors.lastname: Farkas
authors.forename: Marcus N
authors.initials: MN
authors.lastname: Scherer
authors.forename: Andreas
authors.initials: A
authors.lastname: Schnitzbauer
authors.forename: Andreas
authors.initials: A
authors.lastname: Schäffler
authors.forename: Charalampos
authors.initials: C
authors.lastname: Aslanidis
authors.forename: Jürgen
authors.initials: J
authors.lastname: Schölmerich
authors.forename: Christa
authors.initials: C
authors.lastname: Buechler
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D000328:Adult; D000368:Aged; D000818:Animals; D015153:Blotting, Western; D015992:Body Mass Index; D002478:Cells, Cultured; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D037502:Galectin 3 / Q000378:metabolism*; D006442:Glycated Hemoglobin / Q000032:analysis*; D006801:Humans; D050152:Intra-Abdominal Fat / Q000187:drug effects / Q000378:metabolism*; D020738:Leptin / Q000097:blood; D008297:Male; D008687:Metformin / Q000494:pharmacology / Q000627:therapeutic use; D051379:Mice; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism*; D052243:Resistin / Q000097:blood; D018709:Statistics, Nonparametric
chemical_list: D037502:Galectin 3; D006442:Glycated Hemoglobin; D020738:Leptin; D008687:Metformin; D052243:Resistin