title: Metformin increases the novel adipokine cartonectin/CTRP3 in women with polycystic ovary syndrome.
abstract: BACKGROUND
  Recently cartonectin was reported as a novel adipokine, with lower levels in diet-induced obese mice, glucose-lowering effects, and antiinflammatory and cardioprotective properties. Polycystic ovary syndrome (PCOS) is a proinflammatory state associated with obesity, diabetes, dyslipidemia, and cardiovascular complications.
  
  
  OBJECTIVE
  The objective of the study was to investigate cartonectin levels and regulation in sera and adipose tissue (AT) as well as the effects of metformin of women with PCOS and control subjects.
  
  
  METHODS
  This was a cross-sectional study [PCOS (n = 83) and control (n = 39) subjects]. Real-time PCR and Western blotting were used to assess mRNA and protein expression of cartonectin. Serum cartonectin was measured by an ELISA.
  
  
  RESULTS
  Serum and omental adipose tissue cartonectin were significantly lower in women with PCOS compared with control subjects (P < .05 and P < .01, respectively). Furthermore, cartonectin showed a significant negative association with body mass index, waist to hip ratio, glucose, insulin, total cholesterol, low-density lipoprotein-cholesterol, triglycerides, High sensitivity C-reactive protein (hs-CRP) and intima-media thickness (P < .05 and P < .01, respectively); in multiple regression analyses, triglycerides (P =.040) and hs-CRP (P = .031) were predictive of cartonectin levels (P < .05). After 6 months of metformin treatment, there was an associated increase in serum cartonectin (P < .05). Importantly, changes in hs-CRP were significantly negatively correlated with changes in serum cartonectin (P = .033). Finally, cartonectin protein production and secretion into conditioned media were significantly increased by metformin in control human omental AT explants (P < .05).
  
  
  CONCLUSIONS
  Serum and omental AT cartonectin are lower in women with PCOS. Metformin treatment increases serum cartonectin levels in these women and in omental AT explants.
authors.affiliation: Warwick Medical School, University of Warwick, Coventry CV4 7AL, United Kingdom. b.k.tan@warwick.ac.uk.
authors.forename: Bee K
authors.initials: BK
authors.lastname: Tan
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Jiamiao
authors.initials: J
authors.lastname: Hu
authors.forename: Omar
authors.initials: O
authors.lastname: Amar
authors.forename: Harman S
authors.initials: HS
authors.lastname: Mattu
authors.forename: Raghu
authors.initials: R
authors.lastname: Adya
authors.forename: Vanlata
authors.initials: V
authors.lastname: Patel
authors.forename: Manjunath
authors.initials: M
authors.lastname: Ramanjaneya
authors.forename: Hendrik
authors.initials: H
authors.lastname: Lehnert
authors.forename: Harpal S
authors.initials: HS
authors.lastname: Randeva
mesh_terms: D054392:Adipokines / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D015992:Body Mass Index; D002097:C-Reactive Protein / Q000032:analysis; D002318:Cardiovascular Diseases / Q000150:complications / Q000517:prevention & control; D059168:Carotid Intima-Media Thickness; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015228:Hypertriglyceridemia / Q000150:complications; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D008687:Metformin / Q000627:therapeutic use*; D009852:Omentum; D050177:Overweight / Q000150:complications; D011085:Polycystic Ovary Syndrome / Q000150:complications / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D050507:Subcutaneous Fat, Abdominal / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D046509:Tissue Culture Techniques; D048069:Tumor Necrosis Factors / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D054392:Adipokines; D015415:Biomarkers; C506069:C1QTNF3 protein, human; D007004:Hypoglycemic Agents; D048069:Tumor Necrosis Factors; D002097:C-Reactive Protein; D008687:Metformin