title: Circulating irisin, omentin-1, and lipoprotein subparticles in adults at higher cardiovascular risk.
abstract: OBJECTIVE
  Muscle and fat are now recognized as metabolism-regulating endocrine organs. However, muscle and adipocyte-derived novel cytokines such as irisin and omentin-1 remain understudied in relation to metabolic biomarkers that are associated with cardiovascular risk.
  
  
  METHODS
  Thirty-nine subjects with mean (± SD) BMI of 29.2 ± 5.4 kg/m(2) and either diabetes or two other cardiovascular risk factors were enrolled in a 6-month randomized trial of low-dose ethanol. We examined cross-sectional data at baseline, 3-month, and 6-month visits to assess (1) within-person stability of novel cytokines (irisin, omentin-1, visfatin, resistin, and soluble tumor necrosis factor receptor II) and (2) their associations with metabolic parameters, particularly lipoprotein subparticle profile.
  
  
  RESULTS
  Repeated measures of irisin and omentin-1 were highly correlated, with intra-class correlations of 0.84 (95% CI: 0.74, 0.91; P < 0.001) and 0.81 (0.70, 0.89; P < 0.001), respectively. Irisin was negatively correlated with omentin-1 (7.4% irisin decrease per a 1-SD increment in omentin-1; 95% CI: 0.5%, 13.9%; P = 0.04). In models adjusted for age, sex, and race, irisin was negatively associated with HDL cholesterol (7.3% decrease per a 10mg/dL increment; 1.0%, 13.3%; P = 0.02) and large HDL particles (15.5% decrease per a 1-SD or 3.5-μmol/L increment; 5.2%, 24.7%; P=0.005). Omentin-1 was positively associated with mean VLDL size (3.8% increase per a 1-SD increment; 0.06%, 7.8%; P = 0.05). Adjustment for alcohol intervention, BMI, and other cytokines did not materially affect these associations.
  
  
  CONCLUSIONS
  Irisin and omentin-1 are stable within-person, inversely associated with each other, and closely related to lipoprotein profile. These molecules may be promising markers for cardiovascular risk.
authors: Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors: Grigorios
authors: G
authors: Panagiotou
authors: Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors: Lin
authors: L
authors: Mu
authors: Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
authors: Brian
authors: B
authors: Na
authors: Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA. Electronic address: kmukamal@bidmc.harvard.edu.
authors: Kenneth J
authors: KJ
authors: Mukamal
authors: Division of Endocrinology, Diabetes, and Metabolism, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA; Section of Endocrinology, Boston VA Healthcare System, Harvard Medical School, Boston, MA 02130, USA.
authors: Christos S
authors: CS
authors: Mantzoros
mesh_terms: D015415:Biomarkers / Q000097:blood; D002318:Cardiovascular Diseases / Q000097:blood*; D003430:Cross-Sectional Studies; D016207:Cytokines / Q000097:blood*; D005260:Female; D005353:Fibronectins / Q000097:blood*; D058851:GPI-Linked Proteins / Q000097:blood; D006801:Humans; D037102:Lectins / Q000097:blood*; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D052243:Resistin / Q000097:blood; D012307:Risk Factors
chemical_list: D015415:Biomarkers; D016207:Cytokines; C577593:FNDC5 protein, human; D005353:Fibronectins; D058851:GPI-Linked Proteins; C432397:ITLN1 protein, human; D037102:Lectins; D008074:Lipoproteins; D052243:Resistin
keywords: Atherosclerosis; Fibronectin type III domain containing 5; Longitudinal biomarker; Metabolic syndrome; Myokine