title: Evaluation of the relationship between circulating omentin-1 concentrations and components of the metabolic syndrome in adults without type 2 diabetes or cardiovascular disease.
abstract: BACKGROUND
  Dysregulation of omentin-1, a beneficial adipokine, is thought to play a role in the development of type 2 diabetes and cardiovascular disease. The objective of this study was to evaluate the relationship between circulating omentin-1 concentrations and components of the metabolic syndrome in adults without type 2 diabetes or cardiovascular disease, and to determine if sex differences influenced the observed relationships.
  
  
  METHODS
  Fasting blood samples were obtained from 93 adults, ages 30-60 years, without type 2 diabetes and/or cardiovascular disease. Participants were classified as having the metabolic syndrome according to American Heart Association/National Heart, Lung and Blood Institute criteria. Plasma omentin-1 concentrations were measured using a commercially-available enzyme-linked immunosorbent assay, and relationships between plasma omentin-1 and components of the metabolic syndrome were assessed in the entire study cohort, by metabolic syndrome status, and by sex.
  
  
  RESULTS
  On average, participants were 48 ± 8 years of age, 50.5% were women, 54.8% were Caucasian, and 70% had the metabolic syndrome. Plasma omentin-1 concentrations did not differ significantly between individuals with versus without the metabolic syndrome (145.7 ± 70 versus 157.4 ± 79.3 ng/ml, p = 0.50). However, men with the metabolic syndrome had significantly lower omentin-1 levels than men without the metabolic syndrome (129.9 ± 66 versus 186.3 ± 84.3 ng/ml, p = 0.03). Plasma omentin-1 concentrations were significantly correlated with HDL cholesterol in the entire study cohort (r = 0.26; p = 0.01), which was primarily driven by a correlation in men (r = 0.451, p = 0.002) and participants with the metabolic syndrome (r = 0.36; p = 0.003). Plasma omentin-1 concentrations did not differ significantly between men and women; however men with the metabolic syndrome had 20% lower plasma omentin-1 levels than women with the metabolic syndrome (p = 0.06).
  
  
  CONCLUSIONS
  These data demonstrate that circulating omentin-1 levels are associated with HDL cholesterol, primarily in men and in the presence of the metabolic syndrome. In addition, sex appears to influence the relationship between plasma omentin-1 concentrations and components of the metabolic syndrome. Additional studies are needed to explore sexual dimorphism in circulating omentin-1 levels, and the role of omentin-1 in the metabolic syndrome.
authors.forename: Anh
authors.initials: A
authors.lastname: Vu
authors.forename: Maha S
authors.initials: MS
authors.lastname: Sidhom
authors.forename: Brooke C
authors.initials: BC
authors.lastname: Bredbeck
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Kosmiski
authors.affiliation: Department of Pharmaceutical Sciences, University of Colorado Skaggs School of Pharmacy and Pharmaceutical Sciences, 12850 East Montview Boulevard, Mail Stop C238, Aurora, CO 80045 USA. christina.aquilante@ucdenver.edu.
authors.forename: Christina L
authors.initials: CL
authors.lastname: Aquilante