title: Urine 8-isoprostane in relation to adiposity and insulin resistance in individuals at high cardiometabolic risk.
abstract: BACKGROUND
  Oxidative stress has been implicated in the pathogenesis of many conditions, including insulin resistance and obesity. However, in vivo data concerning these relationships are scarce and conflicting. Therefore, the aim of this study was to investigate the association of oxidative stress with abdominal adiposity and insulin resistance in individuals at high cardiometabolic risk.
  
  
  METHODS
  A total of 116 overweight/obese individuals participating in the HealthGrain and Etherpaths European Projects, having waist circumference (WC) and any other component of the metabolic syndrome, were included in this cross-sectional evaluation. 8-Isoprostane concentrations in 24-hr urine were measured as marker of oxidative stress in vivo. Baseline anthropometric and metabolic parameters were analyzed according to quartiles of 8-isoprostanes. Linear regression (LR) analysis was used to assess clinical correlates of oxidative stress.
  
  
  RESULTS
  Urinary 8-isoprostane levels were 52% higher in men than in women (P<0.001). Across the isoprostanes quartiles, there was a significant increase in WC and body weight [P for trend<0.001; analysis of variance (ANOVA) P<0.001] and fasting triglycerides (P for trend<0.05; ANOVA P<0.05), and a significant decrease in high-density lipoprotein cholesterol (P for trend<0.001; ANOVA P=0.001). No significant association between urinary isoprostane concentrations and insulin resistance [homeostasis model assessment of insulin resistance (HOMA-IR)] was found. WC circumference and body weight remained significant after adjustment for age and gender (P=0.023 and P=0.014, respectively) and independently associated with isoprostanes at LR (P<0.005 for both).
  
  
  CONCLUSIONS
  Central obesity was independently associated with oxidative stress even in a population homogeneous for adiposity and cardiometabolic risk, whereas no relationship was observed between oxidative stress and insulin resistance.
authors.affiliation: 1 Department of Clinical Medicine and Surgery, Federico II University , Naples, Italy .
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Costabile
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Della Pepa
authors.forename: Lutgarda
authors.initials: L
authors.lastname: Bozzetto
authors.forename: Giovanni
authors.initials: G
authors.lastname: Annuzzi
authors.forename: Claudia
authors.initials: C
authors.lastname: Vetrani
authors.forename: Rosalba
authors.initials: R
authors.lastname: Giacco
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Della Corte
authors.forename: Francesca Serena
authors.initials: FS
authors.lastname: Conte
authors.forename: Lucrezia
authors.initials: L
authors.lastname: Di Marino
authors.forename: Angela Albarosa
authors.initials: AA
authors.lastname: Rivellese
mesh_terms: D050153:Abdominal Fat; D050154:Adiposity; D000328:Adult; D000367:Age Factors; D000368:Aged; D001835:Body Weight; D008076:Cholesterol, HDL / Q000097:blood; D003430:Cross-Sectional Studies; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000652:urine; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D024821:Metabolic Syndrome / Q000652:urine*; D008875:Middle Aged; D009765:Obesity / Q000652:urine; D050177:Overweight / Q000652:urine; D018384:Oxidative Stress; D018570:Risk Assessment; D012727:Sex Characteristics; D014280:Triglycerides / Q000097:blood; D055105:Waist Circumference
chemical_list: D008076:Cholesterol, HDL; D014280:Triglycerides; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost