title: Elevated circulating levels of lipoprotein-associated phospholipase A2 in obese children.
abstract: BACKGROUND
  Obesity and cardiovascular disease (CVD) often co-exist, but the pathophysiologic mechanisms that link the two are not fully understood. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is involved in the modification of lipids within atheromatous plaques. Recently, circulating Lp-PLA2 was found to be predictive of thromboembolic episodes in adults, independently of a variety of other potential risk factors, including markers of inflammation, renal function, and hemodynamic stress. However, the function of this lipase and its importance as a biomarker in childhood obesity is much less studied. The aim of the study was to study Lp-PLA2, a non-traditional risk factor of CVD, in obese children.
  
  
  METHODS
  Sixty-seven lean [39 boys and 28 girls, mean body mass index (BMI) z-score -0.2±0.8] and 66 obese (32 boys and 34 girls, mean BMI z-score 4.4±1.2) age-matched (p=0.251) children, aged 6-12 years, were studied. BMI z-score was calculated based on the Greek BMI growth curves, and children were categorized as obese according to the Cole criteria. All children underwent physical examination and a fasting morning blood sample was obtained for glucose, insulin, lipid profile, and Lp-PLA2 assessment. Plasma concentrations of Lp-PLA2 were determined by a commercially available Lp-PLA2 enzyme-linked immunosorbent assay kit (PLAC Test), while other measurements were performed using standard methods.
  
  
  RESULTS
  Plasma Lp-PLA2 levels were significantly higher in obese children (322.5±77.8 ng/mL) compared with normal-weight ones (278.0±64.4 ng/mL, p<0.001). Lp-PLA2 concentrations were significantly correlated with the BMI z-score (p=0.004). Receiver operating characteristic analysis on Lp-PLA2 values resulted in significant areas under the curve (AUC) for distinguishing between obese and normal-weight groups of children (AUC, 0.726; p<0.001).
  
  
  CONCLUSIONS
  We found significantly higher Lp-PLA2 levels in obese children than lean controls. Interestingly, they all had levels >200 ng/mL, which are considered to correlate with atherosclerosis and a high thromboembolic risk in adults. The positive correlation of Lp-PLA2 with BMI suggests that Lp-PLA2 might be the link between obesity and increased cardiovascular risk, which can be elevated even at a very young age. Measurement of Lp-PLA2 in plasma could therefore represent a further biomarker for assessing increased CVD risk in obese children and adolescents.
authors.forename: Sophia
authors.initials: S
authors.lastname: Sakka
authors.forename: Tania
authors.initials: T
authors.lastname: Siahanidou
authors.forename: Chronis
authors.initials: C
authors.lastname: Voyatzis
authors.forename: Panagiota
authors.initials: P
authors.lastname: Pervanidou
authors.forename: Christina
authors.initials: C
authors.lastname: Kaminioti
authors.forename: Natalia
authors.initials: N
authors.lastname: Lazopoulou
authors.forename: Christina
authors.initials: C
authors.lastname: Kanaka-Gantenbein
authors.forename: George P
authors.initials: GP
authors.lastname: Chrousos
authors.forename: Ioannis
authors.initials: I
authors.lastname: Papassotiriou
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D015992:Body Mass Index; D002648:Child; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood; D008297:Male; D009765:Obesity / Q000097:blood* / Q000201:enzymology*
chemical_list: D015415:Biomarkers; D008055:Lipids; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase