title: Ghrelin-leptin network influences serum chitinase 3-like protein 1 (YKL-40) levels in obese prepubertal children.
abstract: OBJECTIVE
  This study aimed to investigate any possible interactions between hormonal regulators of weight gain and markers of subclinical inflammation in childhood obesity. Forty-one obese prepubertal children and 41 age- and gender-matched lean controls were included. Children were classified as obese or non-obese according to international age- and gender-specific body mass index (BMI) cutoff points defined by the International Obesity Task Force to define childhood obesity. Anthropometric measurements, serum insulin, chitinase 3-like protein (YKL-40), ghrelin and leptin levels as well as plasma glucose in the fasting state were determined.
  
  
  RESULTS
  Obese children as compared with controls had higher YKL-40 (50.7±15.2 vs 41.0±10.5 ng/ml, p=0.003), higher leptin (33.8±16.0 vs 9.7±7.5 ng/ml, p<0.001) and lower ghrelin serum levels (871.4±368.0 vs 1417.6±387.3 pg/ml, p<0.001). The obese children with ghrelin levels above median (43.8±10.2 ng/ml) as compared to those with ghrelin below median (57.2±16.6 ng/ml) presented lower serum YKL-40 levels (p=0.009), indicating more severe inflammation with lower levels of ghrelin. By contrast, although the obese children with leptin levels above median (49.7±16.3 ng/ml) presented lower serum YKL-40 levels as compared to those with leptin levels below median (51.6±14.6 ng/ml), this difference did not reach the level of statistical significance (p=0.726). Moreover, serum YKL-40 levels were significantly correlated with ghrelin (r=-0.359, p=0.014) but not with leptin levels (r=0.169, p=0.261). A significant negative correlation between ghrelin and leptin levels was also found (r=-0.276, p=0.041). These findings remained unchanged for obese, when analyses were done separately, whereas the significance of correlations was lost for non-obese subjects.
  
  
  CONCLUSIONS
  Ghrelin-leptin network had an impact on serum YKL-40 levels in obese prepubertal children; upregulation of YKL-40 secretion seems to be a consequence of reduced ghrelin rather than elevated leptin concentrations.
authors.affiliation: 4th Department of Pediatrics, Faculty of Medicine, Aristotle University of Thessaloniki, Papageorgiou General Hospital, Thessaloniki, Greece.
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kyrgios
authors.affiliation: 4th Department of Pediatrics, Faculty of Medicine, Aristotle University of Thessaloniki, Papageorgiou General Hospital, Thessaloniki, Greece. Electronic address: gallitsin@gmail.com.
authors.forename: Assimina
authors.initials: A
authors.lastname: Galli-Tsinopoulou
authors.affiliation: 4th Department of Pediatrics, Faculty of Medicine, Aristotle University of Thessaloniki, Papageorgiou General Hospital, Thessaloniki, Greece.
authors.forename: Charilaos
authors.initials: C
authors.lastname: Stylianou
mesh_terms: D054392:Adipokines / Q000097:blood* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D000071451:Chitinase-3-Like Protein 1; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000201:enzymology / Q000378:metabolism; D037102:Lectins / Q000097:blood* / Q000378:metabolism; D020738:Leptin / Q000097:blood*; D063766:Pediatric Obesity / Q000097:blood* / Q000201:enzymology / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D054392:Adipokines; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D054439:Ghrelin; D037102:Lectins; D020738:Leptin