title: Adiposity and low-grade systemic inflammation modulate matrix metalloproteinase-9 levels in Greek children with sleep apnea.
abstract: BACKGROUND
  Matrix metalloproteinase-9 (MMP-9) plasma levels correlate with C-reactive protein (CRP) concentrations and they are both increased in adults with obstructive sleep apnea (OSA). No studies have evaluated MMP-9 levels in children with sleep apnea and CRP is not consistently elevated in pediatric OSA. The aim of this investigation was to evaluate the association of severity of OSA, adiposity, and CRP with MMP-9 plasma levels in Greek children.
  
  
  METHODS
  Consecutive children with snoring who underwent polysomnography and were found to have OSA (obstructive apnea-hypopnea index-OAHI > or = 1 episode/hr) were recruited. Subjects without OSA (OAHI < 1 episode/hr) were included for comparison. Morning plasma MMP-9 and CRP were measured.
  
  
  RESULTS
  Twenty-nine children with moderate-to-severe OSA (age 5.4 +/- 1.5 years; OAHI 13.9 +/- 13.0 episodes/hr), 55 participants with mild OSA (6.4 +/- 2.6 years; OAHI 2.4 +/- 1.1 episodes/hr) and 22 subjects without OSA (6.8 +/- 2.6 years; OAHI 0.6 +/- 0.2 episodes/hr) were studied. Children with moderate-to-severe OSA were similar to those with mild OSA or without OSA regarding ln-transformed MMP-9 values (5.87 +/- 0.60 vs. 5.84 +/- 0.55 vs. 5.80 +/- 0.46; P > 0.05) and CRP concentrations (0.22 +/- 0.29 mg/dl vs. 0.21 +/- 0.36 vs. 0.13 +/- 0.16 mg/dl; P > 0.05). In multiple linear regression, body mass index (P = 0.027) and CRP levels (P = 0.008), but not OAHI or SpO(2) nadir (P > 0.05), were significantly related to MMP-9 values.
  
  
  CONCLUSIONS
  Adiposity and systemic inflammation unrelated to OSA severity, modulate MMP-9 levels in Greek children.
authors.affiliation: University of Thessaly, School of Medicine, Larissa, Greece. kaditia@hotmail.com
authors.forename: Athanasios G
authors.initials: AG
authors.lastname: Kaditis
authors.forename: Emmanouel I
authors.initials: EI
authors.lastname: Alexopoulos
authors.forename: Anastasia
authors.initials: A
authors.lastname: Karathanasi
authors.forename: Georgia
authors.initials: G
authors.lastname: Ntamagka
authors.forename: Smaragda
authors.initials: S
authors.lastname: Oikonomidi
authors.forename: Theodoros S
authors.initials: TS
authors.lastname: Kiropoulos
authors.forename: Elias
authors.initials: E
authors.lastname: Zintzaras
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Gourgoulianis
mesh_terms: D050154:Adiposity; D002097:C-Reactive Protein / Q000032:analysis; D002648:Child; D002675:Child, Preschool; D005260:Female; D006115:Greece; D006801:Humans; D007249:Inflammation / Q000201:enzymology*; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000097:blood*; D017286:Polysomnography; D012720:Severity of Illness Index; D020181:Sleep Apnea, Obstructive / Q000097:blood / Q000201:enzymology*; D012913:Snoring / Q000201:enzymology
chemical_list: D002097:C-Reactive Protein; D020780:Matrix Metalloproteinase 9