title: Serum level of cartilage oligomeric matrix protein is lower in children with idiopathic scoliosis than in non-scoliotic controls.
abstract: OBJECTIVE
  The etiology of idiopathic scoliosis remains unknown, but growth is a risk factor for progression. Growth pattern differs in children with and without scoliosis. Cartilage oligomeric matrix protein (COMP) may be associated with scoliosis and growth. We, therefore, studied COMP in children with and without idiopathic scoliosis.
  
  
  METHODS
  We included 105 children, with mean age 14.4 years (range 10-16), under observation or treatment for idiopathic scoliosis, and 103 children from an age-matched population-based cohort. COMP was measured in serum at the time of inclusion. Growth velocity was estimated from repeated height measurements. T tests, analysis of covariance or linear regression were used for statistical comparisons.
  
  
  RESULTS
  COMP was mean (SD) 11 (5) units/liter (U/L) in children with scoliosis and 13 (5) U/L in the control cohort (p = 0.005, adjusted for sex and sampling time of the day). When patients and controls were analyzed together, high COMP was correlated with high growth velocity (β = 0.19, p = 0.003). When patients and controls were analyzed separately, COMP was correlated with growth velocity in children with scoliosis (β = 0.27, p = 0.007), but not in children without scoliosis (β = 0.02, p = 0.83) (all analyses adjusted for age, sex and sampling time). Low COMP was significantly correlated with large curve size in children with scoliosis (β = -0.29, p = 0.003), but not after adjustment for age, sex and sampling time (β = -0.16; p = 0.14).
  
  
  CONCLUSIONS
  COMP was lower in children with idiopathic scoliosis than in a control cohort. In children with scoliosis, high COMP was modestly correlated with high growth velocity, but not with curve severity.
authors.affiliation: Department of Clinical Sciences, Intervention and Technology (CLINTEC), Karolinska Institutet, Stockholm, Sweden, paul.gerdhem@karolinska.se.
authors.forename: P
authors.initials: P
authors.lastname: Gerdhem
authors.forename: C
authors.initials: C
authors.lastname: Topalis
authors.forename: A
authors.initials: A
authors.lastname: Grauers
authors.forename: J
authors.initials: J
authors.lastname: Stubendorff
authors.forename: A
authors.initials: A
authors.lastname: Ohlin
authors.forename: K M
authors.initials: KM
authors.lastname: Karlsson
mesh_terms: D000293:Adolescent; D064236:Cartilage Oligomeric Matrix Protein / Q000097:blood*; D016022:Case-Control Studies; D002648:Child; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D012600:Scoliosis / Q000097:blood*
chemical_list: D064236:Cartilage Oligomeric Matrix Protein