title: Low-density lipoprotein subclasses in children under 10 years of age.
abstract: OBJECTIVE
  To examine the prevalence of small dense low density lipoprotein (LDL) in a cohort of children under 10 years of age and to investigate the relationship to other biochemical variables and to measures of fatness. A preponderance of small dense LDL (pattern B), is associated with obesity, abdominal fat accumulation, insulin resistance and risk of heart disease in adults.
  
  
  METHODS
  LDL peak particle diameter (PPD) was determined by gel electrophoresis in 53 children under 10 years of age and in 65 of their parents: apoproteins A1 and B were determined by turbidimetry. Anthropometric variables, basic lipid profiles, insulin and leptin had been determined previously. Differences between patterns A (large light particles > 25.5 nm diameter) and B were examined by t-test, Chi-square, or Mann-Whitney test. Relationships between the variables were reported as Pearson correlation coefficients.
  
  
  RESULTS
  Pattern B (PPD of < or = 25.5 nm) prevalence was 7.5% in children and 11% in parents (17% in men and 5% in women). Most of the children (86%) who had PPD < or = 26.0 nm also had parents with PPD in this range. A strong association was found between children's and mother's PPD (r=0.60, P < 0.001), but this was somewhat less with fathers (r=0.40, P=0.02). Children in the lowest tertile of PPD had a tendency towards a higher body mass index, waist, fat mass and insulin.
  
  
  CONCLUSIONS
  The prevalence of small dense LDL is lower in children under 10 years of age than in their parents; fathers had a higher prevalence of pattern B than mothers and there is some evidence of a familial effect in the inheritance of pattern B.
authors.affiliation: Metabolism and Obesity Services, Department of Endocrinology, Royal Prince Alfred Hospital, Sydney, Australia.
authors.forename: K S
authors.initials: KS
authors.lastname: Steinbeck
authors.forename: M A
authors.initials: MA
authors.lastname: Bermingham
authors.forename: D
authors.initials: D
authors.lastname: Mahajan
authors.forename: L A
authors.initials: LA
authors.lastname: Baur
mesh_terms: D017677:Age Distribution; D001315:Australia / Q000453:epidemiology; D015992:Body Mass Index; D016009:Chi-Square Distribution; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008077:Lipoproteins, LDL / Q000032:analysis / Q000097:blood*; D008297:Male; D009765:Obesity / Q000175:diagnosis / Q000453:epidemiology*; D011336:Probability; D012307:Risk Factors; D017678:Sex Distribution; D018709:Statistics, Nonparametric
chemical_list: D008077:Lipoproteins, LDL