title: Studies of LDL particle size and susceptibility to oxidation and association with glucose metabolism in children after heart transplantation.
abstract: BACKGROUND
  Increased concentrations of serum triglyceride and low-density lipoprotein (LDL) cholesterol are common after heart transplantation (HTx). These abnormalities may promote transplant vascular disease and atherosclerosis, especially if LDL is small, dense, and oxidized. There have been no previous studies of LDL particle size and LDL susceptibility to oxidation in children after HTx.
  
  
  METHODS
  Twenty-three HTx recipients (aged 3-19 years) who received triple-drug immunosuppression therapy after HTx and 181 controls within the same age range participated in the study. Total, high-density lipoprotein, and LDL-cholesterol concentrations; triglyceride concentration, and glucose and insulin concentrations during oral glucose tolerance tests were determined an average of 3 years after HTx (range, 1-7 years). Moreover, we determined serum lipoprotein (a) concentration, apolipoprotein E phenotype, LDL particle size, and indices of LDL susceptibility to copper-induced oxidation in 12 HTx recipients.
  
  
  RESULTS
  We found hypertriglyceridemia in 56.5% and hyperinsulinemia in 30.4% of patients. Triglyceride concentration and body mass index were associated significantly with insulin concentration (p < 0.008 for both). Low-density lipoprotein particle size, LDL susceptibility to in vitro oxidation, and lipoprotein (a) concentrations did not differ significantly between HTx patients and controls. Low-density lipoprotein particle size was associated inversely with cyclosporine through level (Neoral, r = -0.59, p = 0.045), whereas weight-adjusted dosage of cyclosporine correlated positively with longer lag time of LDL oxidation (r = 0.69, p = 0.013).
  
  
  CONCLUSIONS
  Hypertriglyceridemia and hyperinsulinemia were common in children receiving triple-drug immunosuppression therapy after HTx. Increased cyclosporine through concentration was associated with small LDL particle size but did not increase LDL susceptibility to oxidation.
authors.affiliation: Paediatric Research Centre, University of Tampere, Tampere, Finland. arja.siirtola@uta.fi
authors.forename: Arja
authors.initials: A
authors.lastname: Siirtola
authors.forename: Marjatta
authors.initials: M
authors.lastname: Antikainen
authors.forename: Marja
authors.initials: M
authors.lastname: Ala-Houhala
authors.forename: Tiina
authors.initials: T
authors.lastname: Solakivi
authors.forename: Hannu
authors.initials: H
authors.lastname: Jokela
authors.forename: Terho
authors.initials: T
authors.lastname: Lehtimäki
authors.forename: Christer
authors.initials: C
authors.lastname: Holmberg
authors.forename: Matti K
authors.initials: MK
authors.lastname: Salo
mesh_terms: D000293:Adolescent; D000328:Adult; D001054:Apolipoproteins A / Q000097:blood; D001055:Apolipoproteins B / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002784:Cholesterol / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D005951:Glucose Tolerance Test; D016027:Heart Transplantation / Q000502:physiology*; D006801:Humans; D007165:Immunosuppression Therapy; D007328:Insulin / Q000097:blood; D008077:Lipoproteins, LDL / Q000737:chemistry*; D008297:Male; D010084:Oxidation-Reduction; D010316:Particle Size; D014280:Triglycerides / Q000097:blood*
chemical_list: D001054:Apolipoproteins A; D001055:Apolipoproteins B; D001786:Blood Glucose; D007328:Insulin; D008077:Lipoproteins, LDL; D014280:Triglycerides; D002784:Cholesterol