title: Heterogeneous properties of intermediate- and low-density lipoprotein subpopulations.
abstract: OBJECTIVE
  Intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) consist of heterogeneous particles whose subpopulations may have different atherogenic characteristics. This study investigated the associations between these subpopulations and other lipids, lipoproteins and atherosclerosis-related markers.
  
  
  METHODS
  A total of 416 subjects (124 males and 292 females, mean age: 50.8 years) were enrolled in this study. Using polyacrylamide gel electrophoresis, serum lipoproteins were separated according to their specific electrophoretic mobility based on particle size. The IDL particles were separated into three midbands (MID-A to C), and the LDL particles were separated into seven subfractions (LDL1 to 7).
  
  
  RESULTS
  MID-B, MID-C, LDL2 and LDL3 to 6 (as a small LDL fraction) were significantly and positively correlated with very LDL (VLDL), while MID-A and LDL1 were significantly and inversely correlated with VLDL. MID-A and LDL1 were significantly and positively correlated with high-density lipoprotein (HDL). The correlation patterns between MID-A or LDL1 and triglycerides, apolipoprotein A-I, glucose, the insulin resistance index, creatinine and the mean LDL particle size had similar trends to those between HDL and these parameters.
  
  
  CONCLUSIONS
  The respective subpopulations of IDL and LDL particles can vary in their ability to predict cardiovascular disease risks. These variations may partially explain why quantitative assessments using LDL-cholesterol concentrations, as typically performed in conventional practice, are not perfect predictors of cardiovascular disease. Further studies are required to determine the clinical relevance of analyzing the IDL and LDL subpopulations.
authors.affiliation: Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand.
authors.forename: Pornpen
authors.initials: P
authors.lastname: Srisawasdi
authors.forename: Somlak
authors.initials: S
authors.lastname: Vanavanan
authors.forename: Mana
authors.initials: M
authors.lastname: Rochanawutanon
authors.forename: Prapaporn
authors.initials: P
authors.lastname: Pornsuriyasak
authors.forename: Visasiri
authors.initials: V
authors.lastname: Tantrakul
authors.forename: Khanat
authors.initials: K
authors.lastname: Kruthkul
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kotani
mesh_terms: D000368:Aged; D016632:Apolipoprotein A-I / Q000097:blood; D050197:Atherosclerosis / Q000097:blood* / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D008078:Cholesterol, LDL / Q000097:blood; D003404:Creatinine / Q000097:blood; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D053419:Lipoproteins, IDL / Q000097:blood* / Q000145:classification; D008077:Lipoproteins, LDL / Q000097:blood* / Q000145:classification; D008079:Lipoproteins, VLDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D010316:Particle Size; D010808:Physical Examination; D014280:Triglycerides / Q000097:blood
chemical_list: D016632:Apolipoprotein A-I; D015415:Biomarkers; D001786:Blood Glucose; D008078:Cholesterol, LDL; D053419:Lipoproteins, IDL; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D003404:Creatinine
keywords: ApoA-I; ApoB; Atherogenic lipoprotein; Atherosclerosis; CVD; Cardiovascular disease; HDL; HDL-C; HOMA-IR; HbA1C; IDL; Intermediate-density lipoprotein; LDL; LDL-C; Lipid; Lipoprotein subpopulation; Low-density lipoprotein; MID; TC; TG; VLDL; apolipoprotein A-I; apolipoprotein B; cardiovascular disease; hemoglobin A1C; high-density lipoprotein; high-density lipoprotein cholesterol; high-sensitivity C-reactive protein; homeostasis model assessment of insulin resistance; hsCRP; intermediate-density lipoprotein; low-density lipoprotein; low-density lipoprotein cholesterol; midband: intermediate-density lipoprotein; total cholesterol; triglyceride; very-low-density lipoprotein