title: Possible relationship between insulin resistance and remnant-like lipoprotein particles in coronary endothelial dysfunction.
abstract: BACKGROUND
  High insulin resistance and elevated remnant lipoprotein levels both correlate with impaired coronary vascular endothelial function. Hyperinsulinemia induces abnormalities of lipid metabolism. However, the correlation among insulin resistance, remnant lipoproteins, and endothelial function has not been clinically elucidated.
  
  
  OBJECTIVE
  This study was designed to elucidate the correlation among insulin resistance, remnant lipoproteins, and acetylcholine (ACh)-induced coronary artery response.
  
  
  METHODS
  Forty-nine patients suspected of having ischemic heart disease, but without angiographically significant atherosclerotic coronary artery disease, underwent an ACh provocation test. Fasting venous blood was taken early in the morning on the day coronary angiography was performed. The insulin resistance index (IR) was determined from fasting plasma glucose and insulin concentrations, using the homeostasis model assessment (HOMA). Serum levels of remnant-like lipoprotein particle cholesterol (RLP-C) were measured.
  
  
  RESULTS
  Homeostasis model assessment IR was significantly higher (3.65 +/- 1.38 vs. 0.75 +/- 0.14, p < 0.05) and log-transformed HOMA (Log HOMA) was even more significantly higher (0.20 +/- 0.12 vs. -0.29 +/- 0.08, p < 0.001) in the ACh-positive group (n = 23) than in the ACh-negative group (n = 26). The serum RLP-C level was also higher in the ACh-positive group than in the ACh-negative group (4.37 +/- 0.63 vs. 2.52 +/- 0.18 mg/dl, p < 0.01). Log HOMA and RLP-C levels correlated with each other (R = 0.54, p < 0.001). Multiple regression analysis indicated that only the RLP-C level was a dependent predictor of Log HOMA in various lipid profiles.
  
  
  CONCLUSIONS
  Both high insulin resistance and elevated remnant lipoprotein levels correlated and might have a crucial role in the impairment of coronary vascular endothelial function, even in patients without angiographically significant coronary artery disease.
authors.affiliation: Department of Cardiology, Koshigaya Hospital, Dokkyo University School of Medicine, Saitama, Japan. inouet@dokkyomed.ac.jp
authors.forename: Teruo
authors.initials: T
authors.lastname: Inoue
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Uchida
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Kamishirado
authors.forename: Masashi
authors.initials: M
authors.lastname: Sakuma
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Sakai
authors.forename: Kan
authors.initials: K
authors.lastname: Takayanagi
authors.forename: Terumi
authors.initials: T
authors.lastname: Hayashi
authors.forename: Shigenori
authors.initials: S
authors.lastname: Morooka
mesh_terms: D000109:Acetylcholine; D001786:Blood Glucose / Q000032:analysis; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D017023:Coronary Angiography; D003331:Coronary Vessels / Q000187:drug effects / Q000503:physiopathology; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005215:Fasting / Q000097:blood; D005260:Female; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D014665:Vasodilator Agents
chemical_list: D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D007328:Insulin; D014665:Vasodilator Agents; D000109:Acetylcholine