title: Relation between hyperinsulinemia and nonculprit plaque characteristics in nondiabetic patients with acute coronary syndromes.
abstract: OBJECTIVE
  We sought to assess whether hyperinsulinemia is associated with percentage lipid and coronary plaque burden in nondiabetic patients with acute coronary syndromes (ACS).
  
  
  BACKGROUND
  Hyperinsulinemia carries an increased risk of cardiovascular disease even in pre-diabetic patients, but the precise mechanisms of its effects remain unclear.
  
  
  METHODS
  Nonculprit coronary lesions associated with mild-to-moderate stenosis in 82 nondiabetic patients with ACS were examined by integrated backscatter intravascular ultrasound (IB-IVUS), using a 40-MHz intravascular catheter. Conventional IVUS and IB-IVUS measurements from the worst 10-mm segment (1-mm intervals) were calculated. All patients underwent a 75-g oral glucose tolerance test (OGTT) to calculate the area under the insulin concentration-time curve (AUC insulin) from 0 to 120 min.
  
  
  RESULTS
  Patients in the high tertile of AUC insulin had a significantly greater percentage lipid area and absolute lipid volume than did patients in the intermediate and low tertiles (tertile 3 vs. tertile 2 vs. tertile 1; 37.6 ± 16.6% vs. 25.8 ± 11.9% vs. 27.5 ± 14.7%, p < 0.01 by analysis of variance [ANOVA], and 29.9 ± 22.6 mm(3) vs. 15.3 ± 12.6 mm(3) vs. 17.7 ± 12.7 mm(3), p < 0.01 by ANOVA, respectively) and a smaller percentage fibrosis area (55.0 ± 11.5% vs. 61.7 ± 9.4% vs. 60.7 ± 9.4%, p = 0.03 by ANOVA). Multiple regression analysis showed that the high tertile of AUC insulin was independently associated with an increased percentage lipid area (p < 0.05). On conventional IVUS analysis, external elastic membrane cross-sectional area was significantly increased with greater plaque volume in patients in the high tertile of AUC insulin (both p < 0.05 by ANOVA).
  
  
  CONCLUSIONS
  Hyperinsulinemia is associated with an increased lipid content and a greater plaque volume of nonculprit intermediate lesions in nondiabetic patients with ACS, suggesting that plaque vulnerability is increased in this subgroup of patients.
authors.affiliation: Division of Cardiology, Yokohama City University Medical Center, Yokohama, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Mitsuhashi
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hibi
authors.forename: Masami
authors.initials: M
authors.lastname: Kosuge
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morita
authors.forename: Naohiro
authors.initials: N
authors.lastname: Komura
authors.forename: Ikuyoshi
authors.initials: I
authors.lastname: Kusama
authors.forename: Fumiyuki
authors.initials: F
authors.lastname: Otsuka
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Endo
authors.forename: Noriaki
authors.initials: N
authors.lastname: Iwahashi
authors.forename: Jun
authors.initials: J
authors.lastname: Okuda
authors.forename: Kengo
authors.initials: K
authors.lastname: Tsukahara
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Ebina
authors.forename: Satoshi
authors.initials: S
authors.lastname: Umemura
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kimura
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood / Q000175:diagnosis / Q000209:etiology*; D000368:Aged; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002114:Calcinosis / Q000150:complications; D017023:Coronary Angiography; D023921:Coronary Stenosis / Q000150:complications* / Q000175:diagnosis / Q000378:metabolism; D018450:Disease Progression; D005260:Female; D005355:Fibrosis; D005951:Glucose Tolerance Test; D006801:Humans; D006946:Hyperinsulinism / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D007328:Insulin / Q000097:blood; D007564:Japan; D008055:Lipids / Q000032:analysis; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012044:Regression Analysis; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D018084:Ultrasonography, Interventional
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D008055:Lipids