title: Insulin resistance is associated with coronary plaque vulnerability: insight from optical coherence tomography analysis.
abstract: OBJECTIVE
  Previous studies have reported that insulin resistance plays an important role in the progression of atherosclerosis. However, the relationship between insulin resistance and coronary plaque instability is not well established. The purpose of this study was to assess the relationship between insulin resistance and coronary plaque characteristics identified by optical coherence tomography (OCT).
  
  
  RESULTS
  This study enrolled 155 consecutive patients undergoing percutaneous coronary intervention. OCT image acquisitions were performed in the culprit lesions. Insulin resistance was identified using the homeostasis model assessment of insulin resistance (HOMA-IR). Subjects were divided into three tertiles according to the HOMA-IR values. Patients in the higher HOMA tertile had more frequent prevalence of lipid-rich plaques than those in the middle and lower tertiles (83 vs. 62 vs. 57%; P = 0.01). The thin-cap fibroatheroma (TCFA) prevalence rates among the higher (>2.5), middle (1.4-2.5), and lower HOMA-IR (<1.4) tertiles were 50, 29, and 26% (P = 0.02). The microvessel prevalence rates of the three tertiles were 54, 39, and 28% (P = 0.02). Furthermore, in the higher HOMA-IR group, the fibrous cap was significantly thinner compared with the other two tertiles (vs. lower HOMA-IR, P = 0.009; vs. middle HOMA-IR, P = 0.008). On multivariate analysis, acute coronary syndrome [odds ratio (OR): 17.98; 95% confidence interval (CI): 7.12-52.02; P < 0.0001] and HOMA-IR >2.50 (OR: 3.57; 95% CI: 1.42-9.55; P = 0.007) were independent predictors for the presence of TCFA.
  
  
  CONCLUSIONS
  This study suggests that insulin resistance might be associated with coronary plaque vulnerability.
authors.affiliation: Department of Cardiovascular Medicine, Osaka City University, Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Iguchi
authors.forename: Takao
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Otsuka
authors.forename: Kenji
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Takanori
authors.initials: T
authors.lastname: Yamazaki
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nishimura
authors.forename: Shinji
authors.initials: S
authors.lastname: Nakata
authors.forename: Shoichi
authors.initials: S
authors.lastname: Ehara
authors.forename: Toru
authors.initials: T
authors.lastname: Kataoka
authors.forename: Kenei
authors.initials: K
authors.lastname: Shimada
authors.forename: Minoru
authors.initials: M
authors.lastname: Yoshiyama
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D015906:Angioplasty, Balloon, Coronary / Q000379:methods; D015331:Cohort Studies; D017023:Coronary Angiography / Q000379:methods; D003324:Coronary Artery Disease / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000628:therapy; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007333:Insulin Resistance; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D058226:Plaque, Atherosclerotic / Q000000981:diagnostic imaging / Q000473:pathology*; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: Insulin resistance; Optical coherence tomography; Vulnerable plaque