title: Borderline ankle-brachial index value of 0.91-0.99 is associated with endothelial dysfunction.
abstract: BACKGROUND
  An ankle-brachial index (ABI) value of 0.91-0.99 is considered borderline and associated with an increased risk of cardiovascular events. However, there is no information on the relationship between borderline ABI and endothelial function.
  
  
  RESULTS
  We measured ABI and assessed vascular function by flow-mediated vasodilation (FMD) and nitroglycerin-induced vasodilation in 389 subjects who underwent health examinations. Subjects were divided into 3 groups according to ABI (normal group: 1.00-1.40, borderline group: 0.91-0.99, abnormal group: ≤0.90 or >1.40). FMD was significantly smaller in both the borderline and the abnormal group than in the normal group. There was no significant difference in the vascular responses to nitroglycerin between the normal and borderline groups. Vascular response to nitroglycerin was significantly higher in the normal group than in the abnormal group. Borderline and abnormal ABI values were significantly associated with an increased odds ratio of low tertile of FMD levels, using the normal ABI group as the reference. Multiple logistic regression analysis for FMD revealed that age, sex, hypertension, diabetes mellitus, and borderline ABI independently remained associated with FMD.
  
  
  CONCLUSIONS
  ABI of 0.91-0.99 is associated with endothelial dysfunction. ABI examination is a simple and cost-effective method for obtaining the additional information on the initial step of atherosclerosis beyond the assessment of peripheral artery disease.
authors.affiliation: Department of Cardiovascular Medicine, Institute of Biomedical & Health Sciences.
authors.forename: Masato
authors.initials: M
authors.lastname: Kajikawa
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Maruhashi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Iwamoto
authors.forename: Akimichi
authors.initials: A
authors.lastname: Iwamoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Matsumoto
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hidaka
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Kihara
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Chayama
authors.forename: Ayumu
authors.initials: A
authors.lastname: Nakashima
authors.forename: Chikara
authors.initials: C
authors.lastname: Goto
authors.forename: Kensuke
authors.initials: K
authors.lastname: Noma
authors.forename: Yukihito
authors.initials: Y
authors.lastname: Higashi
mesh_terms: D000328:Adult; D000368:Aged; D055109:Ankle Brachial Index / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D005996:Nitroglycerin / Q000008:administration & dosage; D058729:Peripheral Arterial Disease / Q000175:diagnosis* / Q000503:physiopathology*; D017539:Tunica Intima / Q000503:physiopathology*; D014664:Vasodilation; D014665:Vasodilator Agents / Q000008:administration & dosage
chemical_list: D014665:Vasodilator Agents; D005996:Nitroglycerin