title: Association of borderline ankle-brachial index with mortality and the incidence of peripheral artery disease in diabetic patients.
abstract: OBJECTIVE
  Peripheral artery disease (PAD) and diabetes mellitus are significant risk factors for all-cause death or cardiovascular death. PAD occurs more frequently in diabetic than in non-diabetic patients. However, the association of ankle-brachial index (ABI), especially borderline ABI, with clinical outcomes has not been fully elucidated in diabetic patients. This study aimed to investigate the association of ABI with mortality and the incidence of PAD in Japanese diabetic patients.
  
  
  METHODS
  This observational study included 3981 diabetic patients (61.0 ± 11.8 years of age, 59.4% men), registered in the Kyushu Prevention Study for Atherosclerosis. Patients were divided into 3 groups according to the value of ABI at baseline: ABI ≤0.90 (abnormal ABI:354 patients), 0.91 ≤ ABI ≤ 0.99 (borderline ABI:333 patients), and 1.00 ≤ ABI ≤ 1.40 (normal ABI:3294 patients).
  
  
  RESULTS
  Cumulative incidence of all-cause death was significantly higher in patients with abnormal and borderline ABI than in those with normal ABI (34.4% vs. 13.5%, P < 0.0001 and 26.1% vs. 13.5%, P < 0.0001, respectively). In multivariate analysis, the risks for all-cause death in patients with abnormal ABI (HR:2.16; 95%CI:1.46-3.14; P = 0.0002) and borderline ABI (HR:1.78; 95%CI:1.14-2.70; P = 0.01) were significantly higher than in those with normal ABI. The incidence of PAD was remarkably higher in patients with borderline ABI than in those with normal ABI (32.2% vs.9.6%, P < 0.0001). After adjustment, the risk for PAD was significantly higher in patients with borderline ABI than in those with normal ABI (HR:3.10; 95%CI:1.90-4.95; P < 0.0001).
  
  
  CONCLUSIONS
  Borderline ABI in diabetic patients was associated with significantly higher risks for mortality and PAD compared with normal ABI.
authors.affiliation: Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Chiharu
authors.initials: C
authors.lastname: Natsuaki
authors.affiliation: Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka, Japan. Electronic address: toyoshi.inoguchi@gmail.com.
authors.forename: Toyoshi
authors.initials: T
authors.lastname: Inoguchi
authors.affiliation: Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Maeda
authors.affiliation: Department of Clinical Epidemiology and Biostatistics, Graduate School of Medicine, Osaka University, Osaka, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Shuji
authors.initials: S
authors.lastname: Sasaki
authors.affiliation: Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka, Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Sonoda
authors.affiliation: Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Shimabukuro
authors.affiliation: Seiwakai, Muta Hospital, Fukuoka, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Nawata
authors.affiliation: Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Takayanagi
mesh_terms: D000368:Aged; D055109:Ankle Brachial Index; D002423:Cause of Death; D003920:Diabetes Mellitus / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality; D005260:Female; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000175:diagnosis* / Q000453:epidemiology* / Q000401:mortality; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors
keywords: Ankle-brachial index; Diabetes mellitus; Mortality; Peripheral artery disease