title: The influence of the obesity paradox and chronic kidney disease on long-term survival in a Japanese cohort with peripheral arterial disease.
abstract: BACKGROUND
  This study analyzed risk factors for mortality in peripheral arterial disease (PAD), including body mass index (BMI) and estimated glomerular filtration rate (eGFR). Risk factors for long-term survival are unclear in patients with PAD. The origin of the obesity paradox, a paradoxical decrease in mortality with increasing BMI, is also uncertain in these patients.
  
  
  METHODS
  A prospective cohort study was performed in 652 patients (aged 71.3 +/- 9.4 years old) with PAD.
  
  
  RESULTS
  The 1-, 5-, 10- and 15-year survival rates were 94.5%, 70.4%, 45.2%, and 21.1%, respectively, in patients with intermittent claudication, and 72.7%, 27.2%, 11.6%, and 5.8%, respectively, in those with critical limb ischemia (CLI). In Cox multivariate analysis, a significant association with all-cause mortality was found for CLI (hazard ratio [HR], 1.931; 95% confidence interval [CI], 1.089-3.422; P = .024), diabetes (HR, 2.111; 95% CI, 1.247-3.572; P = .005), BMI (HR, 0.879; 95% CI, 0.804-0.962; P = .005), and eGFR (HR, 0.985; 95% CI, 0.971-0.998l; P = .028). These parameters were also significant risk factors for cardiovascular mortality. Fibrinogen (HR, 1.003; 95% CI, 1.001-1.005; P = .014) and cerebrovascular disease (HR, 1.730; 95% CI, 1.021-2.930; P = .045) were identified as risk factors for all-cause mortality. The adjusted HR for mortality of BMI <21.5 vs >or=21.5 kg/m(2) was 1.772 (95% CI, 1.378-2.279; P < .001). BMI had positive correlations with triglyceride and albumin concentrations and negative correlations with the fibrinogen level and chronic obstructive pulmonary disease (P = .005).
  
  
  CONCLUSIONS
  Low BMI, eGFR, CLI, and diabetes are significant risk factors for mortality in PAD. The obesity paradox was verified and may be partly explained by low BMI mediated by malnutrition and systemic inflammation due to PAD or chronic obstructive pulmonary disease.
authors.affiliation: Department of Vascular Medicine, Cardiovascular Hospital of Central Japan (Kitakanto Cardiovascular Hospital), Shibukawa-city, Gunma Prefecture, Japan. kumakura@sannet.ne.jp
authors.forename: Hisao
authors.initials: H
authors.lastname: Kumakura
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Kanai
authors.forename: Masahiro
authors.initials: M
authors.lastname: Aizaki
authors.forename: Kito
authors.initials: K
authors.lastname: Mitsui
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Araki
authors.forename: Shu
authors.initials: S
authors.lastname: Kasama
authors.forename: Toshiya
authors.initials: T
authors.lastname: Iwasaki
authors.forename: Shuichi
authors.initials: S
authors.lastname: Ichikawa
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000706:statistics & numerical data*; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000208:ethnology / Q000401:mortality*; D002423:Cause of Death; D016009:Chi-Square Distribution; D002908:Chronic Disease; D003920:Diabetes Mellitus / Q000208:ethnology / Q000401:mortality; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007511:Ischemia / Q000208:ethnology / Q000401:mortality; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D007674:Kidney Diseases / Q000208:ethnology / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000208:ethnology / Q000401:mortality*; D016491:Peripheral Vascular Diseases / Q000208:ethnology / Q000401:mortality*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D017741:Survivors / Q000706:statistics & numerical data*; D013997:Time Factors