title: Obesity, weight change, and functional decline in peripheral arterial disease.
abstract: BACKGROUND
  Our objectives were to determine whether obesity is associated with a greater functional decline compared with the ideal body mass index (BMI) among persons with peripheral arterial disease (PAD) and to determine the associations between weight gain and loss and functional declines in PAD. We hypothesized that baseline obesity and weight gain during follow-up would each be associated with functional declines in persons with PAD.
  
  
  METHODS
  The design was a prospective cohort study. The subjects were 389 men and women with PAD (mean ankle-brachial index, 0.65 +/- 0.14) who were followed up prospectively for a median of 48 months. The main outcome measures were functional assessments (6-minute walk, usual- and rapid-paced 4-m walking speed, and summary performance score). Weight and height were measured at baseline and annually. Results were adjusted for age, sex, race, comorbidities, ankle-brachial index, education, leg symptoms, exercise status, depressive symptoms, pack-years of cigarette smoking, prior-year functioning, and patterns of missing data.
  
  
  RESULTS
  Compared with those with a baseline BMI between 20 and 25 kg/m2, PAD participants with baseline BMI greater than 30 kg/m2 had a significantly greater average annual decline in 6-minute walk performance (-13.1 vs -26.5 m/y; P = .004), usual-paced 4-m walking velocity (-0.028 vs -0.055 m/s per year; P = .024), and fast-paced 4-m walking velocity (-0.053 vs -0.086 m/s per year; P = .012). Persons with weight gain between 5 and 10 pounds after baseline who walked for exercise regularly had significantly less decline in the 6-minute walk than persons without significant weight change who did not walk for exercise (P = .04).
  
  
  CONCLUSIONS
  Obesity is associated with functional decline in persons with PAD. Walking exercise may protect against functional decline in PAD persons with modest weight gain.
authors.affiliation: Department of Medicine, Northwestern University's Feinberg School of Medicine, Chicago, IL 60611, USA. mdm608@northwestern.edu
authors.forename: Mary M
authors.initials: MM
authors.lastname: McDermott
authors.forename: Michael H
authors.initials: MH
authors.lastname: Criqui
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: Lu
authors.initials: L
authors.lastname: Tian
authors.forename: Kiang
authors.initials: K
authors.lastname: Liu
authors.forename: Philip
authors.initials: P
authors.lastname: Greenland
authors.forename: Jin
authors.initials: J
authors.lastname: Tan
authors.forename: Joseph R
authors.initials: JR
authors.lastname: Schneider
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Clark
authors.forename: William H
authors.initials: WH
authors.lastname: Pearce
mesh_terms: D000368:Aged; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007866:Leg / Q000098:blood supply*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000503:physiopathology*; D016491:Peripheral Vascular Diseases / Q000503:physiopathology*; D011446:Prospective Studies; D016138:Walking / Q000502:physiology*; D015430:Weight Gain; D015431:Weight Loss