title: The Intensive Diet and Exercise for Arthritis (IDEA) trial: 18-month radiographic and MRI outcomes.
abstract: OBJECTIVE
  Report the radiographic and magnetic resonance imaging (MRI) structural outcomes of an 18-month study of diet-induced weight loss, with or without exercise, compared to exercise alone in older, overweight and obese adults with symptomatic knee osteoarthritis (OA).
  
  
  METHODS
  Prospective, single-blind, randomized controlled trial that enrolled 454 overweight and obese (body mass index, BMI = 27-41 kg m(-2)) older (age ≥ 55 yrs) adults with knee pain and radiographic evidence of femorotibial OA. Participants were randomized to one of three 18-month interventions: diet-induced weight loss only (D); diet-induced weight loss plus exercise (D + E); or exercise-only control (E). X-rays (N = 325) and MRIs (N = 105) were acquired at baseline and 18 months follow-up. X-ray and MRI (cartilage thickness and semi-quantitative (SQ)) results were analyzed to compare change between groups at 18-month follow-up using analysis of covariance (ANCOVA) adjusted for baseline values, baseline BMI, and gender.
  
  
  RESULTS
  Mean baseline descriptive characteristics of the cohort included: age, 65.6 yrs; BMI 33.6 kg m(-2); 72% female; 81% white. There was no significant difference between groups in joint space width (JSW) loss; D -0.07 (SE 0.22) mm, D + E -0.27 (SE 0.22) mm and E -0.16 (SE 0.24) mm (P = 0.79). There was also no significant difference in MRI cartilage loss between groups; D -0.10(0.05) mm, D + E -0.13(0.04) mm and E -0.05(0.04) mm (P = 0.42).
  
  
  CONCLUSIONS
  Despite the potent effects of weight loss in this study on symptoms as well as mechanistic outcomes (such as joint compressive force and markers of inflammation), there was no statistically significant difference between the three active interventions on the rate of structural progression either on X-ray or MRI over 18-months.
authors.affiliation: Rheumatology Department, Royal North Shore Hospital and Northern Clinical School, University of Sydney, Sydney, NSW Australia. Electronic address: David.Hunter@sydney.edu.au.
authors.forename: D J
authors.initials: DJ
authors.lastname: Hunter
authors.affiliation: Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Beavers
authors.affiliation: Institute of Anatomy, Paracelsus Medical University, Salzburg, Austria; Chondrometrics GmbH, Ainring, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Eckstein
authors.affiliation: Department of Radiology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Guermazi
authors.affiliation: Thurston Arthritis Research Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA; Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC, USA.
authors.forename: R F
authors.initials: RF
authors.lastname: Loeser
authors.affiliation: Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC, USA; Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Nicklas
authors.affiliation: Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA; Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC, USA.
authors.forename: S L
authors.initials: SL
authors.lastname: Mihalko
authors.affiliation: Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC, USA.
authors.forename: G D
authors.initials: GD
authors.lastname: Miller
authors.affiliation: Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: M
authors.initials: M
authors.lastname: Lyles
authors.affiliation: Department of Kinesiology, East Carolina University, Greenville, NC, USA.
authors.forename: P
authors.initials: P
authors.lastname: DeVita
authors.affiliation: Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: C
authors.initials: C
authors.lastname: Legault
authors.affiliation: Department of Radiology, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Carr
authors.affiliation: Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Williamson
authors.affiliation: Department of Health and Exercise Science, Wake Forest University, Winston-Salem, NC, USA; Section on Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, NC, USA; Section on Rheumatology and Immunology, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Messier
mesh_terms: D000368:Aged; D015992:Body Mass Index; D003131:Combined Modality Therapy; D004038:Diet, Reducing; D018450:Disease Progression; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000178:diet therapy; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000209:etiology / Q000628:therapy*; D011859:Radiography; D012720:Severity of Illness Index; D016037:Single-Blind Method; D016896:Treatment Outcome; D015431:Weight Loss
keywords: MRI; Osteoarthritis; Weight loss; X-ray