title: Impact of Diet and/or Exercise Intervention on Infrapatellar Fat Pad Morphology: Secondary Analysis from the Intensive Diet and Exercise for Arthritis (IDEA) Trial.
abstract: OBJECTIVE
  The infrapatellar fat pad (IPFP) represents intra-articular adipose tissue that may contribute to intra-articular inflammation and pain by secretion of proinflammatory cytokines. Here we examined the impact of weight loss by diet and/or exercise interventions on the IPFP volume.
  
  
  METHODS
  Intensive Diet and Exercise for Arthritis (IDEA) was a single-blinded, single-center, 18-month, prospective, randomized controlled trial that enrolled 454 overweight and obese older adults with knee pain and radiographic osteoarthritis. Participants were randomized to 1 of 3 groups: exercise-only control (E), diet-induced weight loss (D), and diet-induced weight loss + exercise (D+E). In a subsample (n = 106; E: n = 36, D: n = 35, and D+E: n = 35), magnetic resonance images were acquired at baseline and at the 18-month follow-up, from which we analyzed IPFP volume, surface areas, and thickness in this secondary analysis.
  
  
  RESULTS
  The average weight loss amounted to 1.0% in the E group, 10.5% in the D group, and 13.0% in the D+E group. A significant (p < 0.01) reduction in IPFP volume was observed in the E (2.1%), D (4.0%), and D+E (5.2%) groups. The IPFP volume loss in the D+E group was significantly greater than that in the E group (p < 0.05) when not adjusting for parallel comparisons. Across intervention groups, there were significant correlations between IPFP volume change, individual weight loss (r = 0.40), and change in total body fat mass (dual-energy X-ray absorptiometry; r = 0.44, n = 88) and in subcutaneous thigh fat area (computed tomography; r = 0.32, n = 82).
  
  
  CONCLUSIONS
  As a potential link between obesity and knee osteoarthritis, the IPFP was sensitive to intervention by diet and/or exercise, and its reduction was correlated with changes in weight and body fat.
authors.affiliation: Institute of Anatomy, Paracelsus Medical University Salzburg and Nuremberg, Salzburg, Austria.
authors.forename: Aarón Leonardo
authors.initials: AL
authors.lastname: Pogacnik Murillo
authors.forename: Felix
authors.initials: F
authors.lastname: Eckstein
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wirth
authors.forename: Daniel
authors.initials: D
authors.lastname: Beavers
authors.forename: Richard F
authors.initials: RF
authors.lastname: Loeser
authors.forename: Barbara J
authors.initials: BJ
authors.lastname: Nicklas
authors.forename: Shannon L
authors.initials: SL
authors.lastname: Mihalko
authors.forename: Gary D
authors.initials: GD
authors.lastname: Miller
authors.forename: David J
authors.initials: DJ
authors.lastname: Hunter
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Messier
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D001168:Arthritis / Q000178:diet therapy*; D001823:Body Composition; D015992:Body Mass Index; D001835:Body Weight; D004032:Diet; D005081:Exercise Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D018709:Statistics, Nonparametric