Impact of Diet and/or Exercise Intervention on Infrapatellar Fat Pad Morphology: Secondary Analysis from the Intensive Diet and Exercise for Arthritis (IDEA) Trial

The infrapatellar fat pad (IPFP) represents intra-articular adipose tissue that may contribute to intra-articular inflammation and pain by secretion of pro-inflammatory cytokines. Here we examined the impact of weight loss by diet and/or exercise interventions on IPFP volume

Impact of Diet and/or Exercise Intervention on Infrapatellar Fat Pad Morphology: Secondary Analysis from the Intensive Diet and Exercise for Arthritis (IDEA) Trial

OBJECTIVES: The infrapatellar fat pad (IPFP) represents intra-articular adipose tissue that may contribute to intra-articular inflammation and pain by secretion of pro-inflammatory cytokines. Here we examined the impact of weight loss by diet and/or exercise interventions on 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; D+E: n=35), magnetic resonance images were acquired at baseline and 18-month follow-up, from which we analyzed IPFP volume, surface areas and thickness in this secondary analysis. RESULTS: Average weight loss in each group amounted to 1.0% in E, 10.5% in D, and 13.0% in D+E. A significant (p< 0.01) reduction in IPFP volume was observed in E (2.1%), D (4.0%) and D+E (5.2%). The IPFP volume loss in D+E was significantly greater than that in E (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 (DXA; r=0.44; n=88) and in subcutaneous thigh fat area (CT; r=0.32; n=82). CONCLUSIONS: As a potential link between obesity and knee OA, the IPFP was sensitive to intervention by diet and/or exercise, and its reduction was correlated with change in weight and body fat