Changes in body weight and knee pain in adults with knee osteoarthritis 3.5 years after completing diet and exercise interventions.

OBJECTIVE To determine whether long-term diet (D) and exercise (E) interventions, alone or in combination (D+E), have beneficial effects for older adults with knee osteoarthritis 3.5-years after the interventions end. METHODS This is a secondary analysis of a subset (N = 94) of the first 184 participants who had successfully completed the Intensive Diet and Exercise in Arthritis (IDEA) trial (N = 399) and who consented to follow-up testing. Participants were older (age ≥ 55 years), overweight and obese adults with radiographic and symptomatic knee osteoarthritis in at least one knee who completed 1.5-year D+E (N=27), D (N=35), or E (N=32) interventions and returned for 5-year follow-up testing an average of 3.5-years later. RESULTS During the 3.5-years following the interventions, weight regain in D+E and D was 5.9 kg (7%) and 3.1 kg (4%), respectively, with a 1 kg (1%) weight loss in E. Compared to baseline, weight (D+E, -3.7 kg, P=.0007; D, -5.8 kg, P<.0001; E, -2.9 kg, P=.003) and WOMAC pain (D+E, -1.2, P=.03; D, -1.5, P=.001; E -1.6, P=.0008) were lower in each group at 5-year follow-up. The effect of group assignment at 5-year follow-up was significant for body weight, with D less than E (-3.5 kg, P=.04). DISCUSSION Older adults with knee osteoarthritis who completed 1.5-year diet or diet plus exercise interventions experienced partial weight regain 3.5 years later, yet relative to baseline, they preserved statistically significant changes in weight loss and reductions in knee pain.