Comparing two low-energy diets for the treatment of knee osteoarthritis symptoms in obese patients: a pragmatic randomized clinical trial

Objectives To evaluate in a prospective, randomized clinical trial (RCT), symptom response among obese knee osteoarthritis (OA) patients following a feasible. intensive weight-loss program for 16 weeks Methods Eligible patients were obese [body mass index (BMI)> 30 kg/m(2)], >50 years old, with primary knee OA Participants were randomized to either a very-low-energy diet (VLED) or a low-energy diet (LED) (415 kcal/day and 810 kcal/clay, respectively), using commercially available formula foods only for the first 8 weeks, managed by dieticians The 8 weeks were followed by an additional 8-week period of a hypo-energetic diet consisting of normal food plus meal replacements (1200 kcal/day) The primary endpoint was the number of patients responding according to the Outcome Measures in Rheumatology Clinical Trials and Osteoarthritis Research Society International (OMERACT-OARSI) responder criterion The statistical analysis was based on a non-responder intention-to-treat gro population (baseline observation carried forward) Results One hundred and ninety two patients (155 (80 7%) females) with a mean age 62 5 years [standard deviation (SD) 64, range 50-78 years), average BMI 37.3 (SD 4 8) were included At 16 weeks, similar proportions of the VLED and LED groups, 59 (61 5%). and 63 (65.6%) patients, respectively, met the OMERACT-OARSI responder criteria, with no statistical significant difference between the groups (P=0 55) Combining the groups the pooled estimate was 64% meeting the responder criteria [95% confidence interval (CI) 57%. 70%] There was an overall reduction in pain, corresponding to an average pain reduction on the visual analogue scale (VAS) of 111 (95%CI 13 6, 8 5) in the combined groups At week 16 weight loss in the combined groups was 128 kg (95%CI 11 84-13 66, P < 0 001) 71% lost >= 10% body weight in both diet groups, with a pooled estimate of 74% (95%CI 68-80%) Conclusion No clinically significant differences were found between the 415 kcal/day and 810 kcal/clay diets A 16-week formula-diet weight-loss program resulted in a fast and effective weight loss with very few adverse events resulting in a highly significant improvement in symptoms in overweight patients with knee OA ChnicalTrials gov Identifier NCT00655941 (C) 2010 Osteoarthritis Research Society International Published by Elsevier Ltd All rights reserved