Evaluation Of Weight Loss Outcomes Between Early Responders And Non-responders In Knee OA Patients

Abstract

Overweight and obese knee osteoarthritis (OA) patients are at risk of progression, severe symptoms, and functional decline. Lifestyle weight management programs that combined exercise and dietary weight loss (EX+DWL) have demonstrated improvements in weight, symptoms, and functional abilities among knee OA patients. However, variations of response to the same lifestyle intervention may result in differences in weight loss outcomes. Evaluation of the weight loss outcomes between Early Responders (ER) and Early Non-Responders (ENR) would inform the design of future trials to improve the effectiveness of weight loss intervention. PURPOSE: The current study compared weight, percent fat mass (%fat), daily steps, and Healthy Eating Index (HEI) between ER and ENR. METHODS: Data from EX+DWL group in the single-blind, randomized controlled trial The Collaborative Lifestyle Intervention Program in Knee Osteoarthritis Patients (CLIP-OA) were used. Weight, %fat, daily steps, and 2015 HEI score were assessed using scale weight, BodPod, ActivPAL, and Food Frequency Questionnaire, respectively. Participants who achieved a ≥ 2% weight loss at 4-week were classified as ER. Mixed linear regression models with ER*time interaction were used to determine the difference between ER and ENR in weight loss outcomes from baseline (BL) to 6-month and 12-month. RESULTS: Among the 78 knee OA patients (M age = 66) included in the analysis, 31 (39.7%) were ER, and 47 (60.3%) were ENR. Compared to ENR, ER had favorable improvements in body weight (Δ BL to 6-month between group = -11.22; 95% CI = -15.91, -6.54; P < .01; Δ BL to 12-month between group = -10.57; 95% CI = -15.32, -5.81; P < .01) and daily steps (Δ BL to 6-month between group = 1237.33; 95% CI = 222.65, 2252.01; P = .02; Δ BL to 12-month between group = 1329.91; 95% CI = 289.20, 2370.62; P = .01). The difference of change in HEI score by ER/ENR was significant at 12-month (P = .02), but not 6-month (P = .12). No difference of change in %fat by ER/ENR was observed at 6- or 12-month. CONCLUSIONS: Findings from this study suggest that ER of a lifestyle intervention for knee OA patients experienced better weight loss outcomes compared to ENR. Future weight loss trials should consider tailored strategies to address unique barriers for ENR to achieve weight loss goals. Supported by NIH/NIA R01AG050725