Nutrition supplementation combined with exercise versus exercise alone in treating knee osteoarthritis: a double-blinded, randomised, placebo-controlled trial

Objective: To investigate the effectiveness of formula nutrition supplementation (mainly containing glucosamine sulphate, chondroitin sulphate and rhizoma drynariae) plus supervised exercise versus exercise alone for the treatment of knee osteoarthritis (OA). Methods: This was a double-blinded, single-centre, randomised, placebo-controlled trial. The study recruited 65 participants (40-75 years) with knee OA. Participants were randomly allocated to nutrition supplementation plus exercise (N + E) group or placebo plus exercise (P + E) group. The intervention lasted for 6 months. The primary outcome was the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. Secondary outcomes included physical function and performance scores, lower extremity strength and serum biomarkers. Results: Among the 65 randomised patients, 56 (86%) completed the trial. At 3 months, more participants in the N + E group than in the P + E group achieved minimum clinically important difference (MCID) in WOMAC total score (19/30 [63.3%] vs 8/26 [30.8%]; P < .01). At 6 months, more participants in the N + E group than in the P + E group achieved MCID in WOMAC stiffness score (19/30 [63.3%] vs 10/26 [38.5%]; P < .05). Meanwhile, at 6 months the decreased percentages of WOMAC stiffness score in the N + E group was greater than in the P + E group (P < .05). The flexor peak torque at 120 degrees/s and 180 degrees/s in the N + E group were significantly higher than those in the P + E group at 3 months (P < .05). Moreover, compared with baseline, improvements in the WOMAC overall and pain score, visual analogue scale pain and 30-second chair stand test were observed in both groups at 6 months. However, these indicators in the N + E group were improved as early as 3 months (P < .05). Conclusions: The improvement effects of nutrition supplementation plus exercise were superior to those of exercise alone, and the improvement occurred earlier. Nutrition supplementation plus exercise would be a more efficient strategy for knee OA.