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

Abstract 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°/s and 180°/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.