Effects of adding glucosamine or glucosamine combined with chondroitin to exercise on pain and physical function in adults with knee osteoarthritis: a systematic review and meta-analysis

It is well known that different types of exercise significantly improve physical function and relieve pain in knee osteoarthritis (KOA) patients. The aim of this study was to investigate the added effects of glucosamine or glucosamine and chondroitin supplementation in combination with an exercise program in the management of KOA. The randomized controlled trials on adding glucosamine (G) or G combined with chondroitin (C) to an exercise program in the treatment of KOA were searched in the PubMed, Cochrane Central Register of Controlled Trials, PEDro, and Web of Science online databases. The Pedro scale tool was used to assess quality of literature. A meta-analysis was performed using the Review Manager 5.4 software. In total, 6 studies (including 297 participants) were included for the final meta-analysis. According to the PEDro scale, the average quality of the studies was rated as good (mean = 8.2 (2)). The results showed that the effect of G, or G and C, in combination with exercise is not significant, as indicated by the assessed knee pain (WOMAC pain: SMD -0.18, 95% CI -0.47 to 0.11, p = 0.23; and VAS pain: SMD -0.34, 95% CI -0.85 to 0.17, p = 0.20) and physical function (SMD -0.13, 95% CI -0.95 to 0.69, p = 0.76). Adding glucosamine alone or a combination of glucosamine and chondroitin to exercise, has no effect on knee pain and physical function compared with exercise alone in KOA patients. Keywords: treatment, dietary supplement, physical activity, older adults.