Analgesic efficacy of collagen peptide in knee osteoarthritis: a meta-analysis of randomized controlled trials

Background The management of knee osteoarthritis involves various treatment strategies. It is important to explore alternative therapies that are both safe and effective. Collagen peptides have emerged as a potential intervention for knee osteoarthritis. This study aims to evaluate the analgesic effects and safety of collagen peptide in patients diagnosed with knee osteoarthritis. Methods We conducted a systematic literature search following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Multiple databases including PubMed, Scopus, EMBASE, Web of Science, Cochrane, and ClinicalTrials.gov were searched for randomized controlled trials (RCTs) published up to 27 May 2023 that focused on the analgesic outcomes and adverse events associated with collagen peptides or hydrolyzed collagen in patients with osteoarthritis. We assessed the quality of the included studies and the strength of evidence using the Cochrane ROB 2.0 tool and Grading of Recommendations, Assessment, Development, and Evaluations. Results Four trials involving 507 patients with knee osteoarthritis were included and analyzed using the random-effects model. All these trials were considered to have a high risk of bias. Our results revealed a significant difference in pain relief between the collagen peptide group and the placebo group in patients with knee osteoarthritis (standardized mean difference: - 0.58; 95% CI - 0.98, - 0.18, p = 0.004; I2: 68%; quality of evidence: moderate). However, there was no significant difference in the risk of adverse events between collagen peptide and placebo (odds ratio: 1.66; 95% CI 0.99, 2.78, p = 0.05; I2: 0%; quality of evidence: very low). Conclusions Our findings demonstrate significant pain relief in patients with knee osteoarthritis who received collagen peptides compared to those who received placebo. In addition, the risk of adverse events did not differ significantly between the collagen peptide group and the placebo group. However, due to potential biases and limitations, well-designed randomized controlled trials are needed to validate and confirm these findings. Keywords: Osteoarthritis, Knee osteoarthritis, Collagen peptide, Pain, Adverse events