Subgroup analyses of the effectiveness of oral glucosamine for knee and hip osteoarthritis: a systematic review and individual patient data meta-analysis from the OA trial bank

Runhaar J, Rozendaal RM, van Middelkoop M, et al. · Annals of the Rheumatic Diseases

No significant main effect of glucosamine over placebo on WOMAC pain or function, at short or long term, and none of the predefined subgroup interactions — baseline pain severity, BMI, sex, radiographic grade, presence of inflammation — reached significance either. Across the trials and stratifications the treatment effect ran from -0.43 to 2.02 on a 0 to 100 WOMAC pain scale. All five trials were rated low risk of bias and heterogeneity was near zero, so no sensitivity analysis was needed.

Population

Individual patient data from 5 placebo-controlled glucosamine trials — 4 knee, 1 hip — with 815 participants on glucosamine and 810 on placebo

Intervention

Oral glucosamine (any preparation)

Comparator

Placebo

Limitations

Of 21 eligible trials, six shared their data and five entered the analysis — the sixth compared glucosamine against green-lipped mussel extract rather than placebo. That covers 55% of everyone randomised in the published placebo-controlled literature. Four data owners were refused permission by their sponsor, and the paper notes that the trials reporting benefit use the Rottapharm compound and were not made available.