Effect of glucosamine sulphate on joint space narrowing, pain and function in patients with hip osteoarthritis; subgroup analyses of a randomized controlled trial

Summary Objective Recently we reported that glucosamine sulphate (GS) did not have an effect on the symptoms and progression of primary care patients with hip osteoarthritis (OA). The aim of this present study was to investigate whether there are subgroups of patients with hip OA for whom GS might be an effective therapy. Method We randomized 222 patients with hip OA that met one of the American College of Rheumatology criteria to either 1500 mg of oral GS or placebo once daily for 2 years. Subgroup analyses were predefined for radiographic severity (Kellgren & Lawrence (KL) = 1 vs ≥2) and for type of OA (localised vs generalised). Additional exploratory subgroup analyses focused on groups based on pain level, pain medication use, baseline joint space width (JSW), and concomitant knee OA at baseline. Primary outcome measures were Western Ontario MacMaster Universities (WOMAC) pain and function scores over 24 months, and joint space narrowing (JSN) after 24 months. Results In the predefined subgroups based on radiographic severity and type of OA, the outcomes WOMAC pain, function and JSN were similar for the GS and placebo group. Conclusion GS was not significantly better than placebo in reducing symptoms and progression of hip OA in subgroups of patients.