Subjects receiving glucosamine and placebo had similar scores relating to pain and narrowing of the hip joint space after 24 months, according to the results of the randomised, controlled trial published in the Annals of Internal Medicine. "Given the lack of clinically important effects on pain, function, and stiffness over 24 months, our results suggest that glucosamine sulphate is not an effective therapy for patients with hip osteoarthritis," wrote lead author Rianne Rozendaal from Erasmus Medical Center in Rotterdam. Glucosamine is extracted from the shell of crabs, lobster and shrimps, and also marketed by Cargill is a non-animal, non-shellfish derived product. The ingredient is often used in combination with chondroitin sulphate, extracted from animal cartilage like shark cartilage. They are the most commonly used supplements for osteoarthritis (OA), with estimated sales of $730m in the US in 2004. Previous studies, including the $14m Glucosamine/chondroitin Arthritis Intervention Trial (GAIT), sponsored by the National Institute of Health, have reported positive results, while other have reported null results, leaving the subject cloudy in uncertainty. Talking to NutraIngredients.com, Rozendaal said: "Based on our results we concluded that glucosamine was not more effective than placebo in these patients with hip OA. In our study there was not much room for doubt. "It is difficult to speculate on the reason why we did not find positive results whereas studies on knee OA did," continued Rozendaal. "There are numerous factors that could be of influence. It's possible that it is due to the difference between the knee and the hip, but we just don't have enough data on the difference to be able to give a meaningful answer to this question." The new study randomly assigned 222 patients (average age 63.4; 69.4 per cent women) with osteoarthritis of the hip to 1500 mg of glucosamine sulphate or placebo for two years. The researchers used Western Ontario and McMaster Universities (WOMAC) pain, function and stiffness subscales to quantify the results. Over the course of the entire study period, no significant differences in WOMAC pain or function was observed between the glucosamine and placebo groups. Moreover, the joint space narrowing did not differ after two years. "Glucosamine sulphate was no better than placebo in reducing symptoms and progression of hip osteoarthritis," concluded the researchers. Putting the results in context with other studies, the researchers stressed that their study looked hip osteoarthritis exclusively, while other have looked at both hip and knee osteoarthritis. "Most available systemic osteoarthritis therapies show similar effectiveness in both hip and knee osteoarthritis," wrote the authors. "However, because the mechanism of action of glucosamine is still not known, we cannot eliminate the possibility that effectiveness of glucosamine is different for the knee than for the hip," they added. Indeed, Rozendaal told this website that more needs to be known about the compounds used in different trials. "Is there a difference in bioavailability between these compounds that could explain the mixed findings?" she asked. "If not, we need to know what does cause the conflicting outcomes." In the journal, the researchers noted that the long-term results of the GAIT study should provide more information on structure modification. "Additional new insights may come from magnetic resonance imaging measurements of structural changes in both the JOG (Effect of Glucosamine on Joint Structure and Quality of Life) and LEGS (Long-Term Evaluation of Glucosamine Sulphate) studies over 6 and 24 months, respectively," they added."In addition, the JOG study is assessing C-terminal telopeptide crosslinks of type II collagen excretion, a marker of cartilage tissue degradation. These trials will contribute to the discussion on effectiveness of glucosamine sulphate in patients with knee osteoarthritis, but they cannot add to the discussion on its effect on hip disease," concluded Rozendaal and co-workers. Approximately seven million people in the UK alone are reported to have long-term health problems associated with arthritis. Around 206 million working days were lost in the UK in 1999-2000, equal to £18 billion (€26 billion) of lost productivity. Source: Annals of Internal Medicine 2008, Volume 148, Pages 268-277 "Effect of Glucosamine Sulfate on Hip Osteoarthritis - A Randomized Trial" Authors: R.M. Rozendaal, B.W. Koes, G.J.V.M. van Osch, E.J. Uitterlinden, E.H. Garling, S.P. Willemsen, A.Z. Ginai, J.A.N. Verhaar, H. Weinans, S.M.A. Bierma-Zeinstra ******************************** Readers' comments "This article brings up some questions for me. First, what characterization was done on the study material? How does the dosage level compare to knee studies? What is the median age of knee study patients compared to hip study patients? To what extent has joint damage progressed before glucosamine therapy was introduced in both studies? These are questions I would need to know to evaluate the studies side-by-side but will never be asked by the major media outlets." - Mr. James Neal-Kababick, Managing Director CEO, Flora Research Laboratories, Oregon, USA.