A review of the use of glucosamine and chondroitin to relieve the symptoms of osteoarthritis, by a group of physicians from Boston university, is published in the Journal of the American Medical Association for March 15. Osteoarthritis is the commonest form of arthritis, and a prominent cause of physical disability, calculated to affect 12 per cent of the population of the United States aged 25 years or more.
Osteoarthritis is commonly taken as an indication for non-steroidal anti-inflammatory agent treatment, but such drugs have a significant toxic potential when taken by elderly people. Treatment with glucosamine or chondroitin or both in conjunction has been advocated as an alternative in the lay press. Glucosamine is a hexosamine sugar which plays a role in the biosynthesis of glycosaminoglycans and protoglycans, which are constituents of articular cartilage. Chondroitin is a glycosaminoglycan occurring in such cartilage. Both compounds, which are found naturally in animal foods, are anti-inflammatory, although their mode of action in arthritis is unknown.
In an analysis of 15 placebo-controlled clinical trials, these compounds were found to produce moderate to substantial benefits for arthritic subjects. The efficacy was less after only four weeks of treatment with glucosamine or chondroitin than after prolonged treatment periods. So far, the methods of treatment and assessment of results have been considered unsatisfactory, and further independent studies will be necessary before the value of the treatment can be accurately judged.
There is evidence that the outcome of small trials which have produced negative results has tended not to be published in medical journals. Moreover, details of the types of patient treated are scanty, as are reports of possible toxic reactions which ought to be balanced against possible benefits. Different preparations of the drugs supplied by different manufacturers tend to vary in purity and content of glucosamine and chondroitin. Trials are planned in which injections of 500mg of glucosamine sulphate and/or 400mg of chondroitin sulphate thrice daily will be used for evaluation of the remedies.