(RxWiki News) Knee arthritis can become more painful and severe as patients lose cartilage. Much research has been devoted to figuring out whether nutritional supplements can slow this process.
A recent study looked at a group of knee osteoarthritis patients to see how different treatments affected structural changes in the knee, like loss of cartilage.
The researchers found that osteoarthritis patients taking glucosamine and chondroitin sulfate, which are over-the-counter supplements, retained more cartilage, regardless of the other arthritis medications they were taking.
The authors of this study wrote that patients with less severe knee damage at baseline benefited most from the supplements.
"Ask your doctor how to slow the joint damage of osteoarthritis."
Johanne Martel-Pelletier, PhD, of the Osteoarthritis Research Unit in the University of Montreal Hospital Research Centre, led this study.
Osteoarthritis is a relatively common condition in which joints become stiff, painful and tender due to loss of cartilage.
Previous studies have suggested that a glucosamine and chondroitin regimen may not work for every patient.
A review led by Simon Wandel, a research fellow at the Institute of Social and Preventive Medicine in the University of Bern, looked at 10 trials that tested glucosamine and chondroitin against a placebo.
Wandel and colleagues concluded that glucosamine and chondroitin, alone or in combination, did not reduce joint pain or reduce joint space width.
That review, included 3,803 patients, was published by BMJ in 2010.
This study by Dr. Martel-Pelletier and colleagues examined the effects of treating knee osteoarthritis using analgesics (painkillers) and non-steroidal anti-inflammatory drugs (NSAIDs).
These researchers also evaluated the effectiveness of glucosamine and chondroitin sulfate.
The researchers used data from 600 patients with knee osteoarthritis.
A total of 300 participants had received at least 24 months of the typical treatment of analgesics and NSAIDs. The remaining 300 had not.
The researchers also collected information about the participants' clinical histories, X-rays and knee MRIs. These patients' knee cartilage volumes were also measured.
Of the 300 patients who had received the standard pharmacological treatment for knee osteoarthritis, 113 also took glucosamine and chondroitin sulfate.
A total of 90 participants in the non-analgesics/NSAIDs group reported taking glucosamine and chondroitin sulfate.
The researchers found that participants taking analgesics and NSAIDs had more severe knee osteoarthritis at the beginning of the study.
Among the participants who did not take analgesics and NSAIDs, those taking glucosamine and chondroitin experienced less than average cartilage loss after 24 months.
Among the participants who took analgesics and NSAIDs, those not taking glucosamine and chondroitin had more cartilage volume loss at 12 and 24 months than those taking the supplements.
The researchers also found that more joint space width, indicating less severe osteoarthritis, at the beginning of the study predicted less cartilage volume loss.
The authors of this study concluded that, among patients who did or did not take analgesics and NSAIDs, supplementation with glucosamine and chondroitin slowed cartilage loss.
They also suggested that patients with milder knee osteoarthritis would benefit more from the supplements.
These researchers acknowledged that their study had limitations. For example, the researchers did not have access to information about exact dosages or quality of the medications.
This study was published in the Annals of the Rheumatic Diseases on December 13.
The research was funded by a public-private partnership including the National Institutes of Health and several pharmaceutical companies. The researchers disclosed some financial ties to those pharmaceutical companies, including Bioiberica and ArthroLab Inc.