Glucosamine/Chondroitin Arthritis Intervention Trial Results

U.S. and European Trial Results Presented for Glucosamine

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At the American College of Rheumatology Annual Scientific Meeting (2005), results from two glucosamine trials were presented. The results of the two trials were highly anticipated by researchers, physicians, and patients who were looking for confirmation that glucosamine was a viable treatment option for arthritis.

GAIT (Glucosamine/Chondroitin Arthritis Intervention Trial) Phase I

In GAIT (Glucosamine/Chondroitin Arthritis Intervention Trial), nearly 1,600 patients with painful knee osteoarthritis were recruited from 16 U.S. academic rheumatology centers for the study. The study participants had experienced significant knee pain and had x-ray evidence of knee osteoarthritis. During the GAIT study, the patients:

  • Were evaluated at beginning of the study.
  • Were evaluated at weeks 4, 8, 16, 24.
  • Patients were randomized to receive glucosamine HCl, sodium chondroitin sulfate, both supplements, celecoxib (brand name Celebrex), or placebo.
  • Patients were allowed up to 4,000 mg daily of acetaminophen.

Results From GAIT (Glucosamine/Chondroitin Arthritis Intervention Trial)

  • Results revealed that the combination of glucosamine and chondroitin is better than placebo but the benefits seem to depend on the severity of pain.
  • In patients with moderate-to-severe osteoarthritis knee pain, 79.2% taking glucosamine/chondroitin combination experienced pain relief.
  • For patients taking celecoxib, 69.4% experienced pain relief. Of patients taking glucosamine alone, 65.7% experienced relief, as did 61.4% of patients taking chondroitin alone. Also, 54.3% taking placebo reported pain relief.
  • In patients with mild knee osteoarthritis pain, the glucosamine/chondroitin combination was not significantly more effective than placebo.

GUIDE (Glucosamine Unum In Die Efficacy)

There were 318 patients in the GUIDE study with knee osteoarthritis (88% women). Patients were randomized to take either oral glucosamine sulfate soluble powder (1500 mg once a day), acetaminophen (1000 mg three times a day), or placebo over a 6-month period. All groups were allowed to take ibuprofen as needed.

Results From GUIDE (Glucosamine Unum In Die Efficacy)

  • Both glucosamine sulfate and acetaminophen were more effective in reducing pain than placebo.
  • Patients taking glucosamine sulfate exhibited more relief than patients on acetaminophen.
  • It was concluded that once-daily 1500 mg oral doses of glucosamine sulfate may be the preferred treatment for knee osteoarthritis.

Phase II and Phase III GAIT Results

Results from a second phase of the GAIT study were published in the journal Arthritis & Rheumatism in 2008. Phase II assessed the combination of glucosamine and chondroitin for preventing joint damage of the knee. The combination of glucosamine and chondroitin was seemingly no more effective at preventing joint damage associated with osteoarthritis than placebo.

Study participants who lost the least amount of joint space over two years were among the groups who took glucosamine or chondroitin alone. Possibly, taking the two supplements together affects absorption, which might explain lower effectiveness of the supplements when used in combination.

Phase III, which considered a total of four years of data, revealed that the supplements in combination or alone had no greater benefit for pain relief of the knee than celecoxib or placebo. The results were published in 2010 in the journal Annals of Rheumatic Disease.

Recommendation's for Glucosamine

  • Before trying glucosamine/chondroitin discuss it with your doctor and ask how it would fit in with your current treatment program.
  • Stay on your prescribed medications. Supplements are not replacements for your prescribed medications.
  • Learn about glucosamine by doing your own research. Find sources of information which are reliable.
  • Follow directions specified by the supplement manufacturer or ask your doctor about proper dosage.
  • Avoid combining various other supplements.
  • Buy from a reputable manufacturer. Know what you are getting.

The Bottom Line

In 2012, The American College of Rheumatology published treatment recommendations for osteoarthritis. In the guidelines, chondroitin or glucosamine was not recommended for the initial treatment of osteoarthritis. Chondroitin and glucosamine supplements alone or in combination may not be an effective treatment for all patients. It may work for certain patients, and if it works for you, continue the treatment -- it is considered safe.

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