The GAIT was a major multicenter, double-blind, placebo, and celecoxib (trade name Celebrex), controlled study that involved 1,583 patients (mean age 58.6 years; 64 percent female, 36 percent male), who were selected from 3,238 screened candidates to study the effects of glucosamine and chondroitin.1 The selection criteria included at least six months of clinical evidence of knee osteoarthritis with radiographic evidence of tibiofemoral osteophytes of at least 1 mm and a pain score on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) of between 125 and 400.
The authors' primary outcome was a 20 percent reduction in pain. The subjects were divided into five groups and took supplements for six months. The groups included placebo; glucosamine hydrochloride, 500 mg t.i.d.; chondroitin sulfate, 400 mg t.i.d.; glucosamine hydrochloride, 500 mg t.i.d. and chondroitin sulfate, 400 mg t.i.d.; and the nonsteroidal anti-inflammatory Celebrex, 200 mg daily.
Glucosamine and chondroitin can be classified as chondroprotective neutraceuticals. Some countries in Europe define them as "slow activity anti-arthritis medications." For more information on glucosamine and chondroitin, visit my Web site: www.andersenchiro.com. I have written six articles on mechanism of action, forms, dosing and other studies.
Results
Because there has been and continues to be so much misinformation regarding this trial, the inclusion of tables provides the reader with the raw data background required to honestly evaluate the results.
Comment on the Spin
There are those in the alternative health community who state that pharmaceutical companies (which cannot patent nutritional supplements) have secondary gain issues for negative or unimpressive outcomes when nutritional supplements are studied.2 In this trial, there were 27 main authors, five of whom received consulting fees from McNeil Pharmaceuticals, two of whom received consulting fees from Pfizer, and two others who received consulting fees from both McNeil and Pfizer. Seven were awarded grants from Pfizer, and one received a grant from McNeil. People who are unhappy with the results of this study will probably use the connections of a few authors as a reason to discount the results; however, the study was not funded by pharmaceutical companies. A contract from the National Center for Complementary and Alternative Medicine and the National Institute of Arthritis and Musculoskeletal and Skin Diseases provided the financing.
Table 1. Results of the GAIT Trial| Treatment: | Placebo | Glucosamine HCL | Chondroitin Sulfate | Glucosamine and Chondroitin | Celebrex |
| Patients (each group) | 313 | 317 | 318 | 317 | 318 |
| Number of patients with 20% less pain | 188 (60.1%) | 203 (64%) | 208 (65.4%) | 211 (66.6%) | 223 (70%) |
| Number of patients with 50% less pain | 132 (42.2%) | 147 (46.4%) | 134 (42.1%) | 147 (46.4%) | 159 (50%) |
Table 2. WOMAC Score of 125 to 300 - Mild Osteoarthritis
| Treatment: | Placebo | Glucosamine HCL | Chondroitin Sulfate | Glucosamine and Chondroitin | Celebrex |
| Patients (each group) | 243 | 247 | 248 | 245 | 246 |
| Number of patients with 20% less pain | 150 (61.7%) | 157 (63.6%) | 165 (66.5%) | 154 (62.9%) | 173 (70.3%) |
| Number of patients with 50% less pain | 109 (44.9%) | 118 (47.8%) | 109 (44%) | 109 (44.5%) | 126 (51.2%) |
Table 3. WOMAC Score of 301-400 - Moderate to Severe Osteoarthritis
| Treatment: | Placebo | Glucosamine HCL | Chondroitin Sulfate | Glucosamine and Chondroitin | Celebrex |
| Patients (each group) | 70 | 70 | 70 | 72 | 72 |
| Number of patients with 20% less pain* | 38 (54.3%) | 46 (65.7%) | 43 (61.4%) | 57 (79.2%) | 50 (69.4%) |
| Number of patients with 50% less pain* | 23 (32.9%) | 29 (41.4%) | 25 (35.7%) | 38 (52.8%) | 33 (45.8%) |
Conversely, scan the Internet or read the popular press and you will find that a very high percentage of those who strongly advocate supplement use (and attack any study that is not totally positive) also derive income from supplement sales.
One only has to read the following three quotes (two negative, one positive) from this paper's abstract to see how easy it is to cherry pick the results to support an agenda:
- "Overall, glucosamine and chondroitin sulfate were not significantly better than placebo in reducing knee pain by 20 percent" (emphasis added).1
- "Glucosamine and chondroitin sulfate alone or in combination did not reduce pain effectively in the overall group of patients with osteoarthritis of the knee" (emphasis added). 1
- "The combination of glucosamine and chondroitin sulfate may be effective in the subgroup of patients with moderate to severe knee pain" (emphasis added). 1
When patients ask about glucosamine and chondroitin, I will give them the same advice as I did prior to the study: Try it for six to eight weeks to see if you are a responder.
References
- Clegg, D.O., Reda, D.J., Harris, C.L., et al. Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. NEJM 2006;254:795-808.
- Lemley, B. One doc's drug complaint. Discover Magazine 2005;25:16-17.
Click here for previous articles by G. Douglas Andersen, DC, DACBSP, CCN.