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Meta-Analysis: Chondroitin for Osteoarthritis of the Knee or Hip

[Reichenbach, S., et. al. Ann. Int. Med. 2007;146:580-90]

Summary and commentary by Jason Theodosakis, M.D.

What is it?

This is the most recent of four major review articles on chondroitin. Note: review articles do not release new information from a new study, they combine (in part or whole) the results from some or all of the previously published studies. Unlike the reviews on chondroitin in the past, this article included results of only three of twenty available clinical studies. This is really a poor way to do a review, as you'll see below...

What was the purpose of this review?

This latest review article attempted to answer one main question...

1) What is the effect of chondroitin sulfate on relieving pain in people with osteoarthritis?

Other questions were also part of this review.

2) Can chondroitin improve cartilage health by slowing or stopping cartilage loss? This is an assessment of the disease modifying ability of chondroitin. It's done using x-rays to evaluate the space between the bones in the knee (also called joint space width). The wider the space and more cartilage is present.

3) How safe is chondroitin sulfate? For instance, did more people have problems taking chondroitin versus taking a placebo?

After reviewing this study, some experts have joked that the real purpose of the review was to try to steer people away from supplements since they are replacing drugs for arthritis.

What did they not review?

The authors fail to discuss any of the excellent outcome data related to chondroitin. For instance, chondroitin has been able to lower the costs of osteoarthritis care by helping to keep people away from physical therapy, medication use, hospitalizations and even surgery. Since this real-world information is really what matters most to patients, some would argue that these outcome data of the most important factor when recommending a treatment such as chondroitin.

How was the review performed?

The authors looked at the 20 major human clinical studies on chondroitin sulfate performed up to 2006. Unlike many review articles in the past, they even included abstracts that have not yet been written up into full format for publication.

Then it gets complicated. No two studies are exactly the same. Most of the time, studies are actually quite different in a number of variables such as:

• The dose or amount of time of chondroitin was given
• Differences in the subjects used in the study (those who have more or less severe disease, different body weight, different sex, different use of co-medication, etc)
• The types of assessments made (different types of pain scales, physical examinations, x-ray procedures), etc.

Trying to combine results from different studies is like trying to add up fractions when the denominators are different. Adjustments have to be made and there's a great deal of argument about which adjustments are valid or appropriate. That's why many professionals who are involved in clinical research dislike these review articles -- it's probably more appropriate just to look at the individual studies to come up with a conclusion about the nature of which are studying. By trying to add all the studies together, there's too many things that can go wrong and to many ways that the authors can pick and choose what they want to come up with the conclusion that they were trying to look for before they started.

For the determination of chondroitin's effect on improving pain and function, the authors ignored the results of 17 of the 20 studies and decided to focus on just three studies. They added up the results for these three studies to come up with their conclusions.

What did they find?

In handpicking the three studies that had subjects with the lowest levels of starting pain, it's no surprise that the researchers concluded the study subjects did not have a significant pain relief compared to placebo.

There are tremendous problems with their conclusion, however.

Two of the three studies they used were not designed to look at pain, but structure by way of x-rays. Both studies (Kahan and Michel showed chondroitin was highly positive for stopping loss of cartilage. The third study, called GAIT, could not be used as evidence against chondroitin because the active drug in the study, Celebrex, failed. This invalidated all of the negative results in GAIT. There was one glaring positive finding in GAIT, however, that the combination of glucosamine + chondroitin in patients with moderate to severe pain performed remarkably - better than any drug in history. 79% of patients in this group had a response, a highly significant value. In the same group, Celebrex was no better than placebo.

Because the authors of this review article used three studies that were not valid for use in such as review, and eliminated, at will, the 17 other, positive studies on chondroitin, this review article is worthless.


So what's this review really about?

The authors were just supposed to comment on their questions and not supposed to make conclusions about whether or not people should be taking chondroitin. Because they did generate such conclusions, despite admitting that this review should be just observational in nature, it appears that this is another obvious effort to try to discredit the use of glucosamine and chondroitin.

See what two other experts say about this chondroitin review

Why would people want to try to harm something that helps so many? Unfortunately, the answer appears to be strictly financial. Chondroitin is financially damaging to the interest of many major pharmaceutical companies whose drugs compete against these supplements. The sales of glucosamine and chondroitin are estimated to cost the pharmaceutical companies over $2 billion in annual revenue from lost sales in anti-inflammatory drugs including COX-2 inhibitors. In my opinion, "experts" who try to steer patients away from cheaper, safer and more effective therapies are, at the very least, in violation of thier oath to "Do No Harm."

































 
 

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90% of people who follow The Arthritis Cure treatment program don't need anti-inflammatories (like Aleve, Celebrex or Advil).
Dr. Theo warned people that these drugs, used first... read more

 

  

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