Systemic Effects of a Commercial Preparation of Chondrotin Sulfate, Hyaluronic Acid and N-Acetyl-D-Glucosamine When Administered Parenterally to Healthy Cats
M.R. Lappin; J.K. Veir; C.B. Webb
This poster investigated an injectable nutraceutical containing glucosamine, chondroitin, and hyaluronic acid. I’ve written about glucosamine/chondroitin before, and despite the fact that oral products are almost universally recommended and used in both human and veterinary medicine, there is very little reason to think they are helpful. There is slightly better hope for injectable products, thought the evidence is still pretty lackluster given how long and widely used these products are. Still, with the lack of safe and effective therapies for arthritis in cats, I understand the desire to keep trying these things in the hopes that one of them will eventually be clearly shown to be of some benefit. The cynic in me also recognizes that they are a lucrative area in the pet care market, and that any evidence supporting a new product could translate into better sales.
In this study, the investigators injected the product into 8 healthy cats 5 times over 4 months and measured a number of indices of inflammation, oxidative stress, and anti-oxidation ability (a total of 14 measures alltogether) as well as routine bloodwork and urinalysis at 4 different measurement points.
No change was observed in routine bloodwork or urinalysis. The measure of oxidative stress decreased at 1/4 measurement points. The measure of blood anti-oxidant ability did not change significantly. Of the 12 measures of inflammatory cells and signaling molecules, 4 showed changes. Two types of inflammatory cell counts decreased, one at 1/4 time points, the other at 4/4 time points. Two inflammatory signaling molecules increased, both at 2/4 time points.
Overall, the study suggests some systemic response to the injection, though only a few of the variables measured exhibited any change. The nature of the change was inconsistent, since some markers of inflammation decreased and others increased. Likewise, the anti-oxidant effects were not robust, with one marker unchanged and the other changed only at 1/4 time points. There was, of course, no control group given that this was a small pilot project, but this makes it impossible to know whether the changes that did occur were strictly due to the product or just the injection process. Also, these clinical laboratory tests are only markers of activity within the body’s inflammatory and anti-oxidant systems, and they do not necessarily indicate any positive or negative clinical effect.
While it is important to conduct such small scale trials to look for safety concerns and to justify further, more clinically relevant research, the data generated here does not strongly suggest the product is likely to have a big impact on inflammatory disease. The authors conclude that, “Some of the findings (decreased oxidative stress, increased anti-oxidant capability, and increased IL10 concentrations) could be of potential benefit to cats with inflammatory diseases and suggest that controlled studies of clinically affected cats are indicated.” This is appropriately qualified (“could be of potential benefit”), but such equivocal findings hardly seem a reason for great optimism, especially given the existing literature on glucosamine/chondroitin products, which is extensive and generally not impressive in terms of supporting a clinical benefit. There’s nothing wrong with further research, of course, and it is true that we lack good therapies for inflammatory urinary tract and joint diseases in cats, but I can’t help but feel this isn’t the most fruitful use of limited research resources, especially given the number of times I’ve had to hear lecturers today say, “At this time, there is no clinical research to support….” with regard to equally or even more pressing problems.