Study: The pharmacokinetics of glucosamine and chondroitin leads to unexpected results

Reference

Jackson CG, Plaas Ah, Sandy JD, et al. The human pharmacokinetics of oral intake of glucosamine and chondroitin sulfate individually or in combination. arthrosis cartilage . 2010; 18: 297-302.

Design

Intervention study to investigate the pharmacokinetic effects of glucosamin-HCL (GHCL) and chondroitine sulfate (CS), either alone or in combination

participant

29 Healthy volunteers and 28 patients with "knee pain" who were not diagnosed radiologically as arthrosis

study medication and dosage

The healthy subjects were administered by the healthy subjects from GHCL (1,500 mg), CS (1,200 mg) or the combination of the two (GHCL+CS). In patients with knee pain, after 3 months of daily supplement with GHCL (500 mg 3 times a day), CS (400 mg 3 times a day) or GHCL+CS single doses in quantities of 1,500 mg GHCL and 1,200 mg CS were administered. In both groups, pharmacokinetic measurements were carried out after administering the individual doses.

primary result dimensions

circulating glucosamine and CS levels as well as the area under the curve (AUC).

most important knowledge

It was somewhat surprising that the endogenous circulating CS levels were not increased by CS supplementation, regardless of whether it was administered alone or with GHCL. The AUC for glucosamine was increased by supplementing GHCL, but this increase in the AUC was significantly weakened when GHCL was combined with CS.

effects on practice

critics of naturopathy may say a lot about the results of this new report. However, I do not think that this findings should have an impact on how we practice. The test subjects of the current study came from the glucosamine/chondroitin arthritis intervention trial (gait). In contrast to most related studies, Gait was essentially not able to determine clinical effectiveness for CS or glucosamine (from GHCL). In view of the fact that the clinical results of GAIT differed from most published reports, we would not expect that an examination of the pharmacokinetics by CS and GHCL, which is used by GAIT researchers, indicate probable therapeutic mechanisms. (It remains unclear why Gait was unable to duplicate the results of the positive randomized studies, although it is not quite the only company that reports on negative effects. An investigation of the GAIT results shows that subjects to whom the combined therapies were given tend to achieve a better result, even if none of the findings were clearly final.)

The current report notes that a CS supplementation affects the pharmacokinetics of GHCL and therefore possibly affects the clinical effects of GHCL. That could be true. In fact, the previous evidence for the use of GHCL with or without inclusion of CS is still inconsistent and poor. Therefore, these new findings usually serve to continue to use the use of GHCL, at least in combination with CS. You tell us little about the pharmacokinetics (or therapeutic effect) of the better examined molecule glucosaminin sulfate.

Although the current report does not justify the choice of GHCL instead of glucosamine sulfate, most studies in which GHCL has been used indicate to have done this, since it is the most common form available on the market.

Although the current report does not justify the choice of GHCL instead of glucosamine sulfate, most studies in which GHCL has been used indicate to have done this, as it is the most common form available on the market. Such a justification seems questionable, since most scientific evidence provides another molecule (glucosamine insulfate).