Glucosamine supplementation demonstrates a negative effect on intervertebral disc matrix in an animal model of disc degeneration.

STUDY DESIGN: Laboratory based controlled in vivo study. OBJECTIVE: To determine the in vivo effects of oral glucosamine sulfate on intervertebral disc degeneration. SUMMARY OF BACKGROUND DATA: Although glucosamine has demonstrated beneficial effect in articular cartilage, clinical benefit is uncertain. A Centers for Disease Control report from 2009 reported that many patients are using glucosamine supplementation for low back pain, without significant evidence to support its use. Because disc degeneration is a major contributor of low back pain, we explored the effects of glucosamine on disc matrix homeostasis in an animal model of disc degeneration. METHODS: Eighteen skeletally mature New Zealand White rabbits were divided into 4 groups: control, annular puncture, glucosamine, and annular puncture + glucosamine. Glucosamine treated rabbits received daily oral supplementation with 107 mg/d (weight based equivalent to human 1500 mg/d). Annular puncture surgery involved puncturing the annulus fibrosus of 3 lumbar discs with a 16-gauge needle to induce degeneration. Serial magnetic resonance images were obtained at 0, 4, 8, 12, and 20 weeks. Discs were harvested at 20 weeks for determination of glycosaminoglycan content, relative gene expression measured by real time polymerase chain reaction, and histological analyses. RESULTS: The magnetic resonance imaging index and nucleus pulposus area of injured discs of glucosamine treated animals with annular puncture was found to be lower than that of degenerated discs from rabbits not supplemented with glucosamine. Consistent with this, decreased glycosaminoglycan was demonstrated in glucosamine fed animals, as determined by both histological and glycosaminoglycan content. Gene expression was consistent with a detrimental effect on matrix. CONCLUSION: These data demonstrate that the net effect on matrix in an animal model in vivo, as measured by gene expression, magnetic resonance imaging, histology, and total proteoglycan is antianabolic. This raises concern about this commonly used supplement, and future research is needed to establish the clinical relevance of these findings.

Quantitation of glucosamine sulfate in plasma by HPLC-MS/MS after administration of powder for oral solution formulation.

A rapid method for the quantification of glucosamine in human plasma using high-performance liquid chromatography coupled to tandem mass spectrometry was developed and validated. The sample preparation includes a simple deproteinization step, using D-[1-¹³C] glucosamine hydrochloride as an internal standard. Chromatographic separation was performed on an ACE Ciano column using isocratic elution with acetonitrile and aqueous 2 mM ammonium acetate containing 0.025% formic acid (80:20). Selected reaction monitoring was performed using the transitions m/z 180.1 → m/z 72.1 and m/z 181.0 → m/z 74.6 to quantify glucosamine and internal standard, respectively. The method was validated and proved to be linear, accurate and precise over the range 50-5000 ng/mL of glucosamine. Recovery rates higher than 90% were obtained for both glucosamine and internal standard. No matrix effect was detected in the samples. The validated method was successfully applied to a pharmacokinetic study after oral administration of a powder for oral solution formulation containing glucosamine sulfate.