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 CDC report from 2009 reported
that many patients are using glucosamine supplementation for low back pain
(LBP), without significant evidence to support its use. Because disc
degeneration is a major contributor of LBP, 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 four groups: control, annular puncture, glucosamine, and annular
puncture+glucosamine. Glucosamine treated rabbits received daily
oral supplementation with 107mg/day (weight based equivalent to human
1500mg/day). Annular puncture surgery involved puncturing the annulus
fibrosus (AF) of 3 lumbar discs with a 16G needle to induce degeneration.
Serial MRIs were obtained at 0, 4, 8, 12, and 20 weeks. Discs were harvested
at 20 weeks for determination of glycosaminoglycan(GAG) content, relative
gene expression measured by RT-PCR, and histological analyses.
Results
The MRI index and NP 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 GAG content. Gene expression was
consistent with a detrimental effect on matrix.
Conclusions
These data demonstrate that the net effect on matrix in an animal
model in vivo, as measured by gene expression, MRI, histology, and total
proteoglycan is anti-anabolic. This raises concern over this commonly used
supplement, and future research is needed to establish the clinical
relevance of these findings.