Evaluation of the effect of glucosamine administration on biomarkers of cartilage and bone metabolism in bicycle racers

Abstract

In the present study, the effect of glucosamine administration (1.5or3g/day) on cartilage and bone metabolism was investigated in bicycle racers, using cartilage‑ and bone‑specific biomarkers, including C‑terminal cross‑linked telopeptides of typeII collagen (CTX‑II), C‑terminal propeptides of typeII procollagen (CPII), N‑terminal telopeptides of bone‑specific typeI collagen (NTx) and bone alkaline phosphatase (BAP). The results indicate that CPII (a marker of typeII collagen synthesis) was not substantially changed, however, CTX‑II (a marker of typeII degradation) was reduced by glucosamine administration, particularly at a dose of 3g/day. Consistent with these observations, the ratio of CTX‑II/CPII was reduced by glucosamine administration and the effect of glucosamine was dose‑dependent. By contrast, the levels of NTx (a bone resorption marker) and BAP (a bone formation marker) were not altered by glucosamine administration. A previous study by this group reported that glucosamine exerts a chondroprotective action in soccer players by preventing typeII collagen degradation but maintaining typeII collagen synthesis. Together these observations indicate that glucosamine may exert a chondroprotective action by preventing typeII collagen degradation in athletes of various sports, including soccer players and bicycle racers.