薬理と治療

Abstract

Objectives The objective of this study was to investigate the effect of D-glucosamine hydrochloride（GlcN）administration on cartilage metabolism in bicycle players, based on stratified analysis utilizing biomarkers for cartilage and bone metabolism. Methods A randomized double-blind placebo-controlled clinical trial was conducted in 27 bicycle players. They were randomly assigned to 2 groups and administrated with a placebo（n＝13）or GlcN 1.5 g╱day（n＝14）for 3 months, and the effect of test supplements on cartilage metabolism was evaluated by analyzing a cartilage typeⅡ collagen degradation marker（CTX-Ⅱ, corrected by urinary creatinine Cr）using urine samples collected before（0 month）and after the administration of test supplements（3 months）. Results CTX-Ⅱ levels were not significantly different between the two groups（placebo group and GlcN 1.5 g╱day group）after the administration of test supplements（P＞0.2）. Next, the subject（n＝18）with small joint loading were evaluated based on the CTX︱Ⅱ level（＜500 ng╱mmol Cr）; CTX︱Ⅱ levels were substantially decreased in GlcN 1.5 g╱day group（n＝9, P＝0.05）compared with a placebo group（n＝9）after the administration of test supplement. Furthermore, among these subjects, the subject（n＝13）with small variation of joint loading （＜20％）were evaluated based on the level of NTx（a bone typeⅠ collagen degradation marker）; CTX︱Ⅱ levels were significantly decreased in GlcN 1.5 g╱day group（n＝7, P＜0.01）compared with a placebo group（n＝6）after the administration of test supplement. Conclusions These observations suggest that the daily administration of GlcN（1.5 g╱day） exhibits the chondroprotective action on the subjects with small joint loading by improving cartilage metabolism via the suppression of typeⅡ collagen degradation.