This research studied the validity and correlation of β-CTx (Betacrosslap) and Pyridinoline (PYD) in 71 cases of
postmenopausal Thai women who attended at the osteoporosis clinic. The validity consisted of sensitivity, specificity and
accuracy of PYD. They were 53.44, 84.6 and 59.15 % respectively. So, the validity of pyridinoline test was rather poor and the
correlation between betacrosslap and pyridinoline was weak (r = 0.123, p = 0.0001) which was not significant in practice.

In conclusion, the pyridinoline test was not proper for bone resorption even pyridinoline was abundant in bone.

Keywords: Pyridinoline (PYD), BetacrossLap, betaCTx, Validity