METHODS	TAP ( by colorimetry ) , serum bone-specific alkaline phosphatase ( BAP ; by enzyme immunoassay ) , serum osteocalcin ( OC ; by ELISA ) , serum bone sialoprotein ( BSP ; by RIA ) , and urinary total pyridinoline ( PYD ; by HPLC ) and deoxypyridinoline ( DPD ; by HPLC ) were measured as markers of bone turnover .\