OBJECTIVETo evaluate the application of bone turnover markers bone alkaline phosphatase (BALP) and N-MID osteocalcin (N-MID) in monitoring of osteoporosis treatment with recombined parathyroid hormone 1-34 (rhPTH1-34).

METHODSThe bone mineral density (BMD) of the lumbar spine L2-L4 and the proximal femur were examined by dual energy X-ray absorptiometry (DXA) before and 6 and 12 months after rhPTH 1-34 treatment. Meanwhile, serum levels of BALP and N-MID were detected by electro-chemiluminescence assay.

RESULTSSix months after rhPTH 1-34 treatment, the BMD of proximal femur remained unchanged, and the BMD of the lumbar L2-L4 spine increased from 0.753 g/cm(2) to 0.781 g/cm(2) (P<0.05); while serum levels of N-MID increased from 15.46 ng/ml to 27.07 ng/ml(P<0.01), BALP from 14.05 μg/ml to 24.31 μg/ml(P<0.01). Twelve months after drug administration, no significant changes were observed in BMD of proximal femur, and the BMD of the lumbar spine L2-L4 increased from 0.753 g/cm(2) to 0.807 g/cm(2)(P<0.01) while serum levels of N-MID and BALP increased from 15.46 ng/ml and 14.05μg/ml to 49.38 ng/ml and 33.99 μg/ml, respectively (both P<0.01).

CONCLUSIONSerum levels of BALP and N-MID are more sensitive than BMD. Combination of two methods may provide better indicators for monitoring of osteoporosis treatment.