Monitoring hormone replacement therapy by biochemical markers of bone metabolism in menopausal women.

Biochemical markers of bone metabolism are divided into two groups: formation and resorption markers. Bone turnover is a dynamic process, which increases in postmenopausal period. Hormone replacement therapy (HRT) can diminish this increased bone turnover. Biochemical markers reflect acute changes in bone metabolism. Therefore, they may be very useful for the prediction of subsequent bone mineral density changes after HRT in menopausal women. Both oral and transdermal routes of HRT are efficacious in decreasing the levels of biochemical markers. However, markers do not replace bone mineral density measurement. Collagen type I cross linked N-telopeptide, collagen type I cross linked C-telopeptide, and osteocalcin are the most promising markers.