Hormone Replacement Therapy in Postmenopausal Women: Urinary N-Telopeptide of Type I Collagen Monitors Therapeutic Effect and Predicts Response of Bone Mineral Density
The ability of the urinary cross-linked N-telopeptides of type I collagen (NTx) to monitor and predict therapeutic effects of hormone replacement therapy (HRT) in postmenopausal women was assessed.
• NTx significantly decreased (p<0.0001), and spine and hip bone mineral density (BMD) significantly increased (p<0.00001 and p<0.005, respectively) in the group treated with HRT. In the control group receiving calcium supplements only, NTx did not change but BMD decreased significantly (p<0.01)
• Subjects in the highest quartile of baseline NTx (67-188 nM BCE/mM creatinine), and those who experienced the greatest decrease in NTx to 6 months of HRT (-66 to -87%), demonstrated the greatest gain in BMD (p<0.05 and p<0.005, respectively).
• The contrast between treated and control groups provides information about risk of BMD loss. A high baseline NTx value (>67 nM BCE/mM creatinine) indicates a 17.3 times higher relative risk of BMD loss if not treated with HRT.
"...these data support the clinical utility of NTx to monitor the antiresorptive effect of HRT in women shortly after the menopause, to predict changes in BMD in response to HRT and thereby to identify women who would benefit from such therapy, and potentially to identify a risk for bone loss in women receiving less than adequate therapy."
Chesnut CH III, et al. Hormone Replacement Therapy in Postmenopausal Women: Urinary N-Telopeptide of Type I Collagen Monitors Therapeutic Effect and Predicts Response of Bone Mineral Density. Am J Med. 1997;102:29-37.