The values of urinary NTx in postmenopausal women undergoing HRT; the role of additional alendronate therapy

Objective: To determine the changes in levels of urinary NTx at the end of the 6th month of oral and transdermal hormone replacement therapy (HRT) and the effects of additional alendronate therapy for osteoporotic women. Method: Of 66 postmenopausal women 23 were treated with oral estradiol+norethisterone acetate (E+P), and 22 were treated with transdermal estradiol+norethisterone acetate. The third group consisted of 21 women with osteoporosis (bone mineral density<100 mg/cm³) and treated with oral E+P plus alendronate 10 mg/day. Result: Significant decreases of urinary NTx levels were seen after HRT in all study groups (P<0.05). But the decline of NTx levels was not different between the oral and transdermal HRT groups (P>0.05). There was no additional decrease in the levels of NTx with alendronate therapy (P>0.05) but NTx excretion diminished more in patients with high baseline levels. Conclusion: The decline of NTx at the end of the 6th month of HRT reflects the decrease of bone resorption and it is not related to the route of administration.