Monitoring bone effect of transdermal hormone replacement therapy by ultrasound investigation at the phalanx: a four-year follow-up study

Objective: A controlled 4-year follow-up study was conducted on a populatio n composed of 112 healthy early postmenopausal women to evaluate the abilit y of ultrasound technology in detecting the effects of hormone replacement therapy (HRT) on bone. At the end of the study, 47 untreated and 25 treated women had been evaluated. Cyclic sequential estrogen/progestogen therapy, 50 mug/day of transdermal 17 beta -estradiol (Rotta Research Laboratorium) plus 5 mg/day of medrogestone (Wyeth-Ayerst) was used. Design: Ultrasound transmission through the distal metaphysis of hand phala nxes was measured by DBM Sonic. Beside amplitude-dependent speed of sound ( AD-SoS, three new parameters could be calculated: pure speed of sound (pSOS ), bone transmission time (BTT), and ultrasound bone profile index (UBPI). Ultrasound measurements were taken at baseline and after 1, 2, and 4 years. Results: Among untreated women a significant decrease of all ultrasound par ameters was observed at follow-up measurements. In the HRT-treated group we observed a significant increase of AD-SoS, pSoS, and BTT. We qualified as "responders" women in the treated group for whom AD-SoS, pSoS, and BTT incr eased by more than 2.77 times the coefficient of variation of the measureme nt, i.e., 95% variability. Women in the treated group were identified as re sponders at 1 years of follow-up by AD-SoS (56%), pSOS (56%), and BTT (60%) . Ultrasound bone profile index declined in both groups, although to a lowe r extent among HRT-treated subjects. Conclusions: The 4-year data confirm the results obtained at 1 and 2 years of follow-up. This study demonstrates that bone tissue investigation by ult rasound at the phalanx can be used to monitor the effect of HRT, and thus i t should be considered a potential technology for the management of menopau se by gynecologists.