BONE LOSS IN ELDERLY WOMEN PREVENTED BY ULTRALOW DOSES OF PARENTERAL 17-BETA-ESTRADIOL

OBJECTIVES: Our purpose was to assess whether an ultralow dose of pare ntal estradiol, aimed for treatment of vaginal atrophy, affects bone m etabolism and bone density. STUDY DESIGN: Thirty healthy women greater than or equal to 60 years old were randomly assigned to a 6-month tre atment with either an ultralow dose of parenteral estradiol (7.5 mu g/ 24 hours) delivered by vaginal rings or no treatment in the proportion 2:1. RESULTS: Forearm bone density increased in estradiol users by 2. 1% (95% confidence interval 0.4 to 3.8, p = 0.008), contrasting to a d ecrease in nonusers of -2.7% (95% confidence interval -5.9 to 0.4, p = 0.077). In analysis of variance the changes in the two study groups d iffered significantly (p = 0.0004). Consistently, serum alkaline phosp hatases, bone-specific alkaline phosphatases, and osteocalcin concentr ations decreased in the treatment group (8%, p = 0.019; 14%, p = 0.000 6; and 9%, p = 0.02, respectively), suggesting reduced bone turnover. No significant changes were found in nonusers. CONCLUSION: Ultralow do ses of estradiol may potentially prevent bone loss in women greater th an or equal to 60 years old.