Randomised trial, 1993
Can estrogen prevent bone loss from GnRH analogue treatment?
Yes. Adding estrogen therapy prevented the significant bone loss that occurred when women took the GnRH drug Zoladex alone.
What they did
Sixty women aged 21-45 were randomly assigned to one of three groups: placebo implant plus placebo pills, Zoladex (a GnRH drug) plus placebo pills, or Zoladex plus estrogen pills (estradiol 2 mg daily with norethisterone on days 22-28). Treatment lasted 6 cycles. Bone density was measured before and after treatment at the lower spine and upper thighbone.
What they found
Women receiving Zoladex plus placebo showed significant bone loss at both the lumbar spine and proximal femur compared to their pre-treatment levels and compared to the placebo-only group. Women receiving Zoladex plus estrogen showed no significant change in bone density compared to their pre-treatment levels or the placebo group.
What it means for you
Estrogen add-back therapy can protect bones when women take GnRH drugs for extended periods. This is important because young women may need long-term GnRH treatment. The main limits are a 32% dropout rate and that the study only lasted 6 cycles.
60
Women in the study
6
Treatment cycles
32%
Dropout rate
About the study
- Original title
- The prevention of bone loss in young women treated with GnRH analogues with "add-back" estrogen therapy
- Authors
- Leather AT, Studd JW, Watson NR et al.
- Journal
- Obstetrics and gynecology
- Year
- 1993
- Study design
- Randomised trial
- Participants
- 60
- What was tested
- Zoladex 3.6 mg with or without estrogen add-back therapy
- Read the paper
- doi.org/10.1016/0020-7292(93)90299-c
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