title: The prevention of bone loss in young women treated with GnRH analogues with "add-back" estrogen therapy.
abstract: OBJECTIVE
  To determine whether the addition of a low dose of oral estrogen replacement therapy (ERT) taken daily can prevent the bone loss associated with continuous GnRH analogue use.
  
  
  METHODS
  In a double-blind, placebo-controlled study, 60 women aged 21-45 years were randomized to one of three treatment groups: placebo implant every 4 weeks plus placebo ERT tablets daily, Zoladex (goserelin 3.6 mg) implant every 4 weeks plus placebo ERT tablets daily, or Zoladex (3.6 mg) implant every 4 weeks plus estradiol valerate, 2 mg/day, with norethisterone 5 mg from days 22-28. A dual x-ray bone density scan was performed before treatment and again after six treatment cycles. The percentage bone change with respect to the initial bone density was calculated.
  
  
  RESULTS
  There was a significant loss of bone density at both the lumbar spine and proximal femur in the group receiving Zoladex plus placebo after 6 months compared with both pre-treatment values and with the group receiving placebo plus placebo. The addition of estrogen "add-back" therapy to GnRH analogue treatment (Zoladex plus ERT) resulted in no significant change in bone density compared with either pre-treatment values or the group receiving placebo plus placebo. The study had a dropout rate of 32%.
  
  
  CONCLUSIONS
  The addition of "add-back" estrogen therapy to continuous GnRH analogue use can prevent bone loss.
authors.affiliation: Premenstrual Syndrome Clinic, Dulwich Hospital, London, United Kingdom.
authors.forename: A T
authors.initials: AT
authors.lastname: Leather
authors.forename: J W
authors.initials: JW
authors.lastname: Studd
authors.forename: N R
authors.initials: NR
authors.lastname: Watson
authors.forename: E F
authors.initials: EF
authors.lastname: Holland
mesh_terms: D000284:Administration, Oral; D000328:Adult; D015519:Bone Density; D004311:Double-Blind Method; D004343:Drug Implants; D004958:Estradiol / Q000008:administration & dosage / Q000031:analogs & derivatives; D004967:Estrogens / Q000008:administration & dosage*; D005260:Female; D017273:Goserelin / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D008875:Middle Aged; D009640:Norethindrone / Q000008:administration & dosage; D010024:Osteoporosis / Q000139:chemically induced / Q000175:diagnosis / Q000517:prevention & control*; D011293:Premenstrual Syndrome / Q000188:drug therapy
chemical_list: D004343:Drug Implants; D004967:Estrogens; D017273:Goserelin; D004958:Estradiol; D009640:Norethindrone