Time-dependent variations in bone turnover parameters during 2 months' cyclic treatment with different doses of combined estrogen and progestogen in postmenopausal women

Metabolism. 1990 Nov;39(11):1122-6. doi: 10.1016/0026-0495(90)90082-n.


We determined the time-dependent variations in biochemical estimates of bone resorption and bone formation in 30 healthy postmenopausal women treated for two consecutive cycles of 28 days with a sequential estrogen/gestagen therapy. The women received either 1, 2, or 4 mg estradiol (E2) for 22 days and 1 mg norethisterone acetate (NETA) from day 13 to 22 of each cycle. Blood samples were drawn twice a week, ie, 16 blood samples in each woman. Biochemical estimates of bone resorption (fasting urinary hydroxyproline/creatinine, fasting urinary calcium/creatinine) decreased significantly during the two treatment cycles. In contrast, there was no overall decrease in bone formation parameters (plasma bone Gla protein [pBGP], serum alkaline phosphatase), and serum alkaline phosphatase decreased significantly during the estrogen-only phase, but increased during the E2 plus NETA phase. The present study supports our previous suggestion that NETA stimulates bone formation in early postmenopausal women.

MeSH terms

  • Animals
  • Bone and Bones / metabolism*
  • Calcium / metabolism
  • Dose-Response Relationship, Drug
  • Drug Combinations
  • Estradiol / therapeutic use*
  • Estrus*
  • Female
  • Humans
  • Menopause* / metabolism
  • Middle Aged
  • Norethindrone / analogs & derivatives*
  • Norethindrone / therapeutic use
  • Norethindrone Acetate
  • Osteocalcin / blood
  • Osteogenesis
  • Time Factors


  • Drug Combinations
  • Osteocalcin
  • Estradiol
  • Norethindrone Acetate
  • Calcium
  • Norethindrone