Effect of orally administered oestrogens on circulating oestrogen profiles in post-menopausal women

The effect of 4 peroral oestrogen regimens without and with levonorgestrel (LNG) supplementation (250 micrograms/day) was studied in 7 post-menopausal women. The regimens were: A: 2.5 mg piperazine oestrone sulphate/day; B: 1.25 mg piperazine oestrone sulphate + 5.0 mg oestriol/day; C: 2.0 mg oestradiol valerate/day and D: 10.0 mg oestriol/day. A randomized complete cross-over design was employed and systemic blood levels of progesterone (P), oestrone (E1), oestradiol (E2), oestriol (E3), oestrone sulphate (E1S), oestradiol sulphate (E2S) and oestriol sulphate (E3S) were analyzed. All subjects were consistently post-menopausal, as indicated by low P, E2, E1S and E3S and high FSH and LH levels. The pretreatment and post-treatment levels of E2 and E2S as well as those of E3 and E3S were invariably below detection limit (60 pmol/l and 220 pmol/l, respectively). Treatment with regimens A, B and C resulted in consistently detectable levels of E2, E2S and E3S, but not of E3, and in grossly elevated E1 and E1S levels. Treatment with regimen D gave rise to very high E3S levels. The oestrogen profiles produced by regimens A and C were almost identical, with the exception of higher E1 and lower E3S levels following the administration of regimen A. Combination with LNG did not modify the levels of unconjugated oestrogens, but in certain cases it seemed to diminish those of oestrogen sulphates. A comparison with the results of a preceding study (Aedo A-R et al., Effect of orally administered oestrogens on gonadotrophins levels in post-menopausal women. Maturitas 1989; 11:) reveals that the gonadotrophin-suppressing effect of all 4 regimens still persisted in the post-treatment period at a time when the levels of all oestrogens analyzed returned to those of the pretreatment period.