Physiological oestradiol administration does not change the biological to immunological ratio of LH in serum from post-menopausal women

An audit of oestradiol levels and implant frequency in women undergoing subcutaneous implant therapy

OBJECTIVES

The aim of the study was to review our long-term use of subcutaneous oestradiol (E2) implant therapy for the treatment of climacteric symptoms in post-menopausal women. On the grounds that the aim is to restore premenopausal serum E2 levels, our declared clinical policy is not to repeat implants even in the presence of symptoms if serum E2 levels are > 400 pmol/l. Therapy was with 50 mg E2 implants inserted subcutaneously in the lower abdominal wall.

DESIGN

All women who had attended the gynaecological/endocrinological clinic who had received subcutaneous E2 implants for the relief of climacteric symptoms between December 1981 and 1992 were included.

RESULTS

Between December 1981 and December 1992, 275 women received a total of 759 50 mg E2 implants. The median length of implant therapy was 34.2 months (range 3.7-109.5 months), and the median number of implants per patient was 4 and ranged from 1 to 13. One hundred and twenty-nine women had more than four implants and their mean recorded serum E2 level was 425 +/- 187 (mean +/- SD) pmol/l; the mean level over the first 24 months of therapy was 408 +/- 157 pmol/l. This was not different from the mean value of the remaining period of therapy (439 +/- 168 pmol/l). Following the second implant there was no significant progressive rise in serum E2 with time and implant number and the mean E2 level per patient was no higher in those patients who received implants more frequently. The mean time between the first two implants was 9.7 +/- 0.4 months and between subsequent ones was 11.7 +/- 0.5 months. After the first two implants there was no progressive change in this interval with time.

CONCLUSION

This study shows that effective, safe and sympathetic management of women with oestrogen deficient symptoms may be achieved by use of two criteria to determine re-treatment; the return of symptoms, and a serum E2 level no higher than 400 pmol/l. Once therapy is established, E2 implants may need to be prescribed only on an annual basis. There appears to be no justification for giving E2 implants more frequently as this policy achieves satisfactory (physiological) premenopausal E2 levels and good symptomatic relief without any evidence for accumulation of E2 or 'tachyphylaxis'.

17 beta-oestradiol counteracts the formation of the more acidic isoforms of follicle-stimulating hormone and luteinizing hormone after menopause

OBJECTIVE

When the gonadotrophin levels increase at midcycle, more basic isoforms of FSH and LH appear in the circulation. However, when these gonadotrophins increase at menopause more acidic forms appear. The present study was done to see whether chronic 17 beta-oestradiol (E2) administration to post-menopausal women could counteract the formation of the more acidic isoforms after the menopause.

DESIGN

Serum samples were obtained from 16 post-menopausal women, mean age 70 years (range 63-84 years), 46-169 days after the subcutaneous insertion of a 20-mg E2-implant. FSH, LH and E2 in the sera were measured with fluoroimmunoassays. The median charge and the degree of charge heterogeneity of the FSH and LH isoforms were determined for each serum by electrophoresis in 0.1% agarose suspension. Sera from an age-matched control group were analysed in parallel.

RESULTS

The E2 levels in the E2-treated women were 230-570 pmol/l, within the range expected during the mid-luteal phase of the normal menstrual cycle. The mean serum FSH and LH levels were similar to normal follicular phase FSH and LH levels (8.6 and 20.8% respectively of the control group). It was estimated that individual serum specimens from both groups contained 20-30 different isoforms for both FSH and LH. The median charges of the isoforms of FSH and LH were more basic in all the E2-treated subjects than in their corresponding untreated controls. The mean median charge for FSH was close to the values for the follicular and luteal phases and that for LH close to that for the luteal phase. In some E2-treated women the isoforms were even more basic with a charge similar to that at the midcycle peak. The degree of charge heterogeneity for the E2-treated group was significantly (P < 0.001) larger than for the controls and similar to that during the normal menstrual cycle.

CONCLUSION

Chronic E2 administration to post-menopausal women counteracted the formation of more acidic isoforms of both FSH and LH after the menopause.