Effect of continuous and sequential oral estrogen-progestogen replacement regimens on postmenopausal bone loss: a 2-year prospective study

Management of postmenopausal women: Collège National des Gynécologues et Obstétriciens Français (CNGOF) and Groupe d'Etude sur la Ménopause et le Vieillissement (GEMVi) Clinical Practice Guidelines

AIM

The aim of these recommendations is to set forth an individualized approach to the management of early postmenopausal women (i.e., within the first 10 years after natural menopause) covering all aspects of lifestyle and therapeutic management, with or without menopause hormone therapy (MHT).

MATERIALS AND METHODS

Literature review and consensus of French expert opinion. Recommendations were graded according to the HAS methodology and levels of evidence derived from the international literature, except when there was no good-quality evidence.

SUMMARY RECOMMENDATIONS

The beginning of menopause is an ideal time for each woman to evaluate her health status by assessing her bone, cardiovascular, and cancer-related risk factors that may be amplified by postmenopausal estrogen deficiency and by reviewing her lifestyle habits. Improving lifestyle, including nutrition and physical activity, and avoiding risk factors (notably smoking), should be recommended to all women. MHT remains the most effective treatment for vasomotor symptoms but it could be also recommended as first-line treatment for the prevention of osteoporosis in early postmenopausal women at low to moderate risk for fracture. The risks of MHT differ depending on its type, dose, duration of use, route of administration, timing of initiation, and whether a progestogen is used. There is reasonable evidence that using transdermal estradiol in association with micronized progesterone or dydrogesterone may limit both the venous thromboembolic risk associated with oral estrogens and the risk of breast cancer associated with synthetic progestins. Treatment should be individualized to each woman, by using the best available evidence to maximize benefits and minimize risks, with periodic reevaluation of its benefit-risk balance. For bothersome genitourinary syndrome of menopause (GSM) symptoms, vaginal treatment with lubricants and moisturizers is recommended as first-line treatment together with low-dose vaginal estrogen therapy, depending on the clinical course. No recommendation of an optimal duration of MHT can be made, but it must take into consideration the initial indication for MHT as well as each woman's benefit-risk balance. Management of gynecological side-effects of MHT is also examined. These recommendations are endorsed by the Groupe d'Etude sur la Ménopause et le Vieillissement hormonal (GEMVI) and the Collège National des Gynécologues-Obstétriciens Français (CNGOF).

[Menopause, menopause hormone therapy and osteoporosis. Postmenopausal women management: CNGOF and GEMVi clinical practice guidelines]

Postmenopausal osteoporosis is a frequent clinical condition, which affects nearly 1 in 3 women. Estrogen deficiency leads to rapid bone loss, which is maximal within the first years after the menopause transition and can be prevented by menopause hormone therapy (MHT). Assessment of the individual risk of osteoporosis is primarily based on the measurement of bone mineral density (BMD) at the spine and femur by DXA. Clinical risk factors (CRFs) for fractures taken either alone or in combination in the FRAX score were shown not to reliably predict fractures and/or osteoporosis (as defined by a T-score<-2.5) in early postmenopausal women. If DXA measurement is indicated in all women with CRFs for fractures, it can be proposed on a case-by-case basis, when knowledge of BMD is likely to condition the management of women at the beginning of menopause, particularly the benefit-risk balance of MHT. MHT prevents both bone loss and degradation of the bone microarchitecture in early menopause. It significantly reduces the risk of fracture at all bone sites by 20 to 40% regardless of basal level of risk with an estrogen-dependent dose-effect. Given the inter-individual variability in bone response, individual monitoring of the bone effect of MHT is warranted when prescribed for the prevention of osteoporosis. This monitoring is based on repeated measurement of lumbar and femoral BMD (on the same DXA measurement system) after 2years of MHT, the response criterion being no significant bone loss. Discontinuation of treatment is associated with a resumption of transient bone loss although there is a large variability in the rate of bone loss among women. Basically, there is a return to the level of fracture risk comparable to that of in untreated woman of the same age within 2 to 5years. Therefore, when MHT is prescribed for the prevention of osteoporosis in women with an increased risk at the beginning of menopause, measurement of BMD is recommended when MHT is stopped in order to consider further management of the risk of fracture whenever necessary (with possibly another anti-osteoporotic treatment).

Available medical choices for the management of menopause

The age at which menopause occurs is a critical factor in the magnitude of its consequences. Most of the medium-to-long-term effects of oestrogen deprivation depend on their duration. The timing of the last menstruation is therefore important, but hypoestrogenic amenorrhoea during the reproductive age is also a relevant factor in the evaluation of individual risks. In recent years, moving post-menopausal women from the lowest point of ovarian hypofunction has been the most important motivation for developing guidelines for the hormonal management of menopause. However, recent data suggest that this may be associated with an unacceptable increase in morbidity in a number of women. Concerns about long-term hormone replacement therapy (HRT) at menopause have recently enhanced interest in a group of molecules that act on the oestrogen receptor with selective effects, known as selective oestrogen receptor modulators (SERMs). Of these, Raloxifene has been approved for the treatment and prevention of osteoporosis, and exhibits a pattern of actions particularly well matched to the needs and concerns of post-menopausal women. Further studies on SERMs may open up new vistas in patient-specific management of post-menopausal health. Finally, debates on the specific health consequences of menopause deal mainly with the risk of chronic disease. Gynaecologists and other health professionals would be advised to develop intervention strategies at menopause according to the continuum of a woman's life, beginning at the post-menarche and extending into later life.

The effect of continuous oestradiol with intermittent norgestimate on bone mineral density and bone turnover in post-menopausal women

OBJECTIVE

To assess in post-menopausal women the efficacy and tolerability of a continuous oestradiol/intermittent norgestimate HRT regimen to prevent and to reverse post-menopausal loss of bone mineral density (BMD) and to determine the effects on serum bone turnover markers markers.

METHODS

A 1-year, multicentre, international, placebo-controlled, randomised, double-blind clinical trial was conducted in 146 post-menopausal women with an intact uterus in order to assess the effect on bone loss of continuous oral 17beta-oestradiol (1 mg per day) combined with norgestimate (90 microg per day), for 3 consecutive days out of every 6-day treatment period (E2/iNGM). During a second year extension, all women agreeing to continue were on the E2/iNGM regimen. BMD was assessed prior to treatment and after 1 and 2 years or at the end of treatment in women stopping participation prematurely after at least 6 months of treatment. Serum bone turnover markers were determined prior to and at 1 year of treatment Adverse events were collected at three-monthly intervals during clinic visits over the treatment period.

RESULTS

BMD in the lumbar spine, the primary endpoint, was evaluable in 117 subjects completing >6 months of treatment. BMD increased on average by 2.4% in women on the intermittent progestin regimen. It decreased by 1.4% in placebo treated women. The change from baseline and the difference between active and placebo treatment (Delta placebo) were highly significant (P < 0.0001). On E2/iNGM, also the BMD in the total hip increased (+1.49%, Delta placebo 3.73%, P < 0.0001). The serum markers for bone formation osteocalcin and type I collagen N-propeptide were significantly reduced compared to baseline by 31 and 44%, respectively and the bone resorption marker C-terminal crosslinked telopeptide of type I collagen by 59%. Minor increases (<10%) of markers in the placebo group were not significant. During a second year extension of the trial, all subjects were on active treatment. Subjects on placebo who lost (median+/-CI 95%) 0.66% (-2.3 to +0.5) of spine BMD during the first year now gained 4.41% (2.7-7.6). They also gained 1.6% (0.1-0.3.6) in the total hip. Subjects continuously on oestradiol/intermittent norgestimate (E2/iNGM) gained an additional 5.7% (2.3-13.5) in the lumbar spine and +0.1% (-0.6 to +2.2) at the total hip. Side effects reported by women on the intermittent progestin regimen significantly in excess over reports from the placebo group were uterine bleeding, abdominal and breast pain, but not headache. Back pain and weight gain was reported by significantly fewer women on active treatment compared to placebo.

CONCLUSION

The continuous oestradiol/intermittent norgestimate HRT regimen is well tolerated, reduces bone turnover and prevents post-menopausal bone loss in healthy post-menopausal women.

Trimegestone in a low-dose, continuous-combined hormone therapy regimen prevents bone loss in osteopenic postmenopausal women

OBJECTIVE

To determine the efficacy of estrogen + progestogen therapy with 1 mg 17beta-estradiol and 0.125 mg trimegestone in the prevention of postmenopausal osteoporosis.

DESIGN

For this study, 360 healthy, postmenopausal women with osteopenia [lumbar spine bone mineral density (BMD) between -1.0 and -2.5 SD of the premenopausal mean value] were enrolled in a 2-year prospective, randomized study, and 70% completed. Treatments were 1 mg 17beta-estradiol + 0.125 mg trimegestone (n = 179) or placebo (n = 181), given as daily oral therapy. All received a daily supplement of 500 mg calcium and 400 IU vitamin D. BMD measurements at the lumbar spine, total hip, and femoral neck as well as blood and urinary biochemical markers of bone turnover (serum osteocalcin), serum bone-specific alkaline phosphatase, serum CrossLaps, and urinary CrossLaps took place regularly.

RESULTS

BMD increases relative to placebo were 6.3%, 3.9%, and 3.8% at the lumbar spine, total hip, and femoral neck, respectively (all P < 0.001). The biochemical markers of bone turnover were suppressed accordingly. Serum CrossLaps and urinary CrossLaps decreased rapidly, by 52% and 54%, respectively, whereas serum osteocalcin and serum bone-specific alkaline phosphatase revealed a more retarded decrease of 40% and 33%, respectively. Of the women receiving hormone therapy, 75% had amenorrhea from the first cycle, and 5% withdrew prematurely due to metrorrhagia or mastalgia.

CONCLUSION

This new estrogen + progestogen therapy is efficient in increasing BMD in an osteopenic postmenopausal population. Furthermore, it is well tolerated, with few adverse events and an early bleeding control, which is likely to improve compliance to the treatment over the long term.