Goserelin (Zoladex) and the skeleton

Crosstalk within a brain-breast-bone axis regulates mineral and skeletal metabolism during lactation

To support the increased calcium demands for milk production during lactation, a dramatic and reversible physiological response occurs to alter bone and mineral metabolism. This coordinated process involves a brain-breast-bone axis that integrates hormonal signals that allow for adequate calcium delivery to milk yet also protects the maternal skeletal from excessive bone loss or decreases in bone quality or function. Here, we review the current knowledge on the crosstalk between the hypothalamus, mammary gland, and skeleton during lactation. We discuss the rare entity of pregnancy and lactation associated osteoporosis and consider how the physiology of bone turnover in lactation may impact the pathophysiology of postmenopausal osteoporosis. Further understanding of the regulators of bone loss during lactation, particularly in humans, may provide insights into new therapies for osteoporosis and other diseases of excess bone loss.

Spine bone mineral density increases after 6 months of exclusive lactation, even in women who keep breastfeeding

This pilot study enrolled 31 women who had breastfed exclusively for 6 months. Lumbar and thoracic BMD increased 4 and 5%, respectively. Femoral neck and total body BMD did not change. Return of menses and progestin-only pill use were two potential signals that predicted a greater increase in BMD.

PURPOSE/INTRODUCTION

The skeleton is resorbed during lactation to provide much of the calcium content of milk. After lactation ceases, these deficits in skeletal mineral content are largely restored, such that lactation has a neutral or protective effect against the long-term risk of low bone mineral density (BMD), osteoporosis, and fragility fractures. We hypothesized that a large observational study may identify the factors that predict a greater increase in BMD after lactation ceases. A pilot study was first needed to test feasibility and the magnitude of expected BMD change.

METHODS

We undertook Factors Affecting Bone formation after Breastfeeding Pilot (FABB Pilot), which enrolled women who had breastfed exclusively for 6 months and planned to wean soon. The main outcome was change in BMD between enrolment and 6 months later.

RESULTS

Thirty-one women were recruited and completed both time points. Lumbar and thoracic spine BMD increased 4 and 5%, respectively; there was no significant change in femoral neck and total body BMD. Most women did not wean their babies as planned but continued to breastfeed multiple times per day. Despite this, a significant increase in BMD was seen in the subsequent 6 months. Return of spontaneous menses and use of a progestin-only pill at recruitment were two potential signals that predicted a greater increase in BMD during the 6 months after exclusive lactation.

CONCLUSIONS

Spine BMD increased significantly during 6 months following exclusive lactation and despite continued lactation. The factors that stimulate skeletal recovery remain to be identified.

Maternal Mineral and Bone Metabolism During Pregnancy, Lactation, and Post-Weaning Recovery

During pregnancy and lactation, female physiology adapts to meet the added nutritional demands of fetuses and neonates. An average full-term fetus contains ∼30 g calcium, 20 g phosphorus, and 0.8 g magnesium. About 80% of mineral is accreted during the third trimester; calcium transfers at 300-350 mg/day during the final 6 wk. The neonate requires 200 mg calcium daily from milk during the first 6 mo, and 120 mg calcium from milk during the second 6 mo (additional calcium comes from solid foods). Calcium transfers can be more than double and triple these values, respectively, in women who nurse twins and triplets. About 25% of dietary calcium is normally absorbed in healthy adults. Average maternal calcium intakes in American and Canadian women are insufficient to meet the fetal and neonatal calcium requirements if normal efficiency of intestinal calcium absorption is relied upon. However, several adaptations are invoked to meet the fetal and neonatal demands for mineral without requiring increased intakes by the mother. During pregnancy the efficiency of intestinal calcium absorption doubles, whereas during lactation the maternal skeleton is resorbed to provide calcium for milk. This review addresses our current knowledge regarding maternal adaptations in mineral and skeletal homeostasis that occur during pregnancy, lactation, and post-weaning recovery. Also considered are the impacts that these adaptations have on biochemical and hormonal parameters of mineral homeostasis, the consequences for long-term skeletal health, and the presentation and management of disorders of mineral and bone metabolism.

Efficacy of tibolone as "add-back therapy" in conjunction with a gonadotropin-releasing hormone analogue in the treatment of uterine fibroids

OBJECTIVE

To assess the efficacy of tibolone add-back therapy with Goserelin treatment of uterine fibroids.

DESIGN

Randomized placebo-controlled study.

SETTING

Gynecology department of an inner-city teaching hospital.

PATIENT(S)

Seventy-five women of reproductive age with uterine fibroids.

INTERVENTION(S)

All women were given monthly SC implants of 3.6 mg goserelin and were randomized to take 3 months of placebo followed by 3 months of tibolone 2.5 mg daily (delayed administration), tibolone 2.5 mg daily for 6 months, or placebo for 6 months.

MAIN OUTCOME MEASURE(S)

Changes in bone mineral density (BMD) at the hip and spine, fibroid and uterine size, and patient symptomatology.

RESULT(S)

In the tibolone group, 2% loss of BMD at the spine was observed compared with 5.5% loss in the placebo group. For total hip, tibolone led to a 0.7% gain in BMD compared with a loss of 1.7% in the placebo group. Tibolone did not affect GnRH analogue-induced fibroid shrinkage. Vasomotor symptom scores in women taking tibolone were 2.2 and were significantly lower than those taking placebo or in the delayed administration groups (mean scores 2.9 and 2.7, respectively).

CONCLUSION(S)

Tibolone appears to be a safe and effective add-back therapy which can be given from the commencement of GnRH analogue treatment for fibroids.

Gonadotrophin-releasing hormone analogues for endometriosis: bone mineral density

BACKGROUND

Gonadotrophin-releasing hormone analogues (GnRHas) are generally well tolerated, and are effective in relieving the symptoms of endometriosis (Prentice 2003). Unfortunately the low oestrogen state that they induce is associated with adverse effects including an acceleration in bone mineral density (BMD) loss.

OBJECTIVES

To determine the effect of treatment with gonadotrophin-releasing hormone analogues (GnRHas) on the bone mineral density of women with endometriosis, compared to placebo, no treatment, or other treatments for endometriosis, including GnRHas with add-back therapy.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group's specialised register of controlled trials (23rd October 2002) and the Cochrane Central Register of Controlled Trials (Cochrane Library, issue 4, 2002). We also carried out electronic searches of MEDLINE (1966 - March Week 2 2003) and EMBASE (1980 - March Week 2 2003). We also searched the reference lists of articles and contacted researchers in the field.

SELECTION CRITERIA

Prospective, randomised controlled studies of the use of GnRHas for the treatment of women with endometriosis were considered, where bone density measurements were an end point. The control arm of the studies was either placebo, no treatment, another medical therapy for endometriosis, or GnRHas with add-back therapy.

DATA COLLECTION AND ANALYSIS

Two reviewers (JF and MS) independently assessed trial quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Thirty studies involving 2,391 women were included, however only 15, involving 910 women, could be included in the meta-analysis. The meta-analysis showed that danazol and progesterone + oestrogen add-back are protective of BMD at the lumbar spine both during treatment and for up to six and twelve months after treatment, respectively. Between the groups receiving GnRHa and the groups receiving danazol/gestrinone, there was a significant difference in percentage change of BMD after six months of treatment, the GnRH analogue producing a reduction in BMD from baseline and danazol producing an increase in BMD (SMD -3.43, 95 % CI -3.91 to -2.95). Progesterone only add-back is not protective; after six months of treatment absolute value BMD measurements of the lumbar spine did not differ significantly from the group receiving GnRH analogues (SMD 0.15, 95 % CI -0.21 to 0.52). In the comparison of GnRHa versus GnRHa + HRT add-back, that is oestrogen + progesterone or oestrogen only, there was a significantly bigger BMD loss in the GnRHa only group (SMD -0.49, 95 % CI -0.77 to -0.21). These numbers reflect the absolute value measurements at the lumbar spine after six months of treatment. Due to the small number of studies in the comparison we are unable to conclude whether calcium-regulating agents are protective. No difference was found between low and high dose add-back regimes but again only one study was identified for this comparison. Only one study comparing GnRH analogues with placebo was identified, but the study gave no data. No studies comparing GnRH with the oral contraceptive pill (OCP) or progestagens were identified.

REVIEWER'S CONCLUSIONS

Both danazol and progesterone + oestrogen add-back have been shown to be protective of BMD, while on treatment and up to six and 12 months later, respectively. However, by 24 months of follow-up there was no difference in BMD in those women who had HRT add-back. Studies of danazol versus GnRHa did not report long-term follow-up. The significant side effects associated with danazol limit its use.

Cyclophosphamide for the treatment of systemic lupus erythematosus

Aggressive immunosuppressive therapy with cyclophosphamide has improved the outcome of major organ disease in lupus patients. Controlled trials have shown that pulse cyclophosphamide is the treatment of choice for patients with moderate to severe proliferative nephritis. Long-term follow-up of patients participating in these controlled trials suggests that combining pulse cyclophoshamide with pulse methylprednisolone increases efficacy but not toxicity. Retrospective case series have also shown that pulse cyclophosphamide therapy may be effective for the management of severe or refractory to standard therapy neuropsychiatric, pulmonary, cardiovascular and hematologic disease. Pulse cyclophosphamide is associated with an increased risk for herpes zoster infections in the short term and with sustained amenorrhea in the long-term. Recent studies have also drawn attention to the lack of response (or incomplete response) and flare of lupus after an initial response. In an effort to circumvent these limitations, current investigations explore the therapeutic potential of high-dose, immunoablative cyclophosphamide therapy or low-dose cyclophosphamide in combination with nucleoside analogs or biologic response modifiers.

Voice changes in women treated for endometriosis and related conditions: the need for comprehensive vocal assessment

Hormonal treatments which have an androgenic effect have the potential to cause vocal changes. The changes in vocal fold structure and voice quality are considered to be irreversible. To date, studies have documented subjective vocal changes or documented single cases without detailed, baseline voice assessments. The impact on laryngeal function of women taking these androgenic treatments requires further detailed, objective assessment. The need for increased awareness of the actions of androgenic hormones on womens' voices, and the benefits of a thorough voice assessment are discussed.