Factors associated with bone density in young women with karyotypically normal spontaneous premature ovarian failure

Bone health in women with premature ovarian insufficiency/early menopause: a 23-year longitudinal analysis

STUDY QUESTION

What is the frequency of, and predictors for, osteoporosis, fractures, and osteoporosis management (investigation, treatment) in women with premature ovarian insufficiency (POI; menopause <40 years) and early menopause (EM; menopause 40-44years)?

SUMMARY ANSWER

Over the 23-year follow-up duration, at a mean age of 68 years, women with POI/EM had higher osteoporosis/fracture risk and prevalence, higher osteoporosis screening and anti-osteoporosis medication use compared to women with usual age menopause; increasing age was predictive of increased risk of osteoporosis/fracture and menopause hormone therapy (MHT) prior to or at study entry (aged 45-50 years) was protective.

WHAT IS KNOWN ALREADY

Women with POI/EM have increased risk of osteoporosis and fractures with limited data regarding risk factors for reduced bone density and fractures. Clinical guidelines recommend screening with dual X-ray absorptiometry (DXA) and treatment with MHT for most women with POI/EM to reduce osteoporosis and fracture risk; however, studies indicate gaps in osteoporosis knowledge, guideline uptake, and management adherence by clinicians and women.

STUDY DESIGN, SIZE, DURATION

The Australian Longitudinal Study on Women's Health is a prospective longitudinal study of Australian women. This study uses the cohort of women born between 1946 and 1951, surveyed nine times between 1996 and 2019. Data from the Australian administrative health records, including hospital admissions data (fractures, osteoporosis), Medicare Benefits Schedule (DXA), and the Pharmaceutical Benefits Scheme (PBS; MHT, anti-osteoporosis medication, available only from 2002) were linked to survey data.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Survey respondents with self-reported age of menopause were included. POI/EM was defined as menopause <45 years. T-test or chi-square were used for comparisons at baseline (P < 0.05 indicates significance). Generalized estimating equations for panel data explored predictors for the longitudinal outcomes of osteoporosis, fractures, DXA rates, MHT use, and anti-osteoporosis medication (in women with osteoporosis/fracture, from Survey 4 onwards only). Univariable regression was performed, and variables retained where P < 0.2, to form the multivariable model, and bootstrapping with 100 repetitions at 95% sampling of the original dataset to ensure robustness of results.

MAIN RESULTS AND THE ROLE OF CHANCE

Eight thousand six hundred and three women were included: 610 (7.1%) with POI/EM. Mean (SD) baseline age was 47.6 (1.45) years in the entire cohort and mean (SD) age of menopause was 38.2 (7.95) and 51.3 (3.04) years in women with POI/EM and usual age menopause, respectively (P < 0.001). Over the 23 years, of women with POI/EM, 303 (49.7%) had osteoporosis/fractures, 421 (69.0%) had DXA screening, 474 ever used MHT (77.7%), and 116 (39.1%) of those with osteoporosis/fractures used anti-osteoporosis medication. Of women with usual age menopause, 2929 (36.6%) had osteoporosis/fractures, 4920 (61.6%) had DXA screening, 4014 (50.2%) used MHT, and 964 (33.0%) of those with osteoporosis/fractures used anti-osteoporosis medication. Compared to women with menopause at age ≥45 years and after adjusting for other risk factors, women with POI/EM had increased risk of osteoporosis (odds ratio [OR] 1.37; 95% CI 1.07-1.77), fractures (OR 1.45; 1.15-1.81), DXA testing (OR 1.64; 1.42-1.90), MHT use (OR 6.87; 5.68-8.30), and anti-osteoporosis medication use (OR 1.50; 1.14-1.98). In women with POI/EM women, increasing age was associated with greater risk of osteoporosis/fracture (OR 1.09; 1.08-1.11), and MHT prior to or at study entry (aged 45-50 years), was protective (OR 0.65, 0.45-0.96). In women with POI/EM, age (OR 1.11; 1.10-1.12), fractures (OR 1.80, 1.38-2.34), current smoking (OR 0.60; 0.43-0.86), and inner (OR 0.68; 0.53-0.88) or outer regional (OR 0.63; 0.46-0.87) residential location were associated with DXA screening. In women with POI/EM, increasing age (OR 1.02; 1.01-1.02), and currently consuming alcohol (OR 1.17; 1.06-1.28), was associated with having ever used MHT. In the 299 women with POI/EM and osteoporosis/fractures, only 39.1% ever received treatment with an anti-osteoporosis medication. Increasing age (OR 1.07; 1.04-1.09) and lower BMI (OR 0.95; 0.92-0.98) were associated with greater likelihood of treatment with anti-osteoporosis medication.

LIMITATIONS, REASONS FOR CAUTION

Survey data including age of menopause were self-reported by participants; fracture questions were not included in the 2001 survey, and location or level of trauma of self-reported fractures was not asked. Additional risk/protective factors such as vitamin D status, calcium intake, and exercise were not able to be included. Due to sample size, POI and EM were combined for all analyses, and we were unable to differentiate between causes of POI/EM. PBS data were only available from 2004, and hospital admissions data were state-based, with all of Australia were only available from 2007.

WIDER IMPLICATIONS OF THE FINDINGS

This study supports previous literature indicating increased risk of osteoporosis and fractures in women with POI, and adds evidence for women with POI/EM, where there was a relative paucity of data. This is the first study to analyse a variety of clinical and demographic risk factors for osteoporosis and fractures in women with POI/EM, as well as analysing investigation and treatment rates. In these women, using MHT prior to or at study entry, aged 45-50 years, was protective for osteoporosis/fractures; however, having ever used MHT was not, highlighting the importance of early treatment with MHT in these women to preserve bone strength. Although women with POI/EM and osteoporosis or fractures were more likely to use anti-osteoporosis medications than those with usual age menopause, overall treatment rates are low at <40%, demonstrating a significant treatment gap that should be addressed to reduce future fracture risk.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by The Australian NHMRC Centre of Research Excellence Women's Health in Reproductive Life (CRE-WHIRL, project number APP1171592). A.R.J. is the recipient of a National Health and Medical Research Council post-graduate research scholarship (grant number 1169192). P.R.E. is supported by a National Health and Medical Research Council grant 1197958. P.R.E. reports grants paid to their institution from Amgen, Sanofi, and Alexion, honoraria from Amgen paid to their institution, and honoraria from Alexion and Kyowa-Kirin.

TRIAL REGISTRATION NUMBER

N/A.

Bone mineral density in patients with primary ovarian insufficiency: A systematic review and Meta-Analysis

INTRODUCTION

Premature menopause is a major complication of primary ovarian insufficiency (POI), and this loss is closely relates to bone mineral density (BMD). Previous research has indicated potential associations between BMD and POI. This study set out to provide the first systematic literature review and meta-analysison account of BMD content among women with POI.

METHODS

Studies including women with POI and controls were eligible from PubMed, Embase, Cochrane Library and Web of Science databases (from their inception to April 2022). Two reviewers independently evaluated study eligibility. The meta-analysis was performed using the DerSimonian and Laird random effects model.

RESULTS

Ten studies featuring 578 women with POI and 480 controls were selected. BMD content of femur neck (SMD:-0.76; 95 % CI: -1.20 to -0.31; P = 0.0008), the BMD content of nondominating forearm (SMD:-0.67; 95 % CI: -1.15 to -0.18; P = 0.007) were significantly decreased in women with POI. However, no differences were seen in other regions (lumbar spine, total hip, hipneck).

DISCUSSION

The results of this study indicate that BMD content altered in patients with primary ovarian insufficiency. An implication of this is the possibility that hormone replacement therapy to minimize the prevalence of fracture morbidity and mortality associated with osteopenia in patients with POI.

Primary Ovarian Insufficiency and Ovarian Aging

Primary ovarian insufficiency (POI) is a complex condition of aberrant ovarian aging. POI etiologies are varied, and most cases have no identifiable underlying cause. Caring for women with POI requires an approach that understands the importance of ovarian function in a variety of target organs and tissues.

Autoimmune polyglandular syndrome type 4: experience from a single reference center

Purpose

To characterize patients with APS type 4 among those affected by APS diagnosed and monitored at our local Reference Center for Autoimmune Polyglandular Syndromes.

Methods

Monocentric observational retrospective study enrolling patients affected by APS diagnosed and monitored in a Reference Center. Clinical records were retrieved and analyzed.

Results

111 subjects (51 males) were affected by APS type 4, mean age at the onset was 23.1 ± 15.1 years. In 15 patients the diagnosis of APS was performed during the first clinical evaluation, in the other 96 after a latency of 11 years (range 1-46). The most frequent diseases were type I diabetes mellitus and celiac disease, equally distributed among sexes.

Conclusions

The prevalence of APS type 4 is 9:100,000 people. Type I diabetes mellitus was the leading indicator of APS type 4 in 78% subjects and in 9% permitted the diagnosis occurring as second manifestation of the syndrome. Our data, showing that 50% of patients developed APS type 4 within the first ten years, don't suggest any particular follow-up time and, more importantly, don't specify any particular disease. It is important to emphasize that 5% of women developed premature ovarian failure.

Characterizing the Adolescent Premature Ovarian Insufficiency Phenotype: A Case Control Study

STUDY OBJECTIVES

To characterize the skeletal, cardiometabolic, cognitive, and mental health phenotype of adolescents with idiopathic premature ovarian insufficiency (POI) DESIGN: Case control SETTING: Pediatric tertiary referral center in Cincinnati, Ohio PARTICIPANTS: Nine adolescents (ages 11-18.99 years) with newly diagnosed POI and 9 normally menstruating controls, matched by age and body mass index MAIN OUTCOME MEASURES: Between-group comparisons of bone characteristics assessed by dual energy x-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT), psychosocial health (anxiety, depression, and quality of life), and cognition and memory by questionnaire RESULTS: Adolescents with POI had lower bone density Z-scores by DXA (lumbar spine -1.93 vs 0.80; whole body less head -2.05 vs 0.00; total hip -1.03 vs 0.83; and femoral neck -1.23 vs 0.91; all P < .001), as well as lower trabecular volumetric bone mineral density (tibia 3% site 226 vs 288 mg/mm³, P < .001; radius 3% site 200 vs 251, P = .001), smaller cortical area (tibia 66% site 251 vs 292 mm², P = .028), and thickness (tibia 66% site 3.56 vs 4.30 mm, P = .001) than controls. No abnormalities in cardiometabolic biomarkers were detected in POI cases. Adolescents with POI were also more likely to report low energy (78% vs 22%, P = .02).

CONCLUSION

Estrogen deficiency adversely affects bone health in adolescents with POI. However, we did not find associations with cardiometabolic, mental health, or cognitive outcomes in this small sample.

Bone mineral density, vertebral fractures and trabecular bone score in primary ovarian insufficiency

PURPOSE

Bone health in primary ovarian insufficiency (POI) is under-investigated. We assessed patients with spontaneous POI for vertebral fractures (VFs) and related parameters of bone health.

METHODS

70 cases with spontaneous POI (age 32.5 ± 7.0 years) and an equal number of controls were assessed for BMD, TBS, and VFs. BMD at the lumbar-spine (L1-L4), left hip, non-dominant forearm, and TBS (iNsight software) were measured on a dual-energy X-ray absorptiometry (DXA) machine. VFs were assessed by Genant's classification. Serum FSH, LH, estradiol, T4, TSH, iPTH, serum 25(OH)D, total calcium, and inorganic phosphorus were measured.

RESULTS

BMD at the lumbar-spine, hip and forearm was reduced by 11.5%, 11.4% and 9.1% in POI as compared to controls (P < 0.001). Degraded or partially degraded microarchitecture on TBS was observed in 66.7% of patients and 38.2% of controls (P = 0.001). 15.7% of the POI patients had VFs, compared to 4.3% of controls (P = 0.045). Age, duration of amenorrhea and duration of HRT use were the significant predictors of TBS (P < 0.01). Serum 25(OH)D was the significant determinant of VFs. TBS abnormalities were higher in patients with POI and VFs. BMD was not significantly different in patients with and without VFs.

CONCLUSION

Thus, lumbar-spine osteoporosis, impaired TBS and VFs were present in 35.7%, 66.7% and 15.7% of patients with spontaneous POI in their early third decade. This indicates need for rigorous investigations for impaired bone health in these young patients and management with HRT, vitamin-D, and possible need for bisphosphonate therapy.

Maintained Bone Density in Young Hypoestrogenized Women with a High BMI: Case Series

Estrogen deficiency and obesity are factors that affect bone mass in a manner that is independent and in opposing directions. Obesity favours higher bone mass and increased bone formation whereas estrogen deficiency leads to significant bone loss in leaner individuals. To report the impact of the competing effects of a hypoestrogenized state and obesity on long-term bone health, we present two cases of young chronically hypoestrogenized females whose bone parameters were assessed with high-resolution peripheral quantitative computed tomography (HR-pQCT) and revealed a bone mineral density and microstructure that did not change despite the long history of a low estrogen state. As evidenced by the outcomes for these patients, the obesity-related effect on bone mass may be dominant when obesity is marked and appears to be highly protective even in the setting of sub-physiologic circulating estrogen. Recognition of this interaction should be considered in decisions around estrogen replacement therapy in such cases.

Musculoskeletal Health in Premature Ovarian Insufficiency. Part Two: Bone

Accelerated bone loss and muscle loss coexist in women with premature ovarian insufficiency (POI), but there are significant gaps in our understanding of musculoskeletal health in POI. This review describes estrogen signaling in bone and its role in skeletal health and disease. Possible mechanisms contributing to bone loss in different forms of POI and current evidence regarding the utility of available diagnostic tests and therapeutic options are also discussed. A literature review from January 2000 to March 2020 was conducted to identify relevant studies. Women with POI experience significant deterioration in musculoskeletal health due to the loss of protective effects of estrogen. In bone, loss of bone mineral density (BMD) and compromised bone quality result in increased fracture risk; however, tools to assess bone quality such as trabecular bone score (TBS) need to be validated in this population. Timely initiation of HRT is recommended to minimize the deleterious effects of estrogen deficiency on bone in the absence of contraindications; however, the ideal estrogen replacement regimen remains unknown. POI is associated with compromised bone health, regardless of the etiology. Ongoing research is warranted to refine our management strategies to preserve bone health in women with POI.

Current Understanding of the Etiology, Symptomatology, and Treatment Options in Premature Ovarian Insufficiency (POI)

Premature ovarian insufficiency (POI) occurs in at least 1% of all women and causes life-long health problems and psychological stress. Infertility caused by POI used to be considered absolute, with infertility treatment having little or no value. Generally, it has been thought that medicine can provide little service to these patients. The etiology of POI has been found to be genetic, chromosomal, and autoimmune. In addition, the increasing numbers of cancer survivors are candidates for iatrogenic POI, along with patients who have undergone ovarian surgery, especially laparoscopic surgery. Over 50 genes are known to be causally related to POI, and the disease course of some cases has been clarified, but in most cases, the genetic background remains unexplained, suggesting that more genes associated with the etiology of POI need to be discovered. Thus, in most cases, the genetic background of POI has not been clarified. Monosomy X is well known to manifest as Turner's syndrome and is associated with primary amenorrhea, but recent studies have shown that some women with numerical abnormalities of the X chromosome can have spontaneous menstruation up to their twenties and thirties, and some even conceive. Hormone replacement therapy (HRT) is recommended for women with POI from many perspectives. It alleviates vasomotor and genitourinary symptoms and prevents bone loss and cardiovascular disease. POI has been reported to reduce quality of life and life expectancy, and HRT may help improve both. Most of the problems that may occur with HRT in postmenopausal women do not apply to women with POI; thus, in POI, HRT should be considered physiological replacement of estrogen (+progesterone). This review describes some new approaches to infertility treatment in POI patients that may lead to new treatments for POI, along with the development of more sensitive markers of secondary/preantral follicles and genetic diagnosis.

Hormonal replacement therapy in adolescents and young women with chemo- or radio-induced premature ovarian insufficiency: Practical recommendations

In women with premature ovarian insufficiency (POI), hormonal therapy (HT) is indicated to decrease the risk of morbidity and to treat symptoms related to prolonged hypoestrogenism. While general recommendations for the management of HT in adults with POI have been published, no systematic suggestions focused on girls, adolescents and young women with POI following gonadotoxic treatments (chemotherapy, radiotherapy, stem cell transplantation) administered for pediatric cancer are available. In order to highlight the challenging issues specifically involving this cohort of patients and to provide clinicians with the proposal of practical therapeutic protocol, we revised the available literature in the light of the shared experience of a multidisciplinary team of pediatric oncologists, gynecologists and endocrinologists. We hereby present the proposals of a practical scheme to induce puberty in prepubertal girls and a decisional algorithm that should guide the clinician in approaching HT in post-pubertal adolescents and young women with iatrogenic POI.

Bone health and evaluation of bone mineral density in patients with premature ovarian insufficiency

Oestrogens exert an influence on skeletal homeostasis during growth and adulthood. Regulation of osteoclasts and osteoblasts generation and apoptosis and prolongation of the lifespan of osteocytes are some of their actions on bone metabolism. Premature ovarian insufficiency (POI) and associated loss of oestrogen action on osteoclasts leads to trabecular perforation and loss of connectivity. Lack of oestrogens acting on osteoblast progenitors also causes a decrease in critical bone mass. Postmenopausal hypoestrogenism is associated with an increase in the number of lymphocyte B-cells expressing nuclear factor κB ligand (RANKL) in the bone marrow and elevated expression of RANKL by B-cells. Increased concentration of RANKL stimulates activation of osteoclasts and leads to oestrogen deficiency-associated bone loss. It has been proven that women with POI have decreased bone mineral density (BMD) measured in lumbar spine and femoral neck. The loss of bone mass associated with oestrogen deficiency is greater in trabecular than in cortical bone, thus women with POI have a significant decrease in BMD, particularly in the lumbar spine vertebrae. Smoking cessation, weight-bearing, and muscle-strengthening exercises on most days of the week, avoidance of excessive alcohol intake, and adequate supplementation of calcium and vitamin D are the main lifestyle rules necessary to avoid decline in BMD. The most important component of decreased BMD treatment in POI patients is systemic hormonal replacement therapy (HRT). HRT should provide hormonal balance and should mimic normal ovarian function as much as possible.

Hormone replacement therapy in young women with primary ovarian insufficiency and early menopause

Primary ovarian insufficiency (POI) is a rare but important cause of ovarian hormone deficiency and infertility in women. In addition to causing infertility, POI is associated with multiple health risks, including bothersome menopausal symptoms, decreased bone density and increased risk of fractures, early progression of cardiovascular disease, psychologic impact that may include depression, anxiety, and decreased perceived psychosocial support, potential early decline in cognition, and dry eye syndrome. Appropriate hormone replacement therapy (HRT) to replace premenopausal levels of ovarian sex steroids is paramount to increasing quality of life for women with POI and ameliorating associated health risks. In this review, we discuss POI and complications associated with this disorder, as well as safe and effective HRT options. To decrease morbidity associated with POI, we recommend using HRT formulations that most closely mimic normal ovarian hormone production and continuing HRT until the normal age of natural menopause, ∼50 years. We address special populations of women with POI, including women with Turner syndrome, women with increased risk of breast or ovarian cancer, women approaching the age of natural menopause, and breastfeeding women.

Committee Opinion No. 698: Hormone Therapy in Primary Ovarian Insufficiency

Primary ovarian insufficiency describes a spectrum of declining ovarian function and reduced fecundity due to a premature decrease in initial follicle number, an increase in follicle destruction, or poor follicular response to gonadotropins. The sequelae of primary ovarian insufficiency include vasomotor symptoms, urogenital atrophy, osteoporosis and fracture, cardiovascular disease, and increased all-cause mortality. In women with primary ovarian insufficiency, systemic hormone therapy (HT) is an effective approach to treat the symptoms of hypoestrogenism and mitigate long-term health risks if there are no contraindications to treatment. Hormone therapy is indicated to reduce the risk of osteoporosis, cardiovascular disease, and urogenital atrophy and to improve the quality of life of women with primary ovarian insufficiency. Although exogenous estrogen replacement is recommended for women with primary ovarian insufficiency, data comparing various hormonal regimens for disease prevention, symptom amelioration, and safety are lacking in this population. As a first-line approach, HT (either orally or transdermally) that achieves replacement levels of estrogen is recommended. Combined hormonal contraceptives prevent ovulation and pregnancy more reliably than HT; despite only modest odds of spontaneous pregnancy in women with primary ovarian insufficiency, this is a critical consideration for those who deem pregnancy prevention a priority. Treatment for all women with primary ovarian insufficiency should continue until the average age of natural menopause is reached (age 50-51 years). Finally, considering the challenges that adolescents and young women may face in coping with the physical, reproductive, and social effects of primary ovarian insufficiency, comprehensive longitudinal management of this condition is essential.

Role of microRNAs in premature ovarian insufficiency

Premature ovarian insufficiency (POI) is a typical disorder of amenorrhea lasting for a minimum of 4 months. The typical characteristics comprised of declined estrogen and raised serum concentrations of follicle-stimulating hormone (FSH) in women <40-year-old, primarily originating from iatrogenic factors, karyotypic abnormalities, and genetic factors. However, the etiology of POI remains unknown in approximately 90% of cases. POI could lead to infertility, osteoporosis, cardiovascular disorder, and cognitive dysfunction. MicroRNAs (miRNAs) are a class of endogenous noncoding RNAs (ncRNAs) that can mediate post-translational silencing of the genes involved in the regulation of proliferation, differentiation, apoptosis, development, tumorigenesis, and hematopoiesis. Recently, the regulatory functions of miRNAs in the development of POI have been the topic of intensive research. The present review addresses the association of miRNAs' machinery genes (Dicer, Drosha, and XPO5) with POI and the miRNA expression profiles in the plasma of patients with POI. In addition, several specific miRNAs (miR-23a, miR-27a, miR-22-3p, miR-146a, miR-196a, miR-290-295, miR-423, and miR-608) related to POI are also examined in order to highlight the issues that deserve further investigation. A thorough understanding of the exact regulatory roles of miRNAs is imperative to gain novel insights into the etiology of idiopathic POI and offer new research directions in the field.

Premature ovarian insufficiency: the context of long-term effects

PURPOSE

Premature ovarian insufficiency (POI) is defined as the cessation of the ovarian function before the age of 40 years. POI aetiology may be related to iatrogenic or endogenous factors and in many cases remains unclear. The aim of this review was to characterize the long-term consequences of POI.

METHODS

The available literature regarding the long-term consequences of POI from MEDLINE has been reviewed.

RESULTS

Lack of ovarian steroids synthesis has serious consequences for women's health. The short-term effects are similar to spontaneous menopause and refer mainly to the climacteric syndrome. In a longer perspective, POI affects a variety of aspects. It obviously and drastically reduces the chances for spontaneous pregnancies. Oestrogen loss leads also to urogenital atrophy. The most common urogenital symptoms include vaginal dryness, vaginal irritation and itching. The urogenital atrophy and hypoestrogenism interferes also with sexual functioning. Patients with POI are threatened by a decrease in bone mineral density (BMD). POI women also experience psychological distress and some studies have shown an increased risk of neurodegenerating diseases. Overall, POI women have a shortened life expectancy, mainly due to cardiovascular disease. Some studies have reported a reduced risk of breast cancer in this group of patients.

CONCLUSIONS

In conclusion there are several well-characterized health risks in POI women. With every patient, an individualized approach is required to properly recognize and prevent these risks.

Premature ovarian insufficiency in young girls: repercussions on uterine volume and bone mineral density

STUDY OBJECTIVE

To evaluate biological differences among young subjects with premature ovarian insufficiency (POI) commencing at different stages of life.

DESIGN

Retrospective observational study.

SETTING

Careggi University Hospital Participants: One hundred sixty-two females aged between 15 and 29 years with premature ovarian insufficiency.

METHODS

Data were collected as a retrospective chart review of baseline evaluation at diagnosis of premature ovarian insufficiency (POI). About 162 participants were divided into four groups based on gynecological age. Two primary outcome variables (uterine development and bone mineral density (BMD)) were analyzed in terms of differences among groups and in a multivariate logistic regression analysis.

RESULTS

Uterine development was clearly jeopardized when estrogen insufficiency started at a very young age. Total body BMD showed significant differences among the four groups studied, clearly corresponding to the duration of ovarian function. Data were discussed in relation to the choice of hormone replacement therapy regimens.

Bone density changes in premature ovarian insufficiency patients who have had term pregnancies

Premature ovarian insufficiency affects 1% of women under the age of 40 and is associated with a hypoestrogenic state, potentially leading to multiple comorbidities including reduced bone density and fertility. An unpredictable ovarian function is observed in 50% of patients with 5-10% being able to achieve a pregnancy. Longitudinal studies have shown a temporary decline in bone mineral density of up to 5% during pregnancy and lactation in healthy women, with the loss of bone density post-partum being proportional to the period of breastfeeding. Effects of pregnancy in women with premature ovarian insufficiency have not been widely documented. Nevertheless, a lower bone mineral density baseline has been observed pre-conceptually, associated with both the hypoestrogenic state of the condition and the possibility that premature ovarian insufficiency was developed prior to achieving peak bone mass. This may suggest that breastfeeding could cause further deterioration in bone mineral density that may not be easy to recover from due to the reduced baseline levels.

Effects of hypogonadism on bone metabolism in female adolescents and young adults

Gonadal steroids, including androgens and oestrogens, play a critical part in bone metabolism, and conditions associated with a deficiency of gonadal steroids can reduce BMD in adults and impair bone accrual in adolescents. In addition, other associated hormone alterations, for example, insulin-like growth factor 1 deficiency or high cortisol levels, can further exacerbate the effect of hypogonadism on bone metabolism, as can factors such as calcium and vitamin D deficiency, low body weight and exercise status. This Review discusses the effects of different hypogonadal states on bone metabolism in female adolescents and young adults, with particular emphasis on conditions associated with low energy availability, such as anorexia nervosa and athletic amenorrhoea, in which many factors other than hypogonadism affect bone. In contrast to most hypogonadal conditions, in which replacement of gonadal steroids is sufficient to normalize bone accrual rates and BMD, gonadal steroid replacement may not be sufficient to normalize bone metabolism in these states of energy deficit.