Endogenous hormones and bone turnover markers in pre- and perimenopausal women: SWAN

The Effectiveness of a Lactobacilli-Based Probiotic Food Supplement on Bone Mineral Density and Bone Metabolism in Australian Early Postmenopausal Women: Protocol for a Double-Blind Randomized Placebo-Controlled Trial

Osteoporosis affects one in three women over the age of 50 and results in fragility fractures. Oestrogen deficiency during and after menopause exacerbates bone loss, accounting for higher prevalence of fragility fractures in women. The gut microbiota (GM) has been proposed as a key regulator of bone health, as it performs vital functions such as immune regulation and biosynthesis of vitamins. Therefore, GM modulation via probiotic supplementation has been proposed as a target for potential therapeutic intervention to reduce bone loss. While promising results have been observed in mouse model studies, translation into human trials is limited. Here, we present the study protocol for a double-blind randomized controlled trial that aims to examine the effectiveness of three lactobacilli strains on volumetric bone mineral density (vBMD), trabecular, and cortical microstructure, as measured using High Resolution peripheral Quantitative Computed Tomography (HR-pQCT). The trial will randomize 124 healthy early postmenopausal women (up to 8 years from menopause) to receive either probiotic or placebo administered once daily for 12 months. Secondary outcomes will investigate the probiotics' effects on areal BMD and specific mechanistic biomarkers, including bone metabolism and inflammatory markers. The trial is registered with Australian New Zealand Clinical Trials Registry (ACTRN12621000810819).

Gene-Dose-Dependent Reduction Fshr Expression Improves Spatial Memory Deficits in Alzheimer's Mice

Alzheimer's disease (AD) is a major progressive neurodegenerative disorder of the aging population. High post-menopausal levels of the pituitary gonadotropin follicle-stimulating hormone (FSH) are strongly associated with the onset of AD, and we have shown recently that FSH directly activates the hippocampal Fshr to drive AD-like pathology and memory loss in mice. To establish a role for FSH in memory loss, we used female 3xTg;Fshr+/+, 3xTg;Fshr+/- and 3xTg;Fshr-/- mice that were either left unoperated or underwent sham surgery or ovariectomy at 8 weeks of age. Unoperated and sham-operated 3xTg;Fshr-/- mice were implanted with 17β-estradiol pellets to normalize estradiol levels. Morris Water Maze and Novel Object Recognition behavioral tests were performed to study deficits in spatial and recognition memory, respectively, and to examine the effects of Fshr depletion. 3xTg;Fshr+/+ mice displayed impaired spatial memory at 5 months of age; both the acquisition and retrieval of the memory were ameliorated in 3xTg;Fshr-/- mice and, to a lesser extent, in 3xTg;Fshr+/- mice- -thus documenting a clear gene-dose-dependent prevention of hippocampal-dependent spatial memory impairment. At 5 and 10 months, sham-operated 3xTg;Fshr-/- mice showed better memory performance during the acquasition and/or retrieval phases, suggesting that Fshr deletion prevented the progression of spatial memory deficits with age. However, this prevention was not seen when mice were ovariectomized, except in the 10-month-old 3xTg;Fshr-/- mice. In the Novel Object Recognition test performed at 10 months, all groups of mice, except ovariectomized 3xTg;Fshr-/- mice showed a loss of recognition memory. Consistent with the neurobehavioral data, there was a gene-dose-dependent reduction mainly in the amyloid β40 isoform in whole brain extracts. Finally, serum FSH levels < 8 ng/mL in 16-month-old APP/PS1 mice were associated with better retrieval of spatial memory. Collectively, the data provide compelling genetic evidence for a protective effect of inhibiting FSH signaling on the progression of spatial and recognition memory deficits in mice, and lay a firm foundation for the use of an FSH-blocking agent for the early prevention of cognitive decline in postmenopausal women.

Pituitary crosstalk with bone, adipose tissue and brain

Traditional textbook physiology has ascribed unitary functions to hormones from the anterior and posterior pituitary gland, mainly in the regulation of effector hormone secretion from endocrine organs. However, the evolutionary biology of pituitary hormones and their receptors provides evidence for a broad range of functions in vertebrate physiology. Over the past decade, we and others have discovered that thyroid-stimulating hormone, follicle-stimulating hormone, adrenocorticotropic hormone, prolactin, oxytocin and arginine vasopressin act directly on somatic organs, including bone, adipose tissue and liver. New evidence also indicates that pituitary hormone receptors are expressed in brain regions, nuclei and subnuclei. These studies have prompted us to attribute the pathophysiology of certain human diseases, including osteoporosis, obesity and neurodegeneration, at least in part, to changes in pituitary hormone levels. This new information has identified actionable therapeutic targets for drug discovery.

To investigate the mechanism of Yiwei Decoction in the treatment of premature ovarian insufficiency-related osteoporosis using transcriptomics, network pharmacology and molecular docking techniques

To investigate the molecular mechanism of Yiwei Decoction (YWD) in preventing Premature ovarian insufficiency (POI)-related osteoporosis from the hypothalamic perspective , and to screen for the key active and acting molecules in YWD. Cyclophosphamide was used to create the POI rat model. Groups A, B, and C were established. The Model + YWD group was group A, the model control group was group B, and the normal control group was group C. ELISA was used to determine serum GnRH and FSH levels after gavage. The transcription levels of mRNAs in each group's hypothalamus tissues were examined using RNA-seq sequencing technology. The GSEA method was used to enrich pathways based on the gene expression levels of each group. The TCM-active ingredient-target-disease network map was created using differentially expressed mRNAs (DEmRNAs) and network pharmacology. The molecular docking method was employed to investigate the affinity of the active ingredient with key targets. GnRH and FSH levels in POI rats' serum were reduced by YWD. Between groups A and B, there were 638 DEmRNAs (P < 0.05) and 55 high-significance DEmRNAs (P-adjust < 0.01). The MAPK, Hedgehog, Calcium, and B cell receptor pathways are primarily enriched in DEmRNAs from Group A and Group B. The GSEA pathway enrichment analysis indicates that YWD may regulate Long-term potentiation, Amphetamine addiction, and the Renin-angiotensin system and play a role in preventing osteoporosis. The Chinese herbal medicine (CHM)-Active ingredient-Target-disease network map includes 137 targets, 4 CHMs, and 22 active ingredients. The result of docking indicated that Stigmasterol, interacts well with the core proteins ALB, VCL and KAT5. Following the screening, we identified the targets, active components, and key pathways associated with YWD osteoporosis prevention. Most of these key targets and pathways are associated with osteoporosis, but further experimental validation is required.

FSH and ApoE4 contribute to Alzheimer's disease-like pathogenesis via C/EBPβ/δ-secretase in female mice

Alzheimer's disease (AD) is the most common dementia. It is known that women with one ApoE4 allele display greater risk and earlier onset of AD compared with men. In mice, we previously showed that follicle-stimulating hormone (FSH), a gonadotropin that rises in post-menopausal females, activates its receptor FSHR in the hippocampus, to drive AD-like pathology and cognitive impairment. Here we show in mice that ApoE4 and FSH jointly trigger AD-like pathogenesis by activating C/EBPβ/δ-secretase signaling. ApoE4 and FSH additively activate C/EBPβ/δ-secretase pathway that mediates APP and Tau proteolytic fragmentation, stimulating Aβ and neurofibrillary tangles. Ovariectomy-provoked AD-like pathologies and cognitive defects in female ApoE4-TR mice are ameliorated by anti-FSH antibody treatment. FSH administration facilitates AD-like pathologies in both young male and female ApoE4-TR mice. Furthermore, FSH stimulates AD-like pathologies and cognitive defects in ApoE4-TR mice, but not ApoE3-TR mice. Our findings suggest that in mice, augmented FSH in females with ApoE4 but not ApoE3 genotype increases vulnerability to AD-like process by activating C/EBPβ/δ-secretase signalling.

Osteoporosis and Fracture Risk among Older US Asian Adults

PURPOSE OF REVIEW

This review summarizes the current knowledge regarding osteoporosis and fracture among older US Asian adults.

RECENT FINDINGS

Asian adults have lower (areal) bone density than non-Hispanic White adults and thus are more likely to be diagnosed and treated for osteoporosis, despite their lower risk of hip fracture. The latter may relate to favorable characteristics in hip geometry, volumetric bone density, and bone microarchitecture; lower risk of falls; and other clinical factors. The fracture risk calculator FRAX accounts for the lower risk of hip fracture among US Asian adults. However, data on major osteoporotic fracture risk remain limited. Fracture rates also vary by Asian subgroup, which may have implications for fracture risk assessment. Furthermore, among women receiving bisphosphonate drugs, Asian race is a risk factor for atypical femur fracture, an uncommon complication associated with treatment duration. Recent clinical trial efficacy data pertaining to lower bisphosphonate doses and longer dosing intervals may be relevant for Asian adults. More research is needed to inform osteoporosis care of US Asian adults, including risk-benefit considerations and the optimal duration of bisphosphonate treatment. Greater evidence-based guidance for primary fracture prevention among US Asian adults will ensure health equity in the prevention of osteoporotic fractures.

Risk factors for osteoporosis in chronic schizophrenia on long-term treatment with antipsychotics: a cross-sectional study

BACKGROUND

Little is known about the laboratory variable risks with bone mineral density (BMD) in patients with schizophrenia. This study was designed to fully investigate the related risk factors for decreased BMD in schizophrenia, as well as evaluate the gender difference of BMD.

METHOD

The BMD of the forearm of 211 patients (males/females = 140/71) who met the diagnostic criteria for DSM-5 schizophrenia was measured by dual-energy X-ray absorptiometry. Basic demographic information, clinical assessments, and laboratory variables (regarding nutrition, hormones, metabolism, and inflammatory markers) were comprehensively collected.

RESULTS

Among 211 subjects, seventy-four (35%) patients had low BMD. Males had a significantly lower BMD T-score than females (P = 0.002). Multiple regression analyses showed that the independent risks with low BMD were lower folate, glycosylated hemoglobin levels, higher age, serum ferritin, and follicle-stimulating hormone (FSH) levels. In female patients, the BMD was mainly associated with age and serum hormones (FSH and testosterone), while the BMD of male patients was primarily related to age, microelements (serum ferritin and 25-OH-VD), and parathyroid hormone.

CONCLUSION

Our study found several meaningful correlations between osteoporosis and schizophrenia, especially regarding laboratory measures, which may provide new clues to identifying or preventing osteoporosis in clinical patients.

Association of follicle-stimulating hormone with bone turnover markers and bone mineral density in Chinese women across the menopausal transition

BACKGROUND

Elevated follicle-stimulating hormone (FSH) is associated with an increased risk of postmenopausal osteoporosis. This study investigated the association of serum FSH with bone turnover markers (BTMs) and bone mineral density (BMD) in healthy women undergoing menopausal transition.

METHODS

A total of 487 healthy women (age 35-65 years, 50 ± 8.5 years) were enrolled in this study. Serum FSH, BTMs, and BMD at lumbar spine and total hip were measured in these subjects.

RESULTS

Follicle-stimulating hormone was positively correlated with various BTMs (r = 0.339-0.583, all p < 0.001) and negatively correlated with lumbar spine and total hip BMD (r = -0.629 and -0.514, all p < 0.001). After adjusting for age and body mass index, the partial correlation coefficients of FSH with BTMs and BMD remained significant. Estimating from the regression equation, for every 10 IU/L increase in serum FSH, BTMs increased by 0.38-3.6 units, and BMD decreased by 0.03-0.05 g/cm2 , respectively. Multiple linear regression analysis showed that FSH was a positive factor for serum bone-specific alkaline phosphatase, osteocalcin, and N-telopeptide of collagen type 1 (β = 0.188-0.403, all p < 0.001), and a negative factor for lumbar spine BMD and serum C-telopeptide of collagen type 1 (β = -0.629 and -0.183, all p < 0.001).

CONCLUSIONS

This study suggests that serum FSH levels are an independent risk factor for BTMs and BMD in menopause-transitioning women, particularly for serum BAP and lumbar spine BMD.

Associations between bone mass, hormone levels, and body composition in postmenopausal women

OBJECTIVES

The aim of this study was to explore body composition parameters and hormone levels as risk factors for low bone mass (osteopenia/osteoporosis) in postmenopausal women.

METHODS

We analyzed biorepository samples from 139 postmenopausal women with no clinical evidence of cardiovascular disease. Inclusion criteria were menopause occurring after 40 years of age and no use of hormone therapy in the past 3 months. Bone mineral density and body composition were assessed by dual-energy x-ray absorptiometry. Sex hormone-binding globulin (SHBG) and follicle-stimulating hormone (FSH) levels were measured in all participants. Serum estradiol was measured by gas chromatography/tandem mass spectrometry in a subset of 57 participants. Free estrogen index was calculated by dividing estradiol by SHBG × 100.

RESULTS

Body mass index (25.0 [22.5-26.5] vs 27.7 [26.6-31.9] kg/m 2 , P < 0.001), estradiol (3.0 [2.7-4.5] vs 6.0 [2.7-15.0] pg/mL, P = 0.006), waist circumference (84 ± 9 vs 93 ± 12 cm, P < 0.001), appendicular lean mass (ALM) (15.739 ± 2.129 vs 17.184 ± 2.104 kg, P = 0.001), and fat mass index (9.36 [7.29-11.43] vs 11.38 [9.95-15.33] kg/m 2 , P < 0.001) were lower in women with low bone mass by dual-energy x-ray absorptiometry. Univariate analysis showed that free estrogen index, time since menopause, SHBG, and fat mass were significant predictors of low bone mass, and ALM was a significant predictor against low bone mass. Appendicular lean mass persisted as an independent predictor against low bone mass in multivariate models with fat mass and SHBG. In turn, fat mass was no longer significant in this multivariate model after inclusion of SHBG. No association of FSH with low bone mass was observed.

CONCLUSIONS

Appendicular lean mass was a significant independent predictor against low bone mass in postmenopausal women. Further prospective studies are needed to investigate whether lean mass, fat mass, and FSH have a direct effect on bone mass in postmenopausal women, adding to the consequences of hypoestrogenism in this group.

C/EBPβ/AEP Signaling Drives Alzheimer's Disease Pathogenesis

Alzheimer's disease (AD) is the most common type of dementia. Almost two-thirds of patients with AD are female. The reason for the higher susceptibility to AD onset in women is unclear. However, hormone changes during the menopausal transition are known to be associated with AD. Most recently, we reported that follicle-stimulating hormone (FSH) promotes AD pathology and enhances cognitive dysfunctions via activating the CCAAT-enhancer-binding protein (C/EBPβ)/asparagine endopeptidase (AEP) pathway. This review summarizes our current understanding of the crucial role of the C/EBPβ/AEP pathway in driving AD pathogenesis by cleaving multiple critical AD players, including APP and Tau, explaining the roles and the mechanisms of FSH in increasing the susceptibility to AD in postmenopausal females. The FSH-C/EBPβ/AEP pathway may serve as a novel therapeutic target for the treatment of AD.

Bone circuitry and interorgan skeletal crosstalk

The past decade has seen significant advances in our understanding of skeletal homeostasis and the mechanisms that mediate the loss of bone integrity in disease. Recent breakthroughs have arisen mainly from identifying disease-causing mutations and modeling human bone disease in rodents, in essence, highlighting the integrative nature of skeletal physiology. It has become increasingly clear that bone cells, osteoblasts, osteoclasts, and osteocytes, communicate and regulate the fate of each other through RANK/RANKL/OPG, liver X receptors (LXRs), EphirinB2-EphB4 signaling, sphingolipids, and other membrane-associated proteins, such as semaphorins. Mounting evidence also showed that critical developmental pathways, namely, bone morphogenetic protein (BMP), NOTCH, and WNT, interact each other and play an important role in postnatal bone remodeling. The skeleton communicates not only with closely situated organs, such as bone marrow, muscle, and fat, but also with remote vital organs, such as the kidney, liver, and brain. The metabolic effect of bone-derived osteocalcin highlights a possible role of skeleton in energy homeostasis. Furthermore, studies using genetically modified rodent models disrupting the reciprocal relationship with tropic pituitary hormone and effector hormone have unraveled an independent role of pituitary hormone in skeletal remodeling beyond the role of regulating target endocrine glands. The cytokine-mediated skeletal actions and the evidence of local production of certain pituitary hormones by bone marrow-derived cells displays a unique endocrine-immune-skeletal connection. Here, we discuss recently elucidated mechanisms controlling the remodeling of bone, communication of bone cells with cells of other lineages, crosstalk between bone and vital organs, as well as opportunities for treating diseases of the skeleton.

Bone Turnover Markers: Basic Biology to Clinical Applications

Bone turnover markers (BTMs) are used widely, in both research and clinical practice. In the last 20 years, much experience has been gained in measurement and interpretation of these markers, which include commonly used bone formation markers bone alkaline phosphatase, osteocalcin, and procollagen I N-propeptide; and commonly used resorption markers serum C-telopeptides of type I collagen, urinary N-telopeptides of type I collagen and tartrate resistant acid phosphatase type 5b. BTMs are usually measured by enzyme-linked immunosorbent assay or automated immunoassay. Sources contributing to BTM variability include uncontrollable components (e.g., age, gender, ethnicity) and controllable components, particularly relating to collection conditions (e.g., fasting/feeding state, and timing relative to circadian rhythms, menstrual cycling, and exercise). Pregnancy, season, drugs, and recent fracture(s) can also affect BTMs. BTMs correlate with other methods of assessing bone turnover, such as bone biopsies and radiotracer kinetics; and can usefully contribute to diagnosis and management of several diseases such as osteoporosis, osteomalacia, Paget's disease, fibrous dysplasia, hypophosphatasia, primary hyperparathyroidism, and chronic kidney disease-mineral bone disorder.

Independent Skeletal Actions of Pituitary Hormones

Over the past years, pituitary hormones and their receptors have been shown to have non-traditional actions that allow them to bypass the hypothalamus-pituitary-effector glands axis. Bone cells-osteoblasts and osteoclasts-express receptors for growth hormone, follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), adrenocorticotrophic hormone (ACTH), prolactin, oxytocin, and vasopressin. Independent skeletal actions of pituitary hormones on bone have been studied using genetically modified mice with haploinsufficiency and by activating or inactivating the receptors pharmacologically, without altering systemic effector hormone levels. On another front, the discovery of a TSH variant (TSH-βv) in immune cells in the bone marrow and skeletal action of FSHβ through tumor necrosis factor α provides new insights underscoring the integrated physiology of bone-immune-endocrine axis. Here we discuss the interaction of each pituitary hormone with bone and the potential it holds in understanding bone physiology and as a therapeutic target.

FSH-blocking therapeutic for osteoporosis

Pharmacological and genetic studies over the past decade have established the follicle-stimulating hormone (FSH) as an actionable target for diseases affecting millions, namely osteoporosis, obesity, and Alzheimer's disease. Blocking FSH action prevents bone loss, fat gain, and neurodegeneration in mice. We recently developed a first-in-class, humanized, epitope-specific FSH-blocking antibody, MS-Hu6, with a KD of 7.52 nM. Using a Good Laboratory Practice (GLP)-compliant platform, we now report the efficacy of MS-Hu6 in preventing and treating osteoporosis in mice and parameters of acute safety in monkeys. Biodistribution studies using 89Zr-labeled, biotinylated or unconjugated MS-Hu6 in mice and monkeys showed localization to bone and bone marrow. The MS-Hu6 displayed a β phase t½ of 7.5 days (180 hr) in humanized Tg32 mice. We tested 217 variations of excipients using the protein thermal shift assay to generate a final formulation that rendered MS-Hu6 stable in solution upon freeze-thaw and at different temperatures, with minimal aggregation, and without self-, cross-, or hydrophobic interactions or appreciable binding to relevant human antigens. The MS-Hu6 showed the same level of "humanness" as human IgG1 in silico and was non-immunogenic in ELISpot assays for IL-2 and IFN-γ in human peripheral blood mononuclear cell cultures. We conclude that MS-Hu6 is efficacious, durable, and manufacturable, and is therefore poised for future human testing.

Efficacy and Safety of Moxibustion for Menopausal Obesity: A Multicentre, Randomized, Controlled Trial Protocol

Background. In the past, moxibustion has been widely used to treat endocrine system disorders, but evidence of its effectiveness is scarce at this point. The aim of this multicenter, randomized, controlled trial is to evaluate the efficacy and safety of treating menopausal obesity with moxibustion. Methods/Design. There are six centers taking part in this randomized, controlled, parallel trial. A total of 216 patients with menopausal obesity will be randomly divided into two equal groups: the “moxibustion for harmonization of Yin and Yang” group and the gentle moxibustion group. A 12-week study period with moxibustion will be preceded by a 1-week baseline, followed by a 12-week follow-up. We will conduct an interim analysis to determine whether or not the treatment is efficacious and safe after 216 participants have completed a 12-week treatment period. Evaluations will be conducted at weeks 0, 4, 8, 12, 18, and 24. The main outcome is waist circumference (WC), and the rate of WC reduction will be compared to the baseline. An intention-to-treat analysis will be performed with a two-sided P value of <0.05 considered significant. Participants who withdraw from the trial will be analyzed according to the intention-to-treat formula (ITT). Discussion. These results will be used to support selecting the right moxibustion prescription and guiding the improvement of clinical efficacy. This trial will provide convincing evidence of moxibustion's effectiveness and safety in the treatment of obesity by “moxibustion for harmonization of Yin and Yang,” which will be conducive to the promotion and clinical application of the theory of “moxibustion for harmonization of Yin and Yang.” Trial Registration. This trial is registered with Clinical Trials.gov: NCT04943705 (registered on June 27, 2021).

Roles of Follicle-Stimulating Hormone on Bone Metabolism in Late Postmenopausal Women

BACKGROUND

The effects of elevated follicle-stimulating hormone (FSH) levels on physiological changes in the bone remain unclear. This study aimed to clarify the association between FSH concentrations and bone mineral density (BMD) and bone turnover markers (BTM) in late postmenopausal women.

METHODS

A total of 169 Korean women were enrolled. The participants' ages ranged from 60 to 84 years (mean age, 69.0±5.1) and reported a mean duration of 19.4±6.6 years since menopause (YSM). The participants showed an average body mass index (BMI) of 24.4±2.8 kg/m2. Age, YSM, estradiol, testosterone, and BMI were confounders in the Pearson's partial correlation. A test for trends across the quartiles of FSH levels was performed for each variable.

RESULTS

The mean FSH and estradiol concentrations were 61.5 IU/L and 2.9 pg/mL, respectively. Serum FSH concentration was not significantly associated with BMD (lumbar, r=0.09, P=0.30; total hip, r=0.00, P=0.96; and femoral neck, r=0.05, P=0.62). BTM across the FSH quartiles did not show any trend association (bone-specific alkaline phosphate, P=0.31; crosslinked C-terminal telopeptide of type I collagen, P=0.90). Instead, FSH levels were negatively correlated with BMI (r=-0.34, P=0.00). In the multivariate regression model adjusted for age, testosterone, and estradiol, only BMI showed a negative value across the FSH quartiles (β coefficient -0.11, P=0.00).

CONCLUSIONS

This study identified that high FSH concentrations were not associated with bone loss or high bone turnover in women in the late postmenopausal period.

Sexual dimorphism in the relation between sex hormones and osteoporosis in patients with type 2 diabetes mellitus

INTRODUCTION

To investigate the association between sex hormones and osteoporosis in type 2 diabetic mellitus (T2DM) patients.

MATERIALS AND METHODS

We performed a retrospective study in patients with T2DM. The patients were assigned into three groups (normal bone mineral density, osteopenia, and osteoporosis) in both sexes. The clinical characteristics, bone metabolic markers, and sex hormones were compared. The relationship between the sex hormones and osteoporosis was analyzed by ordinary regression analysis. Statistical analysis was performed using SPSS 26.0.

RESULTS

A total of 795 T2DM patients (446 men ≥ 50 years old and 349 postmenopausal women) were identified and analyzed. The osteoporosis group had the lowest estradiol level in men (P = 0.013) and the highest follicle-stimulating hormone (FSH) level in women (P = 0.042). In the multivariate analysis, men with lower estradiol levels (< 87.96 pmol/L) had a nearly 1.6-fold increased risk for osteoporosis than those with the higher estradiol levels (> 122.82 pmol/L). In addition, women with lower FSH (< 41.17 IU/L) had nearly 0.6-fold for osteoporosis compared to those with higher FSH (> 60.83 IU/L) after adjusting for age, duration of T2DM, body mass index, pulse pressure, creatinine clearance, glycosylated hemoglobin, fasting C-peptide, and estradiol (in FSH) or FSH (in estradiol).

CONCLUSION

In T2DM, the estrogen level was negatively correlated with osteoporosis in men, and the FSH level was positively correlated with the osteoporosis in women.

FSH may mediate the association between HbA1c and bone turnover markers in postmenopausal women with type 2 diabetes

INTRODUCTION

Recent studies in postmenopausal women have found associations of follicle-stimulating hormone (FSH) levels with both glucose metabolism and bone turnover. The objective of the study was to investigate whether FSH may contribute to suppressed bone turnover markers (BTMs) in postmenopausal women with type 2 diabetes (T2D).

MATERIALS AND METHODS

888 postmenopausal women with T2D, 352 nondiabetes (prediabetes plus normoglycemia) were included from the METAL study. HbA1c, sex hormones, 25-hydroxy vitamin D (25(OH)D), serum procollagen type I N-terminal propeptide (P1NP), and β-C-terminal telopeptide (β-CTX) were measured.

RESULTS

P1NP and β-CTX decreased in postmenopausal T2D women compared with nondiabetes controls (both p < 0.001). The major factors responsible for the changes in P1NP were HbA1c (β = - 0.050, p < 0.001), 25(OH)D (β = - 0.003, p = 0.006), FSH (β = 0.001, p = 0.044) and metformin (β = - 0.109, p < 0.001), for β-CTX were HbA1c (β = - 0.049, p < 0.001), body mass index (BMI) (β = - 0.011, p = 0.005), 25(OH)D (β = - 0.003, p = 0.003), FSH (β = 0.002, p = 0.022) and metformin (β = - 0.091, p = 0.001) in postmenopausal T2D women based on multivariate regression analysis. With the increase in HbA1c, FSH decreased significantly (p for trend < 0.001). Mediation analysis demonstrated that FSH partly mediated the suppression of LnP1NP and Lnβ-CTX by HbA1c (β = - 0.009 and - 0.010, respectively), and Lnβ-CTX by BMI (β = - 0.015) when multiple confounders were considered (all p < 0.05).

CONCLUSION

HbA1c was the crucial determinant contributing to the suppression of BTMs. FSH might play a novel mediation role in BTM suppression due to HbA1c or BMI.

The Role of Sex Hormones on Bone Mineral Density, Marrow Adiposity, and Muscle Adiposity in Middle-Aged and Older Men

PURPOSE

The etiology of age-related bone loss is less clear in men. This study is aimed to observe the variations of endogenous sex hormone concentrations with increasing of age in men, and investigate their relations to bone mass, marrow adiposity, and muscle adiposity.

METHODS

A total of 199 community-dwelling Chinese men (aged 41 to 82 years) were included and measured of serum total estradiol, total testosterone, and follicle-stimulating hormone (FSH) concentrations by enzyme-linked immunosorbent assay (ELISA). Vertebral trabecular volumetric bone mineral density (vBMD) was measured by quantitative computed tomography for all participants, and vertebral marrow fat content and erector muscle fat content were quantified by Chemistry-shift-encoding magnetic resonance imaging in 62 participants.

RESULTS

In this population, FSH concentration increased (p < 0.001) gradually with aging. Lower vBMD was independently associated with higher FSH concentration (β = -0.216, p < 0.001), but not with total estradiol or total testosterone. For each standard deviation increase in FSH there was a 50% higher risk of an individual having osteopenia or osteoporosis (vBMD < 120 mg/cm³). Marrow fat content and erector muscle fat content were greater in osteopenic and osteoporotic men, but there were no associations with sex hormones concentrations.

CONCLUSION

In summary, FSH but not total estradiol or total testosterone is related to vertebral trabecular vBMD in middle-aged and older Chinese men. Neither marrow adiposity nor muscle adiposity is associated with sex hormones.

FSH and bone: Comparison between males with central versus primary hypogonadism

OBJECTIVE

Experimental studies proposed a direct effect of follicle-stimulating hormone (FSH) on the skeletal metabolism, but results of human studies mainly conducted in females are controversial. The present study aims to investigate the possible role of FSH excess in male bone health, by comparing for the first time primary and central hypogonadism.

DESIGN AND METHODS

119 men were enrolled in this cross-sectional observational study at the time of the first diagnosis of hypogonadism. All participants had spontaneous pubertal development. Regarding patients with hypergonadotropic hypogonadism (Hyper-H), Klinefelter syndrome (KS) patients were distinguished from the other forms (non-KS-Hyper-H) based on the onset of FSH elevation. Bone mineral density (BMD) at both lumbar spine (LS) and femoral neck (FN), as well as the prevalence of morphometric vertebral fractures (VFx), were assessed.

RESULTS

Across the whole cohort, higher LS and FN BMD were associated with older age at diagnosis and higher body mass index (BMI), respectively. After adjusting for potential confounders (age at diagnosis, BMI, smoking habits, degree of hypogonadism defined by calculated free testosterone, and 25OH vitamin D levels), non-KS-Hyper-H patients showed significantly lower LS BMD and tended to show lower FN BMD values, as compared to those with hypogonadotropic hypogonadism (Hypo-H). In KS men, LS BMD was significantly lower than in those with non-KS-Hyper-H. No significant differences in the prevalence of VFx were found between the groups.

CONCLUSIONS

These findings suggest a potential negative effect of FSH excess on the male bone mass, especially at spine. The duration of high FSH levels may also contribute to these findings.

Management of Osteoporosis in Men: A Narrative Review

Male osteoporosis is a still largely underdiagnosed pathological condition. As a consequence, bone fragility in men remains undertreated mainly due to the low screening frequency and to controversies in the bone mineral density (BMD) testing standards. Up to the 40% of overall osteoporotic fractures affect men, in spite of the fact that women have a significant higher prevalence of osteoporosis. In addition, in males, hip fractures are associated with increased morbidity and mortality as compared to women. Importantly, male fractures occur about 10 years later in life than women, and, therefore, due to the advanced age, men may have more comorbidities and, consequently, their mortality is about twice the rate in women. Gender differences, which begin during puberty, lead to wider bones in males as compared with females. In men, follicle-stimulating hormones, testosterone, estrogens, and sex hormone-binding levels, together with genetic factors, interact in determining the peak of bone mass, BMD maintenance, and lifetime decrease. As compared with women, men are more frequently affected by secondary osteoporosis. Therefore, in all osteoporotic men, a complete clinical history should be collected and a careful physical examination should be done, in order to find clues of a possible underlying diseases and, ultimately, to guide laboratory testing. Currently, the pharmacological therapy of male osteoporosis includes aminobisphosphonates, denosumab, and teriparatide. Hypogonadal patients may be treated with testosterone replacement therapy. Given that the fractures related to mortality are higher in men than in women, treating male subjects with osteoporosis is of the utmost importance in clinical practice, as it may impact on mortality even more than in women.

The Relationship Between Bone and Reproductive Hormones Beyond Estrogens and Androgens

Reproductive hormones play a crucial role in the growth and maintenance of the mammalian skeleton. Indeed, the biological significance for this hormonal regulation of skeletal homeostasis is best illustrated by common clinical reproductive disorders, such as primary ovarian insufficiency, hypothalamic amenorrhea, congenital hypogonadotropic hypogonadism, and early menopause, which contribute to the clinical burden of low bone mineral density and increased risk for fragility fracture. Emerging evidence relating to traditional reproductive hormones and the recent discovery of newer reproductive neuropeptides and hormones has deepened our understanding of the interaction between bone and the reproductive system. In this review, we provide a contemporary summary of the literature examining the relationship between bone biology and reproductive signals that extend beyond estrogens and androgens, and include kisspeptin, gonadotropin-releasing hormone, follicle-stimulating hormone, luteinizing hormone, prolactin, progesterone, inhibin, activin, and relaxin. A comprehensive and up-to-date review of the recent basic and clinical research advances is essential given the prevalence of clinical reproductive disorders, the emerging roles of upstream reproductive hormones in bone physiology, as well as the urgent need to develop novel safe and effective therapies for bone fragility in a rapidly aging population.

FSH Level and Changes in Bone Mass and Body Composition in Older Women and Men

CONTEXT

FSH may have independent actions on bone remodeling and body fat regulation. Cross-sectionally, we have shown that serum FSH is associated with bone mineral density (BMD) and body fat in older postmenopausal women, but it remains unknown whether FSH predicts bone and fat changes.

OBJECTIVE

We examined whether baseline FSH level is associated with subsequent bone loss or body composition changes in older adults.

SETTING, DESIGN, PARTICIPANTS

We studied 162 women and 158 men (mean age 82 ± 4 years) from the Age, Gene/Environment Susceptibility (AGES)-Bone Marrow Adiposity cohort, a substudy of the AGES-Reykjavik Study of community-dwelling older adults. Skeletal health and body composition were characterized at baseline and 3 years later.

MAIN OUTCOMES

Annualized change in BMD and body composition by dual-energy X-ray absorptiometry (DXA) and quantitative computed tomography (QCT). Models were adjusted for serum estradiol and testosterone levels.

RESULTS

There was no evidence for an association between baseline FSH level and change in BMD or body composition by DXA or QCT. For femoral neck areal BMD, adjusted mean difference (95% CI) per SD increase in FSH was 1.3 (-0.7 to 3.3) mg/cm2/y in women, and -0.2 (-2.6 to 2.2) mg/cm2/y in men. For visceral fat, adjusted mean difference (95% CI) per SD increase in FSH was 1.80 (-0.03 to 3.62) cm2/y in women, and -0.33 (-3.73 to 3.06) cm2/y in men.

CONCLUSIONS

Although cross-sectional studies and studies in perimenopausal women have demonstrated associations between FSH and BMD and body composition, in older adults, FSH level is not associated with bone mass or body composition changes.

The impact of leuprolide acetate-loaded calcium phosphate silicate cement to bone regeneration under osteoporotic conditions

Osteoporosis is detrimental to the health of skeletal structure and significantly increases the risks of bone fracture. Moreover, bone regeneration is adversely impaired by increased osteoclastic activities as a result of osteoporosis. In this study, we developed a novel formulation of injectable bone cement based on calcium phosphate silicate cement (CPSC) and leuprolide acetate (LA). Several combinations of LA-CPSC bone cement were characterized and, it is found that LA could increase the setting time and compressive strength of CPSC in a concentration-dependent manner. Moreover, thein vitroresults revealed that LA-CPSC was biocompatible and able to encourage the osteoblast proliferation via the mTOR signalling pathway. Furthermore, the LA-CPSC was implanted in the osteoporotic rats to evaluate its effectiveness to repair bone fractures under the osteoporotic conditions. The biomarker study and micro-CT analyses indicated that LA-CPSC could effectively reduce the osteoclast activities and promote the bone regeneration. In conclusion, our study demonstrated that LA-CPSC injectable bone cement should be a viable solution to repair bone fractures under the osteoporotic conditions.

Serum FSH Is Associated With BMD, Bone Marrow Adiposity, and Body Composition in the AGES-Reykjavik Study of Older Adults

CONTEXT

Follicle-stimulating hormone (FSH) concentrations increase during the perimenopausal transition and remain high after menopause. Loss of bone mineral density (BMD) and gain of bone marrow adiposity (BMA) and body fat mass also occur during this time. In mice, blocking the action of FSH increases bone mass and decreases fat mass.

OBJECTIVE

To investigate the associations between endogenous FSH levels and BMD, BMA, and body composition in older adults, independent of estradiol and testosterone levels.

DESIGN, SETTING, AND PARTICIPANTS

Older adults from the AGES-Reykjavik Study, an observational cohort study.

MAIN OUTCOME MEASURES

Areal BMD, total body fat, and lean mass were measured with dual-energy x-ray absorptiometry. Lumbar vertebral BMA was measured by 1H-magnetic resonance spectroscopy. Volumetric BMD and visceral and subcutaneous adipose tissue (VAT, SAT) areas were measured with quantitative computed tomography. The least squares means procedure was used to determine sex hormone-adjusted associations between quartiles of serum FSH and BMD, BMA, and body composition.

RESULTS

In women (N = 238, mean age 81 years), those in the highest FSH quartile, compared with the lowest quartile, had lower adjusted mean spine integral BMD (-8.6%), lower spine compressive strength index (-34.8%), higher BMA (+8.4%), lower weight (-8.4%), lower VAT (-17.6%), lower lean mass (-6.1%), and lower fat mass (-11.9%) (all P < 0.05). In men, FSH level was not associated with any outcome.

CONCLUSIONS

Older postmenopausal women with higher FSH levels have higher BMA, but lower BMD and lower fat and lean mass, independent of estradiol and testosterone levels. Longitudinal studies are needed to better understand the underlying mechanisms.

Bone Mineral Density in Different Menopause Stages is Associated with Follicle Stimulating Hormone Levels in Healthy Women

Although estradiol (E2) has been believed to be the most critical factor in the menopause-associated decrease in bone mineral density (BMD), the role of increasing follicle stimulating hormone (FSH) during menopause is relatively unclear. We determined the extent to which hip and lumbar spine BMD differ among the stages of menopause in healthy women, and whether BMD is associated with FSH and E2 levels. A cross-sectional study of 141 healthy women classified as premenopausal (Pre; 38 ± 6 yrs; mean ± SD, n = 30), early perimenopausal (EPeri; 50 ± 3yrs, n = 31), late perimenopausal (LPeri; 50 ± 4yrs, n = 30), early postmenopausal (EPost; 55 ± 3yrs, n = 24), or late postmenopausal (LPost; 62 ± 4 yrs, n = 26), was conducted. Spine/hip BMD and sex hormones were measured using dual-energy X-ray absorptiometry and enzymatic/colorimetric methods, respectively. Compared to EPeri, spine BMD was lower (p < 0.05) in LPeri, EPost, and LPost and hip BMD was lower (p < 0.05) in EPost and LPost. BMD was inversely associated with FSH (spine: r = -0.341; hip: r = -0.271, p < 0.05) and directly associated with E2 (spine: r = 0.274; hip: r = 0.256, p < 0.05). The menopause-related loss of spine and hip BMD is associated not only with low E2 but also higher FSH. Future studies are essential to delineating the mechanisms by which FSH regulates bone health in aging women.

Beyond bone biology: Lessons from team science

Today, research in biomedicine often requires the knowledge and technologies in diverse fields. Therefore, there is an increasing need for collaborative team science that crosses traditional disciplines. Here, we discuss our own lessons from both interdisciplinary and transdisciplinary teams, which ultimately ushered us to expand our research realm beyond bone biology.

First-in-class humanized FSH blocking antibody targets bone and fat

Blocking the action of FSH genetically or pharmacologically in mice reduces body fat, lowers serum cholesterol, and increases bone mass, making an anti-FSH agent a potential therapeutic for three global epidemics: obesity, osteoporosis, and hypercholesterolemia. Here, we report the generation, structure, and function of a first-in-class, fully humanized, epitope-specific FSH blocking antibody with a K _D of 7 nM. Protein thermal shift, molecular dynamics, and fine mapping of the FSH-FSH receptor interface confirm stable binding of the Fab domain to two of five receptor-interacting residues of the FSHβ subunit, which is sufficient to block its interaction with the FSH receptor. In doing so, the humanized antibody profoundly inhibited FSH action in cell-based assays, a prelude to further preclinical and clinical testing.

Osteocalcin, ovarian senescence, and brain health

Menopause, an inevitable event in a woman's life, significantly increases risk of bone resorption and diseases such as Alzheimer's, vascular dementia, cardiac arrest, and stroke. The sole role of bones, as traditionally regarded, is to provide structural support for skeletal muscles and allow for ambulation, however this concept is becoming quickly outdated. New literature has emerged that suggests the bone cell-derived hormone osteocalcin (OCN) plays a pivotal role in cognition. OCN levels are correlated with bone mass density and bone turnover, and thus are strongly influenced by the changes associated with menopause. The goal of the current review is to discuss potential gaps in our knowledge of OCN and cognition, discrepancies in methods of OCN quantification, and therapies to enhance circulating OCN. A discussion on implementing exercise or low frequency vibration interventions at the menopausal transition to reduce risk and severity of neurological diseases and associated cognitive decline is included.

Heat shock protein 90 alpha and 14-3-3η in postmenopausal osteoporotic rats with varying levels of serum FSH

PURPOSE

This study compared the severity of osteoporosis and screened differentially expressed proteins in postmenopausal osteoporotic rats with varying levels of serum follicle stimulating hormone (FSH).

METHODS

Thirty-six Sprague Dawley female rats were divided into four groups: sham operation (sham) group, ovariectomy (OVX) group, FSH and ovariectomy (OVX + FSH) group, and Leuprorelin (LE) and ovariectomy group (OVX + LE). Body weight, serum estradiol, FSH, tartrate-resistant acid phosphatase, alkaline phosphatase, and bone mineral density were measured. We randomly selected six rats each from the OVX and OVX + FSH groups to detect differentially expressed proteins by data-independent acquisition, and we verified the results in the remaining six rats by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Nineteen proteins were upregulated and 36 proteins were downregulated in the OVX + FSH group. The expression of heat shock protein 90 alpha (Hsp90α) and 14-3-3η protein was significantly different between the OVX and OVX + FSH groups, and both were linearly correlated with bone trabecular area. Results were verified by ELISA and were found to be consistent with the results of data-independent acquisition.

DISCUSSION

In rats with high serum FSH, expression of Hsp90α protein was increased and expression of 14-3-3η protein was decreased. Both changes in protein expression were strongly correlated with bone trabecular area.

Neuroendocrine, autocrine, and paracrine control of follicle-stimulating hormone secretion

Follicle-stimulating hormone (FSH) is a glycoprotein hormone produced by gonadotropes in the anterior pituitary that plays a central role in controlling ovarian folliculogenesis and steroidogenesis in females. Moreover, recent studies strongly suggest that FSH exerts extragonadal actions, particularly regulating bone mass and adiposity. Despite its crucial role, the mechanisms regulating FSH secretion are not completely understood. It is evident that hypothalamic, ovarian, and pituitary factors are involved in the neuroendocrine, paracrine, and autocrine regulation of FSH production. Large animal models, such as the female sheep, represent valuable research models to investigate specific aspects of FSH secretory processes. This review: (i) summarizes the role of FSH controlling reproduction and other biological processes; (ii) discusses the hypothalamic, gonadal, and pituitary regulation of FSH secretion; (iii) considers the biological relevance of the different FSH isoforms; and (iv) summarizes the distinct patterns of FSH secretion under different physiological conditions.

Evidence for Gender-Specific Bone Loss Mechanisms in Periprosthetic Osteolysis

Osteolysis adjacent to total hip replacement (THR) prostheses is a major cause of their eventual failure. Periprosthetic osteolysis is associated with the production of bioactive particles, produced by the wear of articulating prosthesis surfaces. Wear particles invade the periprosthetic tissue, inducing inflammation and bone resorption. Previous studies have shown that osteocytes, the most numerous cell type in mineralised bone, can respond to wear particles of multiple orthopaedic material types. Osteocytes play important roles in bone resorption, regulating bone resorption by osteoclasts and directly through osteocytic osteolysis, also known as perilacunar remodelling. In this study, we perform a histological analysis of bone biopsies obtained from cohorts of male and female patients undergoing either primary THR surgery or revision THR surgery for aseptic loosening. The osteocyte lacunae area (Ot.Lac.Ar) and percentage lacunar area/bone area (%Ot.Lac.Ar/B.Ar) were significantly larger overall in revision THR bone than bone from similar sites in primary THR. Analysis by patient gender showed that increased Ot.Lac.Ar, indicative of increased perilacunar remodelling, was restricted to female revision samples. No significant differences in osteoclast parameters were detectable between the cohorts. These findings suggest previously unrecognised gender-specific mechanisms of bone loss in orthopaedic wear particle-induced osteolysis in humans.

Probiotic treatment using a mix of three Lactobacillus strains for lumbar spine bone loss in postmenopausal women: a randomised, double-blind, placebo-controlled, multicentre trial

BACKGROUND

Postmenopausal bone loss in the spine is associated with an increased risk of vertebral fractures. Certain probiotic treatment protects rodents from ovariectomy-induced bone loss. The aim of the present study was to determine if treatment with a combination of three bacterial strains protects against the rapid spine bone loss occurring in healthy early postmenopausal women.

METHODS

This randomised, double-blind, placebo-controlled, multicentre trial was done at four study centres in Sweden. Early postmenopausal women were randomly assigned in a 1:1 ratio to receive probiotic treatment consisting of three Lactobacillus strains (Lactobacillus paracasei DSM 13434, Lactobacillus plantarum DSM 15312, and Lactobacillus plantarum DSM 15313; 1 x 1010 colony-forming units per capsule) or placebo once daily for 12 months. The primary outcome was the percentage change from baseline in lumbar spine bone mineral density (LS-BMD) at 12 months. The primary analysis was done in all participants with BMD measurements available both at baseline and at 12 months. Analyses of adverse events and safety included all participants who had taken at least one capsule of placebo or Lactobacillus. This trial is registered with ClinicalTrials.gov, NCT02722980, and is completed.

FINDINGS

Between April 18 and Nov 11, 2016, 249 participants were randomly assigned to receive probiotic product or placebo, and 234 (94%) completed the analyses required for the primary outcome. Lactobacillus treatment reduced the LS-BMD loss compared with placebo (mean difference 0·71%, 95% CI 0·06 to 1·35). The LS-BMD loss was significant in the placebo group (-0·72%, -1·22 to -0·22), whereas no bone loss was observed in the Lactobacillus-treated group (-0·01%, -0·50 to 0·48). The adverse events were similar between the two groups.

INTERPRETATION

Probiotic treatment using a mix of three Lactobacillus strains protects against lumbar spine bone loss in healthy postmenopausal women.

FUNDING

Probi.

Self-management Processes Used by Healthy Middle-aged Women to Change Behaviors

The purpose of this descriptive qualitative study was to understand the processes women used to change osteoporosis prevention health behaviors. Twenty healthy, predominately white, middle-aged women engaged in an osteoporosis prevention program shared behavior change stories. Results indicated that behavior change was a highly personalized process influenced by a myriad of factors that are unique to the individual. Approaches to behavior change varied across individuals over time and were shaped by personal preferences, capacity, and past experiences. Rather than relying on a systematic approach to health behavior change, women selected and restructured aspects of research-based recommendations to match their personal needs and preferences. We identified four person-initiated behavior change processes: (a) picking and choosing, (b) doing it my way, (c) recognizing how I am doing, and (d) using prompts and feedback. Understanding the process people use to change behaviors might uniquely contribute to increasing the effectiveness of theory, research, intervention development, and clinical care.

Sex hormones and stroke: Beyond estrogens

Stroke risk and poor stroke outcomes in postmenopausal women have usually beeen attributed to decreased levels of estrogen. However, two lines of evidence suggest that this hormone may not be solely responsible for elevated stroke risk in this population. First, the increased risk for CVD and stroke occurs much earlier than menopause at a time when estrogen levels are not yet reduced. Second, estrogen therapy has not successfully reduced stroke risk in all studies. Other sex hormones may therefore also contribute to stroke risk. Prior to menopause, levels of the gonadotrophin Follicle Stimulating Hormone (FSH) are elevated while levels of the gonadal peptide inhibin are lowered, indicating an overall decrease in ovarian reserve. Similarly, reduced estrogen levels at menopause significantly increase the ratio of androgens to estrogens. In view of the evidence that androgens may be unfavorable for CVD and stroke, this elevated ratio of testosterone to estrogen may also contribute to the postmenopause-associated stroke risk. This review synthesizes evidence from different clinical populations including natural menopause, surgical menopause, women on chemotherapy, and preclinical stroke models to dissect the role of ovarian hormones and stroke risk and outcomes.

A Substruction Approach to Assessing the Theoretical Validity of Measures

BACKGROUND

Validity is about the logic, meaningfulness, and evidence used to defend inferences made when interpreting results. Substruction is a heuristic or process that visually represent the hierarchical structure between theory and measures.

PURPOSE

To describe substruction as a method for assessing the toretical validity of research measures.

METHODS

Using Fawcett's Conceptual-Theoretical-Empirical Structure. an exemplar is presented of substruction from the Individual and Family Self-Management Theory to the Striving to be strong study concepts and empirical measures.

RESULTS

Substruction tables display evidence supporting theoretical validity of the instruments used in the study.

CONCLUSION

A high degree of congruence between theory and measure is critical to support the validity of the theory and to support attributions made about moderating, mediating, causal relationships, and intervention effects.

FSH Beyond Fertility

The traditional view of follicle-stimulating hormone (FSH) as a reproductive hormone is changing. It has been shown that FSH receptors (FSHRs) are expressed in various extra-gonadal tissues and mediate the biological effects of FSH at those sites. Molecular, animal, epidemiologic, and clinical data suggest that elevated serum FSH may play a significant role in the evolution of bone loss and obesity, as well as contributing to cardiovascular and cancer risk. This review summarizes recent data on FSH action beyond reproduction.

Extragonadal FSHR Expression and Function-Is It Real?

Expression of the follicle-stimulating hormone receptor (FSHR), besides gonadal tissues, has recently been detected in several extragonadal normal and tumorous tissues, including different types of primary and metastatic cancer and tumor vessel endothelial cells (TVEC). The suggested FSH actions in extragonadal tissues include promotion of angiogenesis, myometrial contractility, skeletal integrity, and adipose tissue accumulation. Non-malignant cells within cancer tissue have been shown to be devoid of FSHR expression, which implies a potential role of FSHR as a diagnostic, prognostic, or even a therapeutic tool. There are shared issues between several of the published reports questioning the validity of some of the conclusion. Firstly, protein expression of FSHR was performed solely with immunohistochemistry (IHC) using either an unavailable "in house" FSHR323 monoclonal antibody or poorly validated polyclonal antibodies, usually without additional methodological quality control and confirmations. Secondly, there is discrepancy between the hardly traceable or absent FSHR gene amplification/transcript data and non-reciprocal strong FSHR protein immunoreactivity. Thirdly, the pharmacological high doses of recombinant FSH used in in vitro studies also jeopardizes the physiological or pathophysiological meaning of the findings. We performed in this review a critical analysis of the results presenting extragonadal expression of FSHR and FSH action, and provide a rationale for the validation of the reported results using additional more accurate and sensitive supplemental methods, including in vivo models and proper positive and negative controls.

Assessment and hormonal management of osteoporosis

Postmenopausal osteoporosis is a frequent health issue in women. Because osteoporosis-related fractures cause a significant increase in mortality and morbidity, it is clinically important to identify as soon as possible women at increased risk for future fracture so that preventive measures can be instituted. At the beginning of menopause, evaluation of the subsequent risk of fracture is not so easy. Most screening tools fail to accurately identify those women who will fracture within the next 10 years. A history of a prior fracture and low bone mineral density are the only major consistently found predictors for the risk of fracture. On the other hand, it is no longer a question whether menopause hormone therapy is efficient not only to prevent postmenopausal bone loss but also the incidence of fragility fracture. Over the last years, utility of menopause hormone therapy for the prevention of osteoporosis has been questioned due to safety concerns. In light of the most recent reports on a more favorable benefit/risk balance than was initially claimed in early postmenopausal women, this needs to be reconsidered. Prevention of bone loss in those women with a moderate or slightly high risk of fracture is likely a strategy to reduce fracture risk in older women. Menopause hormone therapy must be considered as a true primary preventive therapy more than an anti-fracture therapy at an age when the risk of fracture is likely much lower than later in life. Only thereafter should other anti-osteoporotic medications be discussed in women still at high risk for fracture.

Regulation of Skeletal Homeostasis

Landmark advances in skeletal biology have arisen mainly from the identification of disease-causing mutations and the advent of rapid and selective gene-targeting technologies to phenocopy human disease in mice. Here, we discuss work on newly identified mechanisms controlling the remodeling of bone, communication of bone cells with cells of other lineages, and crosstalk between bone and vital organs as these relate to the therapeutic targeting of the skeleton.

FSH, Bone Mass, Body Fat, and Biological Aging

The Study of Women's Health Across the Nation has taught us that impending ovarian failure during late perimenopause is associated with a sharp rise in serum FSH, which coincides with the most rapid rate of bone loss and the onset of visceral adiposity. At this time in a woman's life, serum estrogen levels are largely unaltered, so the hypothesis that hypoestrogenemia is the sole cause of bone loss and visceral obesity does not offer a full explanation. An alternative explanation, arising from animal models and human data, is that both physiologic aberrations, obesity and osteoporosis, arise at least in part from rising FSH levels. Here, we discuss recent findings on the mechanism through which FSH exerts biological actions on bone and fat and review clinical data that support a role for FSH in causing osteoporosis and obesity. We will also provide a conceptual framework for using a single anti-FSH agent to prevent and treat both osteoporosis and obesity in women across the menopausal transition.

Potential Mechanisms of Age Acceleration Caused by Estrogen Deprivation: Do Endocrine Therapies Carry the Same Risks?

Longer duration of endocrine therapy decreases breast cancer recurrence and mortality, but these benefits need to be weighed against potential risks to overall health. Notable side effects of endocrine therapy include cataracts, uterine cancer, thromboembolic events, osteoporosis and fracture risk, chronic musculoskeletal complaints, as well as vaginal dryness and discharge, and vasomotor symptoms. Estrogen deprivation in healthy women younger than 50 years undergoing bilateral oophorectomy has been shown to accelerate the development of diseases related to aging, including coronary artery disease, cardiac arrhythmias, stroke, dementia, and osteoporosis, raising concern that even less dramatic modulation of estrogen homeostasis may adversely affect health outcomes. Diminished available estrogen at the cellular and molecular level may facilitate mechanisms that underlie the aging process, often termed the hallmarks of aging. In this review, we describe estrogen's role in normal physiology across tissues, review the effects of estrogen deprivation on health outcomes in the setting of both surgical and natural menopause, and examine the hallmarks of aging with attention to the effects of estrogen and estrogen blockade on each molecular mechanism underlying the aging process.

Bone Protective Effects of Danggui Buxue Tang Alone and in Combination With Tamoxifen or Raloxifene in vivo and in vitro

Danggui Buxue Tang (DBT), a traditional Chinese Medicine decoction containing Astragali Radix (AR) and Angelicae Sinensis Radix (ASR), is commonly prescribed for women in China as a remedy for menopausal symptoms. Previous study indicated that DBT stimulated cell growth and differentiation of human osteosarcoma MG-63 cells and exhibited estrogenic properties via estrogen receptors (ERs). The present study aimed to study the bone protective effects of DBT and its potential interactions with selective estrogen receptor modulators (SERMs, tamoxifen and raloxifene) in both in vivo and in vitro models as they act via similar ERs. Six-month-old Sprague-Dawley rats were randomly assigned to the following treatments for 12 weeks: (1) sham-operated control group with vehicle (sham), (2) ovariectomized group with vehicle (OVX), (3) OVX with 17β-estradiol (E2, 2.0 mg/kg day), (4) OVX with tamoxifen (Tamo, 1.0 mg/kg day), (5) OVX with raloxifene (Ralo, 3.0 mg/kg day), (6) OVX with DBT (DBT, 3.0 g/kg day), (7) OVX with DBT+Tamoxifen (DBT+Tamo), and (8) OVX with DBT+Raloxifene (DBT+Ralo). Effects of DBT and potential interactions between DBT and SERMs were also evaluated in MG-63 cells. DBT, tamoxifen, raloxifene, and their combinations significantly increased bone mineral density (BMD) and improved trabecular bone properties, including bone surface (BS), trabecular bone number (Tb.N), and trabecular bone separation (Tb.Sp), as well as restored changes in bone turnover biomarkers and mRNA expression of genes involved in bone metabolism in OVX rats. Furthermore, DBT, SERMs, and their combinations significantly increased serum estradiol and suppressed follicle stimulating hormone and luteinizing hormone in OVX rats, suggesting the possible involvement of the hypothalamus–pituitary–gonadal axis in mediating their bone protective effects. However, SERMs, but not DBT, significantly increased uterus index in OVX rats. DBT significantly induced ALP activity and estrogen response element-dependent transcription in MG-63 cells. Our study demonstrated that DBT alone and in combinations with SERMs could exert bone protective effects in vitro and in vivo.

Pituitary Diseases and Bone

Neuroendocrinology of bone is a new area of research based on the evidence that pituitary hormones may directly modulate bone remodeling and metabolism. Skeletal fragility associated with high risk of fractures is a common complication of several pituitary diseases such as hypopituitarism, Cushing disease, acromegaly, and hyperprolactinemia. As in other forms of secondary osteoporosis, pituitary diseases generally affect bone quality more than bone quantity, and fractures may occur even in the presence of normal or low-normal bone mineral density as measured by dual-energy X-ray absorptiometry, making difficult the prediction of fractures in these clinical settings. Treatment of pituitary hormone excess and deficiency generally improves skeletal health, although some patients remain at high risk of fractures, and treatment with bone-active drugs may become mandatory. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary diseases.

Extragonadal Effects of Follicle-Stimulating Hormone on Osteoporosis and Cardiovascular Disease in Women during Menopausal Transition

The risk of osteoporosis and cardiovascular disease increases significantly in postmenopausal women. Until recently, the underlying mechanisms have been primarily attributed to estrogen decline following menopause. However, follicle-stimulating hormone (FSH) levels rise sharply during menopausal transition and are maintained at elevated levels for many years. FSH receptor has been detected in various extragonadal sites, including osteoclasts and endothelial cells. Recent advances suggest FSH may contribute to postmenopausal osteoporosis and cardiovascular disease. Here, we review the key actions through which FSH contributes to the risk of osteoporosis and cardiovascular disease in women as they transition through menopause. Advancing our understanding of the precise mechanisms through which FSH promotes osteoporosis and cardiovascular disease may provide new opportunities for improving health-span for postmenopausal women.

Actions of pituitary hormones beyond traditional targets

Studies over the past decade have challenged the long-held belief that pituitary hormones have singular functions in regulating specific target tissues, including master hormone secretion. Our discovery of the action of thyroid-stimulating hormone (TSH) on bone provided the first glimpse into the non-traditional functions of pituitary hormones. Here we discuss evolving experimental and clinical evidence that growth hormone (GH), follicle-stimulating hormone (FSH), adrenocorticotrophic hormone (ACTH), prolactin, oxytocin and arginine vasopressin (AVP) regulate bone and other target tissues, such as fat. Notably, genetic and pharmacologic FSH suppression increases bone mass and reduces body fat, laying the framework for targeting the FSH axis for treating obesity and osteoporosis simultaneously with a single agent. Certain 'pituitary' hormones, such as TSH and oxytocin, are also expressed in bone cells, providing local paracrine and autocrine networks for the regulation of bone mass. Overall, the continuing identification of new roles for pituitary hormones in biology provides an entirely new layer of physiologic circuitry, while unmasking new therapeutic targets.

Emerging concepts in the epidemiology, pathophysiology, and clinical care of osteoporosis across the menopausal transition

Bone loss in women accelerates during perimenopause, and continues into old age. To-date, there has been little progress made in stratifying for fracture risk in premenopausal and early postmenopausal women. Epidemiologic data suggests that changes in serum FSH could predict decrements in bone mass during peri- and postmenopause. In bone, FSH stimulates osteoclast formation by releasing osteoclastogenic cytokines. Here, we address the evidence for bone loss across the menopausal transition, discuss strategies for detection and treatment of early postmenopausal osteoporosis, and describe the role FSH plays in physiology and likely in pathophysiology of early postmenopausal bone loss.

Epitope-specific monoclonal antibodies to FSHβ increase bone mass

Pituitary hormones have long been thought solely to regulate single targets. Challenging this paradigm, we discovered that both anterior and posterior pituitary hormones, including FSH, had other functions in physiology. We have shown that FSH regulates skeletal integrity, and, more recently, find that FSH inhibition reduces body fat and induces thermogenic adipose tissue. A polyclonal antibody raised against a short, receptor-binding epitope of FSHβ was found not only to rescue bone loss postovariectomy, but also to display marked antiobesity and probeiging actions. Questioning whether a single agent could be used to treat two medical conditions of public health importance--osteoporosis and obesity--we developed two further monoclonal antibodies, Hf2 and Mf4, against computationally defined receptor-binding epitopes of FSHβ. Hf2 has already been shown to reduce body weight and fat mass and cause beiging in mice on a high-fat diet. Here, we show that Hf2, which binds mouse Fsh in immunoprecipitation assays, also increases cortical thickness and trabecular bone volume, and microstructural parameters, in sham-operated and ovariectomized mice, noted on microcomputed tomography. This effect was largely recapitulated with Mf4, which inhibited bone resorption by osteoclasts and stimulated new bone formation by osteoblasts. These effects were exerted in the absence of alterations in serum estrogen in wild-type mice. We also reconfirm the existence of Fshrs in bone by documenting the specific binding of fluorescently labeled FSH, FSH-CH, in vivo. Our study provides the framework for the future development of an FSH-based therapeutic that could potentially target both bone and fat.

The Relationship between Follicle-stimulating Hormone and Bone Health: Alternative Explanation for Bone Loss beyond Oestrogen?

Bone loss in women commences before the onset of menopause and oestrogen deficiency. The increase of follicle-stimulating hormone (FSH) precedes oestrogen decline and may be a cause for bone loss before menopause. This review summarizes the current evidence on the relationship between FSH and bone derived from cellular, animal and human studies. Cellular studies found that FSH receptor (FSHR) was present on osteoclasts, osteoclast precursors and mesenchymal stem cells but not osteoblasts. FSH promoted osteoclast differentiation, activity and survival but exerted negligible effects on osteoblasts. Transgenic FSHR or FSH knockout rodents showed heterogenous skeletal phenotypes. Supplementation of FSH enhanced bone deterioration and blocking of FSH action protected bone of rodents. Human epidemiological studies revealed a negative relationship between FSH and bone health in perimenopausal women and elderly men but the association was attenuated in postmenopausal women. In conclusion, FSH may have a direct action on bone health independent of oestrogen by enhancing bone resorption. Its effects may be attenuated in the presence of overt sex hormone deficiency. More longitudinal studies pertaining to the effects of FSH on bone health, especially on fracture risk, should be conducted to validate this speculation.

Osteoimmunology: The Conceptual Framework Unifying the Immune and Skeletal Systems

The immune and skeletal systems share a variety of molecules, including cytokines, chemokines, hormones, receptors, and transcription factors. Bone cells interact with immune cells under physiological and pathological conditions. Osteoimmunology was created as a new interdisciplinary field in large part to highlight the shared molecules and reciprocal interactions between the two systems in both heath and disease. Receptor activator of NF-κB ligand (RANKL) plays an essential role not only in the development of immune organs and bones, but also in autoimmune diseases affecting bone, thus effectively comprising the molecule that links the two systems. Here we review the function, gene regulation, and signal transduction of osteoimmune molecules, including RANKL, in the context of osteoclastogenesis as well as multiple other regulatory functions. Osteoimmunology has become indispensable for understanding the pathogenesis of a number of diseases such as rheumatoid arthritis (RA). We review the various osteoimmune pathologies, including the bone destruction in RA, in which pathogenic helper T cell subsets [such as IL-17-expressing helper T (Th17) cells] induce bone erosion through aberrant RANKL expression. We also focus on cellular interactions and the identification of the communication factors in the bone marrow, discussing the contribution of bone cells to the maintenance and regulation of hematopoietic stem and progenitors cells. Thus the time has come for a basic reappraisal of the framework for understanding both the immune and bone systems. The concept of a unified osteoimmune system will be absolutely indispensable for basic and translational approaches to diseases related to bone and/or the immune system.