FSH, Bone Mass, Body Fat, and Biological Aging

Follicle-Stimulating Hormone and Diabetes in Postmenopausal Women: A Systematic Review and Meta-Analysis

CONTEXT

The co-occurrence of hormonal changes during menopause and the risk of cardio-metabolic disorders has been well studied.

OBJECTIVE

We explored the association of circulating levels of follicle-stimulating hormone (FSH) with diabetes (DM) among postmenopausal women.

METHOD

In this systematic review and meta-analysis, the search was performed in PubMed, Scopus, Web of Sciences, Epistemonikos, and Cochrane Library up to September 2023. Risk of bias was assessed by Newcastle-Ottawa Quality Assessment Scale. Pooled estimates of mean differences in FSH levels were compared between postmenopausal women with and without DM. Correlations between FSH and fasting blood glucose (FBG)/insulin/homeostatic model assessment for insulin resistance (HOMA-IR) as well as pooled effect sizes with their 95% CIs for risk of DM were calculated.

RESULTS

In this study, 14 articles, including 7878 postmenopausal women, met eligibility criteria. Most of the included studies had a low/moderate risk of bias. Women with DM had significantly lower FSH levels than those without DM (standardized mean difference [SMD] -0.751 [95% CI, -1.129 to -.372], I2 = 82.46%, n = 1416). The pooled effect size for diabetes was 0.861 (95% CI, 0.740-1.001; I2 = 80.11%). The pooled risk estimate for DM based on the categorical FSH levels (high vs low) was (HR = 0.550; 95% CI, 0.356-0.850, I2 = 0). The significant inverse correlation was found between FSH levels and glycemic parameters: FBG (r= -0.285 [95% CI -0.441 to -0.113]; n = 1229), HOMA-IR (r = -0.241[-0.378 to -0.0924]; n = 1229) and insulin (r = -0.337 [-0.434 to -0.232]; n = 959)]. There were no statistically significant differences between estradiol levels among diabetic and nondiabetic groups; however, the SMD for luteinizing hormone was similar to that reported for FSH.

CONCLUSION

The available data indicated an indirect association between FSH levels and glucose disturbances among postmenopausal women, notwithstanding heterogeneity among included studies, and the complexity of various influential factors needs to be considered. Further efforts should be made to clarify the underlying mechanisms.

Crosstalk between bone and brain in Alzheimer's disease: Mechanisms, applications, and perspectives

Alzheimer's disease (AD) is a neurodegenerative disease that involves multiple systems in the body. Numerous recent studies have revealed bidirectional crosstalk between the brain and bone, but the interaction between bone and brain in AD remains unclear. In this review, we summarize human studies of the association between bone and brain and provide an overview of their interactions and the underlying mechanisms in AD. We review the effects of AD on bone from the aspects of AD pathogenic proteins, AD risk genes, neurohormones, neuropeptides, neurotransmitters, brain-derived extracellular vesicles (EVs), and the autonomic nervous system. Correspondingly, we elucidate the underlying mechanisms of the involvement of bone in the pathogenesis of AD, including bone-derived hormones, bone marrow-derived cells, bone-derived EVs, and inflammation. On the basis of the crosstalk between bone and the brain, we propose potential strategies for the management of AD with the hope of offering novel perspectives on its prevention and treatment. HIGHLIGHTS: The pathogenesis of AD, along with its consequent changes in the brain, may involve disturbing bone homeostasis. Degenerative bone disorders may influence the progression of AD through a series of pathophysiological mechanisms. Therefore, relevant bone intervention strategies may be beneficial for the comprehensive management of AD.

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.

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.

Longitudinal patterns of abdominal visceral and subcutaneous adipose tissue, total body composition, and anthropometric measures in postmenopausal women: Results from the Women's Health Initiative

BACKGROUND

Abdominal adiposity, including visceral and subcutaneous abdominal adipose tissue (VAT and SAT), is recognized as a strong risk factor for cardiometabolic disease, cancer, and mortality.

OBJECTIVE

The primary aim of this analysis is to describe longitudinal patterns of change in abdominal adipose tissue in postmenopausal women, overall and stratified by age, race/ethnicity, and years since menopause.

METHODS

The data are from six years of follow up on 10,184 postmenopausal women (7828 non-Hispanic White women, 1423 non-Hispanic Black women, and 703 Hispanic women) who participated in the Women's Health Initiative (WHI). The WHI is a large prospective cohort study of postmenopausal women across the United States. All participants in this analysis had DXA scans in the 1990s as part of the WHI protocol. Hologic APEX software was used to re-analyze archived DXA scans and obtain measures of abdominal adipose tissue. Analyses examined differences in abdominal adipose tissue, overall adiposity, and anthropometric variables.

RESULTS

There were important differences in VAT and SAT by age and race/ethnicity. In women <60 years, VAT increased over the follow-up period, while in women ≥70 years, VAT decreased. Non-Hispanic Black women had the highest levels of SAT. Hispanic women had the highest VAT levels. Women more than ten years since menopause had less SAT and more VAT than women less than ten years since menopause, resulting in a higher VAT/SAT ratio. There was a moderate to strong correlation between measures of abdominal adipose tissue and anthropometric measurements of body size. Still, there were substantial differences in the quantity of VAT and SAT within BMI and waist circumference categories.

CONCLUSIONS

These results demonstrate differences in VAT and SAT according to age, race/ethnicity, time since menopause, and compared to standard measures of body composition in a large and diverse cohort of postmenopausal women.

Androstenedione and Follicle-Stimulating Hormone Concentration Predict the Progression of Frailty Syndrome at One Year Follow-Up in Patients with Localized Breast Cancer Treated with Aromatase Inhibitors

Background: The standard treatment in postmenopausal women with estrogen- and progesterone-positive localized breast cancer consists of aromatase inhibitors (AROi). The ability of AROi to promote or worsen frailty syndrome over time and the relationship with changes in gonadal hormones concentration in blood have not been investigated. Methods: A prospective study to evaluate the relationship between frailty syndrome and gonadal hormones concentrations in blood at baseline (prior to AROi treatment) and after 6 and 12 months under AROi treatment in post-menopausal women with breast cancer. Frailty syndrome was evaluated by the Fried’ criteria. We evaluated whether hormone concentration at baseline could predict frailty syndrome at follow-up. Results: Multinomial regression analysis showed that of the different hormones, those significantly (p < 0.05) associated to the worsening of frailty syndrome were high androstenedione levels and low follicle-stimulating hormone (FSH) levels in blood. Receiver operating characteristic curve analysis showed both androstenedione and FSH significantly (p < 0.05) discriminate patients who developed or presented worsening of frailty syndrome over time, with acceptable sensitivity (approximately 80% in both cases) but low specificity (40%). Conclusion: Hormonal concentrations before AROi treatment constitute possible biomarkers to predict the progression of frailty syndrome.

Dietary Complex and Slow Digestive Carbohydrates Promote Bone Mass and Improve Bone Microarchitecture during Catch-Up Growth in Rats

Catch-up growth is a process that promotes weight and height gains to recover normal growth patterns after a transient period of growth inhibition. Accelerated infant growth is associated with reduced bone mass and quality characterized by poor bone mineral density (BMD), content (BMC), and impaired microarchitecture. The present study evaluated the effects of a diet containing slow (SDC) or rapid (RDC) digestible carbohydrates on bone quality parameters during the catch-up growth period in a model of diet-induced stunted rats. The food restriction period negatively impacted BMD, BMC, and microarchitecture of appendicular and axial bones. The SDC diet was shown to improve BMD and BMC of appendicular and axial bones after a four-week refeeding period in comparison with the RDC diet. In the same line, the micro-CT analysis revealed that the trabecular microarchitecture of tibiae and vertebrae was positively impacted by the dietary intervention with SDC compared to RDC. Furthermore, features of the cortical microstructure of vertebra bones were also improved in the SDC group animals. Similarly, animals allocated to the SDC diet displayed modest improvements in growth plate thickness, surface, and volume compared to the RDC group. Diets containing the described SDC blend might contribute to an adequate bone formation during catch-up growth thus increasing peak bone mass, which could be linked to reduced fracture risk later in life in individuals undergoing transient undernutrition during early life.

Water Extract of Rhizoma Drynaria Selectively Exerts Estrogenic Activities in Ovariectomized Rats and Estrogen Receptor-Positive Cells

Our previous study demonstrated that the bone protective actions of herbal medicine Rhizoma Drynariae (Gusuibu, RD) were mainly mediated by flavonoid phytoestrogens via estrogen receptors, raising concerns about the safety of using RD as it may induce estrogen-like risk-benefit profile and interact with other ER ligands, such as selective estrogen receptor modulators (SERMs), when coadministered. The present study evaluated the estrogenic activities of RD and its potential interaction with tamoxifen, a SERM, in estrogen-sensitive tissues by using mature ovariectomized (OVX) rats and ER-positive cells. Similar to but weaker than tamoxifen, RD at its clinical dose dramatically ameliorated OVX-induced changes in bone and dopamine metabolism-related markers in OVX rats. However, tamoxifen, but not RD, induced uterotrophic effects. No significant alteration in mammary gland was observed in OVX rats treated with RD, which was different from the inhibitory actions of tamoxifen. The two-way ANOVA results indicated the interactions between RD and tamoxifen in the bone, brain, and uterus of OVX rats while RD did not alter their responses to tamoxifen. Our results demonstrate that RD selectively exerts estrogenic actions in a different manner from tamoxifen. Moreover, RD interacts with tamoxifen without altering its effects in OVX rats.

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.

Gonadotropins at Advanced Age - Perhaps They Are Not So Bad? Correlations Between Gonadotropins and Sarcopenia Indicators in Older Adults

Many hormones fluctuate during the aging process. It has been suggested that gonadotropins, which increase with age, contribute to the occurrence of many diseases and syndromes in older life, such as cardiovascular diseases, obesity, frailty syndrome and osteoporosis. This study aims to assess the relationship between circulating gonadotropins and other hormones potentially contributing to age-related functional decline and sarcopenia indicators in 39 male and 61 female community-dwelling seniors, mean age 80 years. According to the definition developed by the second European Working Group on Sarcopenia in Older People (EWGSOP2), the following indicators of the sarcopenia were assessed: bioimpedance-measured body composition, gait speed, handgrip strength, timed up and go test (TUG), chair stand test, Short Physical Performance Battery (SPPB). Blood levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol, testosterone, dehydroepiandrosterone sulphate (DHEAS) and cortisol were also measured. In the men, FSH and partially LH correlated positively with muscle mass percentage, gait speed, handgrip strength and SPPB, and negatively with percent body fat. Additionally, testosterone and DHEAS correlated negatively with the percentage of fat mass in men. Whereas in the women, FSH and LH were mainly negatively associated with body mass and adipose tissue measures. Cortisol did not show any relationship with the examined indicators. The study shows that the indicators of sarcopenia are strongly associated with levels of gonadotropins, sex hormones and DHEAS, especially in older men. The obtained results, after being confirmed in a larger group, may modify prevention and treatment strategies of sarcopenia.

Water extract of Er-xian decoction selectively exerts estrogenic activities and interacts with SERMs in estrogen-sensitive tissues

ETHNOPHARMACOLOGICAL RELEVANCE

The increasing use of "kidney"-nourishing Traditional Chinese Medicine (TCM) like Er-xian decoction (EXD) for management of menopausal symptoms and osteoporosis has aroused concerns about their safety, and whether they interact with prescription drugs as both of them act via estrogen receptors (ERs) and regulate serum estradiol.

AIM OF THE STUDY

The present study aimed to evaluate whether EXD selectively exerted estrogenic activities and interacted with Selective Estrogen Receptor Modulators (SERMs).

MATERIALS AND METHODS

In vivo, mature ovariectomized (OVX) rats were administrated with EXD or combined treatment of EXD and SERMs for 12 weeks. The tissue-selective effect of EXD and its interaction of SERMs were studied in four estrogen sensitive tissues, bone, brain, breast and uterus. In vitro, the interaction of extracts of EXD-treated serum and SERMs in four ER-positive cell lines.

RESULTS

In OVX rats, EXD selectively alleviated estrogen deficiency-induced changes in the bone and brain without inducing any estrogenic effects in the breast or uterus. Two-way ANOVA indicated the presence of interactions between EXD and SERMs in OVX rats but EXD did not significantly alter the tissue responses to SERMs in the bone, breast or brain. Indeed, the combined use of EXD and SERMs appeared to suppress the estrogenic effect of raloxifene and tamoxifen in the uterus. Extract of EXD-treated serum directly stimulated cell proliferation or differentiation in human osteosarcoma MG-63, neuroblastoma SHSY5Y, breast cancer MCF-7, and endometrial Ishikawa cells. Two-way ANOVA revealed that EXD-treated serum interacted with SERMs at various concentrations and altered the effects of tamoxifen in MG-63 and MCF-7 cells.

CONCLUSIONS

EXD exerted estrogenic effects in a tissue-selective manner and interacted with SERMs. Combined treatment of EXD and SERMs did not hamper the beneficial effects of SERMs on the bone or brain but appeared to moderate the estrogenic effect of SERMs in the uterus.

Age-Related Effects on Right Femoral Bone of Male Wistar Rats: A Morphometric and Biomechanical Study

Introduction Study of the variations of bone characteristics with age in different animal models is important to design musculoskeletal studies. Thus, this study aimed to evaluate the bone mass, dimensions, and biomechanical parameters of the femur in young, middle-aged, and aged Wistar rats.

Materials and Methods Thirty male rats (Rattus norvegicus) were divided in three groups (n = 10 per group)—3-month-old young rats, 12-month-old middle-aged rats, and 18-months-old aged rats. The right femurs were subjected sequentially to morphometric study (bone weight, cortical thickness) and biomechanical tests (maximum resistance strength and bone stiffness).

Results We observed a significant increase in femur histological (cortical thickness) and biomechanical (maximum strength and bone stiffness) parameters with aging when compared with young animals.

Conclusions With the advancing age, the right femoral bone of middle-aged and old animals had greater variations when compared with young animals. However, further studies with the aid of a comparison between right and left femur and other long bones in both male and female rats are needed to corroborate with our findings.

Recent advances in understanding gonadotropin signaling

Gonadotropins are glycoprotein sex hormones regulating development and reproduction and bind to specific G protein–coupled receptors expressed in the gonads. Their effects on multiple signaling cascades and intracellular events have recently been characterized using novel technological and scientific tools. The impact of allosteric modulators on gonadotropin signaling, the role of sugars linked to the hormone backbone, the detection of endosomal compartments supporting signaling modules, and the dissection of different effects mediated by these molecules are areas that have advanced significantly in the last decade. The classic view providing the exclusive activation of the cAMP/protein kinase A (PKA) and the steroidogenic pathway by these hormones has been expanded with the addition of novel signaling cascades as determined by high-resolution imaging techniques. These new findings provided new potential therapeutic applications. Despite these improvements, unanswered issues of gonadotropin physiology, such as the intrinsic pro-apoptotic potential to these hormones, the existence of receptors assembled as heteromers, and their expression in extragonadal tissues, remain to be studied. Elucidating these issues is a challenge for future research.

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.

Complete Androgen Insensitivity Syndrome: From Bench to Bed

Complete androgen insensitivity syndrome (CAIS) is due to complete resistance to the action of androgens, determining a female phenotype in persons with a 46,XY karyotype and functioning testes. CAIS is caused by inactivating mutations in the androgen receptor gene (AR). It is organized in eight exons located on the X chromosome. Hundreds of genetic variants in the AR gene have been reported in CAIS. They are distributed throughout the gene with a preponderance located in the ligand-binding domain. CAIS mainly presents as primary amenorrhea in an adolescent female or as a bilateral inguinal/labial hernia containing testes in prepubertal children. Some issues regarding the management of females with CAIS remain poorly standardized (such as the follow-up of intact testes, the timing of gonadal removal and optimal hormone replacement therapy). Basic research will lead to the consideration of new issues to improve long-term well-being (such as bone health, immune and metabolic aspects and cardiovascular risk). An expert multidisciplinary approach is mandatory to increase the long-term quality of life of women with CAIS.

The Relationship between Locomotive Syndrome Risk, Gait Pattern, and Standing Posture in Young Japanese Women: A Cross-Sectional Study

Young people are also at risk of developing locomotive syndrome for unclear reasons. Therefore, we sought to evaluate the locomotive syndrome risk in young Japanese women and the relationship between standing posture and gait patterns. We used survey materials for physical measurements, locomotive syndrome risk tests, normal and maximum walking test, a standing posture test, and physical activity measures. A questionnaire-based cross-sectional survey was conducted with 100 Japanese female university students. The participants were divided into two groups (high-risk and low-risk groups) based on locomotive syndrome risk tests. The high-risk group accounted for 65.0% of the total participants. The high-risk group had a significantly slower walking speed and lower walking stride length than the low-risk group during maximum walking. Additionally, this high-risk group had a more prone posture than the low-risk group. Furthermore, the low-risk group included more individuals who belonged to middle and high school athletic clubs than the high-risk group. The locomotive syndrome risk was related to the walking pattern, standing posture, and past exercise habits. Therefore, long stride length, correct standing posture, and exercise habits acquired from a young age are important measures for preventing locomotive syndrome in young adults.

Biosensing based on field-effect transistors (FET): Recent progress and challenges

The use of field-Effect-Transistor (FET) type biosensing arrangements has been highlighted by researchers in the field of early biomarker detection and drug screening. Their non-metalized gate dielectrics that are exposed to an electrolyte solution cover the semiconductor material and actively transduce the biological changes on the surface. The efficiency of these novel devices in detecting different biomolecular analytes in a real-time, highly precise, specific, and label-free manner has been validated by numerous research studies. Considerable progress has been attained in designing FET devices, especially for biomedical diagnosis and cell-based assays in the past few decades. The exceptional electronic properties, compactness, and scalability of these novel tools are very desirable for designing rapid, label-free, and mass detection of biomolecules. With the incorporation of nanotechnology, the performance of biosensors based on FET boosts significantly, particularly, employment of nanomaterials such as graphene, metal nanoparticles, single and multi-walled carbon nanotubes, nanorods, and nanowires. Besides, their commercial availability, and high-quality production on a large-scale, turn them to be one of the most preferred sensing and screening platforms. This review presents the basic structural setup and working principle of different types of FET devices. We also focused on the latest progression regarding the use of FET biosensors for the recognition of viruses such as, recently emerged COVID-19, Influenza, Hepatitis B Virus, protein biomarkers, nucleic acids, bacteria, cells, and various ions. Additionally, an outline of the development of FET sensors for investigations related to drug development and the cellular investigation is also presented. Some technical strategies for enhancing the sensitivity and selectivity of detection in these devices are addressed as well. However, there are still certain challenges which are remained unaddressed concerning the performance and clinical use of transistor-based point-of-care (POC) instruments; accordingly, expectations about their future improvement for biosensing and cellular studies are argued at the end of this review.

Percent body fat, but not lean mass, is associated with objectively measured physical function in middle-aged women

OBJECTIVES

The relationship between components of body composition and physical function is not well characterized among middle-aged women. This cross-sectional study examined the strength of the associations between lean mass and percent fat and physical function in middle-aged women.

STUDY DESIGN

Body composition, physical function and physical activity were objectively measured in 80 women (mean age 52.58 ± 6.10 years; range = 40-63 years).

MAIN OUTCOME MEASURES

Adiposity (%Fat) and lean mass were measured via dual-energy x-ray absorptiometry. Steps/day and minutes of low-, moderate- and vigorous-intensity physical activity were assessed via accelerometer. Physical function was measured via a seated transfer task, 30-second chair stand, a six-minute walk task, 8-foot timed up and go, and a lift and carry task.

RESULTS

When controlling for steps/day, measures of lean mass were related to performance on the seated transfer task (r = .25) and 30-second chair stand (-.26) (both p > 0.05), while %Fat was related to performance on the seated transfer task (r = .53), 8-foot timed up and go (r = .32), 30-second chair stand (r = -.35), and six-minute walk (r = -.48; all p ≤ 0.05). Linear regression analyses revealed: (1) age, steps/day, and %Fat were independently related to performance on the seated transfer task and 30-second chair stand (both p ≤ 0.05), (2) %Fat was associated with six-minute walk and 8-foot up-and-go performance (p ≤ 0.01); none of the variables included were associated with lift and carry.

CONCLUSIONS

Adiposity but not lean mass was associated with objectively measured physical function in middle-aged women. Interventions that focus on reducing body fat may be an effective method for improving functional performance among women in this age group.

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.

Relationships between Follicle-Stimulating Hormone and Adiponectin in Postmenopausal Women

Beyond fertility, follicle-stimulating hormone (FSH) may exert action on adipocytes, which are the major source of adiponectin and leptin, linking to insulin resistance. Therefore, we evaluated the relationships between FSH and adipocyte-derived hormones. This cross-sectional study enrolled postmenopausal women aged 40–65 years. The variables measured in this study included clinical parameters, fasting levels of sex hormones, glucose, insulin, and adipokines. A total of 261 women without breast cancer, 88 women with breast cancer receiving tamoxifen, and 59 women with breast cancer receiving additional gonadotropin-releasing hormone analogs were enrolled in this study. Significant differences in the levels of adiponectin, leptin, and FSH were observed between the non-breast cancer group and the breast cancer groups. Spearman’s rank test revealed significant associations of FSH with either body mass index (BMI) or homeostatic model assessment of insulin resistance (HOMA-IR) values in the non-breast cancer group. After adjusting for BMI, age, and menopause duration, FSH levels were significantly associated with adiponectin (p < 0.001) and the leptin-to-adiponectin ratio (p = 0.008) in the non-breast cancer group, but they were only significantly associated with adiponectin (p = 0.001) in the breast cancer group receiving tamoxifen. Our data show that FSH levels are independently associated with adiponectin levels in postmenopausal women, suggesting that adiponectin may link FSH to metabolic relationships in postmenopausal female.

Exposure-Safety Analyses Identify Predictors of Change in Bone Mineral Density and Support Elagolix Labeling for Endometriosis-Associated Pain

Elagolix is a novel oral gonadotropin releasing hormone receptor antagonist, that can suppress estradiol in a dose‐dependent manner. It is indicated for management of moderate‐to‐severe pain associated with endometriosis. A population exposure‐response model describing the relationship between elagolix exposure and changes in bone mineral density (BMD) was developed using data from four phase III studies in premenopausal women with endometriosis‐associated pain. Elagolix pharmacokinetic exposure‐dependent changes in BMD were described by an indirect‐response maximum effect (E_max) model through stimulation of bone resorption. African American race, higher body mass index (BMI), and lower type‐I collagen C‐telopeptide concentrations were significantly associated with higher baseline BMD. Higher BMI was significantly associated with higher bone formation rates. Simulations using the final model demonstrated that elagolix 150 mg q.d. dosing for 24 months is predicted to result in −1.45% (−2.04 to −0.814) decrease from baseline in BMD and were used to support corresponding dosing recommendations in the label.

Estrogen Versus FSH Effects on Bone Metabolism: Evidence From Interventional Human Studies

Provocative mouse studies and observational human data have generated considerable enthusiasm for modulating follicle-stimulating hormone (FSH) action in humans to prevent bone loss and, in addition, to treat obesity. This perspective summarizes the strengths and potential weaknesses of the mouse studies examining the skeletal phenotype of FSHβ or FSH receptor null mice, as well as more recent studies using FSH neutralizing antibodies. Although human observational studies do demonstrate correlation of serum FSH levels with postmenopausal bone loss, these studies cannot distinguish whether serum FSH is simply a better biomarker than estradiol or causally related to the bone loss. Establishing causality requires direct interventional studies either suppressing or infusing FSH in humans and to date, such studies have uniformly failed to demonstrate an effect of FSH on bone turnover independent of changes in sex steroid levels. In addition, suppression of FSH is unable to prevent increases in body fat following the induction of sex steroid deficiency, at least in men. Thus, although the preclinical mouse and human observational data are intriguing, there is currently no direct evidence from interventional studies that FSH regulates bone or fat metabolism in vivo in humans.

Crosstalk of Brain and Bone-Clinical Observations and Their Molecular Bases

As brain and bone disorders represent major health issues worldwide, substantial clinical investigations demonstrated a bidirectional crosstalk on several levels, mechanistically linking both apparently unrelated organs. While multiple stress, mood and neurodegenerative brain disorders are associated with osteoporosis, rare genetic skeletal diseases display impaired brain development and function. Along with brain and bone pathologies, particularly trauma events highlight the strong interaction of both organs. This review summarizes clinical and experimental observations reported for the crosstalk of brain and bone, followed by a detailed overview of their molecular bases. While brain-derived molecules affecting bone include central regulators, transmitters of the sympathetic, parasympathetic and sensory nervous system, bone-derived mediators altering brain function are released from bone cells and the bone marrow. Although the main pathways of the brain-bone crosstalk remain ‘efferent’, signaling from brain to bone, this review emphasizes the emergence of bone as a crucial ‘afferent’ regulator of cerebral development, function and pathophysiology. Therefore, unraveling the physiological and pathological bases of brain-bone interactions revealed promising pharmacologic targets and novel treatment strategies promoting concurrent brain and bone recovery.

Muscle and bone mass in middle-aged women: role of menopausal status and physical activity

BACKGROUND

Women experience drastic hormonal changes during midlife due to the menopausal transition. Menopausal hormonal changes are known to lead to bone loss and potentially also to loss of lean mass. The loss of muscle and bone tissue coincide due to the functional relationship and interaction between these tissues. If and how physical activity counteracts deterioration in muscle and bone during the menopausal transition remains partly unresolved. This study investigated differences between premenopausal, early perimenopausal, late perimenopausal, and postmenopausal women in appendicular lean mass (ALM), appendicular lean mass index (ALMI), femoral neck bone mineral density (BMD) and T score. Furthermore, we investigated the simultaneous associations of ALM and BMD with physical activity in the above-mentioned menopausal groups.

METHODS

Data from the Estrogen Regulation of Muscle Apoptosis study were utilized. In total, 1393 women aged 47-55 years were assigned to premenopausal, early perimenopausal, late perimenopausal, and postmenopausal groups based on follicle-stimulating hormone concentration and bleeding diaries. Of them, 897 were scanned for ALM and femoral neck BMD by dual-energy X-ray absorptiometry and ALMI (ALM/height² ) and neck T scores calculated. Current level of leisure-time physical activity was estimated by a validated self-report questionnaire and categorized as sedentary, low, medium, and high.

RESULTS

Appendicular lean mass, appendicular lean mass index, femoral neck bone mineral density, and and T score showed a significant linear declining trend across all four menopausal groups. Compared with the postmenopausal women, the premenopausal women showed greater ALM (18.2, SD 2.2 vs. 17.8, SD 2.1, P < 0.001), ALMI (6.73, SD 0.64 vs. 6.52, SD 0.62, P < 0.001), neck BMD (0.969, SD 0.117 vs. 0.925, SD 0.108, P < 0.001), and T score (-0.093, SD 0.977 vs -0.459, SD 0.902, P < 0.001). After adjusting for potential confounding pathways, a higher level of physical activity was associated with greater ALM among the premenopausal [β = 0.171; confidence interval (CI) 95% 0.063-0.280], late perimenopausal (β = 0.289; CI 95% 0.174-0.403), and postmenopausal (β=0.278; CI 95% 0.179-0.376) women. The positive association between femoral neck BMD and level of physical activity was significant only among the late perimenopausal women (β = 0.227; CI 95% 0.097-0.356).

CONCLUSIONS

Skeletal muscle and bone losses were associated with the menopausal transition. A higher level of physical activity during the different menopausal phases was beneficial, especially for skeletal muscle. Menopause-related hormonal changes predispose women to sarcopenia and osteoporosis and further to mobility disability and fall-related fractures in later life. New strategies are needed to promote physical activity among middle-aged women. Longitudinal studies are needed to confirm these results.

Commentary on the Recent FSH Collection: Known Knowns and Known Unknowns

Follicle-stimulating hormone (FSH) is a dimeric glycoprotein secreted by the anterior pituitary gonadotrope that is necessary for reproductive function in mammals. FSH primarily regulates granulosa cells and follicular growth in females, and Sertoli cell function in males. Since its identification in the 1930s and sequencing in the 1970s, significant progress has been made in elucidating its regulation and downstream function. Recent advances provide deeper insight into FSH synthesis, and effects in the gonads suggest potential roles in extragonadal tissues and examine pharmacological approaches and clinical applications in infertility treatment that now affect 18% of couples. These advances were discussed in detail in a number of reviews published in the last 2 years in Endocrinology. In this brief commentary, we summarize these reviews and point to the outstanding questions that should be answered in the near future to bridge a gap in our understanding of this hormone.

β-Arrestin 1 in Thyrotropin Receptor Signaling in Bone: Studies in Osteoblast-Like Cells

A direct action of thyrotropin (TSH, thyroid-stimulating hormone) on bone precursors in humans is controversial. Studies in rodent models have provided conflicting findings. We used cells derived from a moderately differentiated osteosarcoma stably overexpressing human TSH receptors (TSHRs) as a model of osteoblast precursors (U2OS-TSHR cells) to investigate TSHR-mediated effects in bone differentiation in human cells. We review our findings that (1) TSHR couples to several different G proteins to induce upregulation of genes associated with osteoblast activity-interleukin 11 (IL-11), osteopontin (OPN), and alkaline phosphatase (ALPL) and that the kinetics of the induction and the G protein-mediated signaling pathways involved were different for these genes; (2) TSH can stimulate β-arrestin-mediated signal transduction and that β-arrestin 1 in part mediates TSH-induced pre-osteoblast differentiation; and (3) TSHR/insulin-like growth factor 1 (IGF1) receptor (IGF1R) synergistically increased OPN secretion by TSH and IGF1 and that this crosstalk was mediated by physical association of these receptors in a signaling complex that uses β-arrestin 1 as a scaffold. These findings were complemented using a novel β-arrestin 1-biased agonist of TSHR. We conclude that TSHR can signal via several transduction pathways leading to differentiation of this model system of human pre-osteoblast cells and, therefore, that TSH can directly regulate these bone cells.

Marrow Adipocytes: Origin, Structure, and Function

The skeleton harbors an array of lineage cells that have an essential role in whole body homeostasis. Adipocytes start the colonization of marrow space early in postnatal life, expanding progressively and influencing other components of the bone marrow through paracrine signaling. In this unique, closed, and hypoxic environment close to the endosteal surface and adjacent to the microvascular space the marrow adipocyte can store or provide energy, secrete adipokines, and target neighboring bone cells. Adipocyte progenitors can also migrate from the bone marrow to populate white adipose tissue, a process that accelerates during weight gain. The marrow adipocyte also has an endocrine role in whole body homeostasis through its varied secretome that targets distant adipose depots, skeletal muscle, and the nervous system. Further insights into the biology of this unique and versatile cell will undoubtedly lead to novel therapeutic approaches to metabolic and age-related disorders such as osteoporosis and diabetes mellitus.

Hormonal, metabolic and inflammatory circulating biomarker profiles in obese and non-obese Brazilian middle-aged women

AIM

To investigate circulating hormonal, metabolic and inflammatory biomarker profiles in obese and non-obese middle-aged women.

METHODS

A total of 110 women, aged 40-60 years, were included in this cross-sectional study. Patients were allocated, according to the occurrence of menopause and body mass index (BMI), into four groups: PM0 (premenopausal non-obese), PM1 (premenopausal obese), M0 (postmenopausal non-obese), and M1 (postmenopausal obese). Serum levels of gonadotropins, sex hormones, lipid markers, leptin, hs-CRP and interleukin-6 were obtained using either colorimetric or immunoenzymatic assays. Univariate and correlation analyses were performed among all clinical and laboratorial parameters. Principal component analysis was used to characterize subsets of biomarkers, which had their discriminatory capacity tested using discriminant function analysis.

RESULTS

Levels of gonadotropins and female sex hormones were similar between PM0 and PM1 and between M0 and M1 (p > 0.05), all of them varied between PM0 and M0 (p < 0.05), but only estradiol was significantly altered in the comparison between PM1 and M1 (p = 0.027). Regarding metabolic markers, leptin was lower in PM0 than in M0 (p = 0.010) and higher in M1 than in M0 (p = 0.046). In premenopausal women, BMI correlated only to leptin, while it correlated to several other markers in postmenopausal women. A combination of FSH and leptin serum levels significantly discriminated the four groups (Wilks's lambda < 0.001, in canonical functions 1 and 2).

CONCLUSION

A combined analysis of hormonal biomarkers may potentially distinguish obese from non-obese women with distinct menopause status. Further research is thus required to clarify the clinical significance of such findings.

Modulation of Gonadotropins Activity by Antibodies

Gonadotropins are essential for reproduction control in humans as well as in animals. They are widely used all over the world for ovarian stimulation in women, spermatogenesis stimulation in men, and ovulation induction and superovulation in animals. Despite the availability of many different preparations, all are made of the native hormones. Having different ligands with a wide activity range for a given receptor helps better understand its molecular and cellular signaling mechanisms as well as its physiological functions, and thus helps the development of more specific and adapted medicines. One way to control the gonadotropins' activity could be the use of modulating antibodies. Antibodies are powerful tools that were largely used to decipher gonadotropins' actions and they have shown their utility as therapeutics in several other indications such as cancer. In this review, we summarize the inhibitory and potentiating antibodies to gonadotropins, and their potential therapeutic applications.

FSH Actions and Pregnancy: Looking Beyond Ovarian FSH Receptors

By mediating estrogen synthesis and follicular growth in response to FSH, the ovarian FSH receptor (FSHR) is essential for female fertility. Indeed, ovarian stimulation via administration of FSH to women with infertility is part of the primary therapeutic intervention used in assisted reproductive technology. In physiological and therapeutic contexts, current dogma dictates that once ovulation has occurred, FSH/FSHR signaling is no longer required for successful pregnancy outcomes. However, a continued role for FSH during pregnancy is suggested by recent studies demonstrating extraovarian FSHR in the female reproductive tract. Furthermore, functional roles for FSHR in placenta and in uterine myometrium have now been demonstrated. In placenta, vascular endothelial FSHR of fetal vessels within the chorionic villi (human) or labyrinth (mouse) mediate angiogenesis, and it has further been shown that deletion of placental Fshr in mice has deleterious effects on pregnancy. In uterine myometrium, changes in the densities of FSHR in muscle fiber and stroma in the nonpregnant state, early pregnancy, and term pregnancy differentially regulate contractile activity, suggesting that signaling through myometrial FSHR may contribute to the quieting of contractile activity required for successful implantation and that the temporal upregulation of the FSHR at term pregnancy may be required for the appropriate timing of parturition. In addition, extraovarian expression of mRNAs encoding the glycoprotein hormone α subunit and the FSH β subunit has been demonstrated, suggesting that these novel aspects of extraovarian FSH/FSHR signaling during pregnancy may be mediated by locally synthesized FSH.

Structure-Function Relationships of the Follicle-Stimulating Hormone Receptor

The follicle-stimulating hormone receptor (FSHR) plays a crucial role in reproduction. This structurally complex receptor is a member of the G-protein coupled receptor (GPCR) superfamily of membrane receptors. As with the other structurally similar glycoprotein hormone receptors (the thyroid-stimulating hormone and luteinizing hormone-chorionic gonadotropin hormone receptors), the FSHR is characterized by an extensive extracellular domain, where binding to FSH occurs, linked to the signal specificity subdomain or hinge region. This region is involved in ligand-stimulated receptor activation whereas the seven transmembrane domain is associated with receptor activation and transmission of the activation process to the intracellular loops comprised of amino acid sequences, which predicate coupling to effectors, interaction with adapter proteins, and triggering of downstream intracellular signaling. In this review, we describe the most important structural features of the FSHR intimately involved in regulation of FSHR function, including trafficking, dimerization, and oligomerization, ligand binding, agonist-stimulated activation, and signal transduction.