Relationship of age-related concentrations of serum FSH and LH with bone mineral density, prevalence of osteoporosis in native Chinese women

Neuroendocrinology of bone

The past decade has witnessed significant advances in our understanding of skeletal homeostasis and the mechanisms that mediate the loss of bone in primary and secondary osteoporosis. Recent breakthroughs have primarily emerged from identifying disease-causing mutations and phenocopying human bone disease in rodents. Notably, using genetically-modified rodent models, disrupting the reciprocal relationship with tropic pituitary hormone and effector hormones, we have learned that pituitary hormones have independent roles in skeletal physiology, beyond their effects exerted through target endocrine glands. The rise of follicle-stimulating hormone (FSH) in the late perimenopause may account, at least in part, for the rapid bone loss when estrogen is normal, while low thyroid-stimulating hormone (TSH) levels may contribute to the bone loss in thyrotoxicosis. Admittedly speculative, suppressed levels of adrenocorticotropic hormone (ACTH) may directly exacerbate bone loss in the setting of glucocorticoid-induced osteoporosis. Furthermore, beyond their established roles in reproduction and lactation, oxytocin and prolactin may affect intergenerational calcium transfer and therefore fetal skeletal mineralization, whereas elevated vasopressin levels in chronic hyponatremic states may increase the risk of bone loss.. Here, we discuss the interaction of each pituitary hormone in relation to its role in bone physiology and pathophysiology.

Cascaded autocatalytic hairpin assembly molecular circuit for amplified fluorescent aptamer luteinising hormone assay

The quantitative detection of luteinising hormone (LH) is critical for the study of the physiological mechanism of reproductive function and the assessment of infertility and the clinical treatment of reproductive disorders. However, conventional approaches for LH detection are mostly based on an antibody recognition module with the limitations of sensitivity, simplicity and cost. The development of robust LH sensing methods is therefore highly demanded for facilitating the diagnosis of LH-related diseases. We establish a convenient, amplified and sensitive fluorescent aptamer LH assay based on new target-triggered and cascaded autocatalytic hairpin assembly (C-aCHA) circuit amplification means via initiator sequence replication. Target LH molecules bind the aptamers in the aptamer/initiator duplexes to release the initiator sequences, which trigger CHA formation of DNA three-way junctions (TWJs) and the unfolding of fluorescently quenched signal hairpins to show amplified fluorescence. The TWJs further activate another CHA cycle for the yield of more initiator sequences to form the C-aCHA circuit amplification cycles, which lead to the unfolding of many signal hairpins to exhibit substantially magnified fluorescence recovery for detecting LH down to 8.56 pM in the range from 10 pM to 50 nM. In addition, the monitoring of trace LH in diluted serums by this sensing approach has been also verified. Our LH assay clearly outperforms current existing antibody-based methods and the C-aCHA signal amplification strategy can be easily extended as a robust means for sensitively monitoring various biomolecular markers with simple replacement of the corresponding aptamers for diverse applications.

EMAS position statement: Thyroid disease and menopause

INTRODUCTION

Thyroid diseases are common in women in their late reproductive years; therefore, thyroid disease and menopause may co-exist. Both conditions may present with a wide range of symptoms, leading to diagnostic challenges and delayed diagnosis. Aim To construct the first European Menopause and Andropause Society (EMAS) statement on thyroid diseases and menopause.

MATERIALS AND METHODS

Literature review and consensus of expert opinion (EMAS executive board members/experts on menopause and thyroid disease).

SUMMARY RECOMMENDATIONS

This position paper highlights the diagnostic and therapeutic dilemmas in managing women with thyroid disease during the menopausal transition, aiming to increase healthcare professionals' awareness of thyroid disorders and menopause-related symptoms. Clinical decisions regarding the treatment of both conditions should be made with caution and attention to the specific characteristics of this age group while adopting a personalized patient approach. The latter must include the family history, involvement of the woman in the decision-making, and respect for her preferences, to achieve overall well-being.

Causality between Sex Hormones and Bone Mineral Density in Childhood: Age- and Tanner-Stage-Matched Sex Hormone Level May Be an Early Indicator of Pediatric Bone Fragility

This study aimed to investigate the impact of hypogonadism on bone mineral density (BMD) in children and adolescents with chronic diseases to determine the relationship between sex hormones and BMD. This retrospective study included 672 children and adolescents with chronic diseases such as hemato-oncologic, rheumatoid, gastrointestinal, and endocrinologic diseases. The relationship between the sex- and Tanner-stage-matched Z-scores for sex hormones and the sex- and age-matched lumbar spine BMD (LSBMD) Z-scores was evaluated. Adjustments were made for confounders such as underlying diseases, age at diagnosis, and age- and sex-matched body mass index Z-scores. Patients had a mean LSBMD Z-score of -0.55 ± 1.31. In the multivariate regression analysis, male testosterone showed a positive association with the LSBMD Z-score (p < 0.001), whereas female estradiol, luteinizing hormone, and follicular-stimulating hormone showed no significant association with the LSBMD Z-scores. In the male group, the testosterone level was associated with LSBMD Z-scores > -1.0 (p < 0.001), > -2.0 (p < 0.001), and > -3.0 (p = 0.002), while the estradiol level was associated with LSBMD Z-scores > -2.0 (p = 0.001) and > -3.0 (p = 0.002) in the female group. In conclusion, sex hormones are associated with BMD in children and adolescents with chronic diseases. Therefore, various measures may be necessary to predict future skeletal problems and improve bone health in these patients.

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.

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.

Bones and Hormones: Interaction between Hormones of the Hypothalamus, Pituitary, Adipose Tissue and Bone

The bony skeleton, as a structural foundation for the human body, is essential in providing mechanical function and movement. The human skeleton is a highly specialized and dynamic organ that undergoes continuous remodeling as it adapts to the demands of its environment. Advances in research over the last decade have shone light on the various hormones that influence this process, modulating the metabolism and structural integrity of bone. More recently, novel and non-traditional functions of hypothalamic, pituitary, and adipose hormones and their effects on bone homeostasis have been proposed. This review highlights recent work on physiological bone remodeling and discusses our knowledge, as it currently stands, on the systemic interplay of factors regulating this interaction. In this review, we provide a summary of the literature on the relationship between bone physiology and hormones including kisspeptin, neuropeptide Y, follicle-stimulating hormone (FSH), prolactin (PRL), adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), growth hormone (GH), leptin, and adiponectin. The discovery and understanding of this new functionality unveils an entirely new layer of physiologic circuitry.

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.

Association of Plasma Sex-Related Hormones Levels with Bone Mineral Densities and Risk of Osteoporosis and Osteopenia in Men and Menopausal Women with Type 2 Diabetes Mellitus

OBJECTIVE

This study aimed to examine associations between plasma sex-related hormones with bone mineral density (BMD) and risks of osteoporosis or osteopenia in men and postmenopausal women patients with type 2 diabetes mellitus (T2DM).

METHODS

Baseline information on an ongoing cohort of 149 men and 102 postmenopausal women with T2DM in Xiamen, China were analyzed. Plasma estradiol (E2), total testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH) and prolactin (PRL) were measured. BMD of lumbar spine (L2-4), femoral neck (FN) and total hip (TH) were determined by dual-energy X-ray absorptiometry (DXA). Osteoporosis or osteopenia was defined as the minimum T-scores of BMD of these three different sites of -1.0 or below.

RESULTS

T2DM patients with osteoporosis/osteopenia (66.4% in men and 79.4% in postmenopausal women), compared to those without, showed significantly decreased level of E2 (75.3±28.9 vs. 107.8±25.9pmol/L and 18.4 (18.4-29.5) vs. 22.8 (18.4-40.5) pmol/L for men and postmenopausal women, respectively, both p-values <0.05), but not other sex-related hormones (including T, FSH, LH, or PRL). For all T2DM patients together and men separately, multivariable linear regression and logistic regression analyses showed that higher E2 levels were significantly associated with higher BMD T-scores in L2-4, FN, TH and minimum of these three different sites, lower 10-year probability of major osteoporotic fractures (MOF) and hip fractures (HFs) estimated by Fracture Risk Assessment Tool score, as well as decreased risk of osteoporosis/osteopenia. As for postmenopausal women T2DM patients, E2 level was positively associated with BMD T-scores in L2-4 and minimum of three different sites but was not independently associated with risk of osteoporosis/osteopenia.

CONCLUSION

Higher plasma E2 was significantly associated with increased BMD and lower risk of osteoporosis or osteopenia in T2DM patients, especially for men. Screening of BMD and estradiol levels as well as evaluating risks of osteoporosis/osteopenia are important for T2DM patients.

Relationship between Body Mass Index and Bone Turnover Markers in Girls with Idiopathic Central Precocious Puberty

Background

This study aimed to determine the effect of body mass index (BMI) on bone turnover markers in girls with idiopathic central precocious puberty (ICPP) according to weight status at diagnosis.

Methods

Two hundred and eleven girls with ICPP were divided according to their weight status at diagnosis into three groups: normal weight, overweight, and obese. The serum levels of total procollagen type 1 N-terminal propeptide (P1NP), N-terminal midfragment of osteocalcin, β-C-terminal telopeptide of type 1 collagen, and some biochemical indicators were measured. Associations between variables were evaluated by multiple regression analysis.

Results

Serum P1NP concentrations were significantly different among groups (p < 0.001). No other significant differences were noted in N-terminal midfragment of osteocalcin and β-C-terminal telopeptide of type 1 collagen. BMI was associated with estradiol (r = 0.155, p < 0.05) and inversely associated with P1NP (r = -0.251, p < 0.01), luteinizing hormone peak (r = -0.334, p < 0.01), follicle-stimulating hormone peak (r = -0.215, p < 0.01), and luteinizing hormone/follicle-stimulating hormone peak (r = -0.284, p < 0.01). Multiple regression analysis of factors associated with BMI showed that it was correlated with P1NP, follicle-stimulating hormone base, and luteinizing hormone peak in the overweight group and the obese group.

Conclusions

Our findings showed that BMI was associated with P1NP, revealing the reduction of bone formation in overweight and obese girls with ICPP. During the diagnosis and treatment of girls with ICPP, attention should be paid to body weight and bone metabolism.

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.

Insight into Potential Interactions of Thyroid Hormones, Sex Hormones and Their Stimulating Hormones in the Development of Non-Alcoholic Fatty Liver Disease

Non-Alcoholic Fatty Liver Disease (NAFLD) is a common manifestation of metabolic syndrome. In addition to lifestyle, endocrine hormones play a role in the dysregulation of hepatic metabolism. The most common endocrine hormones contributing to metabolic syndrome are alterations in the levels of thyroid hormones (THs, predominantly in subclinical hypothyroidism) and of sex hormones (in menopause). These hormonal changes influence hepatic lipid and glucose metabolism and may increase hepatic fat accumulation. This review compares the effects of sex hormones, THs and the respective stimulating hormones, Thyroid-Stimulating Hormone (TSH) and Follicle-Stimulating Hormone (FSH), on the development of hepatosteatosis. TSH and FSH may be more relevant to the dysregulation of hepatic metabolism than the peripheral hormones because metabolic changes were identified when only levels of the stimulating hormones were abnormal and the peripheral hormones were still in the reference range. Increased TSH and FSH levels appear to have additive effects on the development of NAFLD and to act independently from each other.

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.

A Risk Assessment Tool for Identifying Osteoporosis in Older Women with Type 2 Diabetes Mellitus

PURPOSE

To develop a simple and clinically useful assessment tool for osteoporosis in older women with type 2 diabetes mellitus (T2DM).

METHODS

A total of 601 women over 60 years of age with T2DM were enrolled in this study. The levels of serum sex hormones and bone metabolism markers were compared between the osteoporosis and non-osteoporosis groups. The least absolute shrinkage and selection operator regularization (LASSO) model was applied to generate a risk assessment tool. The risk score formula was evaluated using receiver operating characteristic analysis and the relationship between the risk score and the bone mineral density (BMD) and T-value were investigated.

RESULTS

Serum sex hormone-binding globulin (SHBG), cross-linked C-telopeptide of type 1 collagen (CTX), and osteocalcin (OC) were significantly higher in the osteoporosis group. After adjustment for age and body mass index (BMI), SHBG was found to be correlated with the T-value or BMD. Then, a risk score was specifically generated with age, BMI, SHBG, and CTX using the LASSO model. The risk score was significantly negatively correlated with the T-value and BMD of the lumbar spine, femoral neck, and total hip (all P<0.05).

CONCLUSION

A risk score using age, BMI, SHBG, and CTX performs well for identifying osteoporosis in older women with T2DM.

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.

Do polyunsaturated fatty acids protect against bone loss in our aging and osteoporotic population?

Age-related bone loss is inevitable in both men and women and there will soon be more people of extreme old age than ever before. Osteoporosis is a common chronic disease and as the proportion of older people, rate of obesity and the length of life increases, a rise in age-related degenerating bone diseases, disability, and prolonged dependency is projected. Fragility fractures are one of the most severe complications associated with both primary and secondary osteoporosis and current treatment strategies target weight-bearing exercise and pharmacological intervention, both with limited long-term success. Obesity and osteoporosis are intimately interrelated, and diet is a variable that plays a significant role in bone regeneration and repair. The Western Diet is characterized by its unhealthy components, specifically excess amounts of saturated fat intake. This review examines the impact of saturated and polyunsaturated fatty acid consumption on chronic inflammation, osteogenesis, bone architecture, and strength and explores the hypothesis that dietary polyunsaturated fats have a beneficial effect on osteogenesis, reducing bone loss by decreasing chronic inflammation, and activating bone resorption through key cellular and molecular mechanisms in our aging population. We conclude that aging, obesity and a diet high in saturated fatty acids significantly impairs bone regeneration and repair and that consumption of ω-3 polyunsaturated fatty acids is associated with significantly increased bone regeneration, improved microarchitecture and structural strength. However, ω-6 polyunsaturated fatty acids were typically pro-inflammatory and have been associated with an increased fracture risk. This review suggests a potential role for ω-3 fatty acids as a non-pharmacological dietary method of reducing bone loss in our aging population. We also conclude that contemporary amendments to the formal nutritional recommendations made by the Food and Nutrition Board may be necessary such that our aging population is directly considered.

High follicle-stimulating hormone levels accelerate cartilage damage of knee osteoarthritis in postmenopausal women through the PI3K/AKT/NF-κB pathway

Osteoarthritis is the main cause of pain and disability in the elderly, with the most commonly affected joint being the knee. The prevalence of knee osteoarthritis (KOA) is significantly increased in postmenopausal women, although the mechanisms underlying KOA remain unclear. The present study aimed to investigate the association between follicle‐stimulating hormone (FSH) and postmenopausal women with KOA aged between 50 and > 70 years, as well as explore its underlying molecular mechanisms. Here, we report that the 50–60 years age group had the highest level of serum FSH. Compared to the low FSH group (< 40 mIU·mL⁻¹) in the same age group, the high FSH group (> 40 mIU·mL⁻¹) showed more severe cartilage damage. Furthermore, phosphorylated (p)‐phosphoinositide 3‐kinase (PI3K)/PI3K, p‐AKT/AKT and p‐nuclear factor kappa B (NF‐κB)/NF‐κB levels were significantly higher in the high FSH group compared to the low FSH group. Immunofluorescence experiments showed that FSH stimulation promoted the translocation of NF‐κB p65 into the nucleus, and decreased type II collagen and aggrecan in ATDC5 cells. Moreover, we used western blotting in ATDC5 cells to demonstrate that FSH decreased type II collagen and increased p‐PI3K/PI3K, p‐AKT/AKT, p‐NF‐κB/NF‐κB and p‐IKB/IKB in a concentration‐dependent manner. Our results suggest that increased FSH levels are associated with KOA for postmenopausal women aged 50–60 years and that high FSH levels might damage the cartilage tissues through the PI3K/AKT/NF‐κB pathway.

A potential association of meditation with menopausal symptoms and blood chemistry in healthy women: A pilot cross-sectional study

Owing to hormonal changes, women experience various psychophysiological alterations over a wide age range, which may result in decreased quality of life as well as in increased risks of diseases, such as cardiovascular diseases. Although studies have been performed to research complementary methods, such as meditation, the research field still requires an adequate amount of studies for public health guidelines. This pilot cross-sectional study aims to investigate a potential association of meditation with menopausal symptoms and blood chemistry for healthy women. In this study, data of 65 healthy women (age range 25-67) including 33 meditation practitioners and 32 meditation-naïve controls were analyzed to compare the Menopausal Rating Scale scores and blood chemistry with 7 more dropouts in the blood chemistry. For blood chemistry, nine components including glucose (GLU) and high-density lipoprotein cholesterol (HDL) were measured. Two-way analysis of variance was performed by dividing the total participants into 2 groups: premenopausal and postmenopausal participants. Compared to the control group, the meditation group showed a trend of reductions in the Menopausal Rating Scale total score (P = .054) and its 2 subcomponents: depressive mood (P = .064) and irritability (P = .061). In HDL level, there was a significant interaction between group and menopausal state (P = .039) with following post hoc results: among the premenopausal participants, a significant increase in the meditation group compared to the control group (P = .005); among the control group, a significant increase in the postmenopausal compared to the premenopausal participants (P = .030). In GLU level, there was a mild interaction between group and menopausal state (P = .070) with following post hoc results: among the postmenopausal participants, a trend of increase in the control group compared to the meditation group (P = .081); among the control group, a significant increase in the postmenopausal compared to the premenopausal participants (P = .040). Our research suggests a potential association of practicing meditation with alleviations in menopausal symptoms and changes in blood chemistry, warranting further studies with a longitudinal study design and larger populations to understand the underlying causal relationships.

FSH-metabolic circuitry and menopause

FSH has a primary function in procreation, wherein it induces estrogen production in females and regulates spermatogenesis in males. However, in line with our discoveries over the past decade of non-unitary functions of pituitary hormones, we and others have described hitherto uncharacterized functions of FSH. Through high-affinity receptors, some of which are variants of the ovarian FSH receptor (FSHR), FSH regulates bone mass, adipose tissue function, energy metabolism, and cholesterol production in both sexes. These newly described actions of FSH may indeed be relevant to the pathogenesis of bone loss, dysregulated energy homeostasis, and disordered lipid metabolism that accompany the menopause in females and aging in both genders. We are therefore excited about the possibility of modulating circulating FSH levels toward a therapeutic benefit for a host of age-associated diseases, including osteoporosis, obesity and dyslipidemia, among other future possibilities.

Effect of surgical and natural menopause on proximal femur morphometry in obese women

The purpose of this study is to determine whether there are differences in proximal femur parameters of women subjected to menopause surgically or naturally. In this study, 10 parameters belonging to proximal femur of a total of 60 women cases of whom 30 had a mean age of 55.53 ± 4.57 years; body mass index, 33.06 ± 4.21 kg/m²; menopause age, 48.10 ± 5.92; and menopause years, 7.50 ± 4.58; and who were subjected to natural menopause; and 30 women whose mean age was 56.10 ± 6.87 years; body mass index, 33.33 ± 3.76 kg/m²; menopause age, 48.00 ± 4.64 years and menopause year, 8.10 ± 7.29; who were subjected to surgical menopause, and who did not use hormone replacement, were examined by radiography. Their anthropometric measurements, body compositions, blood hormone analyses (FSH, LH, estradiol, progesterone) and bone mineral densities (femur neck, femur total, lumbar t-score) were evaluated. It was found that there was no difference between surgical and natural menopause with respect to proximal femur parameters (p > 0.05). It was also found that FSH levels were high in the surgical menopause group and there were significant differences between the groups (p < 0.040). No significant difference was found even though bone mineral density t-score tests were lower in the surgical menopause group (p > 0.05). It was found that the difference in low bone mineral density level and high FSH values in the surgical menopause group do not have a relationship with proximal femur morphometry. It was determined that even though the women did not have ovaries, there was no difference between surgical menopause women and natural menopause women with respect to proximal femur morphometry.

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.

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.

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.

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.

Male Hypogonadism and Osteoporosis: The Effects, Clinical Consequences, and Treatment of Testosterone Deficiency in Bone Health

It is well recognized that bone loss accelerates in hypogonadal states, with female menopause being the classic example of sex hormones affecting the regulation of bone metabolism. Underrepresented is our knowledge of the clinical and metabolic consequences of overt male hypogonadism, as well as the more subtle age-related decline in testosterone on bone quality. While menopause and estrogen deficiency are well-known risk factors for osteoporosis in women, the effects of age-related testosterone decline in men on bone health are less well known. Much of our knowledge comes from observational studies and retrospective analysis on small groups of men with variable causes of primary or secondary hypogonadism and mild to overt testosterone deficiencies. This review aims to present the current knowledge of the consequences of adult male hypogonadism on bone metabolism. The direct and indirect effects of testosterone on bone cells will be explored as well as the important differences in male osteoporosis and assessment as compared to that in females. The clinical consequence of both primary and secondary hypogonadism, as well as testosterone decline in older males, on bone density and fracture risk in men will be summarized. Finally, the therapeutic options and their efficacy in male osteoporosis and hypogonadism will be discussed.

Pituitary-bone connection in skeletal regulation

Pituitary hormones have traditionally been thought to exert specific, but limited function on target tissues. More recently, the discovery of these hormones and their receptors in organs such as the skeleton suggests that pituitary hormones have more ubiquitous functions. Here, we discuss the interaction of growth hormone (GH), follicle stimulating hormone (FSH), thyroid stimulating hormone (TSH), adrenocorticotrophic hormone (ACTH), prolactin, oxytocin and arginine vasopressin (AVP) with bone. The direct skeletal action of pituitary hormones therefore provides new insights and therapeutic opportunities for metabolic bone diseases, prominently osteoporosis.

Beyond Reproduction: Pituitary Hormone Actions on Bone

The long-held belief that pituitary hormones act solely on master targets was first questioned when we documented G protein-coupled receptors for thyroid-stimulating hormone, follicle-stimulating hormone, adrenocorticotrophic hormone, oxytocin, and vasopressin on bone cells. These evolutionarily conserved hormones and their receptors are known to have primitive roles, and exist in invertebrate species as far down as coelenterates. It is not surprising therefore that each such hormone has multiple hitherto unrecognized functions in mammalian integrative physiology, and hence, becomes a potential target for therapeutic intervention. Here we discuss the skeletal actions of pituitary hormones.

Bone Mineral Density in Adolescent Girls with Hypogonadotropic and Hypergonadotropic Hypogonadism

OBJECTIVE

Deficiency of sex steroids has a negative impact on bone mineral content. In studies conducted on postmenopausal women and animal studies, elevated follicle-stimulating hormone (FSH) levels were found to be correlated with a decrease in bone mineralization and osteoporosis. The aim of the present study was to evaluate bone mineral density (BMD) in adolescent girls with hypogonadotropic and hypergonadotropic hypogonadism and also to investigate the correlation between FSH level and BMD.

METHODS

The study group included 33 adolescent girls with hypogonadism (14 with hypogonadotropic hypogonadism and 19 with hypergonadotropic hypogonadism). FSH, luteinizing hormone, estradiol levels, and BMD (using dual energy x-ray absorptiometry) were measured.

RESULTS

There were no statistically significant differences between the chronological age and bone age of the two patient groups, namely, with hypogonadotropic and hypergonadotropic hypogonadism. There was also no significant difference between BMD z-score values obtained from measurements from the spine and the femur neck of patients in the two groups (p-values were 0.841 and 0.281, respectively). In the hypergonadotropic group, a moderately negative correlation was detected between FSH level and BMD z-score measured from the femur neck (ρ=-0.69, p=0.001), whilst no correlation was observed between FSH levels and height adjusted BMD-z scores measured from the spine (ρ=0.17, p=0.493). FSH level was not found to be an independent variable affecting BMD z-score.

CONCLUSION

BMD z-scores were detected to be similar in adolescent girls with hypogonadotropic and hypergonadotropic hypogonadism, and FSH levels were not found to have a clinically relevant impact on BMD.

Correlation between Reproductive Hormonal Level and Osteoporosis among Women in Mongolia

Background

Postmenopausal osteoporosis is the most common bone metabolic disease associated with low bone mineral density (BMD) and osteopathic fragility fractures, which can lead to significant morbidity. The objective of this study was to investigate the relationship between serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) levels and bone mineral density (BMD) across the stages of menopause in Mongolian women.

Methods

Two hundred sixty participants aged 50.1±4.4 years were enrolled in the study. Blood samples were obtained from each participant and analyzed using ELISA. Data were first stratified and analyzed by bone mineral density status (osteoporotic, osteopenic, and normal) and then by menopause status. Between group differences were analyzed using t-tests, and correlations were assessed using the Spearman rank order test, with Bonferonni correction. The data were analyzed using Statistical Package Statistical Software version 20.0 (SPSS Inc., Chicago, IL). Significance was set at p<0.05.

Results

The mean menopausal age was 48.4±3.4, which is comparable to the Mongolian population mean menopausal age. The mean serum estradiol level in the normal BMD group was 18.3±13.1 pg/ml and 15.8±10.7 pg/ml in the osteoporotic group. The mean serum FSH in the normal BMD group was 54.5±44.1 pg/ml and 81.3±34.2 pg/ml in the osteoporotic group. The mean serum LH level in the normal BMD group was 53.1±41.2 and 75.1±26.1 pg/ml in the osteoporotic group. The mean T and Z score were lower in the osteoporotic group. FSH and LH levels significantly differed across menopause stages in that those who were post-menopausal had higher levels compared to those who were pre- or peri-menopausal. Both hormones, FSH and LH, showed weak negative correlations with BMD level, but not E2. There were significant negative correlations between FSH and Speed of Sound (SOS) (r=-0.16; p<0.01), and between osteoporosis with age (r=-0.30, p<0.05) and number of childbirths (r=-0.14 p<0.05).

Discussion

Osteoporosis is a significant problem with associations to hormone levels in post-menopausal women. In our study, mean serum estradiol levels decreased with age, and the mean FSH and LH levels were higher in women of later menopausal stage. Further study is warranted to investigate the bone related studies to establish better statistical references among Mongolian women.

Bone turnover alterations across the menopausal transition in south-eastern Chinese women [corrected]

OBJECTIVES

To explore the serum levels of bone resorption marker C-terminal telopeptide of type I collagen (CTX) and bone formation marker N-amino terminal propeptide of type I collagen (PINP) in Chinese women across the menopausal transition and the correlation between follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol with the bone turnover markers.

METHODS

A cross-sectional study was conducted on 464 healthy Chinese women, separated into pre-, peri- and postmenopausal groups based on their menstruation changes. The serum levels of CTX, PINP, FSH, LH, and estradiol were measured.

RESULTS

The serum levels of CTX and PINP were significantly higher in women in the peri- and postmenopausal groups. The serum levels of FSH were significantly correlated with the serum levels of PINP in premenopausal women. Both serum FSH and LH were positively correlated with serum CTX in perimenopausal women and postmenopausal women. Estradiol was inversely correlated with CTX in the perimenopausal group. Multiple linear regression models show the serum FSH levels were independently related to the bone turnover markers CTX and PINP.

CONCLUSIONS

The elevated serum levels of FSH were independent risk factors for bone loss in peri- and postmenopausal women, and measurement of the serum FSH levels in mid-age women with irregular menses could be used in early diagnosis of postmenopausal osteoporosis.

Follicle-Stimulating Hormone Increases the Risk of Postmenopausal Osteoporosis by Stimulating Osteoclast Differentiation

Objective

The objectives of this study were to observe the changes in follicle-stimulating hormone (FSH) and bone mineral density (BMD) in postmenopausal women, to research the relationship between FSH and postmenopausal osteoporosis, and to observe the effects of FSH on osteoclast differentiation in RAW264.7 cells.

Methods

We analyzed 248 postmenopausal women with normal bone metabolism. A radioimmunoassay (RIA) was used to detect serum FSH, luteinizing hormone (LH), and estradiol (E₂). Dual-energy X-ray absorptiometry was used to measure forearm BMD. Then, we analyzed the age-related changes in serum FSH, LH and E₂. Additionally, FSH serum concentrations were compared between a group of postmenopausal women with osteoporosis and a control group. Osteoclasts were induced from RAW264.7 cells in vitro by receptor activator of nuclear factor kappa B ligand (RANKL), and these cells were treated with 0, 5, 10, and 20 ng/ml FSH. After the osteoclasts matured, tartrate-resistant acid phosphatase (TRAP) staining was used to identify osteoclasts, and the mRNA expression levels of genes involved in osteoclastic phenotypes and function, such as receptor activator of NF-κB (Rank), Trap, matrix metalloproteinase-9 (Mmp-9) and Cathepsin K, were detected in different groups using real-time PCR (polymerase chain reaction).

Results

1. FSH serum concentrations in postmenopausal women with osteoporosis increased notably compared with the control group. 2. RANKL induced RAW264.7 cell differentiation into mature osteoclasts in vitro. 3. FSH increased mRNA expression of genes involved in osteoclastic phenotypes and function, such as Rank, Trap, Mmp-9 and Cathepsin K, in a dose-dependent manner.

Conclusions

The circulating concentration of FSH may play an important role in the acceleration of bone loss in postmenopausal women. FSH increases osteoclastogenesis in vitro.

The impact of serum FSH and estradiol on postmenopausal osteoporosis related to time since menopause

AIM

To determine the impact on osteopenia/osteoporosis of serum follicle-stimulating hormone (FSH), estradiol levels and time since menopause in a group of Turkish postmenopausal women.

METHODS

Four hundred and thirty-three healthy postmenopausal women seen at the Marmara University Menopause Outpatient Clinic were enrolled for this prospective cohort study. The women were allocated to one of three groups according to the bone mineral density (BMD) of the lumbar vertebrae and total hip, as measured by dual energy X-ray absorptiometry (DEXA). Serum FSH, estradiol levels, age and time since menopause were compared between the groups.

RESULTS

The mean serum FSH, LH, estradiol and testosterone levels for women with normal, osteopenic and osteoporotic BMD at lumbar vertrebra L1-L4 and total hip were comparable. Time since menopause had a stronger predictive value for low BMD (osteopenia or osteoporosis) in the lumbar and hip areas than did serum FSH or estradiol levels.

CONCLUSIONS

Our study showed that neither FSH nor E2 has a strong impact on postmenopausal BMD. However it appears that time since menopause has a weak non-significant association with postmenopausal osteopenia and osteoporosis.

Early bone mineral density decrease is associated with FSH and LH, not estrogen

BACKGROUND

It remains unclear whether gonadotropins or estrogen is responsible for early bone mineral density (BMD) decrease in Chinese women.

METHODS

A cross-sectional study was conducted on 368 healthy adult women, aged 35-60 years. We measured BMD, calculated BMD decrease rates (BDRs) and assessed serum follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E(2)) levels.

RESULTS

BDR was significantly negatively correlated with serum FSH (r=-0.429 to -0.622, all p=0.000) and LH (r=-0.359 to -0.526, all p=0.000). After adjustment for age and body mass index, the negative correlations of serum FSH and LH with BDR persisted, but there was no overall correlation between serum E(2) and BDR. Multiple linear stepwise regression analysis suggested that serum FSH is a negative determinant of BDR. Serum E(2) seems to be a positive determinant of BDR in a few parts of the skeleton.

CONCLUSIONS

The decrease of BMD during the menopause is associated with FSH and LH levels, rather than E(2) in Chinese women.

Blocking antibody to the β-subunit of FSH prevents bone loss by inhibiting bone resorption and stimulating bone synthesis

Low estrogen levels undoubtedly underlie menopausal bone thinning. However, rapid and profuse bone loss begins 3 y before the last menstrual period, when serum estrogen is relatively normal. We have shown that the pituitary hormone FSH, the levels of which are high during late perimenopause, directly stimulates bone resorption by osteoclasts. Here, we generated and characterized a polyclonal antibody to a 13-amino-acid-long peptide sequence within the receptor-binding domain of the FSH β-subunit. We show that the FSH antibody binds FSH specifically and blocks its action on osteoclast formation in vitro. When injected into ovariectomized mice, the FSH antibody attenuates bone loss significantly not only by inhibiting bone resorption, but also by stimulating bone formation, a yet uncharacterized action of FSH that we report herein. Mesenchymal cells isolated from mice treated with the FSH antibody show greater osteoblast precursor colony counts, similarly to mesenchymal cells isolated from FSH receptor (FSHR)(-/-) mice. This suggests that FSH negatively regulates osteoblast number. We confirm that this action is mediated by signaling-efficient FSHRs present on mesenchymal stem cells. Overall, the data prompt the future development of an FSH-blocking agent as a means of uncoupling bone formation and bone resorption to a therapeutic advantage in humans.

Role of serum FSH measurement on bone resorption in postmenopausal women

In vitro and animals models have shown follicle-stimulating hormone (FSH) effects on osteoclastic function, and FSH levels seem to influence bone loss independently of estrogen concentrations in humans. Our aim was to evaluate the role of serum FSH measurement in the assessment of bone resorption in postmenopausal women. We conducted a cross-sectional study including 92 postmenopausal healthy women aged 56.2 (3.6) and 7.2 (4) years since menopause. Serum FSH, luteinizing hormone (LH), estradiol (E2) and bone turnover markers as osteocalcin (OC) and C-terminal telopeptide of type I collagen (CTX) were measured. We analyzed the relationship between serum levels of gonadotropins, E2, and bone turnover markers. Serum levels of OC and CTX were positively related to FSH (r = 0.234, P = 0.047 and r = 0.384, P = 0.003) and LH (r = 0.319, P = 0.012 and r = 0.273, P = 0.038). There was no relationship with E2 levels. When gonadotropins levels were divided into quartiles, we found significant differences in bone turnover markers between the first and the fourth quartile. OC levels were higher in the highest quartile of FSH (P = 0.024) and LH (P = 0.001). Serum CTX was also higher in the highest quartile of FSH (P = 0.004) and LH (P = 0.039). FSH levels could explain approximately 14.7% of the chances in CTX. In summary, gonadotropins were related to bone turnover in postmenopausal healthy women. Moreover, the rise in FSH appears to contribute to higher bone resorption. Our results suggest that the measurement of FSH could be usefulness to perform a more comprehensive assessment of bone loss in these women.

Low fatness, reduced fat intake and adequate plasmatic concentrations of LDL-cholesterol are associated with high bone mineral density in women: a cross-sectional study with control group

BACKGROUND

Several parameters are associated with high bone mineral density (BMD), such as overweight, black background, intense physical activity (PA), greater calcium intake and some medications. The objectives are to evaluate the prevalence and the main aspects associated with high BMD in healthy women.

METHODS

After reviewing the database of approximately 21,500 BMD scans performed in the metropolitan area of São Paulo, Brazil, from June 2005 to October 2010, high BMD (over 1400 g/cm² at lumbar spine and/or above 1200 g/cm² at femoral neck) was found in 421 exams. Exclusion criteria were age below 30 or above 60 years, black ethnicity, pregnant or obese women, disease and/or medications known to interfere with bone metabolism. A total of 40 women with high BMD were included and matched with 40 healthy women with normal BMD, paired to weight, age, skin color and menopausal status. Medical history, food intake and PA were assessed through validated questionnaires. Body composition was evaluated through a GE-Lunar DPX MD + bone densitometer. Radiography of the thoracic and lumbar spine was carried out to exclude degenerative alterations or fractures. Biochemical parameters included both lipid and hormonal profiles, along with mineral and bone metabolism. Statistical analysis included parametric and nonparametric tests and linear regression models. P < 0.05 was considered significant.

RESULTS

The mean age was 50.9 (8.3) years. There was no significant difference between groups in relation to PA, smoking, intake of calcium and vitamin D, as well as laboratory tests, except serum C-telopeptide of type I collagen (s-CTX), which was lower in the high BMD group (p = 0.04). In the final model of multivariate regression, a lower fat intake and body fatness as well a better profile of LDL-cholesterol predicted almost 35% of high BMD in women. (adjusted R2 = 0.347; p < 0.001). In addition, greater amounts of lean mass and higher IGF-1 serum concentrations played a protective role, regardless age and weight.

CONCLUSION

Our results demonstrate the potential deleterious effect of lipid metabolism-related components, including fat intake and body fatness and worse lipid profile, on bone mass and metabolism in healthy women.

High bone density and bone health

The aim of this paper is to review the main aspects related to high bone density (HBD) as well as to discuss the physiologic mechanisms involved in bone health. There are still no well-defined criteria for identification of individuals with HBD and there are few studies on the topic. Most studies demonstrate that overweight, male gender, black ethnic background, physical activity, calcium and fluoride intake and use of medications such as statins and thiazide diuretics play a relevant and positive role on bone mineral density. Moreover, it is known that individuals with certain diseases such as obesity, diabetes, estrogen receptor-positive breast or endometrial cancer have greater bone density than healthy individuals, as well as athletes having higher bone density than non-athletes does not necessarily mean that they have healthy bones. A better understanding of risk and protective factors may help in the management of patients with bone frailty and have applicability in the treatment and in the prevention of osteoporosis, especially intervening on non-modifiable risk factors.

Follicle-stimulating hormone and bioavailable estradiol are less important than weight and race in determining bone density in younger postmenopausal women

The association between follicle-stimulating hormone (FSH) and bone density was tested in 111 postmenopausal women aged 50-64 years. In the multivariable analysis, weight and race were important determinants of bone mineral density. FSH, bioavailable estradiol, and other hormonal variables did not show statistically significant associations with bone density at any site.

INTRODUCTION

FSH has been associated with bone density loss in animal models and longitudinal studies of women. Most of these analyses have not considered the effect of weight or race.

METHODS

We tested the association between FSH and bone density in younger postmenopausal women, adjusting for patient-related factors. In 111 postmenopausal women aged 50-64 years, areal bone mineral density (BMD) was measured at the lumbar spine, femoral neck, total hip, and distal radius using dual-energy X-ray absorptiometry, and volumetric BMD was measured at the distal radius using peripheral quantitative computed tomography (pQCT). Height, weight, osteoporosis risk factors, and serum hormonal factors were assessed.

RESULTS

FSH inversely correlated with weight, bioavailable estradiol, areal BMD at the lumbar spine and hip, and volumetric BMD at the ultradistal radius. In the multivariable analysis, no hormonal variable showed a statistically significant association with areal BMD at any site. Weight was independently associated with BMD at all central sites (p < 0.001), but not with BMD or pQCT measures at the distal radius. Race was independently associated with areal BMD at all sites (p ≤ 0.008) and with cortical area at the 33% distal radius (p = 0.004).

CONCLUSIONS

Correlations between FSH and bioavailable estradiol and BMD did not persist after adjustment for weight and race in younger postmenopausal women. Weight and race were more important determinants of bone density and should be included in analyses of hormonal influences on bone.

Oxytocin and bone remodelling: relationships with neuropituitary hormones, bone status and body composition

PURPOSE

There is growing evidence that oxytocin, which regulates appetite, plays a role in bone remodelling and improves osteoporosis. We previously showed a significant decrease in circulating oxytocin levels in postmenopausal osteoporotic women compared to healthy controls. However, factors involved in the pathophysiology of osteoporosis, such as estrogens and leptin, are known to regulate oxytocin secretion. Herein, we evaluated the relationships between oxytocin and other hormonal factors known to regulate bone remodeling and body composition in postmenopausal osteoporotic women, compared to healthy controls.

METHODS

In 20 postmenopausal women with severe osteoporosis compared to 16 healthy controls, we measured serum levels of oxytocin, high sensitive estradiol, testosterone, FSH, LH, SHBG, TSH, osteocalcin, serum type I collagen carboxy-terminal telopeptide, leptin. Bone mineral density and body composition were also measured with DXA.

RESULTS

Osteoporotic women had significantly lower oxytocin, leptin and LH serum levels and higher CTX and SHBG; all other biological parameters were similar in both groups. Fat mass and lean mass were significantly decreased in osteoporotic women. Oxytocin serum levels were significantly correlated to bone mineral density but not to any other measured parameter, including leptin, estradiol and age. In a logistic regression analysis, osteoporosis remained significantly correlated to oxytocin, regardless of age.

CONCLUSIONS

Low oxytocin serum levels appeared to be associated with severe osteoporosis, independently of other factors associated with osteoporosis or known to regulate oxytocin serum levels, such as estradiol or leptin, reinforcing the concept that oxytocin may be involved in the pathophysiology of postmenopausal osteoporosis.

Quantitative trait loci analysis for leg weakness-related traits in a Duroc × Pietrain crossbred population

Background

Leg weakness issues are a great concern for the pig breeding industry, especially with regard to animal welfare. Traits associated with leg weakness are partly influenced by the genetic background of the animals but the genetic basis of these traits is not yet fully understood. The aim of this study was to identify quantitative trait loci (QTL) affecting leg weakness in pigs.

Methods

Three hundred and ten F₂ pigs from a Duroc × Pietrain resource population were genotyped using 82 genetic markers. Front and rear legs and feet scores were based on the standard scoring system. Osteochondrosis lesions were examined histologically at the head and the condylus medialis of the left femur and humerus. Bone mineral density, bone mineral content and bone mineral area were measured in the whole ulna and radius bones using dual energy X-ray absorptiometry. A line-cross model was applied to determine QTL regions associated with leg weakness using the QTL Express software.

Results

Eleven QTL affecting leg weakness were identified on eight autosomes. All QTL reached the 5% chromosome-wide significance level. Three QTL were associated with osteochondrosis on the humerus end, two with the fore feet score and two with the rear leg score. QTL on SSC2 and SSC3 influencing bone mineral content and bone mineral density, respectively, reached the 5% genome-wide significance level.

Conclusions

Our results confirm previous studies and provide information on new QTL associated with leg weakness in pigs. These results contribute towards a better understanding of the genetic background of leg weakness in pigs.

The role of FSH and TSH in bone loss and its clinical relevance

Osteoporosis, a global health problem, is now frequently recognized to be secondary to alterations in the pituitary-bone axis. This review examines the current evidence for how dysregulation of the pituitary-bone axis leads to osteoporotic bone loss. Specifically, perimenopausal bone loss in the context of follicle-stimulating hormone action, and hyperthyroid bone loss in the context of thyroid-stimulating hormone action are explored. From the reviewed scientific findings, recommendations for early diagnosis and better clinical management of bone loss are made.

Commentary-FSH and bone 2010: evolving evidence

Bone loss due to menopause, natural or artificial, has been attributed solely to low estrogen. However, in a woman's life, the most precipitous bone loss begins 2 years prior to the last menstrual period, during which time estrogen levels are unperturbed whereas FSH is elevated. Our cell-based and mouse genetic studies have shown that FSH stimulates bone resorption by osteoclasts directly in a pituitary-bone axis, independently of the estrogen effect. On the basis of this and evolving clinical and scientific evidence, we propose that elevated FSH contributes to bone loss across the menopausal transition, particularly during late perimenopause. In the current issue of the European Journal of Endocrinology, Rendina et al. strengthen the view for a primary role of FSH signaling in the regulation of bone mass and bone remodeling in humans by demonstrating that an 'activating' polymorphism AA rs6166 causes low bone mass and high bone turnover.