FSH and TSH in the regulation of bone mass: the pituitary/immune/bone axis

Association between Serum Oxytocin, Bone Mineral Density and Body Composition in Chinese Adult Females

Background and Objectives: Oxytocin (OT) is a neuropeptide hormone which is known for its classical effects in pregnancy and lactation. Recently, growing evidence demonstrated a close relation between OT and bone. The present study aimed to explore the relationship between OT, bone and osteoporosis risk in Chinese adult females. Materials and Methods: in total, 149 adult females were enrolled. The serum OT levels were measured using ELISA kits. Bone mineral density (BMD) and body composition were measured by dual-energy X-ray absorptiometry (DXA). The study subjects were divided into two groups according to their menopause status and then divided into tertiles based on their serum OT level. Results: Serum OT, serum estradiol and BMD at three skeletal sites were significantly higher in the premenopausal group than in the postmenopausal group (p < 0.001, p = 0.008 and p < 0.001, respectively). In the tertile analysis, relative to tertile 1, significant associations were found for tertile 3 for OT levels and higher BMD in the femoral neck and total hip, in both pre- and postmenopausal groups. Using logistic regression analysis, tertile 3 appeared less likely to have low-BMD osteoporosis than tertile 1 (OR = 0.257, 95% CI = 0.073, 0.910). In multivariate stepwise regression analysis, OT and total lean mass were two positive determinants of BMD in the femoral neck and total hip in the premenopausal group (adjusted R2 for the model = 0.232 and 0.199, respectively; both p < 0.001). Conclusion: Our study demonstrated positive associations between serum OT levels and BMD in a Chinese (non-Caucasian) population. OT appeared to be more strongly associated with hip BMD in premenopausal females. These results may suggest a protective role and potential therapeutic use of OT in osteoporosis, especially for premenopausal women.

Relationship between Oxytocin and Osteoarthritis: Hope or Despair?

Oxytocin (OT) is involved in breastfeeding and childbirth and appears to play a role in regulating the bone matrix. OT is synthesized in the supraoptic and paraventricular nuclei of the hypothalamus and is released in response to numerous stimuli. It also appears to be produced by osteoblasts in the bone marrow, acting as a paracrine–autocrine regulator of bone formation. Osteoarthritis (OA) is a disease of the whole joint. Different tissues involved in OA express OT receptors (OTRs), such as chondrocytes and osteoblasts. This hormone, which levels are reduced in patients with OA, appears to have a stimulatory effect on chondrogenesis. OT involvement in bone biology could occur at both the osteoblast and chondrocyte levels. The relationships between metabolic syndrome, body weight, and OA are well documented, and the possible effects of OT on different parameters of metabolic syndrome, such as diabetes and body weight, are important. In addition, the effects of OT on adipokines and inflammation are also discussed, especially since recent data have shown that low-grade inflammation is also associated with OA. Furthermore, OT also appears to mediate endogenous analgesia in animal and human studies. These observations provide support for the possible interest of OT in OA and its potential therapeutic treatment.

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

CONTEXT

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

OBJECTIVE

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

SETTING, DESIGN, PARTICIPANTS

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

MAIN OUTCOMES

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

RESULTS

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

CONCLUSIONS

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

The Effects of Elaeagnus angustifolia L. on the Thyroid-Stimulating Hormone, Dehydroepiandrosterone-Sulfate, Prolactin and Cortisol Levels in Post-Menopausal Women: A Double-Blind, Randomized, and Placebo-Controlled Study

Menopause is the last menstrual period associated with a decline in ovarian steroid secretion and follicular loss. Hormone profile changes during menopause include a decrease in the production of estrogen, dehydroepiandrosterone (DHEA), and prolactin (PRL), and an increase in thyroid-stimulating hormone (TSH) and cortisol. Herbal medicines are considered as alternatives to hormone therapy. The studies on postmenopausal women have shown that Elaeagnus angustifolia L. (called "Senjed" in Persian) has some efficacy in improving sex hormone and lipid profiles, joint pain, and cardiovascular function, as the decrease in luteinizing hormone, low-density lipoprotein, and heart rate was significant. The aim of the present study was to evaluate the effects of E. angustifolia on TSH, DHEA-S, PRL, and cortisol levels and their ratios in postmenopausal women. It is assumed that the eventual effects of hormones on the brain and other tissues are determined by the balance between interdependent hormones. In the present randomized double-blinded placebo-controlled trial (https://en.irct.ir/search/result?query=IRCT20170227032795N4), fifty-eight postmenopausal women were randomly assigned to one of two medicinal herb (15 g of the whole E. angustifolia fruit powder) and placebo (7.5 g isomalt + 7.5 g cornstarch) groups. After 10 weeks of the treatment, the serum levels of TSH, DHEA-S, PRL, cortisol hormones, and their ratios were measured. The increase in the TSH, and cortisol levels, and cortisol/DHEA-S ratio and the decrease in prolactin and DHEA-S and the PRL/TSH, PRL/cortisol, and DHEA-S/TSH ratios after E. angustifolia consumption were significant only based on within-group but not on the between-group analysis. Based on between-group analyses, the changes in the hormone profile were not significant in the placebo group. According to Iranian tradition and folklore, E. angustifolia fruit is a symbol of female fertility. Therefore, its consumption is highly recommended to maintain health in the elderly, especially women. However, the observed outcomes about the effect of E. angustifolia on menopause were not completely in line with the Iranian folklore. E. angustifolia consumption did not significantly affect the hormone profile and ratios at the end of the ten-week trial, possibly due to the small sample size, short time, and the fact that our participants were postmenopausal women.

Roles of follicle stimulating hormone and its receptor in human metabolic diseases and cancer

Follicle stimulating hormone (FSH) and its receptor (FSHR) play an important role in human metabolic diseases and cancer. Evidence showed that FSHR is not only distributed in ovary and testis but also in other cells or organs such as osteoclast, adipocytes, liver, pituitary cancer and so forth. Moreover, FSH is associated with lipogenesis, inflammation, insulin sensitivity, thermogenesis, skeletal metabolism, osteogenesis and ovarian cancer, all of which have been confirmed closely related to metabolic diseases or metabolic-related cancer. Therefore, FSH and FSHR may be potential therapeutic targets for metabolic diseases and metabolic-related cancer. Epidemiological researches revealed close relationship between FSH/FSHR and metabolic diseases or cancer. Experimental studies elucidated the underlying mechanism both in vivo and in vitro. We reviewed the recent researches and present an integrated framework of FSH/FSHR and metabolic diseases and cancer, which provides potential targets for the treatments of metabolic diseases and cancer.

Evaluation of bone texture imaging parameters on panoramic radiographs of patients with Sheehan's syndrome: a STROBE-compliant case-control study

Sheehan's syndrome (SHS) is a rare condition related to the risk of osteoporosis and evaluation of bone texture imaging features on panoramic radiographs would be suitable for this condition, which was the aim of the present study. Fractal dimension, lacunarity, and trabecular morphologic aspects were significantly altered in these patients.

INTRODUCTION

SHS is an important public health problem particularly in developing countries. It is characterized as postpartum hypopituitarism secondary to obstetric complications-related ischemic pituitary necrosis that shows significant systemic metabolic repercussions. Thus, this study aimed to evaluate bone texture parameters in digital panoramic radiographs of patients with SHS.

METHODS

A case-control study was conducted with 30 SHS patients from an Endocrinology and Diabetology Service of reference in Brazil, and 30 age- and sex-matched healthy controls. A custom computer program measured fractal dimension, lacunarity, and some morphologic features in the following mandibular regions of interest (50 × 50 pixels): below the mental foramen (F1), between the first and second molars (M1), and at the center of the mandibular ramus (R1).

RESULTS

The fractal analysis showed a statistically significant difference between the studied groups in all regions of interest. The fractal dimension in F1 (p = 0.016), M1 (p = 0.043), and R1 (p = 0.028) was significantly lower in SHS group, as well as lacunarity in R1 (p = 0.008). Additionally, several morphologic features were statistically significant in the SHS group (p < 0.05).

CONCLUSION

Therefore, individuals with SHS showed altered imaging texture parameters on panoramic radiographs, which reflect a smaller spatial organization of the bone trabeculae and, possibly, a state of reduced mineral bone density.

Unique Pattern of N-Glycosylation, Sialylation, and Sulfonation on TSH Molecules in Serum of Children Up to 18 Months

CONTEXT

N-glycosylation and glycan composition of human TSH molecules modulate the biological properties of TSH in different physiological and clinical situations. The degree of sialylation of serum TSH was reported to be very low in normal third-trimester fetuses compared with normal adults. The circulating TSH glycoforms and their glycan compositions in young children have hitherto not been determined.

OBJECTIVE

To characterize N-glycosylation and glycan composition of circulating TSH molecules in young children.

DESIGN, PARTICIPANTS, MAIN OUTCOME MEASURES

Serum samples were obtained from euthyroid individuals: 33 children, age 2 weeks to 3 years, and 264 adults. The di-glycosylated TSH and tri-glycosylated TSH glycoforms were determined and characterized with respect to sialylation and sulfonation. The TSH N-glycosylation was also examined in pituitary extracts of 75 individuals.

RESULTS

In children up to 18 months of age, most TSH molecules were low-N-glycosylated, high-sulfonated, and low-sialylated compared with older children and adults. The degree of N-glycosylation was similar in serum and pituitary extracts up to 3 months of age and after that was higher in serum than in pituitary extracts.

CONCLUSIONS

Children up to age 18 months had low-sialylated TSH molecules, similar to those reported for third-trimester fetuses. Most TSH molecules in young children were of smaller size and less negatively charged, favoring transport into their target tissues. The low sialylation favors a high biopotency at thyroid and extrathyroidal TSH receptors. A delayed development of the liver SO3-N-acetylgalactosamine receptor function after birth is a likely explanation of the highly sulfonated TSH molecules in serum samples of infants.

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.

Brain to bone: What is the contribution of the brain to skeletal homeostasis?

The brain, which governs most, if not all, physiological functions in the body, from the complexities of cognition, learning and memory, to the regulation of basal body temperature, heart rate and breathing, has long been known to affect skeletal health. In particular, the hypothalamus - located at the base of the brain in close proximity to the medial eminence, where the blood-brain-barrier is not as tight as in other regions of the brain but rather "leaky", due to fenestrated capillaries - is exposed to a variety of circulating body cues, such as nutrients (glucose, fatty acids, amino acids), and hormones (insulin, glucagon, leptin, adiponectin) [1-3].Information collected from the body via these peripheral cues is integrated by hypothalamic sensing neurons and glial cells [4-7], which express receptors for these nutrients and hormones, transforming these cues into physiological outputs. Interestingly, many of the same molecules, including leptin, adiponectin and insulin, regulate both energy and skeletal homeostasis. Moreover, they act on a common set of hypothalamic nuclei and their residing neurons, activating endocrine and neuronal systems, which ultimately fine-tune the body to new physiological states. This review will focus exclusively on the brain-to-bone pathway, highlighting the most important anatomical sites within the brain, which are known to affect bone, but not covering the input pathways and molecules informing the brain of the energy and bone metabolic status, covered elsewhere [8-10]. The discussion in each section will present side by side the metabolic and bone-related functions of hypothalamic nuclei, in an attempt to answer some of the long-standing questions of whether energy is affected by bone remodeling and homeostasis and vice versa.

MC3T3 infiltration and proliferation in bovine trabecular scaffold regulated by dynamic flow bioreactor and augmented by low-intensity pulsed ultrasound

Background

Low-intensity pulsed ultrasound (LIPUS) has been used in both basic research and clinical settings for its therapeutic potential in promoting tissue healing. Clinical data has shown that LIPUS can accelerate fresh fracture healing. However, the treatment for aging osteoporosis and non-union is still unclear. In addition, the mechanism of ultrasound promoted bone healing has remained unknown.

Objective

It is proposed that noninvasive ultrasound treatment can enhance local fluid flow within the tissue to initiate remodeling and regeneration. The goal of this study was to evaluate the effects of dynamic ultrasound in promoting cellular mechanotransduction within bioengineered organic scaffolds to trigger osteogenesis and mineralization.

Methods

The experiment was designed in two-fold: to evaluate the role of LIPUS on osteoblastic-like (MC3T3) cell proliferation and mineralization in response to acoustic waves, using biomechanical rate-dependent signals in a bioreactor; and, to evaluate the new scaffold experimentation techniques, in order to generate a potential implantable biomaterial for orthopedic tissue regeneration and repair.

Results

LIPUS treatment on MC3T3 cells yielded enhanced cellular mineralization (**p < 0.001) in 3-D scaffolding, but reduced the total cell numbers (*p < 0.05), using Alizarin Red staining and cell counting analyses, respectively, in comparison to the control.

Conclusion

This study suggests that LIPUS, if applied at proper frequency and duty cycle, can promote cell mineralization within the 3-D organic scaffold under in vitro setting. The translational component of this experiment seeks to draw a parallel to the potential pre-treatment of scaffolds for implantation before orthopedic surgery, which could prove to greatly benefit the patient in accelerating fracture healing and tissue regeneration.

The Translational Potential of this Article

LIPUS stimulation was critical in contributing to the mechanical signaling transductions that activated bone enhancement parameters in MC3T3 cells regulated by bioreactor, and thus has potential to change how we pretreat scaffolds for orthopedic surgery and noninvasively accelerate healing in the future, e.g., in an extreme condition such as long-term space mission.

In Vivo and In Vitro Impact of Carbohydrate Variation on Human Follicle-Stimulating Hormone Function

Human follicle-stimulating hormone (FSH) exhibits both macro- and microheterogeneity in its carbohydrate moieties. Macroheterogeneity results in three physiologically relevant FSHβ subunit variants, two that possess a single N-linked glycan at either one of the two βL1 loop glycosylation sites or one with both glycans. Microheterogeneity is characterized by 80 to over 100 unique oligosaccharide structures attached to each of the 3 to 4 occupied N-glycosylation sites. With respect to its receptor, partially glycosylated (hypo-glycosylated) FSH variants exhibit higher association rates, greater apparent affinity, and greater occupancy than fully glycosylated FSH. Higher receptor binding-activity is reflected by greater in vitro bioactivity and, in some cases, greater in vivo bioactivity. Partially glycosylated pituitary FSH shows an age-related decline in abundance that may be associated with decreased fertility. In this review, we describe an integrated approach involving genetic models, in vitro signaling studies, FSH biochemistry, relevance of physiological changes in FSH glycoform abundance, and characterize the impact of FSH macroheterogeneity on fertility and reproductive aging. We will also address the controversy with regard to claims of a direct action of FSH in mediating bone loss especially at the peri- and postmenopausal stages.

Follicle-Stimulating Hormone β-Subunit Potentiates Bone Morphogenetic Protein 9-Induced Osteogenic Differentiation in Mouse Embryonic Fibroblasts

Postmenopausal osteoporosis (PMOP)-related fractures usually result in morbidity and mortality in aging women, so it remains a global public health concern, and new effective safe treatments are urgently needed recently. Efficient osteogenesis from mesenchymal stem cells (MSCs) would have the clinical application potential in treating multiple osteal disorders. Follicle-stimulating hormone (FSH), a pituitary glycoprotein hormone highly associated with menopausal bone turnover, whose peculiar part of receptor binding is follicle-stimulating hormone β-subunit (FSHβ). Bone morphogenetic protein 9 (BMP9), a potent osteogenic factor, can up-regulate FSHβ in mouse embryonic fibroblasts (MEFs). However, it is unclear, whether extrapituitary FSHβ affects BMP9-induced osteogenesis in MEFs. In this study, we investigated the role of FSHβ in BMP9-induced osteogenesis in MEFs. We found that exogenous expression of FSHβ significantly increased BMP9-induced alkaline phosphatase activity (ALP), the expression of osteogenic transcriptional factors, Runx2 and Osx, and the established late osteogenic markers, osteopontin (OPN) and osteocalcin (OCN), so does the ectopic bone formation. Mechanistically, FSHβ dramatically enhanced BMP9-induced BMP/Smad signal transduction, presenting the augment phosphorylation of Smad1/5/8, whereas treatment with anti-FSHβ antibodies suppressed these effects. An adenylate cyclase inhibitor obviously suppressed ALP and BMP/Smad signal transduction induced by BMP9 or the combination of BMP9 and FSHβ in MEFs. Collectively, our findings suggested that FSHβ may promote BMP9-induced activation of BMP/Smad signaling through a FSH/FSH receptor (FSHR)/cAMP dependent pathway in MEFs partly. J. Cell. Biochem. 118: 1792-1802, 2017. © 2016 Wiley Periodicals, Inc.

Bone mineral density is associated with vitamin D related rs6013897 and estrogen receptor polymorphism rs4870044: The Tromsø study

Background

Bone mineral density (BMD) is determined by bone remodeling processes regulated by endocrine, autocrine and genetic mechanisms. Thus, some studies have reported that BMD is associated with single nucleotide polymorphisms (SNPs) associated with vitamin D receptor (VDR), serum 25(OH)D levels and estrogen receptor 1 (ESR1), but without consensus. Therefore, we aimed to map and compare the risk genotypes for forearm and total hip low BMD.

Methods and findings

Data were derived from a population-based study in northern Norway; the Tromsø Study. Distal forearm BMD was measured with a single x-ray absorptiometric device, while total hip BMD was measured with a dual-energy x-ray absorptiometric device. There were 7,317 and 4,082 successful analyses of distal forearm and total hip BMD, respectively, and at least one SNP of interest. We evaluated plausible BMD modulating factors and associations of BMD and SNPs related to vitamin D metabolism (FokI, Cdx2, BsmI, rs2298850, rs10741657, rs3794060, rs6013897), ApaI-BsmI-TaqI haplotypes and ESR1 SNP rs4870044.

Results

Age, BMI, physical activity and smoking were significantly associated with BMD. In a linear regression model with adjustment for age and gender and with the major homozygote as reference, rs6013897 had a standardized beta coefficient (β) of –0.031 (P = 0.024) for total hip BMD. β for ESR1 SNP rs4870044 was –0.016 (P = 0.036) for forearm BMD and –0.034 (P = 0.015) for total hip BMD. The other SNPs nor serum 25(OH)D were significantly associated with BMD.

Conclusions

Both forearm and total hip BMD were associated with ESR1 SNP rs4870044. Of the vitamin D–related genes, only CYP24A1 gene rs6013897 was associated with total hip BMD, but the association was weak and needs confirmation in other studies. Serum 25(OH)D was not associated with BMD in our population, probably due to the generally sufficient vitamin D levels in the population.

Severity and pattern of bone mineral loss in endocrine causes of osteoporosis as compared to age-related bone mineral loss

Background:

Data are scant on bone health in endocrinopathies from India. This study evaluated bone mineral density (BMD) loss in endocrinopathies [Graves’ disease (GD), type 1 diabetes mellitus (T1DM), hypogonadotrophic hypogonadism (HypoH), hypergonadotropic hypogonadism (HyperH), hypopituitarism, primary hyperparathyroidism (PHPT)] as compared to age-related BMD loss [postmenopausal osteoporosis (PMO), andropause].

Materials and Methods:

Retrospective audit of records of patients >30 years age attending a bone clinic from August 2014 to January 2016 was done.

Results:

Five-hundred and seven records were screened, out of which 420 (females:male = 294:126) were analyzed. A significantly higher occurrence of vitamin D deficiency and insufficiency was noted in T1DM (89.09%), HyperH (85%), and HypoH (79.59%) compared to age-related BMD loss (60.02%; P < 0.001). The occurrence of osteoporosis among females and males was 55.41% and 53.97%, respectively, and of osteopenia among females and males was 28.91% and 32.54%, respectively. In females, osteoporosis was significantly higher in T1DM (92%), HyperH (85%), and HypoH (59.26%) compared to PMO (49.34%; P < 0.001). Z score at LS, TF, NOF, and greater trochanter (GT) was consistently lowest in T1DM women. Among men, osteoporosis was significantly higher in T1DM (76.67%) and HypoH (54.55%) compared to andropause (45.45%; P = 0.001). Z score at LS, TF, NOF, GT, and TR was consistently lowest in T1DM men. In GD, the burden of osteoporosis was similar to PMO and andropause. BMD difference among the study groups was not significantly different after adjusting for body mass index (BMI) and vitamin D.

Conclusion:

Low bone mass is extremely common in endocrinopathies, warranting routine screening and intervention. Concomitant vitamin D deficiency compounds the problem. Calcium and vitamin D supplementations may improve bone health in this setting.

Estrogen Receptor β as a Pharmaceutical Target

A major issue in clinical endocrinology today is how to use hormones to achieve the health benefits that they clearly can provide but avoid the negative side effects, that is, how to develop more precise medicines. This problem of how to use hormones is pervasive in clinical endocrinology. It is true for estrogen, progesterone, androgen, vitamin D, and thyroid hormone, and the problem is amplified in the case of new ligands for the more recently discovered nuclear receptors. Selective targeting of hormone receptor subtypes is one attractive way to harness the beneficial effects of hormones while reducing unwanted side effects. Here, we focus on estrogen receptor (ER)β, which has promise as a selective target in hormone replacement therapy, and in breast and prostate cancers.

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.

FSH Levels Predict Bone Loss in Premenopausal Women Treated for Breast Cancer More Than One Year After Treatment

CONTEXT

Biomarkers to predict bone loss in premenopausal women after breast cancer treatment have not been examined.

OBJECTIVE

To determine whether baseline FSH predicts subsequent bone loss.

DESIGN

Secondary data analysis of the Exercise for Bone Health: Young Breast Cancer Survivors study, in which women were randomized to a 12-month exercise program or monthly health newsletter.

SETTING

Community dwelling women.

PARTICIPANTS

A total of 206 women age less than or equal to 55 years at breast cancer diagnosis who had received adjuvant chemotherapy and were at least 1 year after diagnosis.

INTERVENTION

Serum collected at baseline (an average of 302 ± 148 d after completing chemotherapy) was analyzed for FSH.

MAIN OUTCOME MEASURE

Change in bone mineral density.

RESULTS

In linear regression models, baseline FSH levels predicted bone loss over the ensuing 12 months at the lumbar spine and femoral neck including after adjustment for age, ethnicity, treatment group (exercise vs control), baseline bone density, and high-sensitivity C-reactive protein (P < .001). In multiply adjusted models, the 12-month rate of change in bone density was +0.007% in the lowest tertile of FSH (FSH = 9 ± 7 IU/L, mean ± SD), -0.96% in the middle tertile (mean FSH = 41 ± 11 IU/L), and -2.2% in the highest tertile (mean FSH = 86 ± 19 IU/L), P for trend <.001.

CONCLUSIONS

Among premenopausal women with breast cancer treated with chemotherapy, baseline FSH levels are strongly associated with subsequent bone loss. Further studies are needed to establish the optimal timing of FSH measurement in relation to breast cancer treatment and to investigate potential strategies to prevent bone loss.

The Ames dwarf mutation attenuates Alzheimer's disease phenotype of APP/PS1 mice

APP/PS1 double transgenic mice expressing human mutant amyloid precursor protein (APP) and presenilin-1 (PS1) demonstrate robust brain amyloid beta (Aβ) peptide containing plaque deposition, increased markers of oxidative stress, behavioral dysfunction, and proinflammatory gliosis. On the other hand, lack of growth hormone, prolactin, and thyroid-stimulating hormone due to a recessive mutation in the Prop 1 gene (Prop1df) in Ames dwarf mice results in a phenotype characterized by potentiated antioxidant mechanisms, improved learning and memory, and significantly increased longevity in homozygous mice. Based on this, we hypothesized that a similar hormone deficiency might attenuate disease changes in the brains of APP/PS1 mice. To test this idea, APP/PS1 mice were crossed to the Ames dwarf mouse line. APP/PS1, wild-type, df/+, df/df, df/+/APP/PS1, and df/df/APP/PS1 mice were compared at 6 months of age through behavioral testing and assessing amyloid burden, reactive gliosis, and brain cytokine levels. df/df mice demonstrated lower brain growth hormone and insulin-like growth factor 1 concentrations. This correlated with decreased astrogliosis and microgliosis in the df/df/APP/PS1 mice and, surprisingly, reduced Aβ plaque deposition and Aβ 1-40 and Aβ 1-42 concentrations. The df/df/APP/PS1 mice also demonstrated significantly elevated brain levels of multiple cytokines in spite of the attenuated gliosis. These data indicate that the df/df/APP/PS1 line is a unique resource in which to study aging and resistance to disease and suggest that the affected pituitary hormones may have a role in regulating disease progression.

Bone Mineral Status in Children and Adolescents with Klinefelter Syndrome

Objective. Klinefelter syndrome (KS) has long-term consequences on bone health. However, studies regarding bone status and metabolism during childhood and adolescence are very rare. Patients. This cross-sectional study involved 40 (mean age: 13.7 ± 3.8 years) KS children and adolescents and 80 age-matched healthy subjects. For both patient and control groups, we evaluated serum levels of ionised and total calcium, phosphate, total testosterone, luteinising hormone, follicle stimulating hormone, parathyroid hormone (PTH), 25-hydroxyvitamin D (25(OH)D), 1,25-dihydroxyvitamin D, osteocalcin, bone alkaline phosphatase, and urinary deoxypyridinoline concentrations. We also calculated the z-scores of the phalangeal amplitude-dependent speed of sound (AD-SoS) and the bone transmission time (BTT). Results. KS children and adolescents showed significantly reduced AD-SoS (p < 0.005) and BTT (p < 0.0005) z-scores compared to the controls. However, KS patients presented significantly higher PTH (p < 0.0001) and significantly lower 25(OH)D (p < 0.0001), osteocalcin (p < 0.05), and bone alkaline phosphatase levels (p < 0.005). Interestingly, these metabolic bone disorders were already present in the prepubertal subjects. Conclusions. KS children and adolescents exhibited impaired bone mineral status and metabolism with higher PTH levels and a significant reduction of 25-OH-D and bone formation markers. Interestingly, this impairment was already evident in prepubertal KS patients. Follow-ups should be scheduled with KS patients to investigate and ameliorate bone mineral status and metabolism until the prepubertal ages.

Bone Fragility in Turner Syndrome: Mechanisms and Prevention Strategies

Bone fragility is recognized as one of the major comorbidities in Turner syndrome (TS). The mechanisms underlying bone impairment in affected patients are not clearly elucidated, but estrogen deficiency and X-chromosomal abnormalities represent important factors. Moreover, although many girls with TS undergo recombinant growth hormone therapy to treat short stature, the efficacy of this treatment on bone mineral density is controversial. The present review will focus on bone fragility in subjects with TS, providing an overview on the pathogenic mechanisms and some prevention strategies.

The associations of bedtime, nocturnal, and daytime sleep duration with bone mineral density in pre- and post-menopausal women

To explore the association of sleep patterns with bone mineral density (BMD) in pre- and post-menopausal women, we used a questionnaire to evaluate the sleep patterns and performed calcaneal quantitative ultrasound to estimate BMD, in 6,510 women aged 40 years or older, from June to November 2011 in Nanjing City. We found a 1.7-fold risk of osteoporosis in post-menopausalwomen with bedtime of ≥0:00 am (OR = 1.69, 95 % CI 1.39-2.13), compared to those whose bedtime of <0:00 am. post-menopausalwomen with excessive total sleep (>10 h vs. 8-9 h, OR = 1.54, 95 % CI 1.05-2.02) were shown to have a higher risk of osteoporosis, however, this high risk was not detected in those with excessive nocturnal sleep (>10 h vs. 8-9 h, OR = 0.85, 95 % CI 0.62-1.30). By contrast, post-menopausalwomen with inadequate nocturnal sleep (≤7 h vs. 8-9 h, OR = 1.68, 95 % CI 1.32-2.75), excessive daytime sleep (≥180 min vs. 0 min, OR = 1.52, 95 % CI 1.08-2.13), and noontime nap (>60 min vs. 0 min: OR = 1.37, 95 % CI 1.06-1.76) were demonstrated to have higher risk of bone loss. Nevertheless, these associations were not found in premenopausal women. We conclude that delayed bedtime, nocturnal sleep deprivation, excessive daytime sleep, and noontime nap, but not reduced total sleep duration, could promote bone loss in post-menopausalwomen, which might be related to circadian rhythm disturbances. However, they have limited influences to BMD in women who were still in menstruating. Mechanism responsible for the phenomena warrants further investigation.

Osteoporosis in pituitary diseases: lessons for the clinic

Osteoporosis is a systemic disease characterized by bone mass and density loss leading to fragility fractures. Osteoporosis due to endocrine disorders is an example of secondary osteoporosis. The harmful effects on bones are common in patients harboring pituitary tumors (acromegaly, prolactinoma, Cushing's disease) and suffering from hypopituitarism. Increased fracture risk and high healthcare costs of fractured patients are their consequences. The coexistence of some of these disorders and hypogonadism results in severe osteoporosis. The influence of the certain diseases, their activity and therapy and accompanying hypogonadism on bone turnover, bone mineral density and fracture incidence is presented.

Conditional disruption of miR17-92 cluster in collagen type I-producing osteoblasts results in reduced periosteal bone formation and bone anabolic response to exercise

In this study, we evaluated the role of the microRNA (miR)17-92 cluster in osteoblast lineage cells using a Cre-loxP approach in which Cre expression is driven by the entire regulatory region of the type I collagen α2 gene. Conditional knockout (cKO) mice showed a 13-34% reduction in total body bone mineral content and area with little or no change in bone mineral density (BMD) by DXA at 2, 4, and 8 wk in both sexes. Micro-CT analyses of the femur revealed an 8% reduction in length and 25-27% reduction in total volume at the diaphyseal and metaphyseal sites. Neither cortical nor trabecular volumetric BMD was different in the cKO mice. Bone strength (maximum load) was reduced by 10% with no change in bone toughness. Quantitative histomorphometric analyses revealed a 28% reduction in the periosteal bone formation rate and in the mineral apposition rate but with no change in the resorbing surface. Expression levels of periostin, Elk3, Runx2 genes that are targeted by miRs from the cluster were decreased by 25-30% in the bones of cKO mice. To determine the contribution of the miR17-92 cluster to the mechanical strain effect on periosteal bone formation, we subjected cKO and control mice to 2 wk of mechanical loading by four-point bending. We found that the periosteal bone response to mechanical strain was significantly reduced in the cKO mice. We conclude that the miR17-92 cluster expressed in type I collagen-producing cells is a key regulator of periosteal bone formation in mice.

Oxytocin and bone

One of the most meaningful results recently achieved in bone research has been to reveal that the pituitary hormones have profound effect on bone, so that the pituitary-bone axis has become one of the major topics in skeletal physiology. Here, we discuss the relevant evidence about the posterior pituitary hormone oxytocin (OT), previously thought to exclusively regulate parturition and breastfeeding, which has recently been established to directly regulate bone mass. Both osteoblasts and osteoclasts express OT receptors (OTR), whose stimulation enhances bone mass. Consistent with this, mice deficient in OT or OTR display profoundly impaired bone formation. In contrast, bone resorption remains unaffected in OT deficiency because, even while OT stimulates the genesis of osteoclasts, it inhibits their resorptive function. Furthermore, in addition to its origin from the pituitary, OT is also produced by bone marrow osteoblasts acting as paracrine-autocrine regulator of bone formation modulated by estrogens. In turn, the power of estrogen to increase bone mass is OTR-dependent. Therefore, OTR(-/-) mice injected with 17β-estradiol do not show any effects on bone formation parameters, while the same treatment increases bone mass in wild-type mice. These findings together provide evidence for an anabolic action of OT in regulating bone mass and suggest that bone marrow OT may enhance the bone-forming action of estrogen through an autocrine circuit. This established new physiological role for OT in the maintenance of skeletal integrity further suggests the potential use of this hormone for the treatment of osteoporosis.