Endogenous sex steroids and bone mineral density in older women and men: the Rancho Bernardo Study

Nutraceuticals and Functional Foods: A Comprehensive Review of Their Role in Bone Health

Bone health is the result of a tightly regulated balance between bone modeling and bone remodeling, and alterations of these processes have been observed in several diseases both in adult and pediatric populations. The imbalance in bone remodeling can ultimately lead to osteoporosis, which is most often associated with aging, but contributing factors can already act during the developmental age, when over a third of bone mass is accumulated. The maintenance of an adequate bone mass is influenced by genetic and environmental factors, such as physical activity and diet, and particularly by an adequate intake of calcium and vitamin D. In addition, it has been claimed that the integration of specific nutraceuticals such as resveratrol, anthocyanins, isoflavones, lycopene, curcumin, lutein, and β-carotene and the intake of bioactive compounds from the diet such as honey, tea, dried plums, blueberry, and olive oil can be efficient strategies for bone loss prevention. Nutraceuticals and functional foods are largely used to provide medical or health benefits, but there is an urge to determine which products have adequate clinical evidence and a strong safety profile. The aim of this review is to explore the scientific and clinical evidence of the positive role of nutraceuticals and functional food in bone health, focusing both on molecular mechanisms and on real-world studies.

Sex-specific association of serum dehydroepiandrosterone and its sulfate levels with osteoporosis in type 2 diabetes

INTRODUCTION

This study is to investigate the relation between serum dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) levels and the risk of osteoporosis in patients with T2DM.

MATERIALS AND METHODS

This cross-sectional study involved 938 hospitalized patients with T2DM. Linear regression models were used to explore the relationship between DHEA and DHEAS and the BMD at different skeletal sites. Multinominal logistic regression models and the restricted cubic spline (RCS) were used to evaluate the associations of DHEA and DHEAS with the risks of osteopenia and/or osteoporosis.

RESULTS

In postmenopausal women with T2DM, after adjustment for confounders including testosterone and estradiol, DHEA showed a significant positive correlation with lumbar spine BMD (P = 0.013). Moreover, DHEAS exhibited significant positive correlations with BMD at three skeletal sites: including femoral neck, total hip, and lumbar spine (all P < 0.05). Low DHEA and DHEAS levels were associated with increased risk of osteopenia and/or osteoporosis (all P < 0.05) and the risk of osteoporosis gradually decreased with increasing DHEAS levels (P overall = 0.018, P-nonlinear = 0.559). However, DHEA and DHEAS levels in men over the age of 50 with T2DM were not associated with any of above outcomes.

CONCLUSION

In patients with T2DM, independent of testosterone and estradiol, higher DHEA and DHEAS levels are associated with higher BMD and lower risk of osteopenia/osteoporosis in postmenopausal women but not men over the age of 50.

Steroid hormone levels in postmenopausal hysterectomised women with and without ovarian conservation: the continuous endocrine function of the ovaries

This study aims to clarify the effect of postmenopausal bilateral oophorectomy on plasma steroid hormone levels. Women who were submitted in the postmenopausal period to hysterectomy for uterine benign conditions were divided into two groups: 18 women had isolated hysterectomy and 11 had hysterectomy with bilateral salpingo-oophorectomy. In both groups serum hormone levels were quantified by solid phase extraction and gas chromatography and tandem mass spectrometry. Differences in dehydroepiandrosterone (DHEA), testosterone, androstenedione and oestradiol were determined in both groups. The analysis revealed lower steroid levels in the bilateral salpingo-oophorectomy group when compared to the isolated hysterectomy group with statistically significant differences found for DHEA (5.8 ± 3.2 vs. 9.4 ± 4.4 ng/mL; p = 0.019) and oestradiol (0.69 ± 0.4 vs. 1.48 ± 4.3 ng/mL; p = 0.007). The results are consistent with a significant endocrine activity of the postmenopausal ovary. The clinical consequences of these findings need to be clarified and postmenopausal prophylactic bilateral salpingo-oophorectomy re-evaluated.IMPACT STATEMENTWhat is already known on this subject? Although it is consensual that premenopausal prophylactic bilateral oophorectomy should not be performed because it has harmful effects on women's health, the evidence regarding the effects of postmenopausal prophylactic bilateral oophorectomy is scarce and this procedure continues to be a regular practice. Few studies have demonstrated that postmenopausal ovaries still have endocrine activity that may impact older women's health.What do the results of this study add? This is the first study to compare hormone levels of postmenopausal women based on their hysterectomy and oophorectomy status using GC-MS/MS, a highly sensitive bioanalytical assay for the measurement of steroid hormones. Previous studies relied on immunoassays and did not compare DHEA levels, which according to the intracrinology theory is a precursor for androgens and oestrogens. In this study, statistically significant lower levels of DHEA and oestradiol were found after postmenopausal bilateral salpingo-oophorectomy.What are the implications of these findings for clinical practice and/or further research? This is a pilot study that may lead to further investigation in this area to clarify the impact of the prophylactic removal of postmenopausal ovaries on older women's health and lead to changes in surgical procedures.

Changes of androgen and corticosterone metabolites excretion and conversion in cystic fibrosis

Cystic fibrosis (CF) is a life-threatening inherited disease related to a mutation in the CFTR gene, that leads to serious health complications such as chronic pulmonary infections, pancreatic insufficiency, dysfunction of the sweat glands and reproductive system. For the first time, we have described the profile of corticosterone and androgen metabolites in urine, as well as the activity of enzymes involved in steroid genesis and metabolism in people with CF, using gas chromatography/mass spectrometry. A significant reduction in the excretion of most of the measured metabolites in CF was found. These differences were observed in the group of progestagen metabolites, as well as among metabolites of corticosterone and androgens. We revealed higher activities of 17β-hydroxysteroid dehydrogenase and 17,20-lyase in the Δ4 pathway compared with controls, what can promote the androgen synthesis through the backdoor androgen pathway. We have also found the increased conversion activity of 11-oxyganated steroids by 5a-reductase in backdoor pathway. Levels of the most potent and vital androgens (testosterone and dihydrotestosterone) are comparable in both groups. However, the excretion of dehydroepiandrosterone was lower in CF. Decreased cholesterol lipoprotein levels may contribute to limited intracellular cholesterol supply and reduced adrenal steroidogenesis in CF individuals. Changes in the activity of some steroidogenesis enzymes may suggest the presence of some peripheral adaptive mechanisms in CF to maintain androgen balance in the body despite the limited sufficiency of secretion by the adrenal cortex.

Male Reproduction and Aging

Recent publications of well-conducted population studies have informed us that the syndromic prevalence of age-related low testosterone, also known as late-onset hypogonadism, is quite low. Several well-conducted trials in middle-aged and older men with age-related decline in testosterone levels have revealed that efficacy of testosterone therapy is modest with improvement in sexual function, mood, volumetric bone density, and anemia. Although select older men might benefit from testosterone therapy, its effect on prostate cancer risk and major adverse cardiovascular events remains unclear. The results of the ongoing TRAVERSE trial will likely provide important insights into these risks.

Steroid hormone levels and bone mineral density in women over 65 years of age

Previous studies using immunoassays for steroid measurements have focused on the association between steroid hormone levels and bone mineral density (BMD) in postmenopausal women, obtaining contradictory results. This study aimed to assess this association using a highly sensitive bioanalytical method. A total of 68 postmenopausal women, aged 65-89 years, were enrolled in a cross-sectional study. Measurements of the BMD of the hip and lumbar spine were performed using dual energy X-ray absorptiometry, and serum hormone levels were quantified by gas chromatography and tandem mass spectrometry. Associations between estradiol (E2), testosterone, dehydroepiandrosterone (DHEA), androstenedione and T score levels of the hip and lumbar spine were evaluated, after adjustment for confounding variables. The analysis revealed a statistically significant association between testosterone and the T score of the hip (p = 0.035), but not that of the lumbar spine. No statistically significant associations were found between E2, DHEA, androstenedione and the T scores of the hip and the lumbar spine. Using a highly sensitive hormone assay method, our study identified a significant association between testosterone and BMD of the hip in women over 65 years of age, suggesting that lower testosterone increases the risk of osteoporosis.

Bioavailability of calcium in an enriched postbiotic system compared to calcium citrate in healthy postmenopausal females; A randomized, double-blind, comparator-controlled, crossover study

Introduction

Bioavailability of calcium is an important consideration when designing supplements for achieving adequate calcium intake, mainly in high-risk, and aged populations. Alternative supplementation strategies may be able to circumvent absorption issues commonly seen with calcium supplements. The objective of this study was to assess the bioavailability of a single serving of two calcium formulations vs. comparator product in healthy postmenopausal women.

Methods

A total of 24 participants between 45 and 65 years were enrolled in a randomized, double-blind, three-phase, crossover study, with a 7-day washout period between phases. The bioavailability of calcium from calcium-carrying Saccharomyces cerevisiae (Ca-SC) or calcium-carrying Lactobacillus (Ca-LAB) in the form of postbiotic products versus calcium citrate, a conventional salt-based calcium supplement, was determined. Each product provided 630 mg of calcium and 400 IU of vitamin D3. After a 14-h (overnight) fast followed by a single dose of product with a standard low-calcium breakfast, both serum and urine calcium concentrations were assessed for up to 8 and 24 h, respectively.

Results

Ca-LAB resulted in greater calcium bioavailability, demonstrated by significantly higher area under the curve and peak concentration both in blood and urine, and total calcium mass excreted in urine. The bioavailability of calcium was similar for Ca-SC and calcium citrate except for the peak concentration value that was significantly higher for calcium citrate. Both Ca-LAB and Ca-SC were well tolerated with no significant difference in adverse events between the products during the study.

Discussion

These findings suggest that calcium enriched in a Lactobacillus-based postbiotic system is associated with higher levels of bioavailability as compared to calcium citrate, while a calcium-enriched yeast-based postbiotic does not influence calcium absorption.

Bone quality in endocrine diseases: determinants and clinical relevance

PURPOSE

Bone is one of the main targets of hormones and endocrine diseases are frequent causes of secondary osteoporosis and fractures in real-world clinical practice. However, diagnosis of skeletal fragility and prediction of fractures in this setting could be a challenge, since the skeletal alterations induced by endocrine disorders are not generally captured by dual-energy X-ray absorptiometry (DXA) measurement of bone mineral density (BMD), that is the gold standard for diagnosis of osteoporosis in the general population. The aim of this paper is to review the existing evidence related to bone quality features in endocrine diseases, proposing assessment with new techniques in the future.

METHODS

A comprehensive search within electronic databases was performed to collect reports of bone quality in primary hyperparathyroidism, hypoparathyroidism, hyperthyroidism, hypercortisolism, growth hormone deficiency, acromegaly, male hypogonadism and diabetes mellitus.

RESULTS

Using invasive and non-invasive techniques, such as high-resolution peripheral quantitative computed tomography or DXA measurement of trabecular bone score (TBS), several studies consistently reported altered bone quality as predominant determinant of fragility fractures in subjects affected by chronic endocrine disorders.

CONCLUSIONS

Assessment of skeletal fragility in endocrine diseases might take advantage from the use of techniques to detect perturbation in bone architecture with the aim of best identifying patients at high risk of fractures.

Associations of per- and polyfluoroalkyl substances and their alternatives with bone mineral density levels and osteoporosis prevalence: A community-based population study in Guangzhou, Southern China

BACKGROUND

Evidence concerning associations of per- and polyfluoroalkyl substances (PFASs) exposure with bone mineral density (BMD) and osteoporosis is scarce. Additionally, no study has examined the effects of PFAS isomers and alternatives on bone health.

OBJECTIVES

To evaluate the associations of PFASs and PFAS alternatives with BMD levels and osteoporosis prevalence.

METHODS

A total of 1260 healthy adults from southern China were enrolled. Serum concentrations of 32 legacy PFASs, PFAS isomers, and alternatives were measured using modified liquid chromatography-tandem mass spectrometry. Logistic and linear regression models were applied to evaluate the associations of PFASs with osteoporosis prevalence and BMD levels, respectively, adjusting for confounding factors. We performed stratified analyses to assess potential effect modifications of age and sex. We further used sensitivity analyses to testify the robustness of the main findings.

RESULTS

There were 204 (16.2 %) participants diagnosed with osteoporosis. Eleven of the studied PFASs (i.e., PFHpA, PFOA, PFBS, PFHpS, total-PFHxS, n-PFHxS, br-PFHxS, br-PFOS, 1m-PFOS, Σ3 + 4 + 5m-PFOS, and 6:2 Cl-PFESA) showed significant and inverse associations with BMD levels (mean differences ranged from -6.47 to -26.07 per one ln-unit increase in the PFASs). Additionally, we observed that each one ln-unit increase in PFHpA was significantly associated a 23 % (OR = 1.23, 95 % CI = 1.04, 1.45) greater odds of osteoporosis. The above associations were consistent in several sensitivity analyses we performed. Stratified analyses showed stronger associations among women and younger compared to their counterparts.

CONCLUSIONS

Our findings suggested that greater PFAS exposure is associated with poorer bone health, especially in women and younger people.

Aging and Bone Metabolism

Changes in bone architecture and metabolism with aging increase the likelihood of osteoporosis and fracture. Age-onset osteoporosis is multifactorial, with contributory extrinsic and intrinsic factors including certain medical problems, specific prescription drugs, estrogen loss, secondary hyperparathyroidism, microenvironmental and cellular alterations in bone tissue, and mechanical unloading or immobilization. At the histological level, there are changes in trabecular and cortical bone as well as marrow cellularity, lineage switching of mesenchymal stem cells to an adipogenic fate, inadequate transduction of signals during skeletal loading, and predisposition toward senescent cell accumulation with production of a senescence-associated secretory phenotype. Cumulatively, these changes result in bone remodeling abnormalities that over time cause net bone loss typically seen in older adults. Age-related osteoporosis is a geriatric syndrome due to the multiple etiologies that converge upon the skeleton to produce the ultimate phenotypic changes that manifest as bone fragility. Bone tissue is dynamic but with tendencies toward poor osteoblastic bone formation and relative osteoclastic bone resorption with aging. Interactions with other aging physiologic systems, such as muscle, may also confer detrimental effects on the aging skeleton. Conversely, individuals who maintain their BMD experience a lower risk of fractures, disability, and mortality, suggesting that this phenotype may be a marker of successful aging. © 2023 American Physiological Society. Compr Physiol 13:4355-4386, 2023.

Bone health in ageing men

Osteoporosis does not only affect postmenopausal women, but also ageing men. The burden of disease is projected to increase with higher life expectancy both in females and males. Importantly, osteoporotic men remain more often undiagnosed and untreated compared to women. Sex steroid deficiency is associated with bone loss and increased fracture risk, and circulating sex steroid levels have been shown to be associated both with bone mineral density and fracture risk in elderly men. However, in contrast to postmenopausal osteoporosis, the contribution of relatively small decrease of circulating sex steroid concentrations in the ageing male to the development of osteoporosis and related fractures, is probably only minor. In this review we provide several clinical and preclinical arguments in favor of a 'bone threshold' for occurrence of hypogonadal osteoporosis, corresponding to a grade of sex steroid deficiency that in general will not occur in many elderly men. Testosterone replacement therapy has been shown to increase bone mineral density in men, however data in osteoporotic ageing males are scarce, and evidence on fracture risk reduction is lacking. We conclude that testosterone replacement therapy should not be used as a sole bone-specific treatment in osteoporotic elderly men.

Association between testosterone levels and bone mineral density in females aged 40-60 years from NHANES 2011-2016

Growing evidence indicates that testosterone is a conspicuous marker for assessing male bone mineral density (BMD). However, research regarding testosterone levels and BMD is sparse and controversial for females. Hence, we aimed to investigate the association between testosterone levels and BMD among adult females aged 40–60 years in the United States. In this cross-sectional study, all participants were part of the National Health and Nutrition Examination Survey (2011–2016). A weighted general linear model was used to estimate the association between testosterone levels and lumbar BMD. Age, race, income level, education level, body mass index (BMI), blood urea nitrogen (BUN) level, serum uric acid (UA) level, serum calcium (Ca) level, serum phosphorus (P) level, the use of oral contraceptive pills, the use of hormone replacement therapy (HRT), smoking status, drinking status, and the use of corticosteroids were adjusted using a weighted multiple regression model. Subgroup analyses were performed using the same regression model. We included 2198 female participants in the study, and testosterone levels were positively associated with lumbar BMD after adjusting for all the covariates (β = 1.12, 95% CI 0.31, 1.93). In subgroup analyses, the associations in the fourth quartile of testosterone levels were stronger for the participants aged 40–50 years old (quartile 4, β = 42.92, 95% CI 7.53, 78.30 vs. quartile 1) and 50 to 60-year-old (quartile 4, β = 32.41, 95% CI 0.14, 64.69 vs. quartile 1). Similar results were found in other subgroups, including subgroups for race (Non-Hispanic Black, Other), income level (income ≤ 1.3, income > 3.5), education level (college or higher), BMI > 25 kg/m², BUN levels ≤ 20 mg/dL, UA levels ≤ 6 mg/dL, Ca levels ≤ 10.1 mg/dL, P levels ≤ 5 mg/dL, drinking status, never smoker, never taking birth control pills, and HRT user. There was no interaction among the covariates in the association between lumbar BMD and testosterone levels (P for interaction > 0.05). In US adult females aged 40–60 years, the testosterone level was a positive predictor of the lumbar BMD after adjusting for covariates.

Testosterone supplementation and bone parameters: a systematic review and meta-analysis study

BACKGROUND

The role of testosterone (T) replacement therapy (TRT) in subjects with late onset hypogonadism is still the object of an intense debate.

METHODS

All observational studies and placebo-controlled or -uncontrolled randomized trials (RCTs) comparing the effect of TRT on different bone parameters were considered.

RESULTS

Out of 349 articles, 36 were considered, including 3103 individuals with a mean trial duration of 66.6 weeks. TRT improves areal bone mineral density (aBMD) at the spine and femoral neck levels in observational studies, whereas placebo-controlled RTCs showed a positive effect of TRT only at lumber spine and when trials included only hypogonadal patients at baseline (total testosterone < 12 nM). The effects on aBMD were more evident in subjects with lower T levels at baseline and increased as a function of trial duration and a higher prevalence of diabetic subjects. Either T or estradiol increase at endpoint contributed to aBMD improvement. TRT was associated with a significant reduction of bone resorption markers in observational but not in controlled studies.

CONCLUSION

TRT is able to inhibit bone resorption and increase bone mass, particularly at the lumbar spine level and when the duration is long enough to allow the anabolic effect of T and estrogens on bone metabolism to take place.

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.

Osteoporosis in men

Osteoporosis in men is a common but often overlooked disorder by clinicians. The criterion for osteoporosis diagnosis in men is similar to that in women-namely, a bone mineral density (BMD) that is 2·5 standard deviations or more below the mean for the young adult population (aged 20-29 years; T-score -2·5 or lower), measured at the hip or lumbar spine. Sex steroids are important for bone health in men and, as in women, oestrogens have a key role. Most men generally have bigger and stronger bones than women and typically have less bone loss during their lifetime. Men typically fracture less often than women, although they have a higher mortality rate after a fracture. Secondary osteoporosis is more common in men than in women. Lifestyle changes, adequate calcium, vitamin D intake, and exercise programmes are recommended for the management of osteoporosis in men. Bisphosphonates, denosumab, and teriparatide have been shown to increase BMD and are used for pharmacological treatment. In this Review, we report an updated overview of osteoporosis in men, describe new treatments and concepts, and discuss persistent controversies in the area.

Role of sex steroids hormones in the regulation of bone metabolism in men: Evidence from clinical studies

Sex steroids regulate bone metabolism in young men during growth and consolidation. Their deficit during growth compromises longitudinal and radial growth of bones and has a negative impact on body height, bone width, peak areal bone mineral density (aBMD) and bone microarchitecture. In older men, the deficit of sex steroid hormones (mainly 17β-oestradiol) contributes to high bone turnover rate, low aBMD, poor bone microarchitecture, low estimated bone strength, accelerated bone loss and rapid decline of bone microarchitecture. The role of 17β-oestradiol is confirmed by the case of men with congenital oestrogen receptor deficit and with congenital aromatase deficiency. 17β-oestradiol inhibits bone resoption, whereas both hormones regulate bone formation. However, the associations are weak. Prospective data on the utility of blood 17β-oestradiol or testosterone for fracture risk assessment are inconsistent. Men with hypogonadism have decreased aBMD and poor bone microarchitecture. In men with hypogonadism, testosterone replacement therapy increases aBMD and improves bone microarchitecture. In men with prostate cancer, androgen deprivation therapy (gonadoliberin analogues) induces rapid bone loss and severe deterioration of bone microarchitecture.

Peripheral bone structure, geometry, and strength and muscle density as derived from peripheral quantitative computed tomography and mortality among rural south Indian older adults

Multiple studies have observed a relationship of bone mineral density (BMD) measured by Dual energy X-ray absorptiometry (DXA) and mortality. However, areal BMD (aBMD) measured by DXA is an integrated measure of trabecular and cortical bone and does not measure the geometry of bone. Peripheral Quantitative Computed Tomography (pQCT) provides greater insights on bone structure, geometry and strength. To examine whether higher bone phenotypes and muscle density as measured by pQCT are associated with a lower all-cause mortality, we studied 245 men and 254 women (all age >60) recruited in the Mobility and Independent Living among Elders Study in rural south India. Cox proportional hazards models estimated hazard ratios (HR [95% Confidence Intervals]). After an average follow-up of 5.3 years, 73 men and 50 women died. Among men, trabecular volumetric bone mineral density (vBMD) of radius (HR per SD increase in parameter = 0.59 [0.43, 0.81]) and tibia (0.60[0.45, 0.81]), cortical vBMD of radius (0.61, [0.47, 0.79]) and tibia (0.62, [0.49, 0.79]), cortical thickness of radius (0.55, [0.42, 0.7]) and tibia (0.60, [0.47, 0.77]), polar strength strain index (SSIp) of tibia (0.73 [0.54, 0.98]), endosteal circumference of radius (1.63, [1.25, 2.12]) and tibia (1.54, [1.19, 1.98]) were associated with all-cause mortality. Muscle density (0.67, [0.51, 0.87]) was associated with lower mortality in men. Among women cortical vBMD of radius (0.64, [0.47, 0.87]) and tibia (0.60 [0.45, 0.79]), cortical thickness of radius (0.54, [0.37, 0.79]) and tibia (0.43, [0.30, 0.61]), SSIp of radius (0.70 [0.48,1.01]) and tibia (0.58 [0.37, 0.90]) and endosteal circumference of radius (1.33 [0.97, 1.82]) and tibia (1.83, [1.37, 2.45]) were associated with all-cause mortality. Among men, gait speed mediated the association of muscle density and mortality but there was no mediation for any bone parameters. Conclusion: pQCT bone measures and muscle density were independently associated with mortality among rural south Indian elders.

Protective Role of DHEAS in Age-related Changes in Bone Mass and Fracture Risk

PURPOSE

Dehydroepiandrosterone sulfate (DHEAS) from the adrenal cortex substantially decreases with age, which may accelerate osteoporosis. However, the association of DHEAS with bone mineral density (BMD) and fracture is inconclusive. We conducted a Mendelian randomization (MR) analysis to investigate the role of DHEAS in age-related changes in BMD and fracture risk.

METHODS

Single nucleotide polymorphisms (SNPs) associated with serum DHEAS concentrations were used as instrumental variables (4 SNPs for main analysis; 4 SNPs for men and 5 SNPs for women in sex-related analysis). Summary statistics were obtained from relevant genome-wide association studies.

RESULTS

A log-transformed unit (µmol/L) increase in serum DHEAS concentrations was associated with an SD increase in estimated BMD at the heel (estimate, 0.120; 95% CI, 0.081-0.158; P = 9 × 10-10), and decreased fracture (odds ratio, 0.989; 95% CI, 0.981-0.996; P = 0.005), consistent with dual-energy X-ray absorptiometry-derived BMD at the femoral neck and lumbar spine. Their associations remained even after adjusting for height, body mass index, testosterone, estradiol, sex hormone-binding globulin, and insulin-like growth factor 1. The association of DHEAS with fracture remained after adjusting for falls, grip strength, and physical activity but was attenuated after adjusting for BMD. The MR-Bayesian model averaging analysis showed BMD was the top mediating factor for association of DHEAS with fracture. The association between DHEAS and BMD was observed in men but not in women.

CONCLUSION

DHEAS was associated with increased BMD and decreased fracture. DHEAS may play a protective role in decreasing fracture risk, mainly by increasing bone mass.

A Gender Comparison of Bone Metabolic Changes After Gastric Cancer Surgery: A Prospective Observational Study

BACKGROUND/AIM

This study was designed to investigate gender-related differences in changes in bone metabolism after gastric cancer surgery.

PATIENTS AND METHODS

We prospectively recruited 47 patients (38 males and 9 females) who had early gastric cancer. The bone mineral density (BMD), serum levels of 1,25-dihydroxy vitamin D (1,25(OH)₂VD), 25-hydroxy vitamin D (25(OH)VD), and estradiol (E2) were measured before and after surgery.

RESULTS

BMD significantly decreased 12 months after surgery by median degrees of 3.4% and 3.9% in male and female patients, respectively (p<0.001 and p=0.023). There was no significant difference between both genders in the rate of change in BMD after surgery. The serum E2 level in male patients significantly increased by a median value of 22 pg/ml 12 months after gastrectomy (p=0.030). Both the serum 25(OH)VD and 1,25(OH)₂VD levels remained nearly within the normal range throughout the observation period in both male and female patients.

CONCLUSION

BMD significantly decreased within 12 months after gastrectomy in both male and female patients with gastric cancer, and there was no significant gender-related difference in the rate of change in BMD.

Bone Aging, Cellular Senescence, and Osteoporosis

Changes in aging bone that lead to osteoporosis are mediated at multiple levels, including hormonal alterations, skeletal unloading, and accumulation of senescent cells. This pathological interplay is superimposed upon medical conditions, potentially bone-wasting medications, modifiable and unmodifiable personal risk factors, and genetic predisposition that accelerate bone loss with aging. In this study, the focus is on bone hemostasis and its dysregulation with aging. The major physiological changes with aging in bone and the role of cellular senescence in contributing to age-related osteoporosis are summarized. The aspects of bone aging are reviewed including remodeling deficits, uncoupling phenomena, inducers of cellular senescence related to bone aging, roles of the senescence-associated secretory phenotype, radiation-induced bone loss as a model for bone aging, and the accumulation of senescent cells in the bone microenvironment as a predominant mechanism for age-related osteoporosis. The study also addresses the rationale and potential for therapeutic interventions based on the clearance of senescent cells or suppression of the senescence-associated secretory phenotype. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Testosterone and Bone Health in Men: A Narrative Review

Bone fracture due to osteoporosis is an important issue in decreasing the quality of life for elderly men in the current aging society. Thus, osteoporosis and bone fracture prevention is a clinical concern for many clinicians. Moreover, testosterone has an important role in maintaining bone mineral density (BMD) among men. Some testosterone molecular mechanisms on bone metabolism have been currently established by many experimental data. Concurrent with a decrease in testosterone with age, various clinical symptoms and signs associated with testosterone decline, including decreased BMD, are known to occur in elderly men. However, the relationship between testosterone levels and osteoporosis development has been conflicting in human epidemiological studies. Thus, testosterone replacement therapy (TRT) is a useful tool for managing clinical symptoms caused by hypogonadism. Many recent studies support the benefit of TRT on BMD, especially in hypogonadal men with osteopenia and osteoporosis, although a few studies failed to demonstrate its effects. However, no evidence supporting the hypothesis that TRT can prevent the incidence of bone fracture exists. Currently, TRT should be considered as one of the treatment options to improve hypogonadal symptoms and BMD simultaneously in symptomatic hypogonadal men with osteopenia.

Hormones and bone loss across the menopause transition

The menopause transition is a critical period for bone health in women, with rapid losses in bone mass and strength occurring over an approximately 3-year window bracketing the date of the final menstrual period. The onset of the rapid bone loss phase is preceded by large changes in sex steroid hormones, measurements of which may be clinically useful in predicting the onset of the rapid loss phase and identifying the women who will lose the most bone mass during this rapid bone loss phase. Here we summarize recent and new findings related to the ability of sex hormone levels to (1) determine if a woman in her 5th decade of life is about to enter or has already entered the rapid phase of bone loss, and (2) if she will lose more than the average amount of bone mass over the menopause transition.

Late-onset Hypogonadism: Bone health

BACKGROUND

Bone health is underdiagnosed and undermanaged in men. Bone loss occurs in men with hypogonadism and in aging men. Thus, patients with a diagnosis of late-onset hypogonadism (LOH) are at risk of osteoporosis and osteoporotic fractures.

OBJECTIVES

To provide an update on research data and clinical implications regarding bone health in men with LOH by reviewing literature articles on this issue.

MATERIALS AND METHODS

A thorough search of listed publications in PubMed on bone health in older men with hypogonadism was performed, and other articles derived from these publications were further identified.

RESULTS

Late-onset Hypogonadism may be associated with reduced bone mineral density (BMD). In a pathophysiological perspective, the detrimental effects of testosterone (T) deficiency on BMD are partly ascribed to relative estrogen deficiency and both serum T and serum estradiol (E2) need to be above 200 ng/dL and 20 pg/mL to prevent bone loss. The effects of exogenous T on BMD are controversial, but most of the studies confirm that testosterone replacement therapy (TRT) increases BMD and prevents further bone loss in men with hypogonadism. No data are available on TRT and the prevention of fractures.

DISCUSSION AND CONCLUSION

In men with documented LOH, a specific clinical workup should be addressed to the diagnosis of osteoporosis in order to program subsequent follow-up and consider specific bone active therapy. TRT should be started according to guidelines of male hypogonadism while keeping in mind that it may also have positive effects also on bone health in men with LOH.

Follicle-stimulating hormone and estradiol are associated with bone mineral density and risk of fractures in men with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with a higher fracture risk. Sex hormones are important for maintaining skeletal health. It is not clear which sex hormone(s) contribute(s) to bone mineral density (BMD) and fracture risk in males with T2DM. This study investigated the relationships of these parameters in males with T2DM.

METHODS

This study involved 482 men with T2DM. BMDs at the lumbar spine (L2-4), femoral neck (FN), and total hip (TH) were measured by dual-energy X-ray absorptiometry (DXA). The 10-year probability of fractures was assessed using the modified Fracture Risk Algorithm (FRAX) tool. Serum levels of sex hormones were measured.

RESULTS

Follicle-stimulating hormone (FSH) and estradiol (E2) were associated with BMDs at L2-4 (FSH, β = -.162, P < .05; E2, β = .176, P < .001), and E2 was associated with BMD at FN (β = .137, P < .05) and TH (β = .140, P < .05). FSH was associated with major osteoporotic fractures (β = .288, P < .001) and hip fractures (β = .235, P < .001). Higher FSH was a risk factor for osteoporosis/osteopenia (odds ratios [OR] = 2.92, 95% CI = 1.66-5.14, P < .001), whereas higher E2 was a protective factor (OR = 0.37, 95% CI = 0.22-0.60, P < .001). Patients in the higher tertile of FSH and lower tertile of E2 had an increased risk of osteoporosis/osteopenia (OR = 5.05, 95% CI = 1.37-18.65, P < .05).

CONCLUSIONS

For males with T2DM, FSH and E2 are significantly associated with BMD, osteoporosis/osteopenia, and fracture risk.

Construction of reporter gene assays using CWP and PDR mutant yeasts for enhanced detection of various sex steroids

Background

Sex steroid hormone receptors are classified into three classes of receptors: estrogen receptors (ER) α and β, androgen receptor (AR), and progesterone receptor (PR). They belong to the nuclear receptor superfamily and activate their downstream genes in a ligand-dependent manner. Since sex steroid hormones are involved in a wide variety of physiological processes and cancer development, synthetic chemical substances that exhibit sex steroid hormone activities have been applied as pharmaceuticals and consumed in large amounts worldwide. They are potentially hazardous contaminants as endocrine disruptors in the environment because they may induce inappropriate gene expression mediated by sex steroid hormone receptors in vivo.

Results

To develop simple reporter gene assays with enhanced sensitivity for the detection of sex steroid hormones, we newly established mutant yeast strains lacking the CWP and PDR genes encoding cell wall mannoproteins and plasma membrane drug efflux pumps, respectively, and expressing human ERα, ERβ, AR, and PR. Reporter gene assays with mutant yeast strains responded to endogenous and synthetic ligands more strongly than those with wild-type strains. Sex steroid hormone activities in some pharmaceutical oral tablets and human urine were also detectable in these yeast assays.

Conclusions

Yeast reporter gene assay systems for all six steroid hormone receptors, including previously established glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) assay yeasts, are now available. Environmental endocrine disrupters with steroid hormone activity will be qualitatively detectable by simple and easy procedures. The yeast-based reporter gene assay will be valuable as a primary screening tool to detect and evaluate steroid hormone activities in various test samples. Our assay system will strongly support the detection of agonists, antagonists, and inverse agonists of steroid hormone receptors in the field of novel drug discovery and assessments of environmental pollutants.

Tranexamic Acid Protects Ovary and Testis Functions and Ameliorates Osteoporosis in Mice

INTRODUCTION

In a rapidly aging society, the number of people suffering from osteoporosis keeps increasing. However, effective prevention strategies for osteoporosis are not yet currently available.

OBJECTIVE

In this study, we examined the ameliorative effects of tranexamic acid on osteoporosis in 24-month-old mice.

METHODS

During the study period, mice were orally administered tranexamic acid 3 times per week.

RESULTS

Bone mineral density, which is a parameter of osteoporosis, was improved following tranexamic acid administration. In addition, female mice evidenced a stronger phenotypic improvement than male mice. In female mice treated with tranexamic acid, ovary abnormalities were reduced. Furthermore, the levels of transforming growth factor-β, hyaluronic acid, CD44, reactive oxygen species, and apoptosis, as well as the number of infiltrated neutrophils and macrophages in the ovary were lower than those in the control or solvent-administered mice. In addition, 17β-estradiol levels in blood increased when compared with the control or solvent-treated mice. In addition, administration of tranexamic acid to 24-month-old male mice decreased the level of apoptosis in the testis. However, the levels of 17β-estradiol and testosterone in blood increased compared with the control or solvent-administered mice.

CONCLUSIONS

The use of tranexamic acid had an ameliorative effect on osteoporosis, possibly by protecting ovaries and testes.

Perfluoroalkyl substances and changes in bone mineral density: A prospective analysis in the POUNDS-LOST study

BACKGROUND

Recent studies suggested an inverse association between exposures to perfluoroalkyl substances (PFASs) and bone mineral density (BMD). Whether exposures to PFASs are also associated with changes in BMD has not been examined.

METHODS

Five major PFASs (perfluorooctanesulfonic acid, PFOS; perfluorooctanoic acid, PFOA; perfluorohexanesulfonic acid, PFHxS; perfluorononanoic acid, PFNA; perfluorodecanoic acid, PFDA) and BMD (g/cm²) at six bone sites (spine, total hip, femoral neck, hip intertrochanteric area, hip trochanter, and hip Ward's triangle area) were measured at baseline among 294 participants in the POUNDS-LOST study, a weight-loss trial, of whom a total of 175 participants had BMD measured at both baseline and year 2. Linear regression was used to model the differences or changes in BMD for each SD increment of PFAS concentrations. In a secondary analysis, interactions between PFASs and baseline body mass index (BMI), as well as a BMI-related genetic risk score (GRS) derived from 97 BMI-predicting SNPs were examined in relation to changes in BMD.

RESULTS

At baseline, both PFOS and PFOA were significantly associated with lower BMD at several sites. For each SD increase of PFOS, the βs (95% CIs) for BMD were -0.020(-0.037, -0.003) for spine, -0.013(-0.026, 0.001) for total hip, -0.014(-0.028, 0.000) for femoral neck, and -0.013(-0.026, 0.000) for hip trochanter. For PFOA, the corresponding figures were -0.021(-0.038, -0.004) for spine, -0.015(-0.029, -0.001) for total hip, and -0.015(-0.029, -0.002) for femoral neck. After adjusting for baseline covariates and 2-year weight change, higher baseline plasma concentrations of PFOS, PFNA, and PFDA were associated with greater reduction in BMD in the hip; the βs (95% CIs) were -0.005(-0.009, -0.001), -0.006(-0.010, -0.001), and -0.005(-0.009, -0.001), respectively. Similar associations were found in hip intertrochanteric area for all PFASs except PFHxS, with βs ranging from -0.006 for PFOA to -0.008 for PFOS and PFNA. Participants with a higher GRS tended to have less PFAS-related BMD decline in total hip (P_interaction = 0.005) and the hip intertrochanteric area (P_interaction = 0.021). There were similar PFAS-related BMD changes by baseline BMI levels, although the interactions did not achieve statistical significance.

CONCLUSIONS

This study demonstrated that higher plasma PFAS concentrations were not only associated with a lower BMD at baseline, but also a faster BMD loss in a weight-loss trial setting. Genetic predisposition to larger body size may somewhat attenuate the deleterious effects of PFASs on BMD. Further exploration of the possible impact of PFAS exposures on bone density is warranted.

Association Between Drug Treatments for Patients With Osteoporosis and Overall Mortality Rates: A Meta-analysis

IMPORTANCE

Previous studies have reported that drug treatments, particularly treatment with bisphosphonates, is associated with reduced overall mortality rates in addition to decreased fracture risk. If so, drug treatments should be recommended for this reason alone, regardless of a patient's risk of fracture.

OBJECTIVE

To assess whether randomized clinical trials demonstrate that treatment with bisphosphonates, particularly zoledronate, is associated with reduced mortality rates.

DATA SOURCES

Science Direct, MEDLINE, Embase, and the Cochrane Library were searched for randomized placebo-controlled clinical trials of drug treatments for osteoporosis published after 2009 and published or in press before April 19, 2019. Conference abstracts from annual osteoporosis society meetings were also included in the search.

STUDY SELECTION

Included studies were clinical trials that (1) were randomized and placebo-controlled; (2) studied drug treatments with proven antifracture efficacy; (3) used agents at the approved dose for treatment of osteoporosis; and (4) had a duration of 1 year or more. Abstracts from the literature searches were reviewed for inclusion and exclusion criteria, and mortality rate data were abstracted from the article by 1 researcher and validated by a second. A total of 2045 records were screened; 38 (1.8%) were included in the meta-analyses.

DATA EXTRACTION AND SYNTHESIS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist was followed for abstracting data and assessing data quality and validity. Data were pooled using random-effects models, and between-study variability was assessed using the I2 index. The risk of bias for each study was assessed, and funnel plots and Egger and Begg statistics were used to evaluate publication bias.

MAIN OUTCOMES AND MEASURES

Associations of all drug treatments, particularly bisphosphonate and zoledronate treatments, with overall mortality.

RESULTS

Of 38 clinical trials that included 101 642 unique participants, 38 were included in the meta-analyses of all drug treatments (45 594 participants randomized to placebo; 56 048 to treatment); 21 clinical trials, of bisphosphonate treatments (20 244 participants randomized to placebo; 22 623 to treatment); and 6 clinical trials, of zoledronate treatments (6944 participants randomized to placebo; 6926 to treatment). No significant association was found between all drug treatments for osteoporosis and overall mortality rate (risk ratio [RR], 0.98; 95% CI, 0.91-1.05; I2 = 0%). Clinical trials of bisphosphonate treatment (RR, 0.95; 95% CI, 0.86-1.04) showed no significant association with overall mortality. Also, clinical trials of zoledronate treatment (RR, 0.88; 95% CI, 0.68-1.13) showed no association with overall mortality rate; however, evidence existed for heterogeneity of the results (I2 = 48.2%).

CONCLUSIONS AND RELEVANCE

Results of this meta-analysis suggest that bisphosphonate treatment may not be associated with reduced overall mortality rates in addition to decreased fracture risk and should only be recommended to reduce fracture risk. Additional trials are needed to clarify whether treatment with zoledronate reduces mortality rates.

Androgens and Androgen Receptor Actions on Bone Health and Disease: From Androgen Deficiency to Androgen Therapy

Androgens are not only essential for bone development but for the maintenance of bone mass. Therefore, conditions with androgen deficiency, such as male hypogonadism, androgen-insensitive syndromes, and prostate cancer with androgen deprivation therapy are strongly associated with bone loss and increased fracture risk. Here we summarize the skeletal effects of androgens—androgen receptors (AR) actions based on in vitro and in vivo studies from animals and humans, and discuss bone loss due to androgens/AR deficiency to clarify the molecular basis for the anabolic action of androgens and AR in bone homeostasis and unravel the functions of androgen/AR signaling in healthy and disease states. Moreover, we provide evidence for the skeletal benefits of androgen therapy and elucidate why androgens are more beneficial than male sexual hormones, highlighting their therapeutic potential as osteoanabolic steroids in improving bone fracture repair. Finally, the application of selective androgen receptor modulators may provide new approaches for the treatment of osteoporosis and fractures as well as building stronger bones in diseases dependent on androgens/AR status.

Relationship Between Sex Steroids and Deterioration of Bone Microarchitecture in Older Men: The Prospective STRAMBO Study

In older men, low estrogen levels are associated with poor bone microarchitecture. Data on androgens are discordant. We studied the link between baseline sex steroid levels (total 17β -estradiol [17βE2], total testosterone [tT], calculated bioavailable 17βE2 [bio-17βE2], and apparent free testosterone concentration [AFTC]) and bone microarchitecture deterioration assessed prospectively in a 820 older men followed for 8 years. Bone microarchitecture was assessed by HR-pQCT at baseline, then after 4 and 8 years. At both the skeletal sites, the bone microarchitecture deterioration rate did not correlate with serum levels of tT and 17βE2. At the distal radius, cortical area (Ct.Ar) decreased more rapidly in the lowest versus the highest AFTC quartile. At the distal tibia, cortical thickness (Ct.Th) decreased and trabecular area (Tb.Ar) increased more rapidly in the highest versus the lowest AFTC quartile. At the tibia, bone mineral content (BMC), total volumetric bone mineral density (Tt.vBMD), Ct.Th, and Ct.Ar decreased, whereas Tb.Ar increased faster in the lowest versus the highest bio-17βE2 quartile. In men who had both AFTC and bio-17βE2 in the lowest quartile (high-risk group), distal radius cortical vBMD (Ct.vBMD) decreased more rapidly compared with men who had both hormones in the three upper quartiles (reference group). At the distal tibia, Tt.vBMD, Ct.Th, Ct.Ar, and Ct.vBMD decreased, whereas Tb.Ar increased more rapidly in the high-risk group versus the reference group. In men receiving androgen deprivation therapy (ADT) for prostate cancer, BMC, Tt.vBMD, Ct.Th, Ct.Ar, and Ct.vBMD decreased, whereas Tb.Ar increased more rapidly than in men not receiving ADT at both the skeletal sites. Thus, in older men followed up prospectively, low levels of bio-17βE2, and to a smaller extent AFTC, are associated with accelerated cortical bone deterioration. Cortical bone deterioration was strongly accelerated in men receiving ADT who had very low levels of all sex steroids. © 2019 American Society for Bone and Mineral Research.

Body composition of lean outdoor intact cats vs lean indoor neutered cats using dual-energy x-ray absorptiometry

OBJECTIVES

The objectives for this study were to compare the body composition of adult indoor neutered domestic cats with outdoor intact cats with an ideal body condition score using dual-energy x-ray absorptiometry, and to report the body composition findings of free-roaming cats, as this has not been previously reported. Most domestic house cats differ from free-roaming cats as they are confined indoors and neutered. Indoor neutered cats have reduced activity and hormonal alterations that may result in lower muscle mass and higher body fat percentages vs outdoor intact cats, despite similar body condition scores.

METHODS

Twenty-one outdoor intact cats (10 male, 11 female) were selected from a trap-neuter-return program and 16 indoor neutered domestic cats (10 male, six female) were client-owned. Inclusion criteria included an estimated age between 1 and 6 years, complete blood count, biochemistry panel, urinalysis, total thyroxine, feline leukemia virus/feline immunodeficiency virus screening and a body condition score of 4-5/9.

RESULTS

Indoor neutered cats had a higher body fat percentage (22.1% [range 17.3-28.2%]) than outdoor intact cats (17.3% [range 10.0-33.6%]; P = 0.002). Indoor neutered male cats had a higher body fat percentage ( P <0.001) than outdoor intact cats. No difference in body fat percentage was observed in female cats ( P = 0.159). Indoor neutered domestic cats had a higher bone mineral density than outdoor intact cats ( P = 0.023).

CONCLUSIONS AND RELEVANCE

The results of this study suggest indoor confinement and neutering increase body fat percentage and bone mineral density in cats with an ideal body condition score.

Whole-body vibration training and bone health in postmenopausal women: A systematic review and meta-analysis

BACKGROUND

The aims of the present systematic review and meta-analysis were to evaluate published, randomized controlled trials that investigate the effects on whole-body vibration (WBV) training on total, femoral neck, and lumbar spine bone mineral density (BMD) in postmenopausal women, and identify the potential moderating factors explaining the adaptations to such training.

METHODS

From a search of electronic databases (PubMed, Web of Science, and Cochrane) up until September 2017, a total 10 studies with 14 WBV groups met the inclusion criteria. Three different authors tabulated, independently, the selected indices in identical predetermined forms. The methodological quality of all studies was evaluated according to the modified PEDro scale. For each trial, differences within arms were calculated as mean differences (MDs) and their 95% confidence intervals between pre- and postintervention values. The effects on bone mass between exercise and control groups were also expressed as MDs. Both analyses were performed in the total sample and in a specific class of postmenopausal women younger than 65 years of age (excluding older women).

RESULTS

The BMD of 462 postmenopausal women who performed WBV or control protocol was evaluated. Significant pre-post improvements in BMD of the lumbar spine were identified following WBV protocols (P = .03). Significant differences in femoral neck BMD (P = .03) were also found between intervention and control groups when analyzing studies that included postmenopausal women younger than 65 years.

CONCLUSIONS

WBV is an effective method to improve lumbar spine BMD in postmenopausal and older women and to enhance femoral neck BMD in postmenopausal women younger than 65 years.

Sex-dependent correlation between survival and expression of genes related to the circadian oscillator in patients with colorectal cancer

Recent evidence supports the important role of the circadian system in cancer progression in humans. The aim of the present study is to evaluate clock (cry1, cry2 and per2) and clock-controlled (vascular endothelial growth factor-a, early growth response protein 1 and estrogen receptor β) gene expression in colorectal cancer and adjacent tissue and identify a possible link between survival of patients and expression of above mentioned genes. The study includes 64 patients of both sexes with previously diagnosed colorectal cancer. RNA was extracted from the tumor tissue and adjacent parts of the resected colon, and real-time PCR was used for detection of clock gene expression. Expression of cry2 and per2 was significantly downregulated in tumor tissue compared to adjacent tissues. After splitting of the cohort according to sex, we detected downregulated levels of cry2 and per2 in male patients, but not in females. Splitting of male and female sub-cohorts according to presence of metastases revealed significant donwregulation of cry2 expression in female patients without distant metastasis. Better survival rate was associated with low expression of cry2 in female patients. Moreover, we observed an increase in cry1 expression in female patients with distant metastases in tumor compared to adjacent tissue. Accordingly, women with high expression of cry1 in tumor tissue displayed worse survival, which was not observed in men. Taken together, expression of clock and clock-controlled genes in tumors of males and females clustered according to presence of distant metastases correlated with survival analysis. Studied clock-controlled genes also showed sex-dependent changes. Low expression of vegf-a in tumor correlated with better survival in men but not in women. High expression of estrogen receptor β mRNA was related to better survival in women but not in men. Low expression of vegf-a, egr1 and estrogen receptor β was associated with worse survival in women compared to men. Our data indicate sex-dependent associations between clock and clock-controlled gene expression in cancer tissue and patient's survival prognosis.

Low Serum DHEAS Predicts Increased Fracture Risk in Older Men: The MrOS Sweden Study

The adrenal-derived hormones dehydroepiandrosterone (DHEA) and its sulfate (DHEAS) are the most abundant circulating hormones and their levels decline substantially with age. DHEAS is considered an inactive precursor, which is converted into androgens and estrogens via local metabolism in peripheral target tissues. The predictive value of serum DHEAS for fracture risk is unknown. The aim of this study was, therefore, to assess the associations between baseline DHEAS levels and incident fractures in a large cohort of older men. Serum DHEAS levels were analyzed with mass spectrometry in the population-based Osteoporotic Fractures in Men study in Sweden (n = 2568, aged 69 to 81 years). Incident X-ray validated fractures (all, n = 594; non-vertebral major osteoporotic, n = 255; hip, n = 175; clinical vertebral, n = 206) were ascertained during a median follow-up of 10.6 years. DHEAS levels were inversely associated with the risk of any fracture (hazard ratio [HR] per SD decrease = 1.14, 95% confidence interval [CI] 1.05-1.24), non-vertebral major osteoporotic fractures (HR = 1.31, 95% CI 1.16-1.48), and hip fractures (HR = 1.18, 95% CI 1.02-1.37) but not clinical vertebral fractures (HR = 1.09, 95% CI 0.95-1.26) in Cox regression models adjusted for age, body mass index (BMI) and prevalent fractures. Further adjustment for traditional risk factors for fracture, bone mineral density (BMD), and/or physical performance variables as well as serum sex steroid levels only slightly attenuated the associations between serum DHEAS and fracture risk. Similarly, the point estimates were only marginally reduced after adjustment for FRAX estimates with BMD. The inverse association between serum DHEAS and all fractures or major osteoporotic fractures was nonlinear, with a substantial increase in fracture risk (all fractures 22%, major osteoporotic fractures 33%) for those participants with serum DHEAS levels below the median (0.60 μg/mL). In conclusion, low serum DHEAS levels are a risk marker of mainly non-vertebral fractures in older men, of whom those with DHEAS levels below 0.60 μg/mL are at highest risk. © The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.

Aging and sex hormones in males

Several large cohort studies have disclosed the trajectories of sex steroids changes overtime in men and their clinical significance. In men the slow, physiological decline of serum testosterone (T) with advancing age overlaps with the clinical condition of overt, pathological hypogonadism. In addition, the increasing number of comorbidities, together with the high prevalence of chronic diseases, all further contribute to the decrease of serum T concentrations in the aging male. For all these reasons both the diagnosis of late-onset hypogonadism (LOH) in men and the decision about starting or not T replacement treatment remain challenging. At present, the biochemical finding of T deficiency alone is not sufficient for diagnosing hypogonadism in older men. Coupling hypogonadal symptoms with documented low serum T represents the best strategy to refine the diagnosis of hypogonadism in older men and to avoid unnecessary treatments.

Sex differences in mortality following isolated traumatic brain injury among older adults

BACKGROUND

Older adults have the highest rates of hospitalization and mortality from traumatic brain injury (TBI), yet outcomes in this population are not well studied. In particular, contradictory reports on the protective effect of female sex on mortality following TBI may have been related to age differences in TBI and other injury severity and mechanism. The objective of this study was to determine if there are sex differences in mortality following isolated TBI among older adults and compare with findings using all TBI. A secondary objective was to characterize TBI severity and mechanism by sex in this population.

METHODS

This was a retrospective cohort study conducted among adults aged 65 and older treated for TBI at a single large Level I trauma center from 1996 to 2012 (n = 4,854). Individuals treated for TBI were identified using International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Isolated TBI was defined as an Abbreviated Injury Scale score of 0 for other body regions. Our primary outcome was mortality at discharge.

RESULTS

Among those with isolated TBI (n = 1,320), women (45% of sample) were older (mean [SD], 78.9 [7.7] years) than men (76.8 [7.5] years) (p < 0.001). Women were more likely to have been injured in a fall (91% vs. 84%; p < 0.001). Adjusting for multiple injury severity measures, female sex was not significantly associated with decreased odds of mortality following isolated TBI (odds ratio, 1.01; 95% confidence interval, 0.66-1.54). Using all TBI cases, adjusted analysis found that female sex was significantly associated with decreased odd of mortality (odds ratio, 0.73; 95% confidence interval, 0.59-0.89).

CONCLUSION

We found no sex differences in mortality following isolated TBI among older adults, in contrast with other studies and our own analyses using all TBI cases. Researchers should consider isolated TBI in outcome studies to prevent residual confounding by severity of other injuries.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level IV.

Estrogens and Androgens in Skeletal Physiology and Pathophysiology

Estrogens and androgens influence the growth and maintenance of the mammalian skeleton and are responsible for its sexual dimorphism. Estrogen deficiency at menopause or loss of both estrogens and androgens in elderly men contribute to the development of osteoporosis, one of the most common and impactful metabolic diseases of old age. In the last 20 years, basic and clinical research advances, genetic insights from humans and rodents, and newer imaging technologies have changed considerably the landscape of our understanding of bone biology as well as the relationship between sex steroids and the physiology and pathophysiology of bone metabolism. Together with the appreciation of the side effects of estrogen-related therapies on breast cancer and cardiovascular diseases, these advances have also drastically altered the treatment of osteoporosis. In this article, we provide a comprehensive review of the molecular and cellular mechanisms of action of estrogens and androgens on bone, their influences on skeletal homeostasis during growth and adulthood, the pathogenetic mechanisms of the adverse effects of their deficiency on the female and male skeleton, as well as the role of natural and synthetic estrogenic or androgenic compounds in the pharmacotherapy of osteoporosis. We highlight latest advances on the crosstalk between hormonal and mechanical signals, the relevance of the antioxidant properties of estrogens and androgens, the difference of their cellular targets in different bone envelopes, the role of estrogen deficiency in male osteoporosis, and the contribution of estrogen or androgen deficiency to the monomorphic effects of aging on skeletal involution.

Off label therapies for testosterone replacement

The incidence of hypogonadism has been steadily increasing over the last few years. Exogenous testosterone has been the standard treatment for hypogonadal men, but is associated with suppression of spermatogenesis as well as other possible adverse effects. There are other medications, currently considered “off label” for androgen replenishment, that exert their effect through modulation of the hypothalamic-gonadal axis. These medications increase endogenous testosterone levels and offer a different therapeutic approach. This review will focus on these alternative (off-label) therapies for androgen replacement in men.

Genetic influence on the association between bone mineral density and testosterone in Korean men

Low bone mineral density (BMD) leads to an increased risk of osteoporotic fracture. Total testosterone and free testosterone were positively associated with BMD, which was significantly influenced by the additive genetic effects.

INTRODUCTION

This cross-sectional study aimed to evaluate an association between testosterone and BMD and the influence of genetic factors on the association.

METHODS

Study subjects were 1070 Korean men including 144 pairs of monozygotic twins and their family members. Levels of serum total testosterone and sex hormone binding globulin (SHBG) were measured by chemiluminescence immunoassay. Calculated free testosterone (cFT) was then determined using Vermeulen's method. BMDs of the whole body and specific regions were measured using dual-energy X-ray absorptiometry.

RESULTS

Linear mixed regression analyses showed that total testosterone and cFT were positively associated with BMD at most regions, after considering intra-familial relationship and covariates including fat mass, lean mass, and SHBG. SHBG had an inverse association with BMD at the pelvis but not with the BMD at other regions after adjusting for all covariates and cFT. Co-twin control analysis in monozygotic twins found no association between pairwise difference of testosterone and pairwise difference of BMD. Bivariate variance component analysis showed that both total testosterone and cFT had a significant positive additive genetic correlation with BMD at rib, spine, and arm, whereas SHBG had no significant genetic correlation with BMD. Inverse environmental correlations were seen between total testosterone and BMDs at the lumbar spine and arm.

CONCLUSIONS

This Korean twin and family study showed that both total testosterone and free testosterone were positively associated with BMD and that genetic effects were significant on the association between testosterone and BMD.

Reproductive Hormones and Longitudinal Change in Bone Mineral Density and Incident Fracture Risk in Older Men: The Concord Health and Aging in Men Project

The objectives of this study were to examine relationships between baseline levels of reproductive hormones in older men and (1) change in bone mineral density (BMD) over 5 years and (2) incident fractures over an average of 6 years' follow-up. A total of 1705 men aged 70 years and older from the Concord Health and Ageing in Men Project (CHAMP) study were assessed at baseline (2005-2007), 2 years follow-up (2007-2009), and 5 years follow-up (2010-2013). At baseline, testosterone (T), dihydrotestosterone (DHT), estradiol (E2), and estrone (E1) were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS), and sex hormone-binding globulin (SHBG), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) by immunoassay. Hip BMD was measured by dual X-ray absorptiometry (DXA) at all three time-points. Fracture data were collected at 4-monthly phone calls and verified radiographically. Statistical modeling was by general estimating equations and Cox model regression. Univariate analyses revealed inverse associations for serum SHBG, FSH, and LH and positive association for E1 but not DHT or E2 with BMD loss at the hip across the three time points. Serum levels of SHBG (β = -0.071), FSH (β = -0.085), LH (β = -0.070), and E1 (β = 0.107) remained significantly associated with BMD loss in multivariate-adjusted models; however, we were unable to identify any thresholds for accelerated BMD loss according to reproductive steroids. Incident fractures (all, n = 171; hip, n = 44; and nonvertebral, n = 139) were all significantly associated with serum SHBG, FSH, and LH levels in univariate models but none remained significantly associated in multivariate-adjusted model. Serum T, DHT, E2, and E1 levels were not associated with incident fractures in univariate or multivariate-adjusted analyses. In older men, lower serum SHBG, FSH, and LH and higher E1 levels protected against loss of BMD without increasing fracture rate. This means these reproductive variables may be considered as novel biomarkers of bone health during male aging.

The association between serum dehydroepiandrosterone Sulphate (DHEA-S) level and bone mineral density in Korean men

CONTEXT

Many lines of evidence indicate that dehydroepiandrosterone (DHEA) plays a distinct role in bone metabolism and that its sulphated form (DHEA-S), which is easily measured in blood, may be a potential biomarker of osteoporosis-related phenotypes. However, most previous epidemiologic studies focused on postmenopausal women and reported conflicting results.

OBJECTIVE

We aimed to investigate the association between the serum DHEA-S level and bone mass in men.

DESIGN AND METHODS

This large cross-sectional study included 1089 healthy Korean men who participated in a routine health screening examination. Bone mineral density (BMD) at the lumbar spine, total femur, femur neck, and trochanter and serum DHEA-S level were obtained in all subjects.

RESULTS

After adjustment for age, body mass index, lifestyle factors and serum levels of calcium, phosphorus, testosterone, 25-OH-vitamin D3 and cortisol, higher serum DHEA-S concentrations were associated with higher BMD values at all skeletal sites. Consistently, compared to the subjects in the highest DHEA-S quartile (Q4), those in the lowest DHEA-S quartile (Q1) showed significantly lower BMD values. Multiple logistic regression analyses revealed that the odds ratios for the risk of lower BMD (T-score <-1) increased in a dose-dependent manner across decreasing DHEA-S quartiles and the odds for the risk of lower BMD were 2·59-fold higher in Q1 than in Q4.

CONCLUSION

These findings support previous evidences that DHEA-S has favourable effects on bone mass in men and suggest that a low serum DHEA-S level may be a potential risk factor for male osteoporosis.

The Pathophysiology and Treatment of Osteoporosis

PURPOSE

The objectives of this article are to review the pathophysiology of bone loss associated with aging and to review current pharmacologic approaches for the treatment of osteoporosis.

METHODS

A literature search with PubMed was performed with the terms osteoporosis and pathophysiology and osteoporosis and treatment and limited to studies written in English that were published within the preceding 10 years. Given the large number of studies identified, we selectively reviewed those studies that contained primary data related to osteoporosis pathophysiology or osteoporosis pharmacologic treatments and references included within selected studies identified from abstract review.

FINDINGS

Published studies have consistently reported that osteoporosis in older adults is caused by an imbalance of bone resorption in excess of bone formation. The dominant factor leading to bone loss in older adults appears to be gonadal sex steroid deficiency, with multiple genetic and biochemical factors, such as vitamin D deficiency or hyperparathyroidism, that may accelerate bone loss. Conditions that adversely affect growth and development may limit development of peak bone mass and accelerate subsequent bone loss. Studies of bone microarchitecture have shown that trabecular bone loss begins in the third decade of life, before gonadal sex steroid deficiency develops, whereas cortical loss typically begins in the sixth decade, about the time of menopause in women and about the same age in men. Antiresorptive agents for the treatment of osteoporosis act primarily by limiting osteoclast activity, whereas osteoanabolic agents, such as teriparatide, act primarily by stimulating osteoblastic bone formation. Clinical investigation of new compounds for the treatment of osteoporosis is mainly directed to those that stimulate bone formation or differentially decrease bone resorption more than bone formation. Therapies for osteoporosis are associated with adverse effects, but in patients at high risk of fracture, the benefits generally far outweigh the risks.

IMPLICATIONS

Current osteoporosis therapies mitigate or reverse the loss of bone associated with age-related decreases of gonadal sex steroids, increase bone strength, and reduce fracture risk. With improved knowledge of the pathophysiology of osteoporosis, new targets for therapeutic intervention have been identified. Clinical investigations of potential new treatments for osteoporosis are primarily directed to stimulating osteoblastic bone formation or to modulating the balance of bone resorption and formation in ways that improve bone strength.

Effects of food enriched with egg yolk hydrolysate (bone peptide) on bone metabolism in orchidectomized dogs

We examined the effects of chicken egg hydrolysate (also known as “bone peptide” or BP) on bone metabolism in 5- to 8-month-old orchidectomized dogs. The bone formation marker serum bone alkaline phosphatase (BAP) and the bone resorption marker urine deoxypyridinoline (DPD) were used as indicators to measure changes in bone metabolism. The following results were observed that Serum BAP was higher in dogs fed BP-enriched food throughout the clinical investigation. Serum BAP was statistically significantly higher in dogs fed BP-enriched food than in dogs fed non-BP-enriched food at 2 months after orchidectomy. This suggests that BP promoted bone formation immediately after orchidectomy.

The endocrine role of estrogens on human male skeleton

Before the characterization of human and animal models of estrogen deficiency, estrogen action was confined in the context of the female bone. These interesting models uncovered a wide spectrum of unexpected estrogen actions on bone in males, allowing the formulation of an estrogen-centric theory useful to explain how sex steroids act on bone in men. Most of the principal physiological events that take place in the developing and mature male bone are now considered to be under the control of estrogen. Estrogen determines the acceleration of bone elongation at puberty, epiphyseal closure, harmonic skeletal proportions, the achievement of peak bone mass, and the maintenance of bone mass. Furthermore, it seems to crosstalk with androgen even in the determination of bone size, a more androgen-dependent phenomenon. At puberty, epiphyseal closure and growth arrest occur when a critical number of estrogens is reached. The same mechanism based on a critical threshold of serum estradiol seems to operate in men during adulthood for bone mass maintenance via the modulation of bone formation and resorption in men. This threshold should be better identified in-between the ranges of 15 and 25 pg/mL. Future basic and clinical research will optimize strategies for the management of bone diseases related to estrogen deficiency in men.