The effects of cortisol and adrenal androgen on bone mass in Asians with and without subclinical hypercortisolism

Mild autonomous cortisol secretion: impact on bone health and quality of life. A review

INTRODUCTION

Mild autonomous cortisol secretion (MACS) is associated with several cardiometabolic and non-metabolic comorbidities, including osteoporosis, fractures and worse quality of life (QoL).

METHODS

We performed a comprehensive review of the literature including articles that reported the association between MACS and osteoporosis, fractures and impact on QoL.

RESULTS

In relation to bone health, several studies reported that the risk of fractures in patients with MACS is discordant with the degree of bone mineral density loss measured per dual X-ray absorptiometry (DXA), suggesting that a reduction in bone quality rather than density contributes to the increased fracture risk. Nevertheless, in general a greater prevalence of vertebral fractures has been described in MACS compared with nonfunctioning adrenal incidentalomas (NFAIs) patients. Regarding QoL, due to the higher burden of comorbidities and the adverse symptoms linked to MACS diagnosis, MACS patients are overall frailer and have worse QoL than patients with NFAIs or the general population. Higher levels of disability related to mental health, middle insomnia and perceived stress have also been described in patients with MACS when compared to NFAIs patients.

CONCLUSION

MACS patients have a higher prevalence of fractures and osteoporosis, as well as a worse QoL compared to NFAIs and the general population. Thus, both bone health and QoL evaluation should be part of the assessment of patients with MACS diagnosis.

Activation of Follicle-Stimulating Hormone Receptor in Adrenal Zona Fasciculata Cells Promotes Cortisol Secretion: Implications for the Development of Menopause-Associated Diseases

OBJECTIVE

Changes in postmenopausal hormone levels are associated with a variety of disorders. This study elucidated the mechanism by which follicle-stimulating hormone (FSH) increases cortisol production involved in development of menopause-related diseases.

METHODS

The expression of FSH receptors (FSHRs) in murine adrenal zona fasciculata (AZF) cells and ATC7 cells was verified by immunofluorescence, western blotting and RT-PCR. The function of FSHR in promoting cortisol production was analyzed by cell culture and molecular biological methods. FSHR signaling pathways in ATC7 cells were analyzed by ELISA, qRT-PCR, and western blotting. Further, a mouse model was established by ovariectomy. Ovariectomized mice were treated with GnRHa. Ovariectomized mice initially received physiological doses of estrogen and were then injected with recombinant FSH. Then serum FSH, luteinizing hormone (LH), estradiol, and cortisol, and bone mineral density (BMD), blood pressure (BP) and heart rate (HR) were determined.

RESULTS

FSHRs were expressed in murine AZF cells and ATC7 cells. FSH accelerated cortisol production through activated protein kinase A (PKA), cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB), protein kinase B (PKB/AKT) and 5' AMP-activated protein kinase (MAPK) signaling pathways by Gsα-coupled FSHRs in ATC7 cells. Serum FSH levels (P<0.001) were elevated in ovariectomized mice with concurrent increases in cortisol (P<0.01), areal BMD (aBMD) (P<0.05), volumetric BMD (vBMD) (P<0.05), systolic BP (SBP) (P<0.05), diastolic BP (DBP) (P<0.05), and HR (P<0.05). However, the administration of GnRHa suppressed the increase in FSH levels and the elevation of cortisol, aBMD, vBMD, SBP, DBP, and HR induced by ovariectomy, even in the presence of normal serum estradiol levels.

CONCLUSION

The study findings indicate that elevated FSH levels stimulate cortisol secretion, through a mechanism related to FSHRs expression in AZF cells.

Dehydroepiandrosterone and Bone Health: Mechanisms and Insights

BACKGROUND/OBJECTIVES

Dehydroepiandrosterone (DHEA), a steroid hormone produced by the adrenal glands, plays a key role in various physiological processes, including bone health. Its age-related decline is linked to reduced bone density, though the mechanisms by which DHEA affects bone metabolism remain complex. This review summarises the diverse effects of DHEA on bone metabolism and density, highlighting its therapeutic potential; Methods: A literature search on the effects of DHEA on bone-related parameters was conducted from PubMed and Scopus using a specific search string, and after removing duplicates and irrelevant articles, 36 relevant full-text studies were included; Results: DHEA promotes osteoblast differentiation and proliferation, regulates the RANKL/OPG ratio, and inhibits osteoclastogenesis and bone resorption. Its osteogenic effects are mediated through multiple signalling pathways. In ovariectomised rat models, DHEA enhances trabecular bone volume, stimulates osteoblast proliferation, and increases oestradiol production and aromatase activity. In elderly individuals with low androgen levels, DHEA supplementation increases sulphated DHEA and oestradiol levels and improves bone mineral density, particularly in the ultra-distal radius of women and the femoral neck of men. However, the clinical use of DHEA remains debated due to inconsistent study results. Its effects on bone health may vary based on factors such as age, gender, and health conditions, emphasising the need for further research to clarify its mechanisms and optimise its use; Conclusions: In conclusion, while DHEA shows potential as a modulator of bone health, comprehensive clinical trials are required to assess its efficacy and safety, particularly in at-risk populations.

Mild Autonomous Cortisol Secretion (MACS) - Related Osteoporosis

Mild autonomous cortisol secretion (MACS) has thus far been associated with several comorbidities, among which osteoporosis and fractures appear to be highly prevalent. Recent guidelines for adrenal incidentalomas have updated the definition of MACS, currently formulated on serum cortisol after a 1-mg dexamethasone test above 1.8 µg/dL or 50 nmol/L. Previous studies on bone health in adrenal incidentalomas had adopted different definitions of MACS, producing heterogeneous results in terms of fracture prevalence. This review aims to summarize the clinical impact of MACS in relation to fractures, bone quantity and quality, by providing a thorough update on MACS-related osteoporosis (MACS-ROP). This area has a large room for research, and management of this comorbidity still needs to be elucidated.

Fracture risk and bone health in adrenal adenomas with mild autonomous cortisol secretion/subclinical hypercortisolism: a systematic review, meta-analysis and meta-regression

Adrenal adenomas/incidentalomas with mild autonomous cortisol secretion (MACS)/subclinical hypercortisolism (SH) are often associated with metabolic syndrome, glucocorticoid-induced osteoporosis, and fractures. In this background, the present systematic review and meta-analysis aimed to collate the available evidence and provide a summary of the effect of MACS/SH on bone health in terms of fractures, osteoporosis/osteopenia, microarchitecture, and bone turnover. PubMed/MEDLINE, Embase, and Web of Science databases were systematically searched for observational studies reporting prevalence of fractures, osteoporosis/osteopenia or data on bone microarchitecture/bone turnover markers (BTMs). Following literature search, 16 observational studies were included. Pooled prevalence of any fractures (vertebral and non-vertebral), vertebral fractures, and osteoporosis/osteopenia in MACS/SH were 43% [95% confidence intervals (CI): 23%, 62%], 45% (95% CI: 22%, 68%) and 50% (95% CI: 33%, 66%), respectively. On meta-regression, age, sex, 24-hour urinary free cortisol, and dehydroepiandrosterone-sulfate did not predict fracture risk. The likelihood of any fractures [odds ratio (OR) 1.61; 95% CI: 1.18, 2.20; P = 0.0026], vertebral fractures (OR 2.10; 95% CI: 1.28, 3.45; P = 0.0035), and osteoporosis/osteopenia (OR 1.46; 95% CI: 1.15, 1.85; P = 0.0018) was significantly higher in adrenal adenomas and MACS/SH than non-functional adrenal adenomas. Subjects with MACS/SH had significantly lower bone mineral density (BMD) at lumbar spine [mean difference (MD) -0.07 g/cm2; 95% CI: -0.11, -0.03; P = 0.0004) and femoral neck (MD -0.05 g/cm2; 95% CI: -0.08, -0.02; P = 0.0045) than their non-functional counterparts. Limited data showed no significant difference in BTMs. Publication bias was observed in the pooled prevalence of any fractures, vertebral fractures and pooled MD of femoral neck BMD. To conclude, people with adrenal adenomas/incidentalomas and MACS/SH are at a 1.5- to 2-fold higher likelihood of fractures and osteoporosis/osteopenia compared to non-functional adrenal adenomas and should routinely be screened for bone disease. Nevertheless, considering the modest sample size of studies and evidence of publication bias, larger and high-quality studies are required (CRD42023471045).

Unveiling the hidden impact: Subclinical hypercortisolism and its subtle influence on bone health

In recent years, advancements in imaging technologies have led to an increased detection rate of adrenal incidentalomas (AI), with age demonstrating a significant correlation with their incidence. Among the various forms of functional adrenal incidentalomas, subclinical hypercortisolism (SH) stands out as a predominant subtype. Despite the absence of typical symptoms associated with Cushing's syndrome, both domestic and international research consistently establishes a robust link between SH and diverse metabolic irregularities, including hypertension, lipid metabolism disorders, glucose metabolism abnormalities, and disruptions in bone metabolism. Individuals with SH face an elevated risk of cardiovascular events and mortality, highlighting the clinical significance of addressing this condition. Prolonged exposure to elevated cortisol levels poses a significant threat to bone health, contributing to bone loss, alterations in bone microstructure, and an increased susceptibility to fractures. However, comprehensive reviews addressing bone metabolism changes and associated mechanisms in SH patients are currently lacking. Furthermore, the profound impact of concurrent SH on the overall health of the elderly cannot be overstated. A comprehensive understanding of the skeletal health status in elderly individuals with concomitant SH is imperative. This article aims to fill this gap by offering a detailed review of bone metabolism changes and associated mechanisms in SH patients arising from AI. Additionally, it provides a forward-looking perspective on research concerning skeletal health in elderly individuals with concurrent SH.

Comorbidities in mild autonomous cortisol secretion and the effect of treatment: systematic review and meta-analysis

OBJECTIVE

To assess (1) comorbidities associated with and (2) treatment strategies for patients with adrenal incidentalomas and mild autonomous cortisol secretion (MACS; > 1.8 µg/dL (>50 nmol/L) cortisol level cut-off following the 1 mg dexamethasone suppression test).

DESIGN

Systematic review and meta-analysis.

METHODS

Seven databases were searched up to July 14, 2022. Eligible studies were (randomized) trials, cohort studies, and cross-sectional studies assessing comorbidities potentially attributable to cortisol excess or mortality in patients with adrenal incidentaloma with or without MACS or the effects of conservative or surgical management of MACS. Random-effects meta-analysis was performed to estimate pooled proportions (with 95% CIs).

RESULTS

In 30 cross-sectional and 16 cohort studies (n = 17 156 patients in total), patients with MACS had a higher prevalence of diabetes (relative risk [RR] 1.44 [1.23-1.69]), hypertension (RR = 1.24 [1.16-1.32]), and dyslipidemia (RR = 1.23 [1.13-1.34]). All-cause mortality (adjusted for confounders) in patients with MACS, assessed in 4 studies (n = 5921), was increased (hazard ratio [HR] = 1.54 [1.27-1.81]). Nine observational studies (n = 856) and 2 randomized trials (n = 107) suggest an improvement in glucometabolic control (RR = 7.99 [2.95-21.90]), hypertension (RR = 8.75 [3.99-19.18]), and dyslipidemia (RR = 3.24 [1.19-8.82]) following adrenalectomy.

CONCLUSIONS

The present systematic review and meta-analysis highlight the relevance of MACS, since both cardiometabolic morbidities and mortality appeared to have increased in patients with MACS compared to patients with non-functioning incidentalomas. However, due to heterogeneous definitions, various outcomes, selective reporting, and missing data, the reported pooled estimates need to be interpreted with caution. The small number of patients in randomized trials prevents any strong conclusion on the causality between MACS and these comorbidities.

Adrenal steroid metabolites and bone status in patients with adrenal incidentalomas and hypercortisolism

BACKGROUND

Autonomous cortisol secretion (ACS), resulting from cortisol-producing adenomas (CPA), causes endogenous steroid-induced osteoporosis (SIOP). However, the risk of endogenous SIOP cannot be explained by cortisol excess alone, and how other steroid metabolites affect bone status is unclear.

METHODS

ACS was diagnosed as serum cortisol ≥1.8 μg/dL after the 1-mg dexamethasone suppression test (DST-cortisol). Using liquid chromatography tandem mass spectrometry, 21 plasma steroid metabolites were measured in 73 patients with ACS and 85 patients with non-functioning adrenal tumors (NFAT). Expression of steroidogenic enzymes and relevant steroid metabolites were analyzed in some of CPA tissues.

FINDINGS

Discriminant and principal component analyses distinguished steroid profiles between the ACS and NFAT groups in premenopausal women. Premenopausal women with ACS exhibited higher levels of a mineralocorticoid metabolite, 11-deoxycorticosterone (11-DOC), and lower levels of androgen metabolites, dehydroepiandrosterone-sulfate, and androsterone-glucuronide. In premenopausal women with ACS, DST-cortisol negatively correlated with trabecular bone score (TBS). Additionally, 11-DOC negatively correlated with lumbar spine-bone mineral density, whereas androsterone-glucuronide positively correlated with TBS. The CPA tissues showed increased 11-DOC levels with increased expression of CYP21A2, essential for 11-DOC synthesis. Adrenal non-tumor tissues were atrophied with reduced expression of CYB5A, required for androgen synthesis.

INTERPRETATION

This study demonstrates that unbalanced production of adrenal steroid metabolites, derived from both adrenal tumor and non-tumor tissues, contributes to the pathogenesis of endogenous SIOP in premenopausal women with ACS.

FUNDING

JSPS KAKENHI, Secom Science and Technology Foundation, Takeda Science Foundation, Japan Foundation for Applied Enzymology, AMED-CREST, JSTA-STEP, JST-Moonshot, and Ono Medical Research Foundation.

Effects of Menaquinone-7 on the Bone Health of Growing Rats under Calcium Restriction: New Insights from Microbiome-Metabolomics

Insufficient calcium intake during growth is a global public health concern. The aim of this study was to investigate the effects of dietary menaquinone-7 (MK-7) on bone accrual in growing Sprague-Dawley rats under calcium restriction. Following 13 weeks of treatment, various bone quality parameters, including microarchitecture, were measured. Fecal and cecal samples were subjected to microbiome (16S rRNA gene sequencing) analyses, while metabolomics analysis of the cecum and humerus samples was analyzed based on UHPLC-Q/TOF-MS. We found that calcium deficiency diminished the richness of the microbiome and disrupted microbiome composition, accompanied by an elevation in the relative abundance of Parasutterella. Furthermore, calcium insufficiency escalated the level of isovaleric acid and modified the metabolic profiles. MK-7 supplementation significantly increased the cortical thickness, cortical bone area, and the calcium content of the femur. Apart from improving bone calcium deposition and diminishing bone resorption, the mechanisms underlying the beneficial effects of MK on bone quality also involve the modulation of the host's metabolic pathways and the composition of gut microbiota. The gut-bone axis holds promise as an efficacious target for ameliorating calcium deficiency in children's bone quality, and MK-7 is a promising dietary supplement from this perspective.

Association of Endogenous Hormones and Bone Mineral Density in Postmenopausal Women

Aim

The aim of this study was to examine the association between endogenous hormones and bone mineral density (BMD) in postmenopausal women.

Materials and Methods

This was a cross-sectional study of 798 postmenopausal women aged 47-85 years. Data were collected on age, age at menopause, years since menopause, smoking status, body mass index, adiposity, BMD, physical activity, and Vitamin D supplementation. Measured hormonal parameters were: follicle-stimulating hormone (FSH), estradiol, testosterone, dehydroepiandrosterone sulfate, ∆4-androstenedione, cortisol, insulin-like growth factor-1, 25-hydroxyvitamin D, and parathormone (PTH) levels. BMD was measured at the lumbar spine, femoral neck, and total hip using dual-energy X-ray absorptiometry. A directed acyclic graph was used to select potential confounding variables.

Results

Multivariable analysis showed significant associations between cortisol and femoral neck BMD (β: -0.02, 95% confidence interval [CI]: -0.03--0.00), and PTH with femoral neck BMD (β: -0.01, 95% CI: -0.02--0.01) and total hip BMD (β: -0.01, 95% CI: -0.01--0.00). Hormonal factors more likely associated with a higher risk of low BMD (osteopenia or osteoporosis) were FSH (odds ratio [OR]: 1.02, 95% CI: 1.01-1.03) and PTH (OR: 1.02, 95% CI: 1.01-1.04).

Conclusions

Higher cortisol and PTH levels were inversely associated with BMD. Postmenopausal women with higher FSH or PTH levels were likely to have low BMD.

Management of Adrenal Cortical Adenomas: Assessment of Bone Status in Patients with (Non-Functioning) Adrenal Incidentalomas

Our aim is to analyse the bone profile in adults with (non-functioning) adrenal incidentalomas (AIs), specifically addressing the impact of autonomous cortisol secretion (ACS). This narrative review, based on a PubMed search from inception to February 2023 (case reports, non-ACS, and other secondary causes of osteoporosis were excluded), included 40 original studies, a total of 3046 patients with female prevalence (female:male ratio of 1921:1125), aged between 20.5 and 95.5 years old. This three decade-based analysis showed that 37 studies provided dual-energy X-ray absorptiometry (DXA) information; another five studies reports results on bone micro-architecture, including trabecular bone score (TBS), spinal deformity index, and high-resolution peripheral quantitative computed tomography; 20 cohorts included data on bone turnover markers (BTMs), while four longitudinal studies followed subjects between 1 and 10.5 years old (surgical versus non-adrenalectomy arms). Post-dexamethasone suppression test (DST) cortisol was inversely associated with bone mineral density (BMD). TBS predicted incidental vertebral fractures (VFx) regardless of BMD, being associated with post-DST cortisol independently of age and BMD. Low BTMs were identified in ACS, but not all studies agreed. An increased prevalence of ACS-related osteoporosis was confirmed in most studies (highest prevalence of 87.5%), as well as of VFx, including in pre-menopause (42.5%), post-menopause (78.6%), and male patients (72.7%) depending on the study, with a 10-fold increased incidental VFx risk up to a 12-fold increased risk after a 2-year follow-up. No specific medication against osteoporosis is indicated in ACS, but adrenalectomy (according to four studies) should be part of the long-term strategy. This bone profile case sample-based study (to our knowledge, one of the largest of its kind) showed that AIs, including the subgroup designated as having ACS, embraces a large panel of osseous complications. The level of evidence remains far from generous; there are still no homogenous results defining ACS and identifying skeletal involvement, which might be a consequence of different investigation clusters underling adrenal and bone assessments over time. However, bone status evaluations and associated therapy decisions remain an essential element of the management of adults with AIs-ACS.

Systematic evaluation for the causal effects of blood metabolites on osteoporosis: Genetic risk score and Mendelian randomization

Purpose

Osteoporosis is associated with metabolic alterations, but the causal roles of serum metabolites on osteoporosis have not been identified.

Methods

Based on the large individual-level datasets from UK Biobank as well as GWAS summary datasets, we first constructed genetic risk scores (GRSs) for 308 of 486 human serum metabolites and evaluated the effect of each GRS on 2 major osteoporosis phenotypes, i.e., estimated bone miner density (eBMD) and fracture, respectively. Then, two-sample Mendelian Randomization (MR) was performed to validate the casual metabolites on osteoporosis. Multivariable MR analysis tested whether the effects of metabolites on osteoporosis are independent of possible confounders. Finally, we conducted metabolic pathway analysis for the metabolites involved in bone metabolism.

Results

We identified causal effects of 18 metabolites on eBMD and 1 metabolite on fracture with the GRS method after adjusting for multiple tests. Then, 9 of them were further validated with MR as replication, where comprehensive sensitive analyses proved robust of the causal associations. Although not identified in GRS, 3 metabolites were associated with at least three osteoporosis traits in MR results. Multivariable MR analysis determined the independent causal effect of several metabolites on osteoporosis. Besides, 23 bone metabolic pathways were detected, such as valine, leucine, isoleucine biosynthesis (p = 0.053), and Aminoacyl-tRNA biosynthesis (p = 0.076), and D-glutamine and D-glutamate metabolism (p = 0.004).

Conclusions

The systematic causal analyses strongly suggested that blood metabolites have causal effects on osteoporosis risk.

Comorbidities in Mild Autonomous Cortisol Secretion - A Clinical Review of Literature

Mild autonomous cortisol secretion (mACS) is a state of cortisol excess usually associated with existence of adrenal incidentaloma. Because of the lack of symptoms of the disease, the biochemical evaluation is the most important to determine a diagnosis. However, scientific societies have different diagnostic criteria for mACS, which makes the treatment of this disease and using results of original papers in daily practice more difficult. Chronic hypercortisolemic state, even if mild, may lead to diseases that are mostly connected with overt Cushing's syndrome. Some of them can cause a higher mortality of patients with mACS and those problems need to be addressed. In this review we describe the comorbidities associated with mACS: cardiovascular disorders, arterial hypertension, diabetes mellitus, insulin resistance, dyslipidemia, obesity, metabolic syndrome, non-alcoholic fatty liver disease, vertebral fractures and osteoporosis. The point of this paper is to characterise them and determine if and how these conditions should be managed. Two databases - PubMed and Web of Science were searched. Even though the evidence are scarce, this is an attempt to lead clinicians through the problems associated with this enigmatic condition.

Sex Difference in the Association of Osteoporosis and Osteopenia Prevalence in Patients with Adrenal Adenoma and Different Degrees of Cortisol Excess

OBJECTIVE

Osteoporosis and osteopenia (OS/OP) are frequent in patients with adrenal adenomas associated with cortisol excess (CE). However, the relationship between OS/OP and CE severity considering sex differences is unknown.

DESIGN

A cross-sectional observational study from January 2006 to December 2015. Patients. 237 patients with adrenal adenoma associated with CE, including Cushing's syndrome and mild autonomous cortisol secretion (MACS), diagnosed in 10 referral centers in Japan. MACS was defined by 1 mg overnight dexamethasone suppression test (DST) cortisol level >1.8 μg/dL. Measurements. Prevalence of fragility fractures, medication for osteoporosis, and bone mineral density.

RESULTS

In total, 112 of 237 patients, who were predominantly female (P < 0.001) and had lower BMI (P=0.013), had OS/OP. Patients with OS/OP was significantly affected by CE (P < 0.01) than those without. The adjusted odds ratio (OR) for predicting OS/OP was obtained in multivariate logistic regression analysis. Clinical measures of CE, 1 mg DST cortisol levels, were positively associated with OS/OP in total cases (OR 1.124, 95% CI: 1.070-1.181, P < 0.001) and the cases with MACS (OR 1.156, 95%CI: 1.046-1.278, P=0.005). A cutoff value of 1 mg DST cortisol level >5.0 μg/dL was associated with OS/OP differently between men and women. OS/OP risk in men with MACS was significantly affected only by 1 mg DST cortisol levels. However, OS/OP risk in women with MACS was significantly affected by 1 mg DST cortisol levels and age.

CONCLUSIONS

CE severity in adrenal adenoma is positively associated with OS/OP. However, the associated factors of OS/OP in the patients with MACS are different between men and women.

Formation, structure, and function of extra-skeletal bones in mammals

This review describes the formation, structure, and function of bony compartments in antlers, horns, ossicones, osteoderm and the os penis/os clitoris (collectively referred to herein as AHOOO structures) in extant mammals. AHOOOs are extra-skeletal bones that originate from subcutaneous (dermal) tissues in a wide variety of mammals, and this review elaborates on the co-development of the bone and skin in these structures. During foetal stages, primordial cells for the bony compartments arise in subcutaneous tissues. The epithelial-mesenchymal transition is assumed to play a key role in the differentiation of bone, cartilage, skin and other tissues in AHOOO structures. AHOOO ossification takes place after skeletal bone formation, and may depend on sexual maturity. Skin keratinization occurs in tandem with ossification and may be under the control of androgens. Both endochondral and intramembranous ossification participate in bony compartment formation. There is variation in gradients of density in different AHOOO structures. These gradients, which vary according to function and species, primarily reduce mechanical stress. Anchorage of AHOOOs to their surrounding tissues fortifies these structures and is accomplished by bone-bone fusion and Sharpey fibres. The presence of the integument is essential for the protection and function of the bony compartments. Three major functions can be attributed to AHOOOs: mechanical, visual, and thermoregulatory. This review provides the first extensive comparative description of the skeletal and integumentary systems of AHOOOs in a variety of mammals.