Thyroid Hormone Diseases and Osteoporosis

TSH inhibits osteoclast differentiation through AMPK signaling pathway

PURPOSE

It is believed that osteoporosis (OP) is associated with hyperthyroidism as a result of the elevation in thyroxine levels. However, patients with subclinical hyperthyroidism, which is characterized by decreased levels of thyroid-stimulating hormone (TSH) alone, are at equal risk of osteoporosis. Research has shown that TSH receptor (TSHR) is expressed on osteoclasts, but whether TSH directly regulates osteoclasts and the underlying mechanisms remain unclear.

METHODS

In this study, we used osteoclast precursor cell conditional TSHR-knockout (TSHR CKO) mouse to study the effects of TSHR knockout on bone metabolism in mice and the changes in osteoclast differentiation in vitro. Transcriptomics was used to identify differentially expressed genes and signaling pathways.

RESULTS

In vitro, experiments confirmed that TSH inhibited osteoclast differentiation in mouse RAW264.7 monocyte/macrophage cell line and targeted the key signaling pathway AMPK by RNA-seq sequencing. We found TSHR CKO mice exhibited decreased femoral biomechanics and damaged bone microstructure. The serum levels of bone resorption marker were increased, accompanied by an increase in the number of osteoclasts.

CONCLUSION

TSH inhibits osteoclast differentiation by activating the AMPK signaling pathway, and exerts an osteoprotective effect. This study will provide guidance for the diagnosis and treatment of osteoporosis. TSH structural analogs or AMPK activators are expected to provide new ideas for the development of drugs to prevent and treat osteoporosis.

Role of traditional Chinese medicine on fracture, hospitalization, and total mortality risks in patients with hyperthyroidism and osteoporosis

Previous studies have confirmed that hyperthyroidism is one of the common causes of secondary osteoporosis and can aggravate the disease severity in patients with osteoporosis. This study is mainly based on the Taiwan National Health Insurance Database and through big data analysis shows that combining traditional Chinese medicine (TCM) treatment can help the health of patients with hyperthyroidism and osteoporosis. There were 4980 patients who received TCM treatment and 19,920 controls who did not receive TCM treatment selected from Taiwan National Health Insurance Database in a 4:1 ratio of gender, age, and index year. Cox proportional hazards analyzes were performed to compare fracture, inpatient, and all-cause mortality over an average follow-up period of 15 years. A total of 4745/5823/3487 enrolled subjects (19.06%/23.39%/14.00%) suffered fractures/hospitalization/all-cause death which TCM group was 452/987/511 (15.10%/19.82%/10.26%); control group was 3993/4836/2976 (20.05%/24.28%/14.94%). Cox proportional hazards regression analysis showed that subjects in the TCM group had lower fractures, hospital mortality, and all-cause mortality (adjusted HR = 0.563; 95% confidence intervals [CI] = 0.392-0.680, P < .001; adjusted HR = 0.614; 95% CI = 0.474-0.714, P < .001; adjusted HR = 0.691; 95% CI = 0.569-0.792, P < .001). Kaplan-Meier analysis showed that the cumulative risk of fracture, hospitalization and death were lower in TCM group with significant differences (all log-rank P < .001). The analysis of this study shows that patients with hyperthyroidism and osteoporosis even with comorbidity of atrial fibrillation, atrial flutter, or heart failure combined with TCM treatment are associated with a lower risk of fractures, hospitalization, or all-cause death, providing clinicians with a treatment option.

Association between thyroid function and osteopenia or osteoporosis: a cross-sectional study in China

Thyroid dysfunction is associated with bone health, but the relationship with osteopenia remains unclear. This study aimed to investigate the association between thyroid function and osteopenia/osteoporosis across different age groups. The study included 4508 men and 1438 women who underwent health check-ups between January 2021 and December 2023. Bone mineral density (BMD) was measured using dual energy X-ray absorptiometry. Logistic regression analysis was employed to evaluate the association between thyroid function and the risk of osteopenia/osteoporosis. The results showed that in postmenopausal women, both hyperthyroidism and age increased the risk of osteopenia and osteoporosis, while body mass index (BMI) was negatively correlated with both conditions. In men over 50, hyperthyroidism and age were also linked to a higher risk of osteoporosis. Among postmenopausal women, higher thyroid-stimulating hormone (TSH) levels were negatively associated with osteopenia risk. In men aged 50 and above, free thyroxine (fT4) levels were inversely related to osteopenia and osteoporosis risk. In men under 50, fT4 levels were negatively linked to the risk of low bone mass. These findings suggest that TSH and fT4 levels may influence bone health, with these effects varying by age and sex. Further studies are needed to confirm these findings and explore potential mechanisms.

The Role of miRNA in Hyperthyroidism Induced by Excessive Iodine in Drinking Water

In recent years, iodine deficiency-related diseases have been effectively controlled; the prevalence of excessive iodine-induced thyroid diseases has increased, such as hyperthyroidism. However, there are still several controversial outcomes regarding the relationship between excessive iodine intakes and hyperthyroidism. MicroRNAs (miRNAs) extensively participate in the progression of thyroid diseases; nevertheless, the relationship and mechanism between iodine exposure and miRNAs have not been explored in hyperthyroidism patients. In this study, a total of 308 pairs of hyperthyroidism patients and healthy controls were enrolled in. Logistic regression analysis showed that level of water iodine >100 μg/L was an independent risk factor for hyperthyroidism. Compared with the healthy control, the serum thyroglobulin (Tg) content and levels of interferon-γ (IFN-γ), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) were significantly elevated in hyperthyroidism patients. Further, high-throughput miRNA sequencing was applied to find crucial miRNAs involved in the occurrence of hyperthyroidism related to excessive water iodine. Based on the fold change and Q value, miR-144-3p, miR-204-5p, miR-346, miR-23b-5p, and miR-193b-3p were selected for validation by qRT-PCR. Our results showed that miR-346 and miR-204-5p in the case group were significantly lower than those of the control group, and the similar results found under the level of water iodine >300 μg/L. Nonetheless, no significant difference was found at 10-100 μg/L level of water iodine. Furthermore, the ROC curve indicated that miR-346 and miR-204-5p had the ability to diagnose hyperthyroidism patients. Taken together, excessive water iodine may decrease the expression of miR-346 and miR-204-5p, which mediate the elevation of Tg and cytokines, ultimately making contribution to the development of hyperthyroidism.

Treatment Considerations for Severe Osteoporosis in Older Adults

Osteoporosis, a chronic metabolic bone disease, increases the predisposition to fragility fractures and is associated with considerable morbidity, high health care cost as well as mortality. An elevation in the rate of incident fragility fractures will be observed proportional with the increase in the number of older people worldwide. Severe osteoporosis is currently defined as having a bone density determined by dual-energy X-ray absorptiometry that is more than 2.5 standard deviations (SD) below the young adult mean with one or more past fractures due to osteoporosis. Nutrition, physical activity and adequate vitamin D are essential for optimal bone strength throughout life. Hormone (oestrogen/sex steroid) status is also a major determinant of bone health. This review explores mechanisms involved in bone homeostasis, followed by the assessment and management of severe osteoporosis, including an overview of several treatment options in older people that range from anti-resorptive to anabolic therapies.

A high-fructose diet leads to osteoporosis by suppressing the expression of Thrb and facilitating the accumulation of cholesterol

Osteoporosis is classified as a metabolic syndrome, and the consumption of fructose has been linked to various metabolic diseases. However, the specific effects and underlying mechanisms of fructose on bone health remain inadequately understood. In this study, we demonstrate that fructose intake can exacerbate bone loss in murine models by facilitating the accumulation of cholesterol within the bones. We identify Thyroid Hormone Receptor Beta (Thrb) and Protein Kinase C Zeta (Prkcz) as potential therapeutic targets for the treatment of osteoporosis. Mice subjected to a high-fructose diet exhibited a reduction in bone density and a decrease in the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) compared to those on a standard diet. Fructose treatment was found to decrease Thrb expression while increasing Prkcz expression, leading to cholesterol accumulation and hindering the osteogenic differentiation of BMSCs. Furthermore, our findings indicate that the activation of Thrb and the inhibition of Prkcz significantly ameliorate bone loss in mice. This study elucidates the molecular mechanisms by which fructose influences osteogenesis through the Thrb/Prkcz/cholesterol accumulation pathway in the context of osteoporosis, thereby highlighting the therapeutic potential of Thrb and Prkcz as targets for osteoporosis treatment.

Lactoferrin alleviates oxidative stress and endoplasmic reticulum stress induced by autoimmune thyroiditis by modulating the mTOR pathway in the thyroid

Autoimmune thyroiditis (AITD) is a prevalent autoimmune disorder characterized by the immune system's attack on thyroid tissue, potentially leading to thyroid dysfunction, with a current lack of effective treatment modalities. Lactoferrin, a crucial functional dietary component obtainable from food sources, primarily exists in mammalian milk. We aim to investigate whether dietary supplementation with lactoferrin can protect the thyroid in Experimental Autoimmune Thyroiditis (EAT) rats. Our study reveals significantly elevated levels of oxidative stress (OS) and endoplasmic reticulum stress (ERS) in the AITD. Lactoferrin markedly reduces OS and infiltration of inflammatory cells in the thyroid tissue of EAT rats. Furthermore, lactoferrin inhibits ERS levels in the thyroid of EAT rats and alleviates cellular apoptosis. In vivo and in vitro experiments elucidate that its protective effect is primarily achieved through the inhibition of mTOR signaling pathway activation. In summary, lactoferrin, a nutrient readily obtainable from food sources, appears to be effective in mitigating thyroid damage in AITD.

Extracellular phase separation mediates storage and release of thyroglobulin in the thyroid follicular lumen

Thyroid hormones are produced by the thyroid gland and are essential for regulating metabolism, growth and development. Maintenance of circulating thyroid hormone levels within an appropriate range is thus a prerequisite for health. In vivo, this objective is, at least in part, facilitated through an extracellular storage depot of thyroglobulin, the glycoprotein precursor for thyroid hormones, in the thyroid follicular lumen. The molecular basis for how soluble thyroglobulin molecules form such dense depot assemblies remains elusive. Here, we describe in vitro biophysical analysis of thyroglobulin phase behaviour, suggesting that thyroglobulin is prone to undergoing ionic strength-dependent phase separation, leading to the formation of liquid-like condensates. Fluorescence photobleaching measurements further show that these condensates age as a function of time to form reversible gel-like high density storage depots of thyroglobulin. IF experiments on mouse and human thyroid follicles ex vivo reveal that spherical globules of Tg protein dense phase are present in the follicular lumen, consistent with the idea that Tg undergoes phase separation. These findings reveal a molecular mechanism for the last-come-first-served process of thyroglobulin storage and release, suggesting a role for extracellular phase separation in thyroid hormone homeostasis by providing organizational and architectural specificity without requiring membrane-mediated confinement.

Association between Dental Variables and Hashimoto's Disease: A Retrospective Cohort Study

OBJECTIVES

 The present study aimed to compare dental, endodontic, and periodontal status in patients with Hashimoto's disease and healthy patients, as well as to disclose the relation between dental variables and Hashimoto's disease.

MATERIALS AND METHODS

 The research included 85 patients affected by Hashimoto's thyroiditis (analyzed group) and 85 healthy patients (control group). The two groups were matched according to age and gender. Data regarding patients' health status was acquired from their medical records. Data regarding dental, endodontic, and periodontal status were acquired from patients' dental records and digital panoramic radiographs.

STATISTICAL ANALYSIS

 Since a nonnormal distribution of data was detected, a median and interquartile range were used as a measure of central tendency and dispersion. Mann-Whitney U test and chi-squared test were used to test the differences between the groups. Multiple linear regression analysis and logistic regression analysis were used to test the association of the data.

RESULTS

 Healthy participants had significantly higher median number of teeth with secondary caries (median 2; interquartile range 1-3) when compared with participants with Hashimoto's disease (median 1; interquartile range 0-2; p < 0.001). Periodontal disease was present in significantly more participants with Hashimoto's disease than healthy patients (68.2% vs. 45.9%; chi-square = 7.779; p = 0.005). The presence of Hashimoto's disease increased the risk of periodontal disease presence three times (odds ratio [OR] = 3.14; 95% confidence interval [CI] 1.38-7.15; p = 0.007). The presence of periodontal disease increased the risk of Hashimoto's disease presence by 2.5 times (OR 2.54; 95% CI: 1.36-4.73; p = 0.004).

CONCLUSION

 With the study limitations in mind, it may be concluded that a positive relationship between periodontal disease and Hashimoto's thyroiditis exists.

Paradoxical combination of osteosclerosis and osteopenia in an adult woman with biallelic TNFRSF11A loss-of-function variants escaping nonsense-mediated decay

Osteoclasts are essential for bone resorption, playing a crucial role in skeletal development, homeostasis, and remodeling. Their differentiation depends on the RANK receptor encoded by the TNFRSF11A gene, with defects in this gene linked to osteoclast-poor sclerosing skeletal dysplasias. This report presents a 37-yr-old woman with normal height, valgus deformities that were treated surgically, frequent fractures, scoliosis, mildly elevated BMD, sclerotic diaphyseal bone, and metaphyseal widening. Initially suspected of having dysosteosclerosis, her diagnosis shifted toward Pyle disease due to the valgus deformity and prominent metaphyseal widening and translucency. Genetic analysis identified 2 pathogenic TNFRSF11A variants: a nonsense mutation c.1093G>T, p.(Glu365*) and a frameshift mutation c.1266_1268delinsCC, p.(Leu422Phefs*104). Thus, genetic and clinical assessment converged on the diagnosis of a mild form of dysosteosclerosis. Both mutations introduced premature stop codons but escaped complete nonsense-mediated decay, potentially permitting residual protein function. Analysis of patient-derived osteoclasts cultured on glass surfaces showed partial differentiation. However, in vitro resorptive function was strongly impaired, which was clinically reflected by reduced serum concentration of the bone resorption marker CTx. Despite this impairment, the retained residual resorptive function likely explains the patient's relatively mild clinical presentation. These findings underscore the complex genetic interactions that affect osteoclast function, leading to a spectrum of phenotypes in osteoclast-related bone disorders.

A simple and user-friendly machine learning model to detect osteoporosis in health examination populations in Southern Taiwan

Background

Osteoporosis is a growing public health concern in aging populations such as Taiwan, where limited utilization of dual-energy X-ray absorptiometry (DXA) often leads to underdiagnosis and even delayed treatment. Therefore, we leveraged machine learning (ML) and aimed to develop a simple and easily accessible model that effectively identifies individuals at high risk of osteoporosis.

Methods

This retrospective analysis enrolled 5510 men aged ≥50 years and 4720 postmenopausal women who underwent DXA at the Kaohsiung Veterans General Hospital, with another cohort of 610 men and 523 women for validation. We developed separate models for men and women using decision trees, random forests, support vector machines, k-nearest neighbors, extreme gradient boosting, and artificial neural networks (ANNs) to predict osteoporosis. Furthermore, we compared each model with the traditional Osteoporosis Self-Assessment Tool for Asians (OSTA) model.

Results

We identified age, height, weight, and BMI as variables for our prediction model and evaluated the model's performance using the area under the receiver operating characteristic curve (AUC). The ANN model significantly outperformed the OSTA model and all the other ML models for both men and women (AUC: 0.67 for men; 0.77 for women). The validation data for the ANN model showed similar AUCs for both men and women.

Conclusion

This study developed ML models to help identify individuals at high risk of osteoporosis in postmenopausal women and men aged ≥50 years in southern Taiwan. Our ML models, especially the ANN model, surpassed the OSTA model and consistently performed well across different populations.

Unraveling the Mechanisms That Regulate Osteoclast Differentiation: A Review of Current Advances

Osteoporosis is a metabolic bone disease primarily caused by a decreased bone formation and increased bone resorption. Osteoclasts are a special class of terminally differentiated cells that play an important role in normal bone remodeling and bone loss in osteoporosis as well as in a variety of osteolytic diseases. Osteoclasts can be differentiated from monocyte-macrophage cells of the hematopoietic system; they are the key cells in bone resorption. Osteoclast formation and differentiation are regulated by various cytokines and transcription factors. In this review, we summarize recent advances in research on the regulation of osteoclast differentiation and function by factors such as M-CSF, RANKL, AP-1, NFATC1, MITF, and PU.1. Understanding these cytokines and transcription factors can not only help identify targets for osteoclast differentiation but also aid in intervening in the treatment of osteoclast-related diseases.

Effects of levothyroxine therapy on bone and mineral metabolism in hypothyroidism: a systematic review and meta-analysis

BACKGROUND

Thyroid hormone plays an important role in accumulating bone development and regulating bone metabolism. It is established that hypothyroidism is linked to increased risk of osteoporosis and fracture. However, the effects of levothyroxine (LT4) treatment on bone for hypothyroid patients remain controversial.

METHODS

A systematical search was conducted of several databases, from inception until December 9, 2022, and updated the search using the same search strategy on October 30, 2024, for studies evaluating the effects of LT4 treatment on bone in hypothyroidism including subclinical hypothyroidism (SCH) and overt hypothyroidism (OH). The data were reported using a random-effects model with a standardized mean difference (SMD) and 95% conference interval (CI).

RESULTS

Thirteen of the 5996 published articles were included in this meta-analysis. No significance was found in bone mineral density (BMD) at the lumbar spine between SCH patients treated with LT4 and control group either at baseline or after intervention. For OH, BMD at the lumbar spine was statistically lower in LT4 treatment group compared with healthy controls (HCs) (SMD: -0.28, 95%CI: -0.55, -0.02, P = 0.040, I2 = 52%). There were no differences in BMD at the femoral neck, trochanter, and Ward's triangle between OH patients treated with LT4 and HCs. In addition, BMD at the lumbar spine was significantly lower in males with OH undergoing LT4 treatment for a duration of less than five years compared to those treated over five years. Nevertheless, no significant differences were found in bone metabolism biomarkers between OH patients treated with LT4 and HCs.

CONCLUSION

This systematic review and meta-analysis demonstrated that there is a slight adverse effect of LT4 replacement therapy on bone and mineral metabolism in patients with OH, while no observed effect was found in SCH patients.

Styloid process phenotype and atheromatous plaque: Radiographic and bone density assessment in parathyroid disease

Purpose

This study aimed to assess the styloid process (TBSP) phenotype and to identify suggestive images of calcified atheromatous plaques (CAP) in panoramic radiographs of patients with primary hyperparathyroidism (PHPT) and post-surgical hypoparathyroidism (hypoPT). Additionally, it aimed to analyze the association between the bone mineral status of patients with parathyroid diseases and the radiographic findings.

Material and methods

A cross-sectional case-control study was conducted with individuals diagnosed with PHPT (n = 25) and post-surgical hypoPT (n = 25). A control group (n = 50) comprised individuals without parathyroid gland disorders. Panoramic radiographs were utilized for both quantitative (length) and qualitative (mineralization patterns) evaluation of the TBSP, as well as for assessing the prevalence of CAP.

Results

The frequency of TBSP exceeding 30 mm was significantly higher in the PHPT and post-surgical hypoPT groups compared to the control group. CAP occurred more frequently in the PHPT group. Cases of low bone mineral density (BMD) were associated with PHPT. In the PHPT group, low BMD was linked to an increased average TBSP length (p = 0.025) and a higher frequency of elongated TBSP (p = 0.022). Multivariate analysis revealed an inverse relationship between the T-score of the femoral neck and TBSP length in the PHPT group (p = 0.028).

Conclusions

Compared to the control group, individuals with PHPT and post-surgical hypoPT showed distinct imaging findings related to TBSP and CAP. Individuals with PHPT and low BMD showed a higher frequency of elongated TBSP.

Association between sensitivity to thyroid hormones and trabecular bone score in euthyroid individuals: a population-based cross-sectional study

BACKGROUND

Thyroid hormone is a known pivotal factor that affects bone metabolism; however, whether bone microarchitecture is associated with thyroid hormone sensitivity is poorly understood. The trabecular bone score (TBS) serves as an essential indicator for assessing bone microarchitecture. This study aimed to investigate the relationship between sensitivity to thyroid hormones and TBS in euthyroid individuals.

METHODS

This cross-sectional study involved 3320 euthyroid participants from the National Health and Nutrition Examination Survey (NHANES) 2007-2008. Data, including thyroid function, TBS and other related parameters, were extracted and analyzed. The indices of thyroid hormone sensitivity, including the thyrotropin thyroxine resistance index (TT4RI), thyroid-stimulating hormone index (TSHI), thyroid feedback quantile-based index (TFQI) and parametric thyroid feedback quantile-based index (PTFQI), were calculated. Greater values of these indicators indicated a greater degree of impaired thyroid hormone sensitivity.

RESULTS

Impaired sensitivity to thyroid hormones was associated with degraded bone microarchitecture following adjustments for confounding variables (TT4RI: P = 0.005, TSHI: P = 0.008, TFQI: P = 0.003 and PTFQI: P = 0.006). The restricted cubic spline model demonstrated a positive relationship between TT4RI, TSHI, TFQI, PTFQI and degraded bone microarchitecture. Similar findings were observed in the analysis of subgroups stratified by age, sex, race, diabetes status, hypertension status and hyperuricemia status.

CONCLUSIONS

In euthyroid individuals, impaired sensitivity to thyroid hormones is associated with degraded bone microarchitecture. However, further studies are required to confirm this relationship.

Elevated risk of medical and implant-related complications in patients with hypothyroidism after total shoulder arthroplasty: a 1:1 propensity matched cohort analysis

BACKGROUND

There is currently limited work that evaluates the effect of comorbid hypothyroidism on complications and outcomes following total shoulder arthroplasty (TSA). This study aims to evaluate the impact of hypothyroidism on 90-day medical complications as well as 2-year implant related complications and revision rates following TSA.

METHODS

This retrospective database analysis evaluated patients who underwent TSA between October 1, 2015, and March 9, 2022. Patients with 2-year follow-up were categorized based on the presence of preoperative hypothyroidism within three months before TSA versus euthyroid status, resulting in 7716 hypothyroid and 46,568 euthyroid patients. A 1:1 propensity score matching was performed, adjusting for age, gender, race, ethnicity, and comorbid conditions (diabetes, hypertension, chronic kidney disease, tobacco use, obesity, heart failure, and liver diseases). Postoperative complications were assessed at 90 days, and implant-related complications were evaluated at two years. A Bonferroni correction was applied to account for multiple comparisons.

RESULTS

After matching, 7716 matched patients were included in each cohort. Hypothyroid patients had significantly higher risks of sepsis, infection, pulmonary embolism, stroke, and hospital readmission (all P < .0001), as well as higher rates of anemia, pneumonia, renal failure, and blood transfusion requirements (all P < .0001) within 90 days postoperatively. Myocardial infarction did not meet the significance threshold (P = .005). At 2 years, these patients had elevated rates of periprosthetic fractures, prosthetic joint infection, dislocation, revision surgeries, and mechanical loosening (all P < .0001).

CONCLUSION

Hypothyroidism is associated with an increased risk of 90-day medical complications and 2-year implant-related complications following shoulder arthroplasty. Further investigation into these findings and potential for perioperative medical optimization is indicated.

Evaluation of Bone Health in Postmenopausal Women Using Long-Term Levothyroxine Treatment Due to Post-Procedural Hypothyroidism

Purpose

The connection between thyroid disorders and the health of bone is an endocrinological dilemma for physicians. Several studies have been conducted to examine the correlation between levothyroxine use and the risk of fracture. Different results have been obtained in these studies. The objective of the present study is to evaluate the impact of prolonged thyroid hormone replacement therapy on bone health in postmenopausal women.

Patients and Methods

We obtained demographic data, laboratory results, and anthropometric measurements of patients from the hospital database. After the exclusion of patients, 59 patients with post-procedural hypothyroidism (n = 59) and a control group (n = 45) were evaluated. The patient group consisted of individuals who had undergone thyroid surgery for a benign condition and had been on levothyroxine treatment for a minimum of 5 years. Densitometric measurements of bone mass in the hip and spine were performed by bone mineral densitometry.

Results

Groups were similar in age, PTH, vitamin D, bone-specific ALP, and BMI (p>0.05). The control group had a significantly lower total T score-F than the hypothyroidism group (-0.77±1.3 to -0.29±1.02, p= 0.041). However, total T score-LV, total gr/cm2-LV, and total gr/cm2-F were similar in both groups.

Conclusion

This study showed that long-term levothyroxine therapy, which aims to maintain TSH levels within the normal reference range, is associated with increased bone mineral density (BMD) in postmenopausal women compared with the control group. Thus, to maintain bone health and prevent osteoporosis, it is important that postmenopausal women on long-term levothyroxine replacement undergo medical follow-up to prevent TSH suppression.

Leveraging nuclear receptor mediated transcriptional signaling for drug discovery: Historical insights and current advances

Nuclear receptors (NRs) are ligand-activated transcription factors that regulate gene expression in response to physiological signals, such as hormones and other chemical messengers. These receptors either activate or repress the transcription of target genes, which in turn promotes or suppresses physiological processes governing growth, differentiation, and homeostasis. NRs bind to specific DNA sequences and, in response to ligand binding, either promote or hinder the assembly of the transcriptional machinery, thereby influencing gene expression at the transcriptional level. These receptors are involved in a wide range of pathological conditions, including cancer, metabolic disorders, chronic inflammatory diseases, and immune system-related disorders. Modulation of NR function through targeted drugs has shown therapeutic benefits in treating such conditions. NR-targeted drugs, which either completely or selectively activate or block receptor function, represent a significant class of clinically valuable therapeutics. However, the pathways of NR-mediated gene expression and the resulting physiological effects are complex, involving crosstalk between various biomolecular components. As a result, NR-targeted drug discovery is challenging. With improved understanding of how NRs regulate physiological functions and deeper insights into their molecular structure, the process of NR-targeted drug discovery has evolved. While many traditional NR-targeting drugs are associated with side effects of varying severity, new drug candidates are being designed to minimize these adverse effects. Given that NR activity varies according to the tissue in which they are expressed and the specific isoform that is activated or repressed, achieving selectivity in targeting specific tissues and isoform classes may help reduce systemic side effects. In a recent breakthrough, the isoform-selective, hepato-targeted thyroid hormone-β agonist, Resmetirom (marketed as Rezdiffra), was approved for the treatment of non-alcoholic steatohepatitis. This chapter explores the structural and mechanistic principles guiding NR-targeted drug discovery and provides insights into recent developments in this field.

Beyond the Surface: Uncovering Secondary Causes of Osteoporosis for Optimal Management

Osteoporosis (OP), a condition marked by reduced bone mineral density and increased fracture risk, can arise either as a primary disorder or secondary to other diseases and medications. While primary OP typically relates to age-related or postmenopausal changes, secondary OP results from underlying conditions or drug exposures, complicating diagnosis and management. This review explores the pathophysiology, prevalence, and treatment approaches for secondary OP arising from endocrine, renal, gastrointestinal, hematological, and autoimmune disorders, as well as medication side effects. The findings highlight that secondary OP is frequently undiagnosed, particularly in premenopausal women and men, with conditions such as chronic kidney disease, glucocorticoid use, and diabetes among the primary contributors. Management strategies must be tailored to address the underlying conditions to effectively reduce fracture risk and improve outcomes. Ultimately, this review underscores the necessity for increased clinical awareness and more targeted interventions for optimal management of secondary OP.

Correlation of thyroid function and sensitivity to thyroid hormone with spinal bone mineral content, bone mineral density, and osteoporotic vertebral fracture: A cross-sectional study based on NHANES

Previous studies have demonstrated that thyroid hormone plays an important role in normal bone development, bone metabolism, and establishment of peak bone mass. However, the correlation of thyroid status with bone mineral content (BMC), bone mineral density (BMD), and osteoporotic vertebral fracture (OVF) is rarely discussed. The current study probes into the potential association between thyroid status and spinal BMC, BMD, and OVF from a novel perspective of thyroid function (TF) and sensitivity to thyroid hormone based on the National Health and Nutrition Examination Survey database. A total of 1844 participants were included in this study. The association of thyroid status with outcome variables, like spinal BMC, BMD, and OVF, was analyzed using thyroid function indices and sensitivity to thyroid hormone indices as influence factors. The correlation of them were assessed using univariate and multivariable weighted linear regression, weighted logistic regression models, restricted cubic spline model, and subgroup analyses. The results of this study showed that the association of free triiodothyronine (FT3)/free thyroxine (FT4) with BMC remained negatively associated after adjustment for all covariates. Higher thyroid peroxidase antibody (TPOAb) was significantly associated with an increased risk of developing OVF in both unadjusted and adjusted models. In addition, the results of the restricted cubic spline model were consistent with the weighted multivariate regression analysis after adjustment. The results of this cross-sectional study showed that higher FT3/FT4 and TPOAb were associated with decreased spinal BMC and the increased risk of OVF, indicating a complex link between thyroid status and bone health. Therefore, patients with hyperthyroidism, hypothyroidism, autoimmune thyroid disease, or abnormal peripheral thyroid sensitivity, especially who with elevated TPOAb or FT3/FT4, should focus on the prevention of vertebral osteopenia, osteoporosis, and OVF.

Calcium isotope composition in serum and urine for the assessment of bone mineral balance (BMB) - The Osteolabs post-market follow-up study

To further explore the clinical applicability of the calcium (Ca) isotope marker (CIM), we determined the 44Ca/42Ca isotope ratio in blood serum and urine. This ratio is expressed in the conventional δ-notation (as defined in the text below) specifically as CIM-serum for serum and as CIM-urine for urine. Our study tested the hypothesis that CIM values can differentiate between positive and negative bone mineral balance (BMB) across a diverse clinical population considering variables such as age, gender, and diet. The threshold values (CIM-serum: -0.85 ± 0.06 ‰ and CIM-urine: 0.23 ± 0.06 ‰) established in the OsteoGeo study (NCT02967978, Eisenhauer et al., 2019) were evaluated in 2320 participants as part of a surveillance study referred to as Osteolabs study. The earlier study revealed women with osteoporosis had an average CIM-serum value of -0.91 ± 0.21 ‰ (N = 24) and a CIM-urine value of 0.18 ± 0.33 ‰ (N = 71) that are significantly below the threshold values (p = 0.02 for urine, one-sided Wilcoxon rank test, p < 0.001 for serum, one-sided Student's t-test). Diseases affecting BMB such as osteoporosis, acute and chronic kidney disease (CKD), hyperthyroidism, breast cancer, prostate cancer, and myeloma were associated with significantly lower average CIM values, falling below the equilibrium thresholds and indicating negative BMB. In contrast, patients receiving osteoprotective treatments such as denosumab, Romosozumab, bisphosphonates, or hormone replacement therapy for certain diseases, had CIM values above the equilibrium thresholds indicating a positive BMB. Additionally, Ca supplements taken by some of the patients ((N = 22 (serum), N = 49 (urine), median dose: 500 mg) showed a Ca isotope composition approximately 1 ‰ higher than that from a normal diet. Consequently, their CIM values need to be adjusted to account for the amount and duration of supplementation to be comparable to those with a normal diet. Participants taking vitamin D (237 women; 58 men) showed no significant difference from the average values of the study group. Counterintuitively, the possible impact of malnutrition on individual BMB was most pronounced in vegans, who exhibited the highest average CIM-urine values compared to patients on a normal diet (p < 0.001, N = 17). The results of this study were consistent with the registered OsteoGeo study (NCT02967978) and other earlier published Ca isotope-based studies on BMB. We confirm that the CIM threshold values determined in the OsteoGeo study are generally valid for this much larger and diverse surveillance study group covering a diverse population encompassing various medical conditions and therapies.

Divergent associations of inflammatory markers with bone turnover markers in elderly patients with osteoporotic fractures

The association between inflammatory markers (IMs) and bone turnover markers (BTMs) in osteoporotic fracture patients has not been comprehensively studied. Therefore, this study examined the correlation between the platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR), or Monocyte-to-lymphocyte ratio (MLR) and BTMs in osteoporosis (OP) fracture patients. This retrospective cross-sectional study analyzed 740 OP fracture patients admitted to the hospital from January 2017 to July 2022. MLR, NLR, and PLR were calculated based on each patient's complete blood count. The relationship between IMs and BTMs was assessed using three models by adjusting variables. Furthermore, the potential curve relationship between IMs and BTMs was also determined via the threshold effect analysis and curve fittings. In addition, stratified analysis was performed on each adjusted variable to confirm the stability of the results. After adjusting the variables, the results showed that NLR was negatively correlated with procollagen type 1 N-terminal propeptide (P1NP) (β = -1.1788, 95% CI: -1.7230 to -0.6345, P-value < 0.0001) and β-C-terminal telopeptide of type I collagen (β-CTX) (β = -0.0104, 95% CI: -0.0145 to -0.0062, P-value < 0.0001), Furthermore, MLR was negatively correlated with P1NP (β = -17.4523, 95% CI: -27.7335 to -7.1710, P-value = 0.0009) and β-CTX (β = -0.1327, 95% CI: -0.2211 to -0.0443, P-value = 0.0034). However, PLR indicated a positive correlation with P1NP (β = 0.0326, 95% CI: 0.0007 to 0.0645, P-value = 0.0458) and β-CTX (β = 0.0003, 95% CI: 0.0001 to 0.0006, P-value = 0.0204). The threshold effect analysis and curve fittings revealed the presence of a turning point between NLR, MLR, and P1NP, β-CTX. In addition, the stratified analysis validated the result's stability. In conclusion, this study indicates a negative correlation between NLR and MLR with P1NP, while PLR shows a positive correlation with P1NP. Additionally, NLR and MLR exhibit a negative correlation with β-CTX, whereas PLR demonstrates a positive correlation with β-CTX. Further research is required to assess the intricate mechanisms linking IM with bone metabolism.

Dissection of potential anti-osteoporosis mechanism of isopsoralen - a quality control marker in Psoraleae Fructus - by metabolite profiling and network pharmacology

RATIONALE

Isopsoralen (ISO), a quality control marker (Q-marker) in Psoraleae Fructus, is proven to present an obvious anti-osteoporosis effect. Until now, the metabolism and anti-osteoporosis mechanisms of ISO have not been fully elucidated, greatly restricting its drug development.

METHODS

The metabolites of ISO in rats were profiled by using ultrahigh-performance liquid chromatography coupled with time-of-flight mass spectrometry. The potential anti-osteoporosis mechanism of ISO in vivo was predicted by using network pharmacology.

RESULTS

A total of 15 metabolites were characterized in rats after ingestion of ISO (20 mg/kg/day, by gavage), including 2 in plasma, 12 in urine, 6 in feces, 1 in heart, 3 in liver, 1 in spleen, 1 in lung, 3 in kidney, and 2 in brain. The pharmacology network results showed that ISO and its metabolites could regulate AKT1, SRC, NFKB1, EGFR, MAPK3, etc., involved in the prolactin signaling pathway, ErbB signaling pathway, thyroid hormone pathway, and PI3K-Akt signaling pathway.

CONCLUSIONS

This is the first time for revealing the in vivo metabolism features and potential anti-osteoporosis mechanism of ISO by metabolite profiling and network pharmacology, providing data for further verification of pharmacological mechanism.

Preparing the soil: Adjusting the metabolic health of patients with chronic wounds and musculoskeletal diseases

In recent years, systemic inflammation has emerged as a pivotal player in the development and progression of various degenerative diseases. This complex, chronic inflammatory state, often undetected, can have far-reaching consequences for the body's physiology. At the molecular level, markers such as C-reactive protein, cytokines and other inflammatory mediators serve as indicators of systemic inflammation and often act as predictors of numerous musculoskeletal diseases and even certain forms of cancer. The concept of 'meta-inflammation', specifically referring to metabolically triggered inflammation, allows healthcare professionals to understand inflammatory responses in patients with metabolic syndrome. Driven by nutrient excess and the expansion of adipose tissue, meta-inflammation is closely associated with insulin resistance, further propagating the metabolic dysfunction observed in many Western societies. Wound persistence, on the other hand, exacerbates the detrimental effects of prolonged inflammation at the local level. Acute inflammation is a beneficial and essential process for wound healing and infection control. However, when inflammation fails to resolve, it can impede the healing process, leading to chronic wounds, excessive scarring and even the activation of fibrotic pathways. This approach significantly reduces the efficacy of regenerative biological therapies. Our review focuses on the vital role of proteins, vitamins and minerals in collagen synthesis and cell proliferation for tissue healing. We also examine hormonal influences on regeneration, noting the negative effects of imbalances, and emphasize glucose regulation's importance in creating a stable environment for chronic wound healing.

Bone Loss and Fractures in Post-Menopausal Women Living with HIV: A Narrative Review

INTRODUCTION

Post-menopausal women living with Human Immunodeficiency Virus (WLHIV) face an increased risk of bone fractures due to the relationship between HIV-related factors and menopause. This narrative review aims to summarise the current knowledge about fracture risk among post-menopausal WLHIV in particular looking at hormonal changes, combined antiretroviral therapy (cART), lifestyle factors, and psychosocial implications. We also profiled a summary of the significant, recent studies of post-menopausal WLHIV residing in low-income countries (LIC).

METHODS

A thorough search of the literature was performed across PubMed, Medline, Scopus, and Google Scholar, focussing on studies published between 2000 and 2024. Inclusion criteria entailed original research, reviews, and meta-analyses addressing bone mineral density (BMD), fracture incidence, and related risk factors in post-menopausal WLHIV.

RESULTS

The review identified 223 relevant studies. Post-menopausal WLHIV exhibit significantly lower BMD and higher fracture rates compared to both HIV-negative post-menopausal women and pre-menopausal WLHIV. cART, particularly tenofovir disoproxil fumarate (TDF), contributes to reduced BMD. Menopausal status exacerbates this risk through decreased oestrogen levels, leading to increased bone resorption. Moreover, lifestyle choices such as smoking, alcohol consumption, and low physical activity are more prevalent in PWHIV, which further elevates fracture risk. Different psychosocial factors may make WLWHIV more vulnerable at this stage of their life, such as depression, isolation, stigma, and housing and nutritional issues. Women living in LICs face a variety of challenges in accessing HIV care. There are gaps in research related to the prevalence of osteoporosis and bone loss in post-menopausal WLHIV in LICs.

CONCLUSION

Post-menopausal women living with HIV face a significantly higher risk of bone loss and fractures due to the combined effects of HIV and menopause. Antiretroviral therapy (particularly TDF), lifestyle factors, and psychosocial challenges exacerbate this risk. There is a need for careful selection of cART, hormone replacement therapy (HRT), and emerging treatments such as Abaloparatide. A holistic approach including lifestyle changes and psychosocial support is crucial to reduce fracture risk in WLHIV, especially in low-income countries.

Hypothyroidism Impacts Clinical and Healthcare Utilization Outcomes After Primary Total Hip Arthroplasty

BACKGROUND

Our objective was to assess the association of hypothyroidism with outcomes of primary total hip arthroplasty (THA) overall and stratified by underlying diagnosis.

METHODS

We identified patients undergoing primary THA in a national database from 2016 to 2020. We stratified them based on primary diagnoses into hip osteoarthritis (OA; N = 1,761,960), osteonecrosis (ON; N = 78,275), traumatic fracture (N = 532,910), inflammatory arthritis (IA; N = 3,520), and "other" (N = 90,550). We identified hypothyroidism and complications using secondary diagnoses. Among 2,467,215 patients undergoing primary THA, mean age was 68 years (range, 18 to 90), and 58.3% were women. Complications codes only included initial encounters. We performed time-trends analyses and multivariable-adjusted regression analyses adjusted for demographics, expected primary payer, a comorbidity score, elective versus non-elective admission, and hospital characteristic information, with clinical and healthcare utilization outcome as endpoints.

RESULTS

Overall, hypothyroidism was significantly associated with increased LOS, total charges, non-routine discharges, blood transfusions, and prosthetic fractures. In the OA cohort, hypothyroidism was associated with increased LOS, total charges, and non-routine discharges (P < .001 for each), and blood transfusions (P = .02). Hypothyroidism was associated with increased total charges (P = .001) in the ON cohort and with increased LOS, non-routine discharge, and blood transfusion (P < .05 each) in the traumatic fracture cohort.

CONCLUSIONS

Hypothyroidism was associated with blood transfusions, prosthetic fractures, and utilization outcomes in THA patients. Tailored intervention strategies for hypothyroidism should be tested for their efficacy to improve THA peri-operative outcomes.

Mechanisms and Intervention of Prebiotic Foods in Musculoskeletal Health

The review focuses primarily on collating and analyzing the mechanistic research data that discusses the function of prebiotics to halt the frailty of musculoskeletal system. Musculoskeletal diseases (MSDs) are frequently reported to co-occur within their own categories of conditions, such as osteoarthritis, rheumatoid arthritis, gouty arthritis, and psoriatic arthritis owing to their overlapping pathogenesis. Consequently, the same drugs are often used to manage the complications of most types. A few recent studies have addressed the therapeutic functions of gut microbes toward those commonly shared MSD pathway targets. Improving microbial diversity and enriching their population in the gut would promote the regeneration and recovery of the musculoskeletal system. Prebiotics are usually nondigestible substrates that are selectively used or digested by the gut microbes conferring health promotion. The microbial fermentation of prebiotics generates numerous host-beneficial therapeutic molecules. This study inspects the presumptive functions of plant-derived prebiotics for the growth and restoration of intestinal microbiota and the consequent improvement of skeletal health. The review also highlights the discrete functions of prebiotics against inflammation, autoimmunity, infection, physiologic overloading mechanism, and aging-associated loss of metabolism in MSD.

Exploring the Role of Hormones and Cytokines in Osteoporosis Development

The disease of osteoporosis is characterized by impaired bone structure and an increased risk of fractures. There is a significant impact of cytokines and hormones on bone homeostasis and the diagnosis of osteoporosis. As defined by the World Health Organization (WHO), osteoporosis is defined as having a bone mineral density (BMD) that is 2.5 standard deviations (SD) or more below the average for young and healthy women (T score < -2.5 SD). Cytokines and hormones, particularly in the remodeling of bone between osteoclasts and osteoblasts, control the differentiation and activation of bone cells through cytokine networks and signaling pathways like the nuclear factor kappa-B ligand (RANKL)/the receptor of RANKL (RANK)/osteoprotegerin (OPG) axis, while estrogen, parathyroid hormones, testosterone, and calcitonin influence bone density and play significant roles in the treatment of osteoporosis. This review aims to examine the roles of cytokines and hormones in the pathophysiology of osteoporosis, evaluating current diagnostic methods, and highlighting new technologies that could help for early detection and treatment of osteoporosis.

Thyroid dysgenesis associated with dwarfism, osteoporosis and spontaneous fractures in a goat

An 11-month-old female Saanen goat, weighing 12.7 kg, was taken to the Veterinary Hospital of the Federal University of Minas Gerais because of sternal recumbency. On clinical examination, the animal was much smaller than expected and had hair similar to that of puppies and areas of hyperpigmentation on the head and dorsocervical and dorsothoracic cranial regions. Radiographic examination revealed fractures in both femurs and severe generalized osteoporosis. Given the unfavourable prognosis, the animal was euthanized. Necropsy revealed generalized pallor, muscular atrophy of the pelvic limbs and little reserve of subcutaneous adipose tissue. Both femurs had complete and closed diaphyseal fractures. The second lumbar vertebra was severely reduced in length as a result of a fracture, with dorsal displacement of the vertebral body towards the vertebral canal and compression of the spinal cord. Long bones and vertebrae had severe cortical thinning, enlargement of the medullary canal and reduced resistance. The thyroid gland was not in its normal anatomical location. A pale red nodule (1.0 × 0.4 cm) in the serosa of the middle third of the trachea, close to the thoracic entrance, was confirmed as ectopic thyroid tissue. Microscopically, the bones had evidence of growth arrest and severe osteoporosis. The ectopic thyroid nodule was hyperplastic with severe hypertrophy of follicular cells. The spinal cord was compressed by vertebral fractures and had focally extensive and severe myelomalacia. Based on the pathological features, the case was diagnosed as thyroid dysgenesis characterized by eutopic thyroid agenesis and ectopic thyroid tissue, associated with interruption of bone growth with dwarfism, osteoporosis and spontaneous secondary fractures with compression of the lumbar spinal cord.

EMAS position statement: Thyroid disease and menopause

INTRODUCTION

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

MATERIALS AND METHODS

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

SUMMARY RECOMMENDATIONS

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

Dental implant considerations in patients with systemic diseases: An updated comprehensive review

BACKGROUND

Various medical conditions and the drugs used to treat them have been shown to impede or complicate dental implant surgery. It is crucial to carefully monitor the medical status and potential post-operative complications of patients with systemic diseases, particularly elderly patients, to minimize the risk of health complications that may arise.

AIM

The purpose of this study was to review the existing evidence on the viability of dental implants in patients with systemic diseases and to provide practical recommendations to achieve the best possible results in the corresponding patient population.

METHODS

The information for our study was compiled using data from PubMed, Scopus, Web of Science and Google Scholar databases and searched separately for each systemic disease included in our work until October 2023. An additional manual search was also performed to increase the search sensitivity. Only English-language publications were included and assessed according to titles, abstracts and full texts.

RESULTS

In total, 6784 studies were found. After checking for duplicates and full-text availability, screening for the inclusion criteria and manually searching reference lists, 570 articles remained to be considered in this study.

CONCLUSION

In treating patients with systemic conditions, the cost-benefit analysis should consider the patient's quality of life and expected lifespan. The success of dental implants depends heavily on ensuring appropriate maintenance therapy, ideal oral hygiene standards, no smoking and avoiding other risk factors. Indications and contraindications for dental implants in cases of systemic diseases are yet to be more understood; broader and hardcore research needs to be done for a guideline foundation.

The impact of thyroid function on total spine bone mineral density in postmenopausal women

PURPOSE

Osteoporosis has been a widespread concern for older women, especially postmenopausal women. Thyroid function is crucial for bone metabolism. However, the relationship between thyroid function variation within thyroxine reference range and bone mineral density (BMD) remains ambiguous. The objective of this study was to evaluate the effect of subclinical hypothyroidism or hyperthyroidism on total spinal BMD in postmenopausal women.

METHODS

Based on data from the National Health and Nutrition Examination Survey (NHANES) 2007-2010, multivariable weighted logistic regression was used to evaluate the relationships between total spine BMD and TSH among postmenopausal women aged ≥50.

RESULTS

After accounting for a number of variables, this study discovered that the middle TSH tertile was associated with a decreased probability of osteoporosis. Additionally, the subgroup analysis revealed that postmenopausal women over the age of 65 or people with an overweight BMI had a clearer relationship between total spine BMD and TSH.

CONCLUSION

The total spinal BMD had a positive relationship with thyroid stimulating hormone in postmenopausal women, and that appropriate TSH level (1.38-2.32 mIU/L) was accompanied by higher total spinal BMD.

Bone mineral density in adults growth hormone deficiency with different ages of onset: a real-world retrospective study

PURPOSE

Bone mineral density (BMD) impairment is one of the critical factors for long-term quality of life in adults growth hormone deficiency (AGHD). This study aims to investigate the annual changes in BMD in AGHD patients with different ages of onset and to identify predicting factors that influence BMD.

METHODS

AGHD patients (n = 160) with available data for 4 years follow-up from a major tertiary medical center in China were retrospectively included (110 [68.8%] childhood-onset, 119 [74.4%] male). BMD of the axial bone (including total hip, neck of femur, and L1-4) derived from dual X-ray absorptiometry and final height were investigated at the first visit, 12 months, 24 months, 36 months, and 48 months thereafter. Low BMD was defined as Z-score ≤ -2.

RESULTS

The prevalence of low BMD was 30.0% at baseline and 12.5% at 4 years of follow-up. The CO AGHD group presented a significantly lower BMD than the AO AGHD group at the baseline (P = 0.009). In contrast, the CO AGHD group had significantly greater median annual BMD change than the AO AGHD group (0.044 vs. -0.0003 g/cm2/year in L1-4, P < 0.001), indicating a significant difference in the overall BMD trend between CO and AO groups. Childhood-onset (odds ratio [OR] 0.326, P = 0.012), low serum testosterone (OR 0.847; P = 0.004) and FT4 (OR 0.595; P = 0.039) level were independent risk factors for BMD loss.

CONCLUSION

The annual changes of BMD show a different pattern in AGHD patients with varying ages of onset. Patients with CO AGHD have a lower bone mass, and in general, appropriate replacement therapy is necessary for long-term bone health in AGHD patients.

Investigating the causal relationship between thyroid dysfunction diseases and osteoporosis: a two-sample Mendelian randomization analysis

The prevalence of thyroid dysfunction diseases (TDFDs) and osteoporosis (OP) is high. Previous studies have indicated a potential association between TDFDs and OP, yet the causal direction remains unclear. This study aimed to investigate the potential causal relationship between TDFDs and the risk of developing OP and related fractures. We obtained pooled data from genome-wide association studies (GWASs) conducted on TDFDs and OP in European populations and identified single-nucleotide polymorphisms (SNPs) with genome-wide significance levels associated with exposure to TDFDs as instrumental variables. Inverse variance weighted (IVW) was employed as the primary method for Mendelian randomization (MR) analysis, supplemented by MR‒Egger, weighted median, simple mode and weighted mode methods. Sensitivity analyses were conducted to evaluate the robustness of the findings. The IVW method demonstrated an increased risk of OP in patients with TDFDs, including hyperthyroidism and hypothyroidism (TDFDs: OR = 1.11; 95% CI 1.09, 1.13; hypothyroidism: OR = 1.14; 95% CI 1.10, 1.17; hyperthyroidism: OR = 1.09; 95% CI 1.06, 1.12). These findings were supported by supplementary analysis, which revealed a positive correlation between TDFDs and the risk of OP. Multiple sensitivity analyses confirmed the absence of horizontal pleiotropy in the study, thus indicating the robustness of our results. The causal relationship between TDFDs and increased risk of OP implies the need for early bone mineral density (BMD) screening and proactive prevention and treatment strategies for individuals with TDFDs.

Diagnosis and therapeutic approach to bone health in patients with hypopituitarism

The results of many studies in recent years indicate a significant impact of pituitary function on bone health. The proper function of the pituitary gland has a significant impact on the growth of the skeleton and the appearance of sexual dimorphism. It is also responsible for achieving peak bone mass, which protects against the development of osteoporosis and fractures later in life. It is also liable for the proper remodeling of the skeleton, which is a physiological mechanism managing the proper mechanical resistance of bones and the possibility of its regeneration after injuries. Pituitary diseases causing hypofunction and deficiency of tropic hormones, and thus deficiency of key hormones of effector organs, have a negative impact on the skeleton, resulting in reduced bone mass and susceptibility to pathological fractures. The early appearance of pituitary dysfunction, i.e. in the pre-pubertal period, is responsible for failure to achieve peak bone mass, and thus the risk of developing osteoporosis in later years. This argues for the need for a thorough assessment of patients with hypopituitarism, not only in terms of metabolic disorders, but also in terms of bone disorders. Early and properly performed treatment may prevent patients from developing the bone complications that are so common in this pathology. The aim of this review is to discuss the physiological, pathophysiological, and clinical insights of bone involvement in pituitary disease.

Body composition changes in patients with differentiated thyroid cancer after iodine-131 treatment and short-term levothyroxine replacement and suppression therapy

PURPOSE

The purposes of this study were to assess the changes in body composition in patients who underwent thyroidectomy due to differentiated thyroid cancer (DTC) after radioactive iodine therapy (RAI) and short-term levothyroxine (LT4) supplementation and to explore the correlations between body composition distribution and corresponding blood indices.

METHODS

Fifty-seven thyroidectomized DTC patients were included. Serum was tested for several biochemical indices of thyroid function, lipids, and bone metabolism, and body composition parameters were measured via dual-energy X-ray absorptiometry before and 4-6 weeks after RAI and LT4 supplementation.

RESULTS

The body composition of DTC patients changed after RAI. Fat mass in all parts of the body decreased (range of relative change (RRC) -12.97--2.80%). Bone mineral content (BMC) increased throughout the body (relative change (RC) 12.12%), head (RC 36.23%), pelvis (RC 9.00%), and legs (RC 3.15%). Similarly, bone mineral density (BMD) increased in different regions (RRC 3.60-26.43%), except for the arms. Notably, lean mass in the arms (RC 4.30%) and legs (RC 3.67%) increased, while that in the head decreased (RC -2.75%), while total lean mass did not change at 4-6 weeks after LT4 supplementation. Furthermore, changes in fat distribution in the android region were related to the changes in total cholesterol (r = -0.390) and low-density lipoprotein cholesterol (r = -0.354), and changes in the BMC and BMD of the lumbar spine were positively associated with the changes in calcitonin (r = 0.302 and 0.325, respectively).

CONCLUSIONS

After RAI and short-term LT4 supplementation in DTC patients, body composition rapidly and positively changed and was characterized by decreased fat mass and increased BMC and BMD.

Bone Metabolism and Dental Implant Insertion as a Correlation Affecting on Marginal Bone Remodeling: Texture Analysis and the New Corticalization Index, Predictor of Marginal Bone Loss-3 Months of Follow-Up

Background/Objectives: The general condition of implantology patients is crucial when considering the long- and short-term survival of dental implants. The aim of the research was to evaluate the correlation between the new corticalization index (CI) and patients' condition, and its impact on marginal bone loss (MBL) leading to implant failure, using only radiographic (RTG) images on a pixel level. Method: Bone near the dental implant neck was examined, and texture features were analyzed. Statistical analysis includes analysis of simple regression where the correlation coefficient (CC) and R2 were calculated. Detected relationships were assumed to be statistically significant when p < 0.05. Statgraphics Centurion version 18.1.12 (Stat Point Technologies, Warrenton, VA, USA) was used to conduct the statistical analyses. Results: The research revealed a correlation between MBL after 3 months and BMI, PTH, TSH, Ca2+ level in blood serum, phosphates in blood serum, and vitamin D. A correlation was also observed between CI and PTH, Ca2+ level in blood serum, vitamin D, LDL, HDL, and triglycerides on the day of surgery. After 3 months of the observation period, CI was correlated with PTH, TSH, Ca2+ level in blood serum, and triglycerides. Conclusion: The results of the research confirm that the general condition of patients corresponds with CI and MBL. A patient's general condition has an impact on bone metabolism around dental implants. Implant insertion should be considered if the general condition of the patient is not stable. However, CI has not yet been fully investigated. Further studies are necessary to check and categorize the impact of corticalization on marginal bone loss near dental implants.

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

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

Effects of selenium and iodine on Kashin-Beck disease: an updated review

Kashin-Beck disease (KBD) is an endochondral osteogenesis disorder characterised by epiphysis damage and secondary deformable arthropathy induced by multiple external factors, among which selenium (Se) and iodine deficiency are important influencing factors. Iodine deficiency is usually accompanied by a low Se content in the soil in the KBD areas of China. Se can reverse oxidative damage to chondrocytes. In addition, Se is related to the bone conversion rate and bone mineral density. Low Se will hinder growth and change bone metabolism, resulting in a decrease in the bone conversion rate and bone mineral density. Thyroid hormone imbalance caused by thyroid dysfunction caused by iodine deficiency can damage bone homeostasis. Compared with Se deficiency alone, Se combined with iodine deficiency can reduce the activity of glutathione peroxidase more effectively, which increases the vulnerability of chondrocytes and other target cells to oxidative stress, resulting in chondrocyte death. Clinical studies have shown that supplementation with Se and iodine is helpful for the prevention and treatment of KBD.

Environmental perchlorate, thiocyanate, and nitrate exposures and bone mineral density: a national cross-sectional study in the US adults

Associations of perchlorate, thiocyanate, and nitrate exposures with bone mineral density (BMD) in adults have not previously been studied. This study aimed to estimate the associations of individual and concurrent exposure of the three chemicals with adult BMD. Based on National Health and Nutrition Examination Survey (NHANES, 2011-2018), 1618 non-pregnant adults (age ≥ 20 years and 47.0% female) were included in this study. Survey-weighted linear regression models were used to estimate individual urinary perchlorate, thiocyanate, and nitrate concentrations with lumbar spine BMD and total BMD in adults. Then, weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) models were conducted to evaluate associations of co-occurrence of the three chemicals with adult BMD. In all participants, nitrate exposure was inversely associated with lumbar spine BMD (β =  - 0.054, 95%CI: - 0.097, - 0.010). In stratification analyses, significant inverse associations were observed in female and participants older than 40 years old. In WQS regressions, significant negative associations of the weighted sum of the three chemicals with total and lumbar spine BMD (β =  - 0.014, 95%CI: - 0.021, - 0.007; β =  - 0.011, 95%CI: - 0.019, - 0.004, respectively) were found, and the dominant contributor was nitrate. In the BKMR models, non-linear dose-response associations of nitrate exposure with lumbar spine and total BMD were observed. These findings suggested that environmental perchlorate, thiocyanate, and nitrate exposure may reduce adult BMD and nitrate is the main contributor.

Chronic Excess Iodine Intake Inhibits Bone Reconstruction Leading to Osteoporosis in Rats

BACKGROUND

Although iodine modulates bone metabolism in the treatment of thyroid disease, the effect of iodine intake on bone metabolism remains less known.

OBJECTIVE

This study evaluated the effect of excess iodine intake in rats on bone reconstruction in the 6th and 12th month of intervention.

METHOD

Rats were treated with different doses of iodinated water: the normal group (NI, 6.15 μg/d), 5-fold high iodine group (5HI, 30.75 μg/d), 10-fold high iodine group (10HI, 61.5 μg/d), 50-fold high iodine group (50HI, 307.5 μg/d), and 100-fold high iodine group (100HI, 615 μg/d). Thyroid hormone concentrations were determined by a chemiluminescent immunoassay. Morphometry and microstructure of bone trabecula were observed by hematoxylin and eosin staining and microcomputed tomography, respectively. Alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) staining were performed to evaluate the activity of osteoblasts and osteoclasts, respectively.

RESULTS

The 24-h urine iodine concentration increased with iodine intake. The rats in the HI groups had higher serum thyroid-stimulating hormone and decreased serum free thyroxine concentrations in the 12th month than the NI group (all P < 0.05). The percentage of the trabecular bone area and osteoblast perimeter in the 100HI group were significantly lower than those in the NI group (P < 0.05). Increased structure model index was observed in the 50HI and 100HI groups compared with the NI group in the 6th month and increased trabecular separation in the 12th month (all P < 0.05). ALP and TRAP staining revealed osteoblastic bone formation was reduced, and the number of TRAP+ multinucleated cells decreased with increasing iodine intake.

CONCLUSIONS

Excess iodine intake may increase the risk of hypothyroidism in rats. Chronic excess iodine intake can lead to abnormal changes in skeletal structure, resulting in reduced activity of osteoblasts and osteoclasts, which inhibits the process of bone reconstruction and may lead to osteoporosis.

Evaluation of multiple organophosphate insecticide exposure in relation to altered thyroid hormones in NHANES 2007-2008 adult population

The thyroid gland is susceptible to chemical exposure such as organophosphate insecticides (OPIs). With the ubiquitous nature of these products, humans are simultaneously exposed to a multitude of chemicals. This study aimed to evaluate the association between an individual and a mixture of OPI metabolites and changes in serum thyroid hormone (TH) concentrations. The analyzed data were 1,434 participants from the United States National Health and Nutrition Examination Surveys (NHANES) cycle 2007-2008. Generalized linear model (GLM) regression, weighted quantile sum (WQS), and adaptive least absolute shrinkage and selection operator (adaptive LASSO) regression were used to investigate the associations between urinary OPI metabolites and altered serum THs. In GLM, all of the five urinary OPI metabolites were inversely associated with free triiodothyronine (FT3) among the male subjects; meanwhile, higher thyroglobulin (Tg) was related to dimethylphosphate (DMP). Moreover, in WQS models, the metabolite mixture induced FT3 down-regulation (β = -0.209 (95% CI: -0.310, -0.114)), and caused an increased Tg concentration (β = 0.120 (95% CI: 0.024, 0.212)), however, any significant association was observed among female participants. Consistently, the weighted index and LASSO coefficient demonstrated dimethylthiophosphate (DMTP) as the strongest metabolite in the FT3 model (mean weight= 3.449e-01 and β =-0.022, respectively), and dimethylphosphate (DMP) represented the highest association in the Tg model (mean weight= 9.873e-01 and β =-0.020, respectively). Further research is required to confirm our results and investigate the clinical impacts of these disruptions.

Risk factors of primary Sjögrens syndrome combined with osteoporosis

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease that is prevalent in middle-aged and elderly women, characterized by dry mouth, dry eyes, fatigue, and joint pain. Nearly one-third pSS patients have been suffering with osteoporosis (OP), displaying symptoms of lumbago, back pain, and even fracture, all of which severely affect their life quality. Common risk factors for pSS and OP include gender and age, persistent state of inflammation, immune disorders, intestinal flora imbalance, vitamin D deficiency, dyslipidemia and sarcopenia. Meanwhile, the comorbidities of pSS, such as renal tubular acidosis, primary biliary cholangitis, autoimmune thyroid diseases, and drugs (glucocorticoids, methotrexate, and cyclophosphamide) are unique risk factors for pSS complicated with OP. Education, guidance of healthy lifestyle, and OP screening are recommended for bone management of pSS patients. Early detection and intervention are crucial for keeping bone health and life quality in pSS patients.

Bone Mineral Density and Vitamin D Status in Patients with Autoimmune Polyglandular Syndromes: A Single Tertiary Care Center Experience

Immunological abnormalities, the resulting endocrinopathies, and their treatments may impact bone health and 25-hydroxyvitamin D (25-OHD) in patients with autoimmune polyglandular syndromes (APS). Several etiologies contribute to increased risk for low bone mineral density (BMD), including vitamin D deficiency. This study evaluated the vitamin D level and BMD of patients with APS. We performed a cross-sectional study on 44 patients with APS and 55 age and gender-matched control subjects. Among patients with APS, 14 were classified as APS-2 [Addison's disease (AD)+autoimmune thyroid disease (ATD) and/or type 1 diabetes(T1D)]. In contrast, the other 30 were APS-3 (ATD+T1D+other autoimmune diseases). Serum samples were analyzed for vitamin D levels. The lumbar spine and femoral neck BMD were measured by dual X-ray absorptiometry. Z-scores were obtained by comparison with age- and gender-matched average values (both patients and controls). The accepted normal levels were Z-score>-1 and 25-OHD>30 ng/ml. Patients with APS showed 25-OHD levels and BMD significantly lower than healthy controls (p<0.001 and p<0.05, respectively). The highest prevalence of abnormal BMD was observed in the APS-2 subgroup (13 out of 14 patients, 92.6%). Identifying and treating vitamin D deficiency and low BMD is critical in APS patients. The fact that the significant endocrine component of APS-2 is AD, and these patients receive chronic long-term glucocorticoid therapy can be shown as the reason for this result. However, more extensive prospective controlled studies are needed to confirm these findings.

The impact of diabetes, anemia, and renal function in the relationship between osteoporosis and fasting blood glucose among Taiwanese women: a cross-sectional study

BACKGROUND

The aim of this study was to investigate the association between fasting blood glucose and osteoporosis in women with diabetes, anemia, and renal function.

METHODS

The medical records of women who underwent a general health examination at a regional hospital in southern Taiwan were retrospectively reviewed. Logistic regression analysis was performed to assess the association between osteoporosis and fasting blood glucose separately for the eight subgroups (diabetes or non-diabetes, anemia or non-anemia, normal or decreased renal function), adjusting for other clinical characteristics and laboratory findings.

RESULTS

A total of 11,872 women were included in the study. Among women with diabetes, anemia, and decreased renal function, an increment of 10 mg/dL in fasting blood glucose was associated with an increased risk of osteoporosis (adjusted odds ratio [aOR] = 1.57, p = 0.004). Among women without diabetes, fasting blood glucose was significantly associated with an increased risk of osteoporosis in those with anemia and normal renal function (OR = 1.14, p = 0.023) and those without anemia and normal renal function (OR = 1.04, p = 0.015), but these associations were not significant after adjusting for other covariates.

CONCLUSIONS

Higher fasting blood glucose levels in women with diabetes, anemia, and decreased renal function were associated with an increased risk of osteoporosis. Clinicians should be vigilant about glucose control in patients with diabetes to reduce the risk of fracture.

Basal Metabolic Rate Versus Dietary Vitamin D and Calcium Intakes and the Association With Body Composition and Bone Health After Chronic Spinal Cord Injury

We examined the association among basal metabolic rate (BMR) as well as dietary intakes of vitamin D (Vit D) and calcium on body composition and bone mineral density (BMD) after spinal cord injury (SCI). Cross-sectional design. Veterans Affairs Medical Center, Richmond, VA. About 33 individuals with chronic SCI who recorded their food consumption 3 days per week for 2 weeks. BMR was measured after 10 to 12 h of overnight fast. Average daily vit D and calcium intakes, and total caloric intake were recorded and analyzed using the Nutrition Data System for Research (NDSR) software. Fasting blood analysis for 25-hydroxyvitamin D (25[OH]D) status and Triiodothyronine (T3) status was performed (n = 10). Total and regional BMD, % fat mass (FM), and % lean mass (LM) were measured by dual X-ray absorptiometry scans. Participants consumed less than the Institute of Medicine (IOM) recommended daily allowances (RDA) for vit D (600-800 IU) and calcium (1000-1200 mg) for adults. BMR was positively related to total-lean mass (r = .62, P = .0001; n = 32) and leg-lean mass (r = .51, P = .003; n = 32). Adjusted BMR was negatively related to BMD of the left (r = -.38, P = .047; n = 28) and the right (r = -.41, P = .032; n = 28) proximal tibia. Vit D intake was negatively related to percentage total-FM (r = -.33, P = .07; n = 29) and legs-%FM (r = -.37, P = .047; n = 29). Multivariate regression models indicated that adjusted BMR explained the variance in leg fat mass (34%; P = .002) and percentage fat mass (44%; P < .0001). Persons with SCI are likely to consume less than the RDAs for vit D and calcium. BMR may explain the changes in body composition and bone metabolism. Dietary vit D should be considered as a prophylactic intervention in maintenance of bone health after SCI.

Engineered Dynamic Hydrogel Niches for the Regulation of Redox Homeostasis in Osteoporosis and Degenerative Endocrine Diseases

Osteoporosis and degenerative endocrine diseases are some of the major causes of disability in the elderly. The feedback loop in the endocrine system works to control the release of hormones and maintain the homeostasis of metabolism, thereby regulating the function of target organs. The breakdown of this feedback loop results in various endocrine and metabolic disorders, such as osteoporosis, type II diabetes, hyperlipidemia, etc. The direct regulation of redox homeostasis is one of the most attractive strategies to redress the imbalance of the feedback loop. The biophysical regulation of redox homeostasis can be achieved through engineered dynamic hydrogel niches, with which cellular mechanics and redox homeostasis are intrinsically connected. Mechanotransduction-dependent redox signaling is initiated by cell surface protein assemblies, cadherins for cell-cell junctions, and integrins for cell-ECM interactions. In this review, we focused on the biophysical regulation of redox homeostasis via the tunable cell-ECM interactions in the engineered dynamic hydrogel niches. We elucidate processes from the rational design of the hydrogel matrix to the mechano-signaling initiation and then to the redox response of the encapsulated cells. We also gave a comprehensive summary of the current biomedical applications of this strategy in several degenerative endocrine disease models.

Studying the activity of matrix metalloproteinases and antibodies to DNA in patients with autoimmune thyroiditis

Background. In autoimmune thyroiditis, in addition to impaired immunological tolerance, a significant role is played by biochemical markers such as matrix metalloproteinases and antibodies to deoxyribonucleic acid (DNA), which can contribute to the pathogenesis of the disease. Aim. Studying the activity of metalloproteinases-3, -7 and the level of antibodies to DNA in patients with autoimmune thyroiditis. Material and methods. In 2019–2021 a non-randomized study in the research laboratory at the Department of Biochemistry of the Azerbaijan Medical University, during which the blood serum of 170 patients with autoimmune thyroiditis, 64 (37.6%) men, average age 39.4±11.2 years and 106 (62.4%) women, average age 37.8±9.05 years, was conducted. Inclusion criteria: men and women aged 18 years and older with a primary diagnosis of “autoimmune thyroiditis” without concomitant allergic or other autoimmune diseases and severe somatic disorders. The control group consisted of 65 people (average age 38.7±10.8 years) without any thyroid disease or autoimmune pathology. Analysis of clinical and laboratory studies with determination of the level of thyroid-stimulating hormone, free thyroxine and free triiodothyronine made it possible to divide patients into two groups: the first group — 74 patients with a subclinical form of the disease; the second group — 96 patients with a manifest form of the disease. In all patients, the activity of metalloproteinases-3 and -7 in the blood serum was determined by enzyme-linked immunosorbent assay, and the content of antibodies to native and denatured DNA was determined by enzyme-linked immunosorbent assay. Intergroup comparisons on quantitative indicators were carried out using the nonparametric Mann–Whitney rank test, taking into account the difference in the distribution of the analyzed indicators from the normal one. Qualitative characteristics were assessed as percentages. Results. The median activity of metalloproteinases-3 and -7 in the total group of patients was 56 (51.0; 59.0) and 4.6 (4.3; 5.2) ng/ml, respectively, which was significantly higher than the control values — 23.0 (16.0; 26.0) and 3.6 (3.4; 4.1) ng/ml, respectively (p=0.0001252 and p=0.00054). There were no statistically significant differences in the level of metalloproteinase-7 in patients with subclinical and manifest thyroiditis (p=0.097), while the median activity of metalloproteinase-3 in the manifest group was 59.0 (56.0; 65.0) ng/ml and it was higher than in patients of the subclinical group by 13.2%. The content of antibodies to native DNA in patients was 4.4 (2.3; 9.9) units/ml, which was statistically significantly higher compared to the control group — 2.6 (1.5; 3.6) units/ml (p 0.001), while no significant differences were found in the levels of antibodies to denatured DNA in patients compared to control values. Conclusion. The worsening of the autoimmune process is accompanied by an increase in the activity of metalloproteinases and antinuclear antibodies.

Exploring the Association between Thyroid Function and Frailty: Insights from Representative Korean Data

BACKGRUOUND

This study investigates the association between thyroid function and frailty in the old patients using representative data.

METHODS

The study was conducted using data from the Korea National Health and Nutrition Examination Survey conducted from 2013 to 2015. The study population included 2,416 participants aged 50 years and older with available thyroid function test data. Frailty assessment was performed using the Fried frailty phenotype. The prevalence of frailty was analyzed across different thyroid diseases and thyroid function parameters.

RESULTS

The significant association between thyroid dysfunction and frailty was observed in overt hyperthyroidism and subclinical hyperthyroidism. After adjusting for various factors, the association between thyroid dysfunction and frailty remained significant. On the other hand, overt hypothyroidism did not show a significant association with frailty in the adjusted analysis. For individuals with overt hyperthyroidism and subclinical hyperthyroidism, higher levels of free thyroxine (FT4) were significantly associated with an increased risk of frailty (aOR >999; 95% CI, >999 to 999). Among individuals with overt hypothyroidism, lower level of FT4 levels and high thyrotropin (TSH) levels showed a significant association with frailty risk (FT4: aOR, <0.01; TSH: aOR, 999). In participants with subclinical hypothyroidism, there were no significant associations between parameters for thyroid and frailty risk.

CONCLUSION

These findings suggest that thyroid dysfunction, particularly overt hyperthyroidism and subclinical hyperthyroidism, may be associated with an increased risk of frailty in the old patients.