Role of nutritional vitamin D in osteoporosis treatment

Alkaline Water Mitigates Bone Loss in Streptozotocin-Induced Type II Diabetic Rats

Background A decline in bone mineral density is a defining feature of osteoporosis, which is a prevalent bone complication associated with diabetes. This study aims to shed light on the protective effect of Zamzam water (ZW), a famous alkaline water, on diabetes-induced osteoporosis. Methodology Of a total of 40 male rats, 10 male rats each were divided into the following four groups: group I (normal control rats), group II (ZW group), group III (diabetic rats), and group IV (DM + ZW). Anteroposterior and lateral X-rays were taken of the rats in each group before the end of the experiment. The study assessed serum levels of inflammatory markers including interleukin 6, interleukin-1 beta, and tumor necrosis factor-alpha; bone formation markers including osteocalcin (OC); alkaline phosphatase (ALP); and bone resorption markers including the N-terminal telopeptide of collagen type I (NTX-1), bone deoxypyridinoline (DPD), and tartrate-resistant acid phosphatase 5b (TRAP-5b). Results Rats with diabetes who consumed ZW exhibited a significant (p < 0.001) increase in OC and ALP bone formation markers and a decrease in NTX-1, DPD, and TRAP-5b bone resorption markers, with improvements in the X-ray image of the vertebral column at the L6 vertebra level. Conclusions ZW improved diabetes-induced osteoporosis in rats by enhancing osteoblastic activity and downregulating osteoclastic activity.

The role and mechanism of RNA-binding proteins in bone metabolism and osteoporosis

Osteoporosis is a prevalent chronic metabolic bone disease that poses a significant risk of fractures or mortality in elderly individuals. Its pathophysiological basis is often attributed to postmenopausal estrogen deficiency and natural aging, making the progression of primary osteoporosis among elderly people, especially older women, seemingly inevitable. The treatment and prevention of osteoporosis progression have been extensively discussed. Recently, as researchers delve deeper into the molecular biological mechanisms of bone remodeling, they have come to realize the crucial role of posttranscriptional gene control in bone metabolism homeostasis. RNA-binding proteins, as essential actors in posttranscriptional activities, may exert influence on osteoporosis progression by regulating the RNA life cycle. This review compiles recent findings on the involvement of RNA-binding proteins in abnormal bone metabolism in osteoporosis and describes the impact of some key RNA-binding proteins on bone metabolism regulation. Additionally, we explore the potential and rationale for modulating RNA-binding proteins as a means of treating osteoporosis, with an overview of drugs that target these proteins.

Analyzing the factors associated with efficacy among teriparatide treatment in postmenopausal women with osteoporosis

BACKGROUND

Teriparatide (TPTD) is a widely used anabolic agent for the treatment of osteoporosis. Several factors have been identified to be related to bone mineral density (BMD) increase in anti-osteoporosis treatment with other agents; however, there has been no systematic analysis to summarize the associated determinants of BMD reaction to daily teriparatide treatment.

METHODS

In this retrospective study, we performed a comprehensive investigation involving not only clinical data but also several relevant lifestyle factors to be examined for their potential contribution to BMD response. This post-hoc analysis included 258 post-menopaused patients with osteoporosis who received TPTD at 20 µg/day for 12 months. Univariate and multivariate analyses were conducted to distinguish the response variables of lumbar spine (LS) BMD transformation, the principal outcome measure of efficacy, from the baseline at 12 months.

RESULTS

Twelve months of TPTD treatment resulted in an absolute 0.39 ± 0.37 increase in T-score of LS BMD. Gastrointestinal disease, prior bisphosphonate or glucocorticoid treatment, no vitamin K2 supplementation, low levels of serum 25(OH)D and PINP, weak increment of PINP and β-CTX at 3 months, unhealthy lifestyle (excessive smoking, tea, coffee, and drinking), vegetarian diet pattern, low ALT level, and high BMD at baseline were determined by univariate analyses to be related to the weak reaction of TPTD treatment (P < 0.10). In the multiple regression model, postmenopausal women with vitamin K2 supplementation, higher baseline serum 25(OH)D level, and higher PINP concentration at 3 months indicated a good reaction of LS BMD at 12 months (P < 0.05). Patients with gastrointestinal disease, prior bisphosphonate and glucocorticoid treatment, vegetarian diet pattern, and higher baseline BMD were significantly more likely to have a lower absolute LS BMD response compared to patients without these characteristics (P < 0.05). Further analysis confirmed the negative effect of unhealthy lifestyle on TPTD treatment.

CONCLUSION

Our results emphasize the significance of a comprehensive assessment of clinical or lifestyle-related characteristics of postmenopausal women with osteoporosis in the management of TPTD therapy in routine care.

Revisiting the significance of nano-vitamin D for food fortification and therapeutic application

OBJECTIVE

Vitamin D (a prohormone) is an important micronutrient required by the body for skeletal homeostasis and a range of non-skeletal actions. Calcitriol, the active form of vitamin D, regulates a variety of cellular and metabolic processes through both genomic and nongenomic pathways. Often prescribed for treating rickets and osteoporosis, vitamin D deficiency can exacerbate various other medical conditions.

SIGNIFICANCE, METHODS, AND RESULTS

Despite its multifunctional uses, the sensitivity of vitamin D makes formulating an efficient drug delivery system a challenging task, which is further complicated by its poor aqueous solubility. Enhancing the oral absorption of vitamin D is vital in utilizing its full efficacy. Recent developments in encapsulation and nanotechnology have shown promising results in overcoming these constraints.

CONCLUSION

This review thus offers an insight to adequately comprehend the mechanistic pharmacology of vitamin D, its pathophysiological role, and justification of its medical indications, along with the benefits of utilizing nanotechnology for vitamin D delivery.

Pain Management in Osteoporosis

The most prevalent metabolic bone disease, osteoporosis, is characterized by a decrease in bone mineral density and alterations to the bone's microstructure, both of which can result in fragility fractures. It affects a significant section of the population. Acute or chronic pain from these fractures is typical in elderly adults with other coexisting conditions. Since the antiresorptive medication only partially reduces pain, other analgesics are required for effective pain management. NSAIDs or selective COX-2 inhibitors can reduce acute pain, but persistent neuropathic pain is difficult to manage with these drugs. Opioids have their adverse effects and safety concerns, although they can be used to address acute or chronic pain. Hence, a multifaceted approach is to be implemented, including pharmacological and nonpharmacological therapy and surgical treatment in a selected number of cases. This chapter briefly describes the etiology of pain, its mechanism, and pain management in osteoporotic patients.

The self-care behaviors and health literacy can play important preventive roles in older female osteoporosis

BACKGROUND

Osteoporosis is a common complication of aging and menopause. Self-care and health literacy are among the factors affecting health status. The purpose of this research was to determine the preventive roles of self-care behaviors and health literacy in older women with osteoporosis.

METHODS

This cross‑sectional analytical research was conducted on 250 postmenopausal women consisting of 125 osteoporotic and 125 healthy people aged 60-70. They were selected by purposive sampling in Tabriz Sina Hospital from September 2021 to December 2021. Data collection instruments were a demographic questionnaire, a Menopausal Self‑Care Questionnaire, and a European Health Literacy Survey Questionnaire. Data were analyzed using SPSS 23 software.

RESULTS

The mean (SD) total score of self-care in healthy women was 118.97 (19.92) and in women with osteoporosis was 84.7 (14.98) (p < 0.001). Also, healthy women all had sufficient health literacy (100%), but 52.8% of women with osteoporosis had insufficient health literacy. The odds of osteoporosis decreased significantly with the rise in the total score of self-care behaviors [Odds ratio 95% confidence interval (95% CI); p: 0.909 (0.880 to 0.939); p < 0.001] and its subdomains as well as with increasing health literacy level [OR (95% CI); p: 0.322 (0.266 to 0.383); p < 0.001]. There was a significant positive correlation between self-care behaviors and health literacy (r = 0.616, p < 0.001).

CONCLUSIONS

Self-care in aged women is particularly important in reducing the risk of osteoporosis, and empowering women in the field of health literacy is an important factor in improving self-care behaviors and ultimately the health of these people.

Vitamin D Knowledge, Awareness, and Attitudes of Adolescents and Adults: A Systematic Review

INTRODUCTION

The aims of this systematic review were 2-fold: (1) evaluate the effect of vitamin D educational interventions on serum 25-hydroxyvitamin D (25-OHD) concentration in adolescents (aged 10-19 years) and adults, and (2) assess the association between serum 25-OHD concentration and vitamin D knowledge, awareness of vitamin D deficiency risk, and attitudes toward behaviors associated with acquiring vitamin D.

METHODS

Medline, CINAHL, Embase, and SPORTDiscus were systematically searched for studies reporting associations between serum 25-OHD concentration and vitamin D knowledge, awareness, and attitudes. Results were summarized narratively. Effect sizes were calculated when data were available.

RESULTS

Eight studies reported experimental effects (2 randomized controlled trials, 1 cluster randomized trial, 4 quasi-experiments, 1 clinical audit), and 14 reported cross-sectional associations. Seven of 8 interventions reported no effect of educational interventions on serum 25-OHD concentration. A slight majority (53%; κ = 19) of studies reported statistically significant associations between serum 25-OHD concentration and vitamin D knowledge and attitudes.

IMPLICATIONS FOR RESEARCH AND PRACTICE

The few educational interventions employed to increase serum 25-OHD concentration lack effectiveness. Future studies may use randomized controlled trial designs, enroll those at risk for vitamin D insufficiency and underrepresented in the literature, increase the salience of the information to the target population, and include safe sun exposure recommendations.

Mechanistic advances in osteoporosis and anti-osteoporosis therapies

Osteoporosis is a type of bone loss disease characterized by a reduction in bone mass and microarchitectural deterioration of bone tissue. With the intensification of global aging, this disease is now regarded as one of the major public health problems that often leads to unbearable pain, risk of bone fractures, and even death, causing an enormous burden at both the human and socioeconomic layers. Classic anti-osteoporosis pharmacological options include anti-resorptive and anabolic agents, whose ability to improve bone mineral density and resist bone fracture is being gradually confirmed. However, long-term or high-frequency use of these drugs may bring some side effects and adverse reactions. Therefore, an increasing number of studies are devoted to finding new pathogenesis or potential therapeutic targets of osteoporosis, and it is of great importance to comprehensively recognize osteoporosis and develop viable and efficient therapeutic approaches. In this study, we systematically reviewed literatures and clinical evidences to both mechanistically and clinically demonstrate the state-of-art advances in osteoporosis. This work will endow readers with the mechanistical advances and clinical knowledge of osteoporosis and furthermore present the most updated anti-osteoporosis therapies.

Role of nutritional vitamin D in chronic kidney disease-mineral and bone disorder: A narrative review

Chronic kidney disease-mineral and bone disorder has complex and diverse clinical manifestations, including the simplest abnormalities of calcium, phosphorus and parathyroid hormone detected in blood, abnormalities of bone transformation and mineralization in bone, and calcification of blood vessels or other soft tissues detected on imaging. Patients with CKD-MBD combined low bone mineral density and fragility fractures are referred to as CKD-MBD with low bone mineral density. Vascular calcification refers to ectopic deposition of calcium phosphate in the blood vessel walls and heart valves. The degree of vascular calcification was inversely proportional to bone mineral density. The more severe the degree of vascular calcification, the lower the bone mineral density, and the higher the risk of death, indicating that the bone-vascular axis exists. Activation and alteration of the Wnt signaling pathway are central to the treatment of vascular diseases in uremia. Vitamin D supplementation can prevent secondary hyperparathyroidism, activate osteoblasts, relieve muscle weakness and myalgia, and reduce vascular calcification. Nutritional vitamin D may improve vascular calcification in uremia patients by regulating Wnt signaling pathway.

Iron Deficiency and Iron Deficiency Anemia: Potential Risk Factors in Bone Loss

Iron is one of the essential mineral elements for the human body and this nutrient deficiency is a worldwide public health problem. Iron is essential in oxygen transport, participates in many enzyme systems in the body, and is an important trace element in maintaining basic cellular life activities. Iron also plays an important role in collagen synthesis and vitamin D metabolism. Therefore, decrease in intracellular iron can lead to disturbance in the activity and function of osteoblasts and osteoclasts, resulting in imbalance in bone homeostasis and ultimately bone loss. Indeed, iron deficiency, with or without anemia, leads to osteopenia or osteoporosis, which has been revealed by numerous clinical observations and animal studies. This review presents current knowledge on iron metabolism under iron deficiency states and the diagnosis and prevention of iron deficiency and iron deficiency anemia (IDA). With emphasis, studies related to iron deficiency and bone loss are discussed, and the potential mechanisms of iron deficiency leading to bone loss are analyzed. Finally, several measures to promote complete recovery and prevention of iron deficiency are listed to improve quality of life, including bone health.

Osteoporosis pathogenesis and treatment: existing and emerging avenues

Osteoporotic fractures lead to increased disability and mortality in the elderly population. With the rapid increase in the aging population around the globe, more effective treatments for osteoporosis and osteoporotic fractures are urgently required. The underlying molecular mechanisms of osteoporosis are believed to be due to the increased activity of osteoclasts, decreased activity of osteoblasts, or both, which leads to an imbalance in the bone remodeling process with accelerated bone resorption and attenuated bone formation. Currently, the available clinical treatments for osteoporosis have mostly focused on factors influencing bone remodeling; however, they have their own limitations and side effects. Recently, cytokine immunotherapy, gene therapy, and stem cell therapy have become new approaches for the treatment of various diseases. This article reviews the latest research on bone remodeling mechanisms, as well as how this underpins current and potential novel treatments for osteoporosis.

Position Statement: Vitamin D Intake to Prevent Osteoporosis and Fracture in Adults

Adequate vitamin D status is essential for bone health. New randomized controlled trials investigating the effect of vitamin D supplementation on bone health have recently been published. This position statement updates and expands on the previous 2015 position statement of the Korean Society for Bone and Mineral Research on the adequate vitamin D status for healthy older adults (age ≥ 70 years) and those at high risk of osteoporosis and fracture (adults on osteoporosis medications) to maintain serum 25-hydroxy-vitamin D (25[OH]D) levels ≥ 20 ng/mL but < 50 ng/mL. A serum 25(OH)D level of 30 ng/mL may be beneficial for those on anti-resorptives. Vitamin D can be obtained from ultraviolet light exposure and diet. To reach the target vitamin D status through intake, adults must consume at least 400 IU/day to reach 20 ng/mL and 800 to 1,000 IU/day to reach 30 ng/mL. Foods familiar to the Korean diet that are high in vitamin D content or consumed frequently enough to positively impact vitamin D status are introduced in addition to the amount required to help reach one's target vitamin D status.

Bioconversion of vitamin D3 to bioactive calcifediol and calcitriol as high-value compounds

Biological catalysis is an important approach for the production of high-value-added compounds, especially for products with complex structures. Limited by the complex steps of chemical synthesis and low yields, the bioconversion of vitamin D₃ (VD₃) to calcifediol and calcitriol, which are natural steroid products with high added value and significantly higher biological activity compared to VD₃, is probably the most promising strategy for calcifediol and calcitriol production, and can be used as an alternative method for chemical synthesis. The conversion efficiency of VD₃ to calcifediol and calcitriol has continued to rise in the past few decades with the help of several different VD₃ hydroxylases, mostly cytochrome P450s (CYPs), and newly isolated strains. The production of calcifediol and calcitriol can be systematically increased in different ways. Specific CYPs and steroid C25 dehydrogenase (S25DH), as VD₃ hydroxylases, are capable of converting VD₃ to calcifediol and calcitriol. Some isolated actinomycetes have also been exploited for fermentative production of calcifediol and calcitriol, although the VD₃ hydroxylases of these strains have not been elucidated. With the rapid development of synthetic biology and enzyme engineering, quite a lot of advances in bioproduction of calcifediol and calcitriol has been achieved in recent years. Therefore, here we review the successful strategies of promoting VD₃ hydroxylation and provide some perspective on how to further improve the bioconversion of VD₃ to calcifediol and calcitriol.

COVID-19 Pandemic and Osteoporosis in Elderly Patients

Coronavirus disease 2019 (COVID-19), which is caused by an infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is rapidly becoming a worldwide epidemic and poses a significant threat to human life and health. SARS-CoV-2 can cause damage to organs throughout the body through ACE2 receptors. It may have direct and indirect effects on osteoclasts, and osteoblasts and lead to osteoporosis. Vitamin D (VitD) is a key hormone for bone health and has immunomodulatory actions of relevance in the context of the COVID-19 pandemic. Vitamin D deficiency has a significant positive association with both infection and the mortality rate of COVID-19. Elderly patients infected by COVID-19 were more likely to develop acute respiratory distress syndrome (ARDS), which was primarily caused by an inflammation storm. The production of proinflammatory cytokines increases with COVID-19 infection and immobilization may result in bone loss and bone resorption in seriously ill patients, especially aging patients. It is well known that glucocorticoids are beneficial in the treatment of acute respiratory distress syndrome (ARDS) because they reduce inflammation and improve the functioning of the lung and extrapulmonary organs. Glucocorticoid therapy is widely used to treat patients with COVID-19 in most parts of the world. During COVID-19 clinical treatment, glucocorticoids may accelerate bone loss in elderly people, making them more susceptible to the development of osteoporosis. Therefore, it is worthwhile to draw the attention of clinicians and researchers to the linkages and interactions between COVID-19, glucocorticoids, and osteoporosis (especially in elderly patients).

Value of Biochemical Indexes of Bone Metabolism in Predicting Osteoporotic Lumbar Fractures

Objective

To investigate the value of bone metabolism indexes such as type I procollagen N-terminal propeptide (P1NP), 25-hydroxyvitamin D (25(OH)D), osteocalcin (OSTEOC), and parathyroid hormone (PTH) in predicting osteoporotic lumbar fractures.

Methods

120 female patients with osteoporosis treated in our hospital were selected as research objects. There were 76 cases in the fracture group and 44 cases in the nonfracture group. The relationship between the levels of P1NP, 25(OH)D, OSTEOC, and PTH and the incidence of osteoporotic lumbar fractures were detected and compared between the two groups. The predictive value of biochemical indexes of bone metabolism in patients with osteoporosis was analyzed by ROC curve.

Results

The levels of P1NP and PTH in the fracture group were significantly higher than those in the nonfracture group, while 25(OH)D and OSTEOC levels were lower than those in the nonfracture group. Moreover, the levels of P1NP, 25(OH)D, OSTEOC, and PTH are important factors affecting the pathogenesis of osteoporosis. The area under the curve (AUC) of fracture in patients with osteoporosis predicted by the combination of P1NP, 25(OH)D, OSTEOC, and PTH levels was 0.886, which was greater than the AUC predicted by each index (0.796, 0.753, 0.670, and 0.824). The best sensitivity and specificity of comprehensive prediction of each index were 78.95% and 79.10%, respectively.

Conclusion

The abnormal changes of P1NP, 25(OH)D, OSTEOC, and PTH in female patients with osteoporotic lumbar fracture are closely related to the occurrence of the disease. The combination of these indicators has relatively significant application value in predicting the occurrence of fracture, which is helpful to formulate and guide relevant preventive measures for female patients with osteoporotic lumbar fracture and improve the prognosis.

In vitro Effects of Biologically Active Vitamin D on Myogenesis: A Systematic Review

Vitamin D (VD) deficiency is associated with muscle weakness. A reduction in the incidence of falls in the elderly following VD supplementation and identification of the VD receptor within muscle cells suggests a direct effect of VD on muscle, but little is known about the underlying mechanisms. Here we systematically searched the literature to identify effects of active VD [1,25(OH)2D3] on skeletal muscle myogenesis in vitro, with no restriction on year of publication. Eligibility was assessed by strict inclusion/exclusion criteria and agreed by two independent investigators. Twelve relevant pa-pers were identified using four different cell types (C2C12, primary mouse satellite cells, primary chick myoblasts, and primary human myoblasts) and a range of myogenic markers (myoD, myogenin, creatine kinase, myosin heavy chain, and myotube size). A clear inhibitory effect of 1,25(OH)2D3 on proliferation was reported, while the effects on the different stages of differentiation were less consistent probably due to variation in cell type, time points and doses of 1,25(OH)2D3 used. However, myotube size was consistently increased by 1,25(OH)2D3. Overall, the evidence suggests that 1,25(OH)2D3 inhibits proliferation and promotes differentiation of myoblasts, but future studies should use time courses to gain a clearer understanding.

Vitamin D level and fractures in children and adolescents: a systematic review and meta-analysis

INTRODUCTION

The aim of the study was to determine the relationship between vitamin D levels and the risk of bone fractures in children and adolescents.

MATERIALS AND METHODS

PubMed, Embase, and Cochrane library databases were searched using subject and free words. The Newcastle-Ottawa scale form was used to assess literature quality. ReVman 5.2 and Stata 13.0 were used for statistical analyses. The results were expressed as the mean difference (MD)/odds ratio (OR) and 95% confidence interval (95% CI). The heterogeneity test was conducted according to I² and Q tests. Egger's test was used to evaluate publication bias.

RESULTS

Thirteen studies (3943 participants ≤ 18 years old) were included, and the quality of the literature was acceptable. Regarding the 25-hydroxyvitamin D (25OHD) level in the random effects model, the MD = - 0.12 ng/mL (95% CI: -1.93, 1.69), I² = 83%, and P < 0.00001, indicating large heterogeneity. Subgroup analyses were conducted according to vitamin D supplementation and 25OHD level, the sources of heterogeneity were not found. Regarding the proportion of subjects with vitamin D deficiency in the random effects model, OR = 1.09 (95% CI: 0.67, 1.79), I² = 79%, and P < 0.0001. By sensitivity analysis, after removing Al-Daghri's study, OR = 1.22 (95% CI: 0.96, 1.56), I² = 0%, and P = 0.64.

CONCLUSION

There is no relationship between vitamin D level and the risk of bone fractures in children and adolescents.

The Human Gut Microbiota: A Key Mediator of Osteoporosis and Osteogenesis

An expanding body of research asserts that the gut microbiota has a role in bone metabolism and the pathogenesis of osteoporosis. This review considers the human gut microbiota composition and its role in osteoclastogenesis and the bone healing process, specifically in the case of osteoporosis. Although the natural physiologic processes of bone healing and the pathogenesis of osteoporosis and bone disease are now relatively well known, recent literature suggests that a healthy microbiome is tied to bone homeostasis. Nevertheless, the mechanism underlying this connection is still somewhat enigmatic. Based on the literature, a relationship between the microbiome, osteoblasts, osteoclasts, and receptor activator of nuclear factor-kappa-Β ligand (RANKL) is contemplated and explored in this review. Studies have proposed various mechanisms of gut microbiome interaction with osteoclastogenesis and bone health, including micro-RNA, insulin-like growth factor 1, and immune system mediation. However, alterations to the gut microbiome secondary to pharmaceutical and surgical interventions cannot be discounted and are discussed in the context of clinical therapeutic consideration. The literature on probiotics and their mechanisms of action is examined in the context of bone healing. The known and hypothesized interactions of common osteoporosis drugs and the human gut microbiome are examined. Since dysbiosis in the gut microbiota can function as a biomarker of bone metabolic activity, it may also be a pharmacological and nutraceutical (i.e., pre- and probiotics) therapeutic target to promote bone homeostasis.

Fibroblast growth factor 21 (FGF21) is a sensitive marker of osteoporosis in haemodialysis patients: a cross-sectional observational study

Introduction

Osteoporosis is one of the important bone abnormalities in chronic kidney disease-mineral and bone disorder (CKD-MBD) and still lacks a sensitive biomarker to diagnose. Fibroblast growth factor 21 (FGF21) can stimulate bone loss in patients with diabetes and increase in CKD patients. In this study, we investigated whether FGF21 could serve as a biomarker to predict osteoporosis in a haemodialysis cohort.

Methods

We recorded demographic information, biochemical data, and serum FGF21 and FGF23 levels and measured the CT attenuation values of 339 haemodialysis patients from two large medical centres. We assessed the correlation of CT attenuation values with serum FGF21 and FGF23 levels and tested whether they were independent factors for osteoporosis. ROC curves were constructed to compare the prognostic value of FGF21 and FGF23 for osteoporosis.

Results

Based on the CT attenuation value, serum FGF21 levels were higher in our osteoporosis group (median 640.86 pg/ml vs. 245.46 pg/ml, P ˂ 0.01). Meanwhile, FGF21 (r = -0.136, P < 0.05) and FGF23 (r = -0.151, P < 0.05) were both negatively associated with osteoporosis. Moreover, FGF21 (β = -0.067, P < 0.05) was an independent factor for osteoporosis. Furthermore, FGF21 combined with age yielded a marked specificity (90.5 %) and sensitivity (61.8 %) in predicting osteoporosis of haemodialysis patients with less residual renal function.

Conclusions

FGF21 has a positive relationship with the incidence of osteoporosis in patients on haemodialysis. FGF21 combined with age is a good predictive biomarker for osteoporosis in patients on haemodialysis, especially those with less residual renal function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-021-02393-z.

Association of Hydrogen Sulfide with Femoral Bone Mineral Density in Osteoporosis Patients: A Preliminary Study

Background

Accumulated evidence has suggested that hydrogen sulfide (H₂S) has a role in bone formation and bone tissue regeneration. However, it is unknown whether the H₂S content is associated with bone mineral density (BMD) in patients with osteopenia/osteoporosis.

Material/Methods

In the present study, we aimed to explore the changes of serum H₂S in osteopenia and osteoporosis patients. We analyzed femur expression of cystathionine β synthase (CBS), cystathionine γ lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3-MST), which are key enzymes for generating H₂S.

Results

Sixteen (16%) patients had osteopenia, 9 (9%) had osteoporosis, and 75 (75%) had normal BMD. In comparison with patients with normal BMD (controls), the serum levels of H₂S were unexpectedly increased in patients with osteopenia and osteoporosis. This increase was much higher in patients with osteoporosis than in those with osteopenia. Serum H₂S levels were negatively correlated with femoral BMD, but not lumbar BMD. Interestingly, the expression of CBS and CSE were downregulated in femur tissues in patients with osteoporosis, whereas the expression of 3-MST remained unchanged. Serum phosphorus levels, alkaline phosphatase, hemoglobin, and triglycerides were found to be closely associated with CBS and CSE scores in femur tissues.

Conclusions

Serum H₂S levels and femur CBS and CSE expression may be involved in osteoporosis pathogenesis.

Vitamin D protects against immobilization-induced muscle atrophy via neural crest-derived cells in mice

Vitamin D deficiency is a recognized risk factor for sarcopenia development, but mechanisms underlying this outcome are unclear. Here, we show that low vitamin D status worsens immobilization-induced muscle atrophy in mice. Mice globally lacking vitamin D receptor (VDR) exhibited more severe muscle atrophy following limb immobilization than controls. Moreover, immobilization-induced muscle atrophy was worse in neural crest-specific than in skeletal muscle-specific VDR-deficient mice. Tnfα expression was significantly higher in immobilized muscle of VDR-deficient relative to control mice, and was significantly elevated in neural crest-specific but not muscle-specific VDR-deficient mice. Furthermore, muscle atrophy induced by limb immobilization in low vitamin D mice was significantly inhibited in Tnfα-deficient mice. We conclude that vitamin D antagonizes immobilization-induced muscle atrophy via VDR expressed in neural crest-derived cells.

Nutritional Support and Physical Modalities for People with Osteoporosis: Current Opinion

Osteoporosis is a vital healthcare issue among elderly people. During the aging process, a gradual loss of bone mass results in osteopenia and osteoporosis. Heritable factors account for 60%-80% of optimal bone mineralization, whereas modifiable factors such as nutrition, weight-bearing exercise, body mass, and hormonal milieu affect the development of osteopenia and osteoporosis in adulthood. Osteoporosis substantially increases the risk of skeletal fractures and further morbidity and mortality. The effective prevention of fractures by reducing the loss of bone mass is the primary goal for physicians treating people with osteoporosis. Other than pharmacologic agents, lifestyle adjustment, nutritional support, fall prevention strategies, exercise, and physical modalities can be used to treat osteoporosis or prevent further osteoporotic fracture. Each of these factors, alone or in combination, can be of benefit to people with osteoporosis and should be implemented following a detailed discussion with patients. This review comprises a systematic survey of the current literature on osteoporosis and its nonpharmacologic and nonsurgical treatment. It provides clinicians and healthcare workers with evidence-based information on the assessment and management of osteoporosis. However, numerous issues regarding osteoporosis and its treatment remain unexplored and warrant future investigation.

The Paradoxical Role of Uric Acid in Osteoporosis

Because of its high prevalence worldwide, osteoporosis is considered a serious public health concern. Many known risk factors for developing osteoporosis have been identified and are crucial if planning health care needs. Recently, an association between uric acid (UA) and bone fractures had been explored. Extracellular UA exhibits antioxidant properties by effectively scavenging free radicals in human plasma, but this benefit might be disturbed by the hydrophobic lipid layer of the cell membrane. In contrast, intracellular free oxygen radicals are produced during UA degradation, and superoxide is further enhanced by interacting with NADPH oxidase. This intracellular oxidative stress, together with inflammatory cytokines induced by UA, stimulates osteoclast bone resorption and inhibits osteoblast bone formation. UA also inhibits vitamin D production and thereby results in hyper-parathyroidism, which causes less UA excretion in the intestines and renal proximal tubules by inhibiting the urate transporter ATP-binding cassette subfamily G member 2 (ABCG2). At normal or high levels, UA is associated with a reduction in bone mineral density and protects against bone fracture. However, in hyperuricemia or gout arthritis, UA increases bone fracture risk because oxidative stress and inflammatory cytokines can increase bone resorption and decrease bone formation. Vitamin D deficiency, and consequent secondary hyperparathyroidism, can further increase bone resorption and aggravated bone loss in UA-induced osteoporosis.

Magnesium Is a Key Regulator of the Balance between Osteoclast and Osteoblast Differentiation in the Presence of Vitamin D₃

Magnesium (Mg) is crucial for bone health. Low concentrations of Mg inhibit the activity of osteoblasts while promoting that of osteoclasts, with the final result of inducing osteopenia. Conversely, little is known about the effects of high concentrations of extracellular Mg on osteoclasts and osteoblasts. Since the differentiation and activation of these cells is coordinated by vitamin D₃ (VD3), we investigated the effects of high extracellular Mg, as well as its impact on VD3 activity, in these cells. U937 cells were induced to osteoclastic differentiation by VD3 in the presence of supra-physiological concentrations (>1 mM) of extracellular Mg. The effect of high Mg concentrations was also studied in human bone-marrow-derived mesenchymal stem cells (bMSCs) induced to differentiate into osteoblasts by VD3. We demonstrate that high extra-cellular Mg levels potentiate VD3-induced osteoclastic differentiation, while decreasing osteoblastogenesis. We hypothesize that Mg might reprogram VD3 activity on bone remodeling, causing an unbalanced activation of osteoclasts and osteoblasts.

Vitamin D Daily versus Monthly Administration: Bone Turnover and Adipose Tissue Influences

Vitamin D is involved in bone metabolism and in many various extra-skeletal diseases such as malabsorption syndromes, cardiovascular and metabolic diseases, cancer, and autoimmune and neurological diseases. However, data on the optimal route of administration are not consistent. The aims of our study were to analyze not only the influence of daily vs. monthly administration of vitamin D on bone metabolism and bone turnover, but also the effects of different routes of administration on fat mass in a cohort of adults with low levels of 25(OH) vitamin D3 at baseline. We analyzed 44 patients with hypovitaminosis at baseline and after six months of two different regimens of administration: seven drops (1750 IU)/day vs. 50,000 IU/month. We found that the two regimens were equivalent; 36 out of 44 patients reached the normal range of vitamin D after six months of treatment. Interestingly, the main determinant of vitamin D at baseline was the waist circumference. In addition, 22 patients treated by monthly regimen were evaluated after 18 months of treatment. At the end of follow-up, patients showed normal levels of vitamin D, with increased calcium levels and decreased bone turnover. Waist circumference also decreased. Our results support the efficacy of vitamin D3 given monthly both for correcting hypovitaminosis and for maintaining vitamin D levels. The relationship between serum 25(OH)vitamin D3 concentration and waist circumference supports vitamin D having a protective role in the current setting, since waist size is directly associated with the risk of cardiovascular and metabolic diseases.

The facile synthesis of copper oxide quantum dots on chitosan with assistance of phyto-angelica for enhancing the human osteoblast activity to the application of osteoporosis

Osteoblasts are an important key factor for the pathogenesis of several bone-related diseases, notably in osteoporosis. Osteoporosis is a disorder categorized based on the bone mineral density (BMD) and an alteration in the bone micro-architecture had been considered as the major determinant for increasing the fracture risk. The available medicine for curing the osteoporosis shows a minimal or no activity against the genesis or function of osteoblasts. The present study was conducted to determine the influence of phyto Angelica species (Ang.) mediated synthesized copper quantum dots decorated chitosan on human osteoblast cells for application of osteoporosis. The phyto compound of Angelica sp. was extracted by ethanol as solvent and it has been characterized through spectral analyses. An Angelica sp. mediated synthesized copper oxide quantum dots (CuO QDs) and the presence of CuO QDs on chitosan have been analyzed and exhibited by important spectral investigations. The morphological observation of CuO QDs on the chitosan (CS) was visualized by the microscopic analyses. The MTT assay results showed that cell growth of CuO QDs/CS-Ang. by the concentration dependent. The highest cell growth (87%) was noted at 5 μg/mL followed by 80 and 77% at 15 and 25 μg/mL respectively. The functional groups and potential compounds of Angelica sp. with CuO QDs/CS has been improved the osteoblast cell activity as prophylactic potentials against osteoporosis.

BCPA {N,N'-1,4-Butanediylbis[3-(2-chlorophenyl)acrylamide]} Inhibits Osteoclast Differentiation through Increased Retention of Peptidyl-Prolyl cis-trans Isomerase Never in Mitosis A-Interacting 1

Osteoporosis is caused by an imbalance of osteoclast and osteoblast activities and it is characterized by enhanced osteoclast formation and function. Peptidyl-prolyl cis-trans isomerase never in mitosis A (NIMA)-interacting 1 (Pin1) is a key mediator of osteoclast cell-cell fusion via suppression of the dendritic cell-specific transmembrane protein (DC-STAMP). We found that N,N′-1,4-butanediylbis[3-(2-chlorophenyl)acrylamide] (BCPA) inhibited receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis in a dose-dependent manner without cytotoxicity. In addition, BCPA attenuated the reduction of Pin1 protein during osteoclast differentiation without changing Pin1 mRNA levels. BCPA repressed the expression of osteoclast-related genes, such as DC-STAMP and osteoclast-associated receptor (OSCAR), without altering the mRNA expression of nuclear factor of activated T cells (NFATc1) and cellular oncogene fos (c-Fos). Furthermore, Tartrate-resistant acid phosphatase (TRAP)-positive mononuclear cells were significantly decreased by BCPA treatment compared to treatment with the Pin1 inhibitor juglone. These data suggest that BCPA can inhibit osteoclastogenesis by regulating the expression of the DC-STAMP osteoclast fusion protein by attenuating Pin1 reduction. Therefore, BCPA may be used to treat osteoporosis.

A Review on Properties of Natural and Synthetic Based Electrospun Fibrous Materials for Bone Tissue Engineering

Bone tissue engineering is an interdisciplinary field where the principles of engineering are applied on bone-related biochemical reactions. Scaffolds, cells, growth factors, and their interrelation in microenvironment are the major concerns in bone tissue engineering. Among many alternatives, electrospinning is a promising and versatile technique that is used to fabricate polymer fibrous scaffolds for bone tissue engineering applications. Copolymerization and polymer blending is a promising strategic way in purpose of getting synergistic and additive effect achieved from either polymer. In this review, we summarize the basic chemistry of bone, principle of electrospinning, and polymers that are used in bone tissue engineering. Particular attention will be given on biomechanical properties and biological activities of these electrospun fibers. This review will cover the fundamental basis of cell adhesion, differentiation, and proliferation of the electrospun fibers in bone tissue scaffolds. In the last section, we offer the current development and future perspectives on the use of electrospun mats in bone tissue engineering.