Plain vitamin D or active vitamin D in the treatment of osteoporosis: where do we stand today?

Clinical outcomes and safety of combined calcitriol and bisphosphonates in treating postmenopausal osteoporosis: a retrospective cohort study

OBJECTIVE

Despite the well-known benefits of calcitriol and bisphosphonates in managing osteoporosis, limited research has explored the combined therapeutic effects of these agents on bone metabolism, immune function, and clinical outcomes in postmenopausal osteoporosis patients. This study aims to evaluate the clinical efficacy and safety of calcitriol combined with bisphosphonates in the treatment of postmenopausal osteoporosis through a retrospective cohort analysis.

METHODS

A total of 152 postmenopausal osteoporosis patients treated at our hospital from March 2019 to June 2021 were enrolled and divided into two groups based on the treatment received. The control group received calcitriol alone, while the study group received calcitriol combined with bisphosphonates. Treatment outcomes were assessed by comparing Visual Analogue Scale (VAS) scores for pain, Barthel Index for daily living ability, and Oswestry Disability Index (ODI) for dysfunction before and after treatment. Bone metabolism markers (BALP, BGP, PINP, TRACP), immune cytokines (IL-6, TGF-β1, TNF-α, IL-10), and bone mineral density (BMD) were measured. The incidence of adverse reactions was also recorded.

RESULTS

The total effective rate in the study group was 96.05%, significantly higher than 84.21% in the control group (P < 0.05). Post-treatment VAS and ODI scores decreased significantly in both groups, with greater improvement in the study group (P < 0.05). Barthel Index scores increased more in the study group (P < 0.05). Bone metabolism markers (BALP, BGP, PINP, TRACP) and inflammatory cytokines (IL-6, TGF-β1, TNF-α) decreased more significantly in the study group, while IL-10 levels and BMD increased more markedly (P < 0.05). The incidence of adverse reactions was lower in the study group (2.63%) than in the control group (5.26%), but the difference was not statistically significant (P > 0.05).

CONCLUSION

The combination of calcitriol and bisphosphonates demonstrates superior clinical efficacy and safety in treating postmenopausal osteoporosis, effectively reducing pain and disability, enhancing bone metabolism and immune function, and improving bone mineral density and daily living ability.

A Landscape of Micronutrient Dietary Intake by 15- to 65-Years-Old Urban Population in 8 Latin American Countries: Results From the Latin American Study of Health and Nutrition

BACKGROUND

Latin American countries have shifted from traditional diets rich in micronutrients to a Westernized diet rich in high energy-dense foods and low in micronutrients.

OBJECTIVE

This study aimed to determine the prevalence of adequate micronutrient intakes in urban populations of 8 Latin American countries.

METHOD

Micronutrient dietary intake data were collected from September 2014 to August 2015 from 9216 men and women aged 15.0 to 65.0 years living in urban populations of 8 Latin American countries. Dietary intake was collected using two 24-hour recalls on nonconsecutive days. Micronutrient adequacy of intake was calculated using the Estimated Average Requirement cut-off method.

RESULTS

In general terms, the prevalence of inadequate intake of thiamine, riboflavin, niacin, folate, cobalamin, iron, phosphorus, copper, and selenium ranged from 0.4% to 9.9%. In contrast, the prevalence of inadequacy of pyridoxine, zinc, vitamin C, and vitamin A ranged from 15.7% to 51.5%. The nutrients with a critical prevalence of inadequacy were magnesium (80.5%), calcium (85.7%), and vitamin D (98.2%). The highest prevalence of inadequate intakes was observed in the low educational level, participants with overweight/obesity, in men, and varies according to socioeconomic status.

CONCLUSIONS

There is an urgent need to define direct regional actions and strategies in Latin America aimed at improving micronutrient adequacy, either through staple food fortification programs, agronomic biofortification, or food policies that facilitate economic access to micronutrient-rich foods.

Target Values for 25-Hydroxy and 1,25-Dihydroxy Vitamin D Based on Their Associations with Inflammation and Calcium-Phosphate Metabolism

Target values for 25-hydroxy vitamin D and 1,25(OH)2D or 1,25-dihydroxy vitamin D remain a topic of debate among clinicians. We analysed data collected from December 2012 to April 2020 from two cohorts. Cohort A, comprising 455,062 subjects, was used to investigate the relationship between inflammatory indicators (white blood cell [WBC] count and C-reactive protein [CRP]) and 25(OH)D/1,25(OH)2D. Cohort B, including 47,778 subjects, was used to investigate the connection between 25(OH)D/1,25(OH)2D and mineral metabolism markers (phosphate, calcium, and intact parathyroid hormone [iPTH]). Quadratic models fit best for all tested correlations, revealing U-shaped relationships between inflammatory indicators and 25(OH)D and 1,25(OH)2D. Minimal CRP and WBC counts were observed at 1,25(OH)2D levels of 60 pg/mL and at 25(OH)D levels of 32 ng/mL, as well as of 42 ng/mL, respectively. iPTH correlated inversely with both 1,25(OH)2D and 25(OH)D, while phosphate as well as calcium levels positively correlated with both vitamin D forms. Calcium-phosphate product increased sharply when 25(OH)D was more than 50 ng/mL, indicating a possible risk for vascular calcification. Multiple regression analyses confirmed that these correlations were independent of confounders. This study suggests target values for 25(OH)D between 30-50 ng/mL and for 1,25(OH)2D between 50-70 pg/mL, based particularly on their associations with inflammation but also with mineral metabolism markers. These findings contribute to the ongoing discussion around ideal levels of vitamin D but require support from independent studies with data on clinical endpoints.

Vitamin D efficacy in type 1 and type 2 diabetes

It is well known that vitamin D has a profound effect on calcium and bone metabolism, but its influence on other organs (extraskeletal effect) has been proposed. Consistently, vitamin D deficiency is associated with an increased incidence of various diseases, including type 1 and type 2 diabetes, as reported by many observational studies. However, there has been no consensus on whether vitamin D deficiency is a causative factor in the incidence of diabetes mellitus. There have been no randomized controlled trials (RCTs) aimed at preventing the onset of type 1 diabetes with vitamin D intake. In addition, the results of RCTs evaluating the preventive effect of vitamin D supplementation on type 2 diabetes development have been inconsistent. The recent observational studies, randomized controlled trials, and meta-analyses are confirming that vitamin D or active vitamin D administration is effective in preventing the incident of type 1 and type 2 diabetes.

A Health Technology Assessment Based on Chinese Guideline: Active Vitamin D and Its Analogs in the Treatment of Osteoporosis

Objective

To quantitatively assess all dosage forms of three active vitamin D and its analogs, namely, calcitriol, alfacalcidol, and eldecalcitol, to provide a basis for the selection of active vitamin D and its analogs in hospitals.

Methods

In this study, three active vitamin D and its analogs were evaluated by quantitative scoring in five dimensions, including pharmaceutical properties (28 points), efficacy (27 points), safety (25 points), economy (10 points), and other attributes (10 points).

Results

The final scores of quantitative assessment for the selection of alfacalcidol soft capsules, calcitriol soft capsules I, calcitriol soft capsules II, alfacalcidol tablets, alfacalcidol capsules, alfacalcidol oral drops, calcitriol injection, and eldecalcitol soft capsules were 73.17, 72.06, 71.52, 71.29, 69.62, 68.86, 65.60, 64.05 points.

Conclusion

Based on the scoring results, alfacalcidol soft capsules, calcitriol soft capsules I, calcitriol soft capsules II, alfacalcidol tablets can be entered into the medication list of medical institutions as strongly recommended drugs. This study offers guidance on selecting and using active vitamin D and its analogs in hospitals, with consideration for the patient's needs.

The potential benefits and mechanisms of protein nutritional intervention on bone health improvement

Osteoporosis commonly occurs in the older people and severe patients, with the main reason of the imbalance of bone metabolism (the rate of bone resorption exceeding the rate of bone formation), resulting in a decrease in bone mineral density and destruction of bone microstructure and further leading to the increased risk of fragility fracture. Recent studies indicate that protein nutritional support is beneficial for attenuating osteoporosis and improving bone health. This review summarized the classical mechanisms of protein intervention for alleviating osteoporosis on both suppressing bone resorption and regulating bone formation related pathways (promoting osteoblasts generation and proliferation, enhancing calcium absorption, and increasing collagen and mineral deposition), as well as the potential novel mechanisms via activating autophagy of osteoblasts, altering bone related miRNA profiles, regulating muscle-bone axis, and modulating gut microbiota abundance. Protein nutritional intervention is expected to provide novel approaches for the prevention and adjuvant therapy of osteoporosis.

Active vitamin D treatment in the prevention of sarcopenia in adults with prediabetes (DPVD ancillary study): a randomised controlled trial

BACKGROUND

Observational studies show inverse associations between serum 25-hydroxyvitamin D concentrations and sarcopenia incidence; however, it remains unclear whether treatment with vitamin D prevents its development. We aimed to assess whether treatment with active vitamin D (eldecalcitol [0·75 μg per day]) can reduce the development of sarcopenia among adults with prediabetes.

METHODS

This randomised, double-blind, placebo-controlled, multicenter trial as an ancillary study was conducted at 32 clinics and hospital sites in Japan. Participants were assigned (1:1) by using a central randomisation method in which a randomisation list was made for each hospital separately using a stratified permuted block procedure. The primary endpoint was sarcopenia incidence during 3 years in the intention-to-treat population defined as weak handgrip strength (<28 kg for men and <18 kg for women) and low appendicular skeletal muscle index (<7·0 kg/m2 for men and <5·7 kg/m2 for women in bioelectrical impedance analysis). Although the usual criterion of hypercalcaemia was 10·4 mg/dL (2·6 mmol/L) or higher, hypercalcaemia that was enough to discontinue the study was defined as 11·0 mg/dL or higher. This study is registered with the UMIN clinical trials registry, UMIN000005394.

FINDINGS

A total of 1094 participants (548 in the eldecalcitol group and 546 in the placebo group; 44·2% [484 of 1094] women; mean age 60·8 [SD 9·2] years) were followed up for a median of 2·9 (IQR 2·8-3·0) years. Eldecalcitol treatment as compared with placebo showed statistically significant preventive effect on sarcopenia incidence (25 [4·6%] of 548 participants in the eldecalcitol group and 48 [8·8%] of 546 participants in the placebo group; hazard ratio 0·51; 95% CI 0·31 to 0·83; p=0·0065). The incidence of adverse events did not differ between the two groups.

INTERPRETATION

We found that treatment with eldecalcitol has the potential to prevent the onset of sarcopenia among people with prediabetes via increasing skeletal muscle volume and strength, which might lead to a substantial risk reduction of falls.

FUNDING

Kitakyushu Medical Association.

TRANSLATION

For the Japanese translation of the abstract see Supplementary Materials section.

Treatment of Osteoporosis after Hip Fracture: Survey of the Korean Hip Society

Purpose

To assess current practice in the treatment of osteoporosis in patients who underwent treatment for hip fracture in South Korea.

Materials and Methods

A survey of 97 members of the Korean Hip Society, orthopedic hip surgeons who administer treatment for hip fractures in South Korea, was conducted. The survey was conducted for assessment of demographic data and perceptions regarding the management of osteoporosis in patients who have undergone treatment for hip fracture. Analysis of the data was performed using descriptive statistical methods.

Results

The majority of participants were between the age of 41 and 50 years, and 74% were practicing in tertiary hospitals. Testing for serum vitamin D levels (82%) was the most commonly performed laboratory test. Calcium and vitamin D were prescribed for more than 80% of patients by 47% and 52% of participants, respectively. Denosumab was the most commonly used first-line treatment option for osteoporosis in hip fracture patients. Bisphosphonate was most often perceived as the cause of atypical femoral fractures, and the most appropriate time for reoperation was postoperative 12 months. Teriparatide was most preferred after cessation of bisphosphonate and only prescribing calcium and vitamin D was most common in high-risk patients for prevention of atypical femoral fracture.

Conclusion

The results of this study that surveyed orthopedic hip surgeons showed that most participants followed the current strategy for management of osteoporosis. Because the end result of osteoporosis is a bone fracture, active involvement of orthopedic surgeons is important in treating this condition.

Study on the relationship between tea polyphenols alleviating osteoporosis and the changes of microorganism-metabolite-intestinal barrier

Tea polyphenols are known to alleviate osteoporosis; however, the role of intestinal flora in this process has not been studied. This research employed 16s rRNA sequencing and non-targeted metabonomics to investigate the potential link between osteoporosis mitigation and changes in intestinal flora. MicroCT and tissue staining results demonstrated that tea polyphenols improved bone microstructure, modulated bone metabolism, and significantly alleviated osteoporosis. The administration of tea polyphenols led to alterations in the intestinal flora's composition, marked by increased abundance of Firmicutes and Lactobacillus and decreased prevalence of Bacteroidetes and Bacteroides. Concurrently, the levels of serum metabolites such as Spermidine and 5,6-Dihydrouracil, associated with intestinal microorganisms, underwent significant changes. These variations in intestinal flora and metabolites are closely linked to bone metabolism. Furthermore, tea polyphenols partially repaired intestinal barrier damage, potentially due to shifts in intestinal flora and their metabolites. Overall, our findings suggest that tea polyphenol intervention modifies the intestinal flora and serum metabolites in osteoporotic mice, which could contribute to the repair of intestinal barrier damage and thereby mitigate osteoporosis. This discovery aids in elucidating the mechanism behind tea polyphenols' osteoporosis-relieving effects.

Diets intervene osteoporosis via gut-bone axis

Osteoporosis is a systemic skeletal disease that seriously endangers the health of middle-aged and older adults. Recently, with the continuous deepening of research, an increasing number of studies have revealed gut microbiota as a potential target for osteoporosis, and the research concept of the gut-bone axis has gradually emerged. Additionally, the intake of dietary nutrients and the adoption of dietary patterns may affect the gut microbiota, and alterations in the gut microbiota might also influence the metabolic status of the host, thus adjusting bone metabolism. Based on the gut-bone axis, dietary intake can also participate in the modulation of bone metabolism by altering abundance, diversity, and composition of gut microbiota. Herein, combined with emerging literatures and relevant studies, this review is aimed to summarize the impacts of different dietary components and patterns on osteoporosis by acting on gut microbiota, as well as underlying mechanisms and proper dietary recommendations.

Metabolic bone disorders and the promise of marine osteoactive compounds

Metabolic bone disorders and associated fragility fractures are major causes of disability and mortality worldwide and place an important financial burden on the global health systems. These disorders result from an unbalance between bone anabolic and resorptive processes and are characterized by different pathophysiological mechanisms. Drugs are available to treat bone metabolic pathologies, but they are either poorly effective or associated with undesired side effects that limit their use. The molecular mechanism underlying the most common metabolic bone disorders, and the availability, efficacy, and limitations of therapeutic options currently available are discussed here. A source for the unmet need of novel drugs to treat metabolic bone disorders is marine organisms, which produce natural osteoactive compounds of high pharmaceutical potential. In this review, we have inventoried the marine osteoactive compounds (MOCs) currently identified and spotted the groups of marine organisms with potential for MOC production. Finally, we briefly examine the availability of in vivo screening and validation tools for the study of MOCs.

BushenHuoxue formula promotes osteogenic differentiation via affecting Hedgehog signaling pathway in bone marrow stem cells to improve osteoporosis symptoms

BACKGROUND

The BushenHuoxue formula (BSHX) has been previously demonstrated to ameliorate osteoporosis, but the mechanisms underlying this phenomenon are currently unclear. The present study aims at investigating the mechanisms that BSHX induces osteogenesis.

METHODS

We established an osteoporosis model in rats by bilateral ovariectomy and then treated the rats with an osteogenic inducer (dexamethasone, β-sodium glycerophosphate and Vitamin C) and BSHX. After that, bone marrow density and histopathological bone examination were evaluated by using HE staining and immunohistochemistry, respectively. We also assessed the differentiation of bone marrow mesenchymal stem cells (BMSCs) into osteoblasts by using immunofluorescence staining. ALP, BMP, and COL1A1 levels were determined by ELISA. We identified genes involved in pathogenesis of osteoporosis through Gene Expression Omnibus (GEO) database and subsequently selected Hedgehog signaling-related genes Shh, Ihh, Gli2, and Runx2 for assessment via qRT-PCR and ELISA, Western blotting. Network pharmacology analysis was performed to identify bioactive metabolites of BSHX.

RESULTS

BSHX treatment in osteoporosis model rats promoted tightening of the morphological structure of the trabecular bone and increased the bone mineral density (BMD). BSHX also increased levels of osteoblast makers ALP, BMP, and COL1A1. Additionally, bioinformatics analysis of the GEO dataset showed that Hedgehog signaling pathway was involved in pathogenesis of osteoporosis, especially related genes Shh, Ihh, Gli2, and Runx2. Remarkably, BHSX upregulated these genes indispensably involved in the osteogenesis-related Hedgehog signaling pathway in both bone tissue and BMSCs. Importantly, we identified that quercetin was the active compounds that involved in the mechanism of BSHX-improved OP via affecting Hedgehog-related genes.

CONCLUSION

Our results indicate that BSHX promotes osteogenesis by improving BMSC differentiation into osteoblasts via increased expression of Hedgehog signaling-related genes Shh, Ihh, Gli2, and Runx2, and quercetin was the bioactive compound of BSHX.

Epigallocatechin gallate alleviates osteoporosis by regulating the gut microbiota and serum metabolites in rats

Osteoporosis, one of the serious public health problems worldwide, can lead to degeneration of the bone structure and increased risk of fractures. Epigallocatechin gallate (EGCG) is a natural product with potential efficacy in inhibiting bone loss. However, the specific mechanism remains unclear. This study first investigated the role of EGCG in preventing dexamethasone (DEX)-induced osteoporosis by regulating intestinal microbiota and serum metabolites. We detected the bone density, bone microstructure, and changes in intestinal microorganisms and serum metabolites. According to our results, EGCG inhibited the decline of bone density, protected the bone microstructure, increased microbial diversity, promoted the abundance of beneficial bacteria such as Prevotellaceae and Ruminococcus, and inhibited the abundance of pathogenic bacteria such as Peptostreptococcaceae. There were also significant changes in serum metabolites among different treatments. Differential metabolites were mainly involved in sphingolipid metabolism and glycerophospholipid metabolism pathways, especially ceramide (d18:0/16:0(2OH)), phosphatidylserine (P-20:0/20:4(5Z,8Z,11Z,14Z)), phosphatidylserine (18:2(9Z,12Z)/12:0), and phosphatidylethanolamine (O-16:0/0:00), which were increased after EGCG treatment. Notably, most of the above metabolites were positively correlated with bone mineral density, BV/TV and Tb·Th, and negatively correlated with Tb·Sp. In summary, EGCG can prevent bone damage, promote the production of beneficial bacteria and metabolites, and enhance immune function. This study provides a basis and reference for the prevention and treatment of osteoporosis, as well as the application of EGCG in maintaining body health.

Low energy availability reduces bone mass and gonadal function in male mice

INTRODUCTION

In women, the female athlete triad, marked by low energy availability, functional hypothalamic amenorrhea and osteoporosis, is a recognized risk for stress fractures. Stress injuries also occur in men, but by contrast risks and mechanisms underlying them are less characterized.

MATERIALS AND METHODS

5 week-old wild-type male mice were fed ad libitum (ad) or subjected to 60% food restriction (FR) for five weeks. In both groups, some mice were allowed access to an exercise wheel in cages to allow voluntary wheel running (ex) and/or treated with active vitamin D analogues. Mice were sacrificed and analyzed at 10 weeks of age.

RESULT

Male FR mice exhibited significantly reduced testicle weight, serum testosterone levels and bone mass. Such bone losses in FR male mice were enhanced by exercise. Histological analysis revealed that both bone-resorbing and -forming activities were significantly reduced in FR or FR plus exercise (FR + ex) mice, mimicking a state of low bone turnover. Significantly reduced bone mass in FR or FR + ex male mice was significantly rescued by treatment with active vitamin D analogues, with significant restoration of osteoblastic activities. Serum levels of insulin-like growth factor I (IGF-I), which is critical for bone remodeling, were significantly lower in FR versus control male mice.

CONCLUSIONS

Low energy availability puts men at risk for stress injuries as well, and low energy availability is upstream of gonadal dysfunction and osteoporosis in males. Active vitamin D analogues could serve as therapeutic or preventive options for stress injuries in men.

Static magnetic field: A potential tool of controlling stem cells fates for stem cell therapy in osteoporosis

Osteoporosis is a kind of bone diseases characterized by dynamic imbalance of bone formation and bone absorption, which is prone to fracture, and seriously endangers human health. At present, there is a lack of highly effective drugs for it, and the existing measures all have some side effects. In recent years, mesenchymal stem cell therapy has brought a certain hope for osteoporosis, while shortcomings such as homing difficulty and unstable therapeutic effects limit its application widely. Therefore, it is extremely urgent to find effective and reliable means/drugs for adjuvant stem cell therapy or develop new research techniques. It has been reported that static magnetic fields(SMFs) has a certain alleviating and therapeutic effect on varieties of bone diseases, also promotes the proliferation and osteogenic differentiation of mesenchymal stem cells derived from different tissues to a certain extent. Basing on the above background, this article focuses on the key words "static/constant magnetic field, mesenchymal stem cell, osteoporosis", combined literature and relevant contents were studied to look forward that SMFs has unique advantages in the treatment of osteoporosis with mesenchymal stem cells, which can be used as an application tool to promote the progress of stem cell therapy in clinical application.

Bifidobacterium lactis Probio-M8 improves bone metabolism in patients with postmenopausal osteoporosis, possibly by modulating the gut microbiota

PURPOSE

Postmenopausal osteoporosis (PMO) is usually managed by conventional drug treatment. However, prolonged use of these drugs cause side effects. Gut microbiota may be a potential target for treatment of PMO. This work was a three-month intervention trial aiming to evaluate the added effect of probiotics as adjunctive treatment for PMO.

METHODS

Forty patients with PMO were randomized into probiotic (n = 20; received Bifidobacterium animalis subsp. lactis Probio-M8 [Probio-M8], calcium, calcitriol) and placebo (n = 20; received placebo material, calcium, calcitriol) groups. The bone mineral density of patients was measured at month 0 (0 M; baseline) and month 3 (3 M; after three-month intervention). Blood and fecal samples were collected 0 M and 3 M. Only 15 and 12 patients from Probio-M8 and placebo groups, respectively, provided complete fecal samples for gut microbiota analysis.

RESULTS

No significant change was observed in the bone mineral density of patients at 3 M. Co-administering Probio-M8 improved the bone metabolism, reflected by an increased vitamin D3 level and decreased PTH and procalcitonin levels in serum at 3 M. Fecal metagenomic analysis revealed modest changes in the gut microbiome in both groups at 3 M. Interestingly, Probio-M8 co-administration affected the gut microbial interactive correlation network, particularly the short-chain fatty acid-producing bacteria. Probio-M8 co-administration significantly increased genes encoding some carbohydrate metabolism pathways (including ABC transporters, the phosphotransferase system, and fructose and mannose metabolism) and a choline-phosphate cytidylyltransferase.

CONCLUSIONS

Co-administering Probio-M8 with conventional drugs/supplements was more efficacious than conventional drugs/supplements alone in managing PMO. Our study shed insights into the beneficial mechanism of probiotic adjunctive treatment.

REGISTRATION NUMBER OF CLINICAL TRIAL

Chinese Clinical Trial Registry (identifier number: ChiCTR1800019268).

Hypoxia Pathway in Osteoporosis: Laboratory Data for Clinical Prospects

The hypoxia pathway not only regulates the organism to adapt to the special environment, such as short-term hypoxia in the plateau under normal physiological conditions, but also plays an important role in the occurrence and development of various diseases such as cancer, cardiovascular diseases, osteoporosis. Bone, as a special organ of the body, is in a relatively low oxygen environment, in which the expression of hypoxia-inducible factor (HIF)-related molecules maintains the necessary conditions for bone development. Osteoporosis disease with iron overload endangers individuals, families and society, and bone homeostasis disorder is linked to some extent with hypoxia pathway abnormality, so it is urgent to clarify the hypoxia pathway in osteoporosis to guide clinical medication efficiently. Based on this background, using the keywords "hypoxia/HIF, osteoporosis, osteoblasts, osteoclasts, osteocytes, iron/iron metabolism", a matching search was carried out through the Pubmed and Web Of Science databases, then the papers related to this review were screened, summarized and sorted. This review summarizes the relationship and regulation between the hypoxia pathway and osteoporosis (also including osteoblasts, osteoclasts, osteocytes) by arranging the references on the latest research progress, introduces briefly the application of hyperbaric oxygen therapy in osteoporosis symptoms (mechanical stimulation induces skeletal response to hypoxic signal activation), hypoxic-related drugs used in iron accumulation/osteoporosis model study, and also puts forward the prospects of future research.

Eldecalcitol effectively prevents alveolar bone loss by partially improving Th17/Treg cell balance in diabetes-associated periodontitis

Background: Diabetes-associated periodontitis (DPD) is an inflammatory and destructive disease of periodontal tissues in the diabetic population. The disease is manifested as more severe periodontal destruction and is more difficult to treat when compared with periodontitis (PD). Eldecalcitol (ELD) is a novel active vitamin D3 analog; however, little clinical evidence is available on its role on improving PD and DPD, and its specific mechanisms remain unclear. In this study, we evaluated the preventative effects of ELD toward PD and DPD and explored its underlying molecular mechanisms. Methods: Experimental PD and DPD mouse models were established by ligation combined with lipopolysaccharide (LPS) from Porphyromonas gingivalis injection in C57BL/6J and C57BLKS/J Iar- + Leprdb/+Leprdb (db/db) mice, respectively. Simultaneously, ELD (0.25 μg/kg) was orally administered to mice via an intragastric method. Micro-computed tomography (CT), hematoxylin-eosin (HE) staining, immunohistochemistry (IHC), and tartrate-resistant acid phosphatase (TRAP) staining were used to evaluate alveolar bone alterations in vivo. Flow cytometry, immunofluorescence, and real-time polymerase chain reaction (qRT-PCR) were also used to examine gene expression and probe systemic and local changes in Treg and Th17 cell numbers. Additionally, western blotting and immunofluorescence staining were used to examine changes in STAT3/STAT5 signaling. Results: Micro-CT and HE staining showed that the DPD group had higher alveolar bone loss when compared with the PD group. After applying ELD, alveolar bone loss decreased significantly in both PD and DPD groups, and particularly evident in the DPD group. IHC and TRAP staining also showed that ELD promoted osteoblast activity while inhibiting the number of osteoclasts, and after ELD treatment, the receptor activator of nuclear factor-κB ligand (RANKL) to osteoprotegerin (OPG) ratio decreased. More importantly, this decreasing trend was more obvious in the DPD group. Flow cytometry and qRT-PCR also showed that the systemic Th17/Treg imbalance in PD and DPD groups was partially resolved when animals were supplemented with ELD, while immunofluorescence staining and qRT-PCR data showed the Th17/Treg imbalance was partially resolved in the alveolar bone of both ELD supplemented groups. Western blotting and immunofluorescence staining showed increased p-STAT5 and decreased p-STAT3 levels after ELD application. Conclusion: ELD exerted preventative effects toward PD and DPD by partially rectifying Th17/Treg cell imbalance via STAT3/STAT5 signaling. More importantly, given the severity of DPD, we found ELD was more advantageous in preventing DPD.

Vitamin D ameliorates insulin resistance-induced osteopenia by inactivating the nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome

Objective

Osteoporosis (OP) can be considered a chronic complication of type 2 diabetes mellitus (T2DM). Aberrant activation of the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome is associated with the pathogenesis of various inflammation-related diseases, e.g., T2DM and OP. Vitamin D affects the inflammatory pathway and inhibits an excessive inflammatory response. The current study investigated the inter-relationship between vitamin D and inflammasome activation in T2DM.

Method

Hepatocellular carcinoma (HepG2) cells and bone marrow stromal cells (BMSCs) were treated with Conditioned Medium of bone marrow mesenchymal stem cells after VitD treatment (CM-VitD), as well as phosphoinositide 3-kinase (PI3K) specific agonist, 740Y-P, or the PI3K specific inhibitor, LY294002, respectively, or both. 40 Eight-week-old female Sprague Dawley rats were selected and established as a DM model. The rats were injected with CM-VitD, as well as the 740Y-P specific agonist, or the LY294002 inhibitor, respectively, or both. A quantitative reverse transcription polymerase chain reaction and western blotting were conducted to evaluate the expression of messenger ribonucleic acid and protein in the RUX2 gene, alkaline phosphatase (ALP), OsteoPontiN (OPN), peroxisome proliferator-activated receptor gamma (PPARγ), fatty acid-binding protein 4 (FABP4), protein kinase B (AKT), PI3K, NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), caspase-1, interleukin (IL)-1 beta (β), IL-18, and tumor necrosis factor alpha (TNF-α) in the BMSCs and liver tissue of rats. Enzyme-linked immunosorbent assay was used to detect the concentration of inflammatory factors in the cell supernatant and serum of rats.

Results

An isolated co-culture of HepG2/insulin-resistance cells and BMSCs promoted the adipogenic transformation of the latter and inhibited the transformation of BMSCs into osteogenesis. The PI3K specific agonist, 740Y-P, significantly increased the expression of PI3K, AKT, NLRP3, ASC and Caspase-1 while the PI3K specific inhibitor, LY294002, does the opposite. Additionally, CM-VitD reduced the expression of NLRP3, ASC, caspase-1, IL-1β, and IL-18 in BMSCs and rat liver via the PI3K/AKT pathway.

Conclusion

Vitamin D can inhibit the inflammatory response induced by T2DM and promote the osteogenesis of BMSCs, which may play a key role in the treatment of type 2 diabetes patients with OP.

Porous gelatin microsphere-based scaffolds containing MC3T3-E1 cells and calcitriol for the repair of skull defect

There is an increasing demand for biomaterials with skull regeneration for clinical application. However, most of the current skull repair materials still have limitations, such as inadequate sources, poor cell adherence, differentiation, tissue infiltration, and foreign body sensation. Therefore, this study developed porous microsphere-based scaffolds containing mouse embryonic osteoblast precursor cells (MC3T3-E1 cells) and calcitriol (Cal) using gelatin and gelatin/hydroxyapatite through green freeze-crosslinking and freeze-drying. Gelatin was employed to prepare porous microspheres with a particle size of 100-300 μm, containing open pores of 2-70 μm and interconnected paths. Furthermore, the addition of Cal to porous gelatin microsphere-based scaffolds containing MC3T3-E1 cells (PGMSs-MC) and porous gelatin/hydroxyapatite composite microspheres containing MC3T3-E1 cells (HPGMSs-MC) improved their osteoinductivity and cell proliferation and promoted the formation of mature and well-organized bone. The developed Cal-HPGMSs-MC and Cal-PGMSs-MC displayed a good porous structure and cytocompatibility, histocompatibility, osteoconductivity, and osteoinduction. Thus, the designed scaffolds provide a promising prospect for tissue-engineered constructs with skull growth and integration, laying a foundation for further research on the reconstruction of skull defects.

Astrocyte Dysregulation and Calcium Ion Imbalance May Link the Development of Osteoporosis and Alzheimer’s Disease

The typical symptoms of patients with Alzheimer’s disease (AD) are amyloid-β (Aβ) plaques and tau hyperphosphorylation. However, recent studies show that these symptoms are not the cause of the disease but are generated after the pathogenesis. Compared with other types of dementia, AD has the obvious features of pineal gland calcification and decreased melatonin production. The pineal gland is mainly composed of pinealocytes that release melatonin and astrocytes. Astrocytes function to maintain a balanced concentration of calcium ions, provide nerve cell nutrients, and migrate nutrients in vivo. Calcium ions are among the most important neurotransmitters. Once triggered, a calcium wave can be formed between astrocytes to activate other astrocytes to transmit information. Most calcium is stored in the skeleton. Bone tissue is composed mainly of osteocytes, osteoblasts, and osteoclasts. Of these, osteocyte is a kind of astrocyte which regulates the activity of osteoclasts and osteoblasts. The pineal gland is composed mainly of astrocytes; osteocytes are also a kind of astrocyte. Therefore, we conclude that when astrocytes are gradually disabled, calcium may be lost from the bones, prompting osteoporosis. The calcium ions then released into the blood may accumulate and cause ectopic calcification in the pineal gland, which promotes the occurrence of AD. Finally, this study used aspects of drugs and hormones (bone and calcium metabolism hormones and melatonin) to infer the hypothesis, which proposes that astrocyte dysregulation promotes the long-term imbalance of calcium ions in vivo and leads to osteoporosis and AD.

Anthropometric, biochemical, and nutritional risk factors for osteoporosis in Korean adults based on a large cross-sectional study

Background

Osteoporosis a common bone disorder characterized by decreases in bone mass, tension, and strength. Although many previous studies worldwide have sought to identify the risk factors for osteoporosis, studies that simultaneously examine a variety of factors, such as biochemical, anthropometric and nutritional components, are very rare. Therefore, the objective of this study was to simultaneously examine the association of osteoporosis with biochemical profiles, anthropometric factors, and nutritional components in a large-scale cross-sectional study.

Method

This cross-sectional study was based on data from the Korea National Health and Nutrition Examination Survey (KNHANES VI-VII) from 2015 to 2018. Based on data from 16,454 participants, logistic regression was used to examine the association between various parameters in a crude analysis and in models adjusted for confounders.

Results

In men, osteoporosis was significantly associated with the anthropometric variables height and weight; the biochemical components hemoglobin, hematocrit, urea nitrogen and urine pH and creatinine; and the nutritional components total food intake, energy, water, protein, phosphorus, and kalium. However, these associations disappeared in adjusted model 2. In women, osteoporosis was significantly related to the anthropometric measures height, weight, and systolic blood pressure; the biochemical components hemoglobin, hematocrit and urine pH; and the nutritional components total food intake, water, calcium, phosphorus, and kalium. Most of these associations were maintained in the adjusted models.

Conclusion

Osteoporosis was linked to various anthropometric, biochemical and urine and nutritional components in Korean women, but the association between osteoporosis and risk factors differed according to sex.

Osteoporosis, an Inevitable Circumstance of Chronic Kidney Disease: A Systematic Review

Nowadays, chronic kidney disease (CKD) and osteoporosis have become crucial health-related issues globally. CKD-induced osteoporosis is a systemic disease characterized by the disruption of mineral, hormone, and vitamin homeostasis that elevates the likelihood of fracture. Here, we review recent studies on the association of CKD and osteoporosis. In particular, we focus on the pathogenesis of CKD-associated osteoporosis, including the homeostasis and pathways of several components such as parathyroid hormone, calcium, phosphate, vitamin D, fibroblast growth factor, and klotho, as well as abnormal bone mineralization, remodeling, and turnover. In addition, we explore the diagnostic tools and possible therapeutic approaches for the management and prevention of CKD-associated osteoporosis. Patients with CKD show higher osteoporosis prevalence, greater fracture rate, increased morbidity and mortality, and an elevated occurrence of hip fracture. We also rule out that increased severity of CKD is related to a more severe condition of osteoporosis. Furthermore, supplements such as calcium and vitamin D as well as lifestyle modifications such as exercise and cessation of smoking and alcohol help in fracture prevention. However, new approaches and advancements in treatment are needed to reduce the fracture risk in patients with CKD. Therefore, further collaborative multidisciplinary research is needed in this regard.

Vitamin D and Platelets: A Menacing Duo in COVID-19 and Potential Relation to Bone Remodeling

Global data correlate severe vitamin D deficiency with COVID-19-associated coagulopathy, further suggesting the presence of a hypercoagulable state in severe COVID-19 patients, which could promote thrombosis in the lungs and in other organs. The feedback loop between COVID-19-associated coagulopathy and vitamin D also involves platelets (PLTs), since vitamin D deficiency stimulates PLT activation and aggregation and increases fibrinolysis and thrombosis. Vitamin D and PLTs share and play specific roles not only in coagulation and thrombosis but also during inflammation, endothelial dysfunction, and immune response. Additionally, another ‘fil rouge’ between vitamin D and PLTs is represented by their role in mineral metabolism and bone health, since vitamin D deficiency, low PLT count, and altered PLT-related parameters are linked to abnormal bone remodeling in certain pathological conditions, such as osteoporosis (OP). Hence, it is possible to speculate that severe COVID-19 patients are characterized by the presence of several predisposing factors to bone fragility and OP that may be monitored to avoid potential complications. Here, we hypothesize different pervasive actions of vitamin D and PLT association in COVID-19, also allowing for potential preliminary information on bone health status during COVID-19 infection.

Seasonal variation of serum 25-hydroxyvitamin D level in hemodialysis patients in the northernmost island of Japan

BACKGROUND

Serum vitamin D level shows a seasonal variation, being lower in winter than in summer in healthy subjects. The aim of this study was to determine whether there is presence of such a seasonal variation in hemodialysis patients.

METHODS

A total of 102 patients on hemodialysis were enrolled in February 2017 (winter) for analyses of serum levels of 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)₂D] and treatments for chronic kidney disease-mineral and bone disorder (CKD-MBD). The examinations were repeated in August 2017 (summer). After exclusion of patients with malignancy, loss of follow-up and missing data, 78 patients contributed to the analyses.

RESULTS

Serum level of 25(OH)D, but not that of 1,25(OH)₂D, was significantly lower in winter (14.0 ng/mL) than in summer (15.5 ng/mL), though there was no significant difference in regimen for CKD-MBD treatment including vitamin D receptor activators (VDRAs) between the two seasons. Serum intact parathyroid hormone level tended to be higher and alkaline phosphatase was significantly higher in winter than in summer. Linear mixed-effects model analysis showed that level of 25(OH)D, but not that of 1,25(OH)₂D, was significantly associated with season (winter and summer) after adjustment of age, sex, dialysis vintage, albumin level and use of drugs for CKD-MBD.

CONCLUSION

Serum 25(OH)D has a seasonal variation, being lower in winter than in summer, independent of CKD-MBD treatment including treatment with VDRAs in Japanese hemodialysis patients. The impact of the seasonal variation on risk of vitamin D deficiency and its effect on prognosis remain to be investigated.