Association between vitamin D receptor BsmI polymorphism and bone mineral density in pediatric patients: A meta-analysis and systematic review of observational studies

Vitamin D status and VDR gene polymorphisms in patients with growth hormone deficiency: A case control Tunisian study

Introduction

Growth Hormone Deficiency (GHD) is a rare disease marked by a complete or partial reduction in the production of growth hormone. Vitamin D deficiency is frequent and may be associated with several pathologies. However, the association between GHD and vitamin D deficiency has not been extensively studied. This study aimed to analyse VDR gene polymorphisms related to vitamin D status to ensure better care for patients with GHD.

Material and methods

A case-control study was conducted at the Children's Hospital of Tunis in collaboration with the Farhat Hached's Hospital of Sousse, including patients with GHD and healthy subjects. Genetic analysis of the VDR gene polymorphisms was performed using PCR-RFLP technique. Haplotypes were examined with Haploview software, while statistical analyses were carried out using SPSS and R programming language.

Results

Our study revealed significant differences in vitamin D (p = 0, 049) and calcium concentrations between patients and healthy subjects, which were lower in the GHD group (p = 0,018). A comparison of allelic and genotypic frequencies of the five polymorphisms indicated an association between the FokI polymorphism and GHD. Furthermore, significant difference was observed between the ApaI genotypes and PTH (p = 0,019) and ALP (p = 0,035). FokI genotypes were associated with phosphorus (p = 0,021). Additionally, One haplotype, CTAGT, exhibited a significant difference between the patients and healthy subjects (p = 0,002).

Conclusion

Our study findings indicate that hypovitaminosis D is common among patients with GHD, even when undergoing treatment with rhGH. This underscores the critical importance of vitamin D supplementation during treatment.

The Impact of Vitamin D Deficiency on Gestational Diabetes Mellitus Risk: A Retrospective Study

Background Nowadays, there has been growing attention to vitamin D deficiency's impact on women of reproductive age, both during pregnancy and the preconception period. Because of its possible impact on female reproductive ability, vitamin D deficiency may have multiple implications for maternal and fetal health. Currently, the correlation between vitamin D deficiency and gestational diabetes mellitus (GDM) is gaining attention, mainly due to contradictory findings in the literature. Methods We conducted a single-center, retrospective study involving data from 106 pregnant women to establish a possible link between vitamin D deficiency and GDM risk. We analyzed variables such as vitamin D status, the occurrence of gestational diabetes, and body mass index to identify significant statistical correlations among them. Results Within our study group, the average vitamin D level was 19.5 ± 7.8 ng/mL. Regarding vitamin D status, 59 (55.7%) pregnant women had vitamin D deficiency, 36 (34%) had vitamin D insufficiency, and 11 (10.4%) had optimal vitamin D levels. GDM was diagnosed in 18 cases, representing 17%. After the statistical analysis, we found a positive correlation between gestational diabetes and vitamin D deficiency (chi-square = 4.472, p = 0.049). However, we did not find a significant correlation between gestational diabetes and optimal vitamin D status. Conclusions Pregnant women with vitamin D deficiency are at an increased risk of developing GDM and may benefit from vitamin D supplementation. We believe that further research is necessary to have a comprehensive understanding of vitamin D's effects on pregnancy.

Impact of Vitamin D Receptor Genotypes on Taiwan Hallux Valgus

BACKGROUND/AIM

Hallux valgus (HV) is the most prevalent deformity affecting the forefoot; however, its genetic etiology remains unclear. In the literature, vitamin D receptor (VDR) genotypes have been reported to be associated with the risk of skeletal malformations accompanied by inflammation. This study aimed to examine the hypothesis that VDR genotypes are associated with the risk of HV.

MATERIALS AND METHODS

The VDR rs731236, rs1544410, rs2228570 and rs7975232 genotypes of 150 HV patients and 600 non-HV subjects were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology and examined regarding their associations with HV risk.

RESULTS

The results showed that none of the genetic frequency distributions of VDR rs731236, rs1544410, rs2228570, or rs7975232 were significant between the HV cases and non-HV controls (p for trend=0.4055, 0.2170, 0.7220, 0.5509, respectively). Additionally, allelic frequency analysis showed that none of the allelic frequencies of VDR rs731236, rs1544410, rs2228570, or rs7975232 were significantly distributed (p=0.2285, 0.1572, 0.9278, and 0.5547, respectively). Furthermore, stratified analysis showed that no correlation was observed between VDR rs731236 and different age groups (either younger or older than 51) or sex (p=0.3953 and p=0.9576). Moreover, no correlation was found between VDR rs731236 genotype and the risk of HV in individuals within subgroups of height, weight, or body mass index (BMI) (p=0.8317, 0.5346, and p=0.8783, respectively).

CONCLUSION

VDR rs731236, rs1544410, rs2228570, and rs7975232 may not serve as indicators for a higher risk of HV.

La osteocalcina se asocia con la densidad mineral ósea y los polimorfismos del gen VDR en la diabetes tipo 1 y 2

Objetivos

El metabolismo óseo se encuentra alterado en la diabetes mellitus (DM). El objetivo de este estudio es evaluar la relación entre los marcadores de remodelado óseo (MRO), los polimorfismos en el gen receptor de la vitamina D (VDR) y la densidad mineral ósea (DMO) en la DM tipo 1 (T1D) y tipo 2 (T2D).

Métodos

Se incluyó a 165 pacientes (53 T1D y 112 T2D). La DMO se midió mediante absorciometría de rayos X de energía dual (DEXA). Se realizó un análisis de la osteocalcina (OC) en plasma, beta-CrossLaps (β-CTX), propéptido aminoterminal del procolágeno tipo 1 (P1NP) y los polimorfismos en el gen VDR.

Resultados

Se incluyó a 53 pacientes con T1D (41 años (31–48)) y 112 con T2D (60 años [51–66]). No se observaron diferencias estadísticamente significativas en relación a la DMO. Los pacientes con T1D presentaron niveles superiores de OC (p<0,001) y P1NP (p<0,001). Las áreas bajo la curva para la predicción de patología ósea para la OC fueron 0,732 (p=0,038) en T1D y 0,697 (p=0,007) en T2D. Se observó una relación estadísticamente significativa entre el alelo A de BsmI (p=0,03), el alelo A de ApaI (p=0,04) y el alelo C de Taql (p=0,046) y una menor DMO. Así mismo, se encontró una correlación significativa entre los niveles elevados de OC y el alelo G de BsmI (p=0,044), el alelo C de ApaI (p=0,011), el alelo T de Taql (p=0,006) y el alelo C de FokI (p=0,004).

Conclusiones

El elevado valor predictivo negativo del punto de corte de la OC indica que la OC podría ser útil a la hora de descartar el riesgo de pérdida ósea, lo que permitiría diseñar un tratamiento personalizado para prevenir dicha patología.

Osteocalcin associates with bone mineral density and VDR gene polymorphisms in type 1 and type 2 diabetes

Objectives

Bone metabolism is impaired in diabetes mellitus (DM). Our objective is to evaluate the association of bone turnover markers (BTM) and vitamin D receptor (VDR) gene polymorphisms with bone mineral density (BMD) in DM type 1 (T1D) and DM type 2 (T2D).

Methods

A total of 165 patients (53 T1D and 112 T2D) were enrolled. BMD was measured by dual-energy X-ray absorptiometry (DEXA). Plasma osteocalcin (OC), beta-CrossLaps (β-CTX) and N-amino terminal propeptide of type I collagen (P1NP) and VDR gene polymorphisms were evaluated.

Results

Participants were 53 T1D (41 years [31-48]) and 112 T2D (60 years [51-66]). BMD were not statistically different between the groups. OC (p<0.001) and P1NP levels (p<0.001) were higher in patients with T1D. The areas under the curve for the prediction of bone pathology were 0.732 (p=0.038) for OC in T1D and 0.697 (p=0.007) in T2D. A significant association was found between lower lumbar BMD and the A allele of BsmI (p=0.03), the A allele of ApaI (p=0.04) and the allele C of the Taql (p=0.046). Also, a significant correlation was found with higher OC levels and the G allele of BsmI (p=0.044), C allele of ApaI (p=0.011), T allele of Taql (p=0.006) and with C allele of FokI (p=0.004).

Conclusions

The high negative predictive value of the cut-off point for OC suggests that could be useful in excluding the risk suffering bone loss, allowing offering a personalized clinical approach to prevent this pathology.

Effects of Isoflavonoid and Vitamin D Synergism on Bone Mineral Density-A Systematic and Critical Review

Phytoestrogens are non-steroidal plant compounds, which bind to α and β estrogen receptors, thereby causing specific effects. The best-known group of phytoestrogens are flavonoids, including isoflavonoids-genistein and daidzein. They play a role in the metabolism of bone tissue, improving its density and preventing bone loss, which contributes to reducing the risk of fractures. Vitamin D is found in the form of cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2) and is traditionally recognized as a regulator of bone metabolism. The aim of this review was to evaluate the synergistic effect of isoflavonoids and vitamin D on bone mineral density (BMD). The MEDLINE (PubMed), Scopus and Cochrane databases were searched independently by two authors. The search strategy included controlled vocabulary and keywords. Reference publications did not provide consistent data regarding the synergistic effect of isoflavonoids on BMD. Some studies demonstrated a positive synergistic effect of these compounds, whereas in others, the authors did not observe any significant differences. Therefore, further research on the synergism of isoflavonoids and vitamin D may contribute to a significant progress in the prevention and treatment of osteoporosis.

What is New in Pediatric Orthopaedic: Basic Science

BACKGROUND

An understanding of musculoskeletal basic science underpins most advancements in the field of orthopaedic surgery. Knowledge of biomechanics, genetics, and molecular pathways is integral to the understanding of the pathophysiology of disease and guides novel treatment options to improve patient outcomes. The purpose of this review is to provide a comprehensive and current overview of musculoskeletal basic science relevant to pediatric orthopaedic surgery.

METHODS

Comprehensive Pubmed database searches were performed for all English language articles published between January 2016 and November 2021 using the following search terms: basic science, pediatric orthopaedics, fracture, trauma, spine, scoliosis, DDH, hip dysplasia, Perthes, Legg-Calve-Perthes, clubfoot, and sports medicine. Inclusion criteria focused on basic science studies of pediatric orthopaedic conditions. Clinical studies or case reports were excluded. A total of 3855 articles were retrieved. After removing duplicates and those failing to meet our inclusion criteria, 49 articles were included in the final review.

RESULTS

A total of 49 papers were selected for review based on the date of publication and updated findings. Findings are discussed in the subheadings below. Articles were then sorted into the following sub-disciplines of pediatric orthopaedics: spine, trauma, sports medicine, hip, and foot.

CONCLUSIONS

With this review, we have identified many exciting developments in pediatric orthopaedic trauma, spine, hip, foot, and sports medicine that could potentially lead to changes in disease management and how we think of these processes.

LEVEL OF EVIDENCE

Level V.

Filamin B extensively regulates transcription and alternative splicing, and is associated with apoptosis in HeLa cells

Post-transcriptional mechanisms are an important approach in the treatment of cancer, and may also be hijacked by tumor cells to help adapt to the local microenvironment. Filamin B (FLNB), an actin-binding protein that provides crucial scaffolds for cell motility and signaling, has also been identified as an RNA-binding protein. Recent studies demonstrated that FLNB might play an important role, not only in skeletal development, but also in regulating tumorigenesis; however, the effects of dysregulated expression of FLNB at the molecular level are not clear. In the present study, RNA-sequencing was performed to analyze changes in overall transcriptional and alternative splicing between the knocked-down FLNB and the control in HeLa cells. Decreased FLNB levels resulted in significantly lower apoptosis compared with control cells. FLNB knockdown extensively regulated the expression of genes in cell apoptosis, tumorigenesis, metastases, transmembrane transport and cartilage development. Moreover, FLNB regulated alternative splicing of a large number of genes involved in ‘cell death’ and the ‘apoptotic process’. Some genes and alternative splicing related to skeletal development were enriched and regulated by FLNB. Reverse transcription-quantitative-PCR identified FLNB-regulated transcription and alternative splicing of genes, such as NLR family apoptosis inhibitory protein, interleukin 23 subunit α, metastasis associated lung adenocarcinoma transcript 1, phosphofurin acidic cluster sorting protein 2, bone morphogenetic protein 7, matrix metallopeptidase 13, collagen type II α 1 chain, fibroblast growth factor receptor 2 and vitamin D receptor. The present study is the first study, to the best of the authors’ knowledge, to provide transcriptome-wide analysis of differential gene expression and alternative splicing upon FLNB silencing. The present results suggested that FLNB may play an important regulatory role in cervical cancer cell apoptosis via regulation of transcription and alternative splicing, which provide insight for the current understanding of the mechanisms of FLNB-mediated gene regulation.

Current Knowledge Regarding the Interaction Between Oral Bone Metabolic Disorders and Diabetes Mellitus

Diabetes mellitus, a major chronic disease affecting human health, has been increasing in prevalence in recent years. Diabetes mellitus can cause bone metabolic disorders in patients, leading to osteoporosis, a higher risk of traumatic fracture, and other bone diseases. Bone metabolic disorders in the oral cavity principally manifest as periodontitis, loss of alveolar bone, and failure of implant osseointegration. In recent years, numerous studies have shown that there is a complex interaction between bone metabolic disorders and diabetes mellitus. This paper reviews the adverse effects of diabetes on oral bone metabolism disorders such as alveolar osteoporosis and bone loss in patients with periodontitis, discusses the potential mechanisms of diabetic bone loss, and suggests potential ways to prevent and treat oral bone loss in patients with diabetes mellitus.

Association of vitamin D receptor gene polymorphisms with disc degeneration

PURPOSE

Numerous candidate genes and single-nucleotide polymorphisms (SNPs) have been identified in the background of lumbar disc degeneration (LDD). However, in most of these underpowered studies, definitions of LDD are inconsistent; moreover, many of the findings have not been replicated and are contradictory. Our aim was to characterize LDD by well-defined phenotypes and possible endophenotypes and analyse the association between these and candidate vitamin D receptor (VDR) gene polymorphisms on a large (N = 1426) dataset.

METHODS

Seven candidate VDR SNPs were genotyped. Individual association, haplotype and gene-gene interaction analyses were performed. All degenerative endophenotypes were significantly associated with one or more candidate VDR gene variants.

RESULTS

Haplotype analyses confirmed the association between the 3'-end VDR variants (BsmI, ApaI, TaqI) and Modic changes as well as the relationship of 5'-end variants (Cdx2, A1012G) with endplate defects. We also found significant interactions between the 3'- and 5'-end regulatory regions and endplate defects. Based on our results, VDR and its gene variants are highly associated with specific degenerative LDD endophenotypes.

CONCLUSION

Understanding relationships between phenotype and gene variants is crucial for describing the pathways leading to the multifactorial, polygenic degeneration process and LDD-related conditions. These slides can be retrieved under Electronic Supplementary Material.

Association of Vitamin D Receptor BsmI Gene Polymorphism with BMD Z-Score in Iranian Children and Adolescents (9 - 18 Years Old)

BACKGROUND

The vitamin D receptor (VDR) gene variants are known as the main risk factor for low bone mass.

OBJECTIVES

In this study, the association of vitamin D receptor genetic variants, BsmI (rs1544410) and FokI (rs2228570), with bone mass in Iranian children and adolescents, was evaluated.

METHODS

The study population comprised of children and adolescents aged between 9 to 18 years (FokI: 123 boys and 120 girls, BsmI: 108 boys and 110 girls). Vitamin D, calcium, phosphorus, total cholesterol (TC), High-density lipoprotein-cholesterol (HDL-C) and triglyceride (TG) concentrations were assayed. Bone mineral density and body composition parameters were measured by the Hologic system DXA. BMD Z-score ≤ -2 was considered as low bone density for chronologic age. PCR-restriction fragment length polymorphism was done for genotyping of BsmI and FokI polymorphisms. The association between VDR variants and bone mineral density was investigated using logistic regression analysis.

RESULTS

No significant differences in body composition and biochemical parameters were detected among the evaluated VDR genotypes. For VDR BsmI, the mean values for Z-score of the lumbar spine, neck, inter and total femur was greater in the bb genotype compared to BB and Bb genotypes. Logistic regression analysis revealed a significant association between femoral neck Z-score and VDR BsmI genotypes in an additive genetic model (unadjusted model (P = 0.035; Bb vs. bb), model 1 (adjusted for age and sex, P = 0.021; Bb vs. bb), model 2 (adjusted for age, sex and BMI, P = 0.013; Bb vs. bb) and model 3 (adjusted for age, sex, BMI and puberty, P = 0.011; Bb vs. bb, P = 0.049; BB vs. bb)) and dominant genetic model ((unadjusted model, P = 0.033; BB+Bb vs. bb), model 1 (adjusted for age and sex, P = 0.023; BB+Bb vs. bb), model 2 (adjusted for age, sex and BMI, P = 0.012; BB+Bb vs. bb and model 3 (adjusted for age, sex, BMI and puberty, P = 0.012; BB+Bb vs. bb)).

CONCLUSIONS

This investigation indicated that VDR BsmI polymorphism may be associated with BMD Z-score of the femoral neck but not the lumbar spine, in Iranian children and adolescents.