Evaluation of Association Studies and an Updated Meta-Analysis of VDR Polymorphisms in Osteoporotic Fracture Risk

Comparative analysis of the parapatellar and subpatellar approaches in reducing peripheral knee pain post-intramedullary tibial fracture surgery

INTRODUCTION

Intramedullary tibial nailing is a standard treatment for tibial shaft fractures. Postoperative knee pain significantly impacts functional recovery; however, studies on this issue are limited. This study evaluated the effect of the parapatellar approach for intramedullary nailing on postoperative knee pain.

MATERIALS AND METHODS

A total of 29 patients with tibial shaft fractures treated with intramedullary nails from March 2019 to January 2022 were divided into two groups based on the surgical approach: the semi-extended lateral parapatellar approach and the conventional subpatellar ligament split approach. Recorded metrics included operation time, intraoperative fluoroscopy count, intraoperative bleeding volume, Visual Analog Scale (VAS) scores for knee pain at 24 h, 72 h, 1 week, and 1 month postoperatively, fracture healing time and Lysholm knee functional scores at 12 months.

RESULTS

Both groups completed the operation without significant differences in operation time, intraoperative bleeding, fracture healing time, or intraoperative fluoroscopy (P > 0.05). The parapatellar group showed significantly better VAS scores for knee pain at 24 h, 72 h, and 1 week postoperatively compared to the control group (P < 0.05), with no significant difference at 1 month. After 12 months, Lysholm scores indicated no significant differences in knee support, locking, and swelling (P > 0.05); however, the parapatellar group showed significant improvements in lameness, instability, stair climbing, squatting, and pain (P < 0.05). Overall, the parapatellar group outperformed the control group (P = 0.01). Additionally, long-term follow-up revealed potential advantages of the parapatellar approach in improving long-term functional outcomes.

CONCLUSIONS

Using the parapatellar approach for tibial intramedullary nailing avoids splitting the patellar ligament and entering the joint cavity, minimizing knee joint impact and effectively reducing postoperative knee pain, with potential benefits in long-term functional recovery.

Bone Fracture Incidence in Postmenopausal Women: Results of a 10 Year Follow Up in a RAC-OST-POL Study of rs1544410, rs7975232 and rs731236 Polymorphisms

BACKGROUND

The clinical significance of the genetic influence of vitamin D receptor polymorphisms has still not been well-analyzed.

OBJECTIVES

To verify whether rs1544410, rs7975232 and rs731236 polymorphisms are associated with a higher 10-year fracture risk in postmenopausal women.

METHODS

The study group was a subset of a pre-defined population as part of the broader epidemiological research called the RAC-OST-POL Study and consisted of 358 postmenopausal women, chosen randomly from Racibórz (Poland) inhabitants (mean baseline age 65 ± 6.9 years, BMI 31.2 ± 5.5 kg/m2). From all participants' medical history, data concerning co-morbidities, fracture history, the medication used, parental history of bone fractures, cigarettes and alcohol use were taken at baseline. Moreover, rs1544410, rs7975232 and rs731236 polymorphisms were analyzed. Next, over the following 10 years, participants were contacted once a year and questioned concerning new fractures events and their circumstances.

RESULTS

We did not find statistically significant main effects on the fracture incidence of single-polymorphism variants. However, there were some significant findings dependent on the co-existence of these polymorphisms and medical factors. Women with a positive history of parental fracture and configuration of CC rs7975232, AA rs731236 and CC rs1544410 had a higher fracture incidence. The risk of bone fracture was also significantly higher in the group of heterozygotes of AC rs7975232 if their BMI value was in the categories of normal weight or overweight, or if they were treated with calcium or vitamin D.

CONCLUSIONS

Polymorphisms of rs1544410, rs7975232 and rs731236 are connected with the fracture incidence in postmenopausal women. Nevertheless, its influence should be considered with co-existing clinical factors, especially paternal fracture history, prior fracture, BMI value, any osteoporotic treatment or calcium/vit. D supplementation.

Association of VDR Polymorphisms with Muscle Mass Development in Elite Young Soccer Players: A Pilot Study

The vitamin D receptor (VDR) is an important candidate gene in musculoskeletal phenotypes. Polymorphisms in the VDR have been previously associated with several pathologies and muscular strength in athletes and elderly people; however, the literature reported contradictory results. The object of this research was to verify the association between the most studied VDR variants (rs2228570, rs7975232, and rs1544410) and the increase in muscle mass in elite young soccer players. A sample of 55 soccer players (15-18 years old) from a professional team were selected for this study. DNA was extracted by the salting-out method, and polymorphisms were genotyped by PCR-RFLP, followed by 2% agarose gel electrophoresis. To test the effect of the three SNPs (single nucleotide polymorphisms), a logistic regression analysis was applied. The body composition determination was carried out through the skinfold thickness method, and the muscular area of the arm and lower limb were calculated using the Frisancho formula. All three polymorphisms met the Hardy-Weinberg equilibrium (p > 0.05) and their frequencies fell within the worldwide variability. A significant correlation between rs1544410 and the increase in calf muscle mass was observed. Individuals carrying the A allele showed higher calf muscular mass than those carrying the G allele (p = 0.034). Moreover, a haplotype analysis applied to the two SNPs in linkage disequilibrium (rs7975232 and rs1544410) showed that the AG haplotype appeared negatively correlated to the calf muscle area. In conclusion, we confirm an association between VDR polymorphisms and muscular mass that could encourage the genetic screening of the VDR gene to identify a potential risk of injury and for individual nutritional interventions.

Association of rs4516035 Polymorphism with Osteoporosis in the Southeastern Iranian Population: A Case-Control Study

BACKGROUND

Genetic polymorphisms are known to play a crucial role in the development of osteoporosis. Vitamin D3 regulates bone homeostasis through the vitamin D receptor (VDR). Reduced VDR activity increases osteoporosis risk. Study Design: A case-control study.

METHODS

This case-control study investigated the potential association between six single-nucleotide polymorphisms (SNPs) within the VDR gene (rs11568820, rs4516035, rs2228570, rs1544410, rs7975232, and rs731236) and the occurrence of osteoporosis in Kerman province. The genotypes of the SNPs were analyzed using polymerase chain reaction-restriction fragment length polymorphism, tetra primer amplification refractory mutation system-PCR, and sequencing in two groups of osteoporosis patients (n=40) and controls (n=42). Additionally, the levels of calcium and vitamin D3 in the serum of the patients were measured, and the in silico analysis of the VDR structure and interaction was performed using I-TASSER, ProSA, PROCHECK, GeneMANIA, GTEx, and GPS 6.0.

RESULTS

None of the patients exhibited calcium or vitamin D3 deficiencies. Among the six SNPs, only the T allele in rs4516035, which leads to a shorter variant called VDRA, showed a significant association with susceptibility to osteoporosis (odds ratio=3.061, P=0.007). The in silico analysis demonstrated that the 3D structure, expression, and post-transcriptional modification of VDRA are distinct from those of the more extended variant, VDRB1. VDRB1 is upregulated in sun-exposed skin, and its interactions with its partners differ from those of VDRA.

CONCLUSION

Despite adequate vitamin D levels, the VDRA variant, which has lower activity, could increase the predisposition to osteoporosis in the studied population. These findings clarify the importance of genetic screening for personalized medicine and the effectiveness of prevention and treatment strategies.

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.

Modulation of the vitamin D/vitamin D receptor system in osteoporosis pathogenesis: insights and therapeutic approaches

Osteoporosis is a prevalent bone disorder characterized by low bone mineral density (BMD) and deteriorated bone microarchitecture, leading to an increased risk of fractures. Vitamin D (VD), an essential nutrient for skeletal health, plays a vital role in maintaining bone homeostasis. The biological effects of VD are primarily mediated through the vitamin D receptor (VDR), a nuclear receptor that regulates the transcription of target genes involved in calcium and phosphate metabolism, bone mineralization, and bone remodeling. In this review article, we conduct a thorough literature search of the PubMed and EMBASE databases, spanning from January 2000 to September 2023. Utilizing the keywords "vitamin D," "vitamin D receptor," "osteoporosis," and "therapy," we aim to provide an exhaustive overview of the role of the VD/VDR system in osteoporosis pathogenesis, highlighting the most recent findings in this field. We explore the molecular mechanisms underlying VDR's effects on bone cells, including osteoblasts and osteoclasts, and discuss the impact of VDR polymorphisms on BMD and fracture risk. Additionally, we examine the interplay between VDR and other factors, such as hormonal regulation, genetic variants, and epigenetic modifications, that contribute to osteoporosis susceptibility. The therapeutic implications of targeting the VDR pathway for osteoporosis management are also discussed. By bringing together these diverse aspects, this review enhances our understanding of the VD/VDR system's critical role in the pathogenesis of osteoporosis and highlights its significance as a potential therapeutic target.

Association between the ESR1 and ESR2 polymorphisms and osteoporosis risk: An updated meta-analysis

BACKGROUND

Gene polymorphisms of estrogen receptor (ESR) 1 PvuII (rs2234693), XbaI (rs9340799), G2014A (rs2228480), ESR2 AluI (rs4986938), and RsaI (rs1256049) had been reported to be associated with the risk of osteoporosis. However, these conclusions were inconsistent, therefore, an updated meta-analysis was conducted to further explore these issues.

OBJECTIVE

To evaluate the association between gene polymorphisms of ESR1 PvuII (rs2234693), XbaI (rs9340799), G2014A (rs2228480), ESR2 AluI (rs4986938), RsaI (rs1256049), and osteoporosis risk.

MATERIALS AND METHODS

PubMed, Medline, Ovid, Embase, CNKI, and China Wanfang databases were searched. Association was assessed using odds ratio with 95% confidence interval. Moreover, the false-positive reporting probability, Bayesian false-finding probability, and Venetian criteria were used to assess the credibility of statistically significant associations.

RESULTS

Overall, ESR1 PvuII (rs2234693) and XbaI (rs9340799) were associated with the risk of osteoporosis in Indians. Moreover, ESR1 G2014A (rs2228480) was associated with the decreased risk of osteoporosis in East Asians. Moreover, ESR2 Alul (rs4986938) was associated with the increased risk of osteoporosis in East Asians and Caucasians. There was a significant association between ESR2 Rsal (rs1256049) and osteoporosis risk in overall population. When only high-quality and Hardy-Weinberg equilibrium studies were included in the sensitivity analysis, all results did not change in the present study. When the credibility was evaluated applying false-positive reporting probability, Bayesian false-finding probability, and Venetian criteria, all significant associations were considered as false positive results.

CONCLUSIONS

In summary, this study shows that all substantial associations between gene polymorphisms of ESR1 (PvuII, XbaI, and G2014A) and ESR 2 (AluI and RsaI) and osteoporosis risk are possibly false positive results instead of real associations or biological variables.

Vitamin D Receptor Gene Polymorphisms Affect Osteoporosis-Related Traits and Response to Antiresorptive Therapy

The present study analyzed the effect of vitamin D receptor (VDR) gene polymorphisms (ApaI, TaqI, BsmI, FokI, and Cdx2) on bone mineral density (BMD), biochemical parameters and bone turnover markers, fracture prevalence, and response to three types of antiresorptive therapy (estrogen-progesterone, raloxifene, and ibandronate) in 356 postmenopausal women from Slovakia. Association analysis revealed a significant effect of BsmI polymorphism on lumbar spine BMD, serum osteocalcin (OC), and β-CrossLaps levels. While ApaI and Cdx2 polymorphisms were associated with OC and alkaline phosphatase, TaqI polymorphism affected all turnover markers. ApaI, TaqI, and BsmI genotypes increased the risk of spinal, radial, or total fractures with odds ratios ranging from 2.03 to 3.17. Each of therapy types evaluated had a beneficial effect on all osteoporosis-related traits; however, the VDR gene affected only ibandronate and raloxifene treatment. ApaI/aa, TaqI/TT, and BsmI/bb genotypes showed a weaker or no response to ibandronate therapy in femoral and spinal BMD. The impact of aforementioned polymorphisms on turnover markers was also genotype dependent. On the contrary, only TaqI and BsmI polymorphisms influenced raloxifene therapy, even only in lumbar spine BMD. These results point to the potential of using the VDR gene in personalized pharmacotherapy of osteoporosis.