Serum 25-hydroxyvitamin D, serum calcium and vitamin D receptor (VDR) polymorphisms in a selected population with lumbar disc herniation-A case control study

Potential causal association between serum vitamin D levels and intervertebral disc degeneration: A mendelian randomization study

OBJECTIVES

Intervertebral disc degeneration (IDD) is a prevalent musculoskeletal disorder with substantial implications for disability and healthcare expenditures. The role of serum vitamin D (25-Hydroxyvitamin D, 25(OH)D) levels in the pathogenesis of various musculoskeletal conditions has been explored in prior observational studies, suggesting a potential association. While previous observational studies have suggested an association between the two conditions, it might confound the effect of 25(OH)D on IDD. This Mendelian randomization (MR) study seeks to elucidate the causal relationship between 25(OH)D and IDD.

METHODS

We performed a MR analysis using summary-level data from genome-wide association studies (GWAS) of 25(OH)D (sample size = 441,291 European) and IDD (sample size = 336,439 (cases = 41,669, controls = 294,770) European). Single nucleotide polymorphisms (SNPs) significantly associated with 25(OH)D (p < 5 × 10-8) were selected as instrumental variables. The associations between genetically predicted 25(OH)D and IDD were estimated using the inverse-variance weighted (IVW) method, with sensitivity analyses employing the weighted median, MR-Egger, and MR-PRESSO approaches to assess the robustness of the findings.

RESULTS

In the primary IVW analysis, genetically predicted 25(OH)D was unrelated associated with IDD (odds ratio (OR) = 0.9671, 95% confidence interval (CI): 0.8956-1.0444, p = 0.39). The results remained consistent across the sensitivity analyses, and no significant directional pleiotropy was detected (MR-Egger intercept: p = 0.64).

CONCLUSIONS

This study found no obvious evidence that 25(OH)D is causally associated with IDD risks. We call for larger sample size studies to further unravel the potential causal relationship and the exact mechanism.

1,25(OH)₂D₃ inhibits ferroptosis in nucleus pulposus cells via VDR signaling to mitigate lumbar intervertebral disc degeneration

Lumbar intervertebral disc degeneration (LIDD) serves as a principal contributor to low back pain, a condition that poses considerable global health and socioeconomic challenges. Recent studies have emphasized the significance of ferroptosis, an iron-dependent mechanism of programmed cell death, in the degeneration of nucleus pulposus cells (NPCs). This research examines the protective role of 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃], the active metabolite of Vitamin D (VD), in LIDD through the modulation of ferroptosis. The results indicate that 1,25(OH)₂D₃ significantly inhibits ferroptosis in NPCs through the reduction of lipid peroxidation, restoration of glutathione levels, and enhancement of antioxidant defenses. 1,25(OH)₂D₃ exerts its effects by activating the VD receptor (VDR) signaling pathway, which regulates important ferroptosis-associated molecules, including glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11). The findings indicate the therapeutic potential of 1,25(OH)₂D₃ in alleviating LIDD, presenting a new strategy to inhibit ferroptosis and maintain intervertebral disc function.

Incidence of and risk factors for lumbar disc herniation with radiculopathy in adults: a systematic review

BACKGROUND

Lumbar disc herniation (LDH) with radiculopathy is associated with greater pain, disability, healthcare use, and costs compared with nonspecific low back pain. Reliable information about its incidence and risk factors were lacking.

QUESTIONS

(1) What is the incidence of lumbar disc herniation (LDH) with radiculopathy in adults? (2) What are the risk factors for LDH with radiculopathy in adults?

METHODS

Systematic review. We searched five electronic databases from 1970 to September 2023. Eligible cohort and case-control studies were identified and independently assessed for risk of bias. A qualitative best evidence synthesis of low and moderate risk of bias studies was conducted.

RESULTS

We critically reviewed 87 studies and synthesised data from 59 (68%) studies; 12 were of low and 47 of moderate risk of bias. The lower and upper bound limits of the 95% CIs of annual incidence estimates ranged from 0.3 to 2.7 per 1000 persons for surgical case definitions, from 0.04 to 1.5 per 1,000 persons for hospital-based case definitions, and from 0.1 to 298.3 per 1,000 persons for clinical case definitions. Factors associated with the development of LDH with radiculopathy included middle-age (30-50 years), smoking, higher BMI, presence of cardiovascular risk factors (in women), and greater cumulative occupational lumbar load by forward bending postures and manual materials handling, with effect sizes ranging from ranging from 1.1 (1.0-1.3) to 3.7 (2.3-6.0).

CONCLUSIONS

Incidence of LDH varies in different populations and according to case definition. Risk factors include individual, behavioural, and work-related variables. Our findings support the need to develop standardised case definitions that validly classify the clinical spectrum of LDH and for future low risk of bias studies examining causal relationships for LDH with radiculopathy in adults.

Association of TaqI (rs731236) Polymorphism of Vitamin D Receptor Gene with Lumbar Degenerative Disc Disease

BACKGROUND

Lumbar degenerative disc disease (LDDD) significantly contributes to low back pain, with a complicated etiology involving genetic and environmental facts. The aim of study was to investigate the association between the TaqI (rs731236) polymorphism of the vitamin D receptor (VDR) gene with LDDD.

METHODS

In total, 248 patients with symptomatic LDDD and 146 control subjects were examined. The evaluation of clinical features of patients with LDDD comprised radiodiagnostic magnetic resonance imaging, neurologic examinations, pain scores including the visual analog scale (VAS), and disability investigation with Oswestry Disability Index (ODI). Genotyping of the VDR gene polymorphism was conducted using polymerase chain reaction-based methods.

RESULTS

Individuals of the LDDD group who were VDR TaqI AA genotype carriers were significantly greater than the other group (P = 0.014), whereas those with GG genotype were significantly lower (P = 0.028) in the patient group. In addition, VAS and ODI scores were significantly lower in the GG genotype carrier group, whereas AA genotype carriers had the greatest scores (P = 0.004). Carrying the G allele decreased the risk of LDDD 1.7 times (P = 0.014) and carrying the A allele enhanced the risk 1.8 times (P = 0.028). Moreover, G-allele carriers had significantly lower VAS (P = 0.002) and ODI scores (P < 0.0001).

CONCLUSIONS

VDR TaqI (rs731236) GG genotype and G allele have protective potential, whereas the AA genotype and A allele are risk factors for LDDD. The findings reveal a statistically significant association of the TaqI (rs731236) polymorphism of VDR gene polymorphism with LDDD. This result highlights the potential role of genetic factors in developing LDDD and suggests avenues for future research in genetic screening and personalized treatment strategies.

Correlation between serum angiotensin-converting enzyme (ACE) levels and intervertebral disc degeneration

Studies have shown that the renin-angiotensin system (RAS) might play an essential role in intervertebral disc degeneration (IDD). The study aimed to investigate the relationship between serum angiotensin-converting enzyme (ACE) concentration and IDD and its predictive value for severe disc degeneration. 245 patients who came to our hospital for low back pain were recruited, and blood samples were collected for routine examination. Descriptive data and demographic parameters were collected. The cumulative grade 1 was calculated by summing up the Pfirrmann grade of all lumbar discs. ACE concentration grouping was determined via tertile split. Correlation analysis and multivariable linear regression analysis were performed to determine the relationship between ACE and IDD. The receiver's degree of disc degeneration (ROC) curve determined the ACE's predictive value. Results indicated that there was no significant difference in demographic parameters among groups. Correlation analysis and multivariate linear analysis showed that ACE was an independent risk factor for IDD. The cumulative grade 1 increased significantly with the increase in ACE concentration, which was consistent with the correlation analysis. Average Pfirrmann grade &lt; 4 indicates mild to moderate degeneration, and grade ≥ 4 indicates severe degeneration in terms of an individual disc. From L1/2 to L5/S1, the mean plasma ACE concentration was significantly higher in the severe degeneration group than in the mild to moderate degeneration group. According to the ROC curve, the cut-off value of ACE levels was 22.5. patients with ACE &gt; 22.5 had severe degeneration. The sensitivity and specificity were 0.762 and 0.521, respectively.

VDR promotes nucleus pulposus cell mitophagy as a protective mechanism against oxidative stress injury

Intervertebral disk degeneration (IDD) is a common aging disease. Excessive apoptosis of nucleus pulposus (NP) cells has been widely considered a main contributor to IDD. Emerging science has shown that autophagy plays a protective role against apoptosis under oxidative stress. Vitamin D receptor (VDR) is a steroid hormone receptor that can regulate autophagy. The purpose of this study was to clarify whether VDR alleviates IDD by promoting autophagy. H₂O₂ stimulation was used to establish oxidative stress conditions. Initially, the expression level of VDR in human degenerative NP tissues was measured by immunohistochemistry. In addition, the CRISPR-dCas9-VPR system and siRNA were utilized to upregulate or downregulate VDR and Parkin expression, respectively. Autophagic and apoptotic markers were determined by Western blotting and RT-qPCR. Transmission electron microscopy was used to monitor the occurrence of autophagy in rat NP cells. VDR expression was downregulated in human degenerative NP tissues and H₂O₂-stimulated rat NP cells, indicating a negative correlation between VDR expression and IDD. VDR overexpression promoted mitophagy and prevented apoptosis and mitochondrial injury under oxidative stress. Additionally, mitophagy inhibition by 3-MA abolished the protective effect of VDR activation in vitro. Furthermore, VDR activation promoted mitophagy via the PINK1/Parkin pathway in H₂O₂-treated NP cells. This study demonstrates that VDR activation ameliorates oxidative damage and decreases NP cell apoptosis by promoting PINK1/Parkin-dependent mitophagy, indicating that VDR may serve as a promising therapeutic target in the management of IDD.

Vitamin D/VDR in the pathogenesis of intervertebral disc degeneration: Does autophagy play a role?

To date, the underlying mechanisms involved intervertebral disc degeneration (IDD) remain unclear, which has hindered the development of molecular biological therapy for IDD. Autophagy is vital for intracellular quality control and metabolic balance in intervertebral disc cells. Hence, autophagy homeostasis is important. Emerging evidence has implicated vitamin D (VD) and the vitamin D receptor (VDR) in IDD progression because of their effects on different autophagy steps. However, the results of clinical trials in which VD supplementation was assessed as a treatment for IDD are controversial. Furthermore, experimental studies on the interplay between VD/VDR and autophagy are still in their infancy. In view of the significance of the crosstalk between VD/VDR and autophagy components, this review focuses on the latest research on VD/VDR modulation in autophagy and investigates the possible regulatory mechanisms. This article will deepen our understanding of the relationship between VD/VDR and autophagy and suggests novel strategies for IDD prevention and treatment.

Association of Single Nucleotide Polymorphism rs2228570 with Lumbar Disc Degeneration: A Case-Control Study and Meta-Analysis

Objective

To examine the association between single nucleotide polymorphisms (SNPs) rs2228570, rs731236, rs7975232, and rs1544410 and lumbar disc degeneration (LDD) predisposition.

Methods

A search strategy was carried out, and the data were extracted after being chosen by the inclusion and exclusion criteria. Pooled odds ratios and 95% confidence intervals were calculated to assess the association between the aforementioned SNPs and LDD under allelic, dominant, recessive, heterozygous, and homozygous genetic models. In addition, a case–control study involving 46 LDD cases and 45 controls was also performed in the analysis to verify the result.

Results

A total of 17 studies were included in this meta-analysis. The pooled results did not show any association between vitamin D receptor (VDR) gene polymorphisms and LDD. But, interestingly, in subgroup analysis, the rs2228570 polymorphism was associated with LDD under the allelic (OR = 0.70, 95% CI = 0.56–0.87, p = 0.002), recessive (OR = 0.60, 95% CI = 0.43–0.84, p = 0.003), and homozygous (OR = 0.47, 95% CI= 0.28–0.79, p = 0.004) genetic models in the Asian population. SNPs rs731236 and rs7975232 still did not show any obvious association. We obtained a similar result from the case–control study: rs2228570 had an obvious relationship with LDD under allelic and homozygous genetic models. At the same time, we found that rs2228570 was also associated with the degree of low back pain (visual analogue scale, VAS score) in LDD population.

Conclusion

SNP rs2228570 was significantly associated with LDD predisposition and the degree of low back pain in the Asian population.

The role of TaqI, ApaI and BsmI polymorphisms of VDR gene in lumbar spine pathologies: systematic review and meta-analysis

PURPOSE

The objective of the present meta-analysis was to evaluate the association between TaqI (rs731236), ApaI (rs7975232) and BsmI (rs1544410) polymorphisms of the VDR gene and lumbar spine pathologies such as lumbar disc herniation and lumbar disc degeneration.

BACKGROUND

VDR gene polymorphisms have been reported to be associated with an increased risk of lumbar spine pathologies.

MATERIALS AND METHODS

A systematic search was performed up to February 2020 using PubMed, EBSCO and Web of Science databases. We used the keywords and combinations "lumbar disc degeneration," "lumbar disc herniation," "lumbar spine pathologies" and "VDR polymorphism." Subsequently, we performed a meta-analysis with the results of the included studies.

RESULTS

We found that the TaqI polymorphism was associated with an increased risk of developing lumbar spine pathologies (recessive model OR 1.25, 95% CI 1.01-1.54) and lumbar disc degeneration (allelic model OR 1.26, 95% CI 1.07-1.48; recessive model OR 1.34, 95% CI 1.06-1.69), but not with lumbar disc herniation. Additionally, ApaI was associated with an increased risk of developing lumbar spine pathologies (heterozygous model OR 1.45, 95% CI 1.06-1.98), but not with lumbar disc herniation or lumbar disc degeneration.

CONCLUSIONS

Our findings indicate that TaqI and ApaI polymorphisms of the VDR gene are important risk factors for developing lumbar spine pathologies. Moreover, the TaqI polymorphism is a risk factor for lumbar disc degeneration.

Vitamin D receptor gene polymorphisms and risk of intervertebral disc degeneration: An updated meta-analysis based on 23 studies

BACKGROUND

Numerous studies have investigated the associations between Vitamin D receptor (VDR) gene polymorphisms and risk of intervertebral disc degeneration but the results remain controversial. This study aimed to drive a more precise estimation of association between VDR gene polymorphisms and risk of intervertebral disc degeneration.

METHODS

PubMed, EMBASE, Cochrane library, Web of Science and China Knowledge Resource Integrated Database for papers on VDR gene polymorphisms and risk of intervertebral disc degeneration were searched. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association in the homozygote model, heterozygote model, dominant model, recessive model and an additive model.

RESULTS

Overall, 23 articles were included in the final meta-analysis. The subgroup analyses by ethnicity showed a significant association of VDR FokI mutation with disc degeneration risk in Caucasians (recessive model, OR with 95%CI 1.301, [1.041, 1.626]; additive model, OR with 95%CI 1.119, [1.006, 1.245]). The results of subgroup analyses by ethnicity showed a significant association of VDR TaqI mutation with disc degeneration risk in Asians but not in Caucasians. There was a significant association between VDR ApaI mutation and risk of disc degeneration and subgroup analyses by ethnicity showed a significant association in Caucasians and in Asians.

CONCLUSIONS

In summary, VDR FokI polymorphisms was associated with disc degeneration risk among Caucasians but not Asians, VDR TaqI polymorphisms was associated with disc degeneration risk among Asians but not Caucasians, while VDR ApaI polymorphism was associated with disc degeneration risk among Asians and Caucasians.

Association Between FokI Polymorphism of Vitamin D Receptor Gene and Lumbar Spine Disc Degeneration: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of the present meta-analysis was to explore the association between FokI polymorphism of the vitamin D receptor gene and lumbar spine disc degeneration.

DESIGN

The search was performed in PubMed, Scopus, and Web of Science databases up to January 2020. The authors selected nine studies comprising a total of 1549 cases and 1672 controls. The association analysis included the allelic, dominant, recessive, homozygous, and heterozygous genetic models. Odds ratios with 95% confidence intervals were used to evaluate the association. The Newcastle-Ottawa Scale was used to measure the quality of the studies included in the analyses; a cut-off of 6 stars was applied.

RESULTS

This meta-analysis indicated that FokI polymorphism is significantly associated with lumbar degenerative disc disorder and disc herniation in the homozygous (odds ratio, 1.77; 95% confidence interval, 1.23-2.54; Z test P = 0.002, Q test P = 0.416) and recessive (odds ratio, 1.53; 95% confidence interval, 1.23-1.90; Z test P < 0.000, Q test P = 0.224) models.

CONCLUSIONS

This study indicates that the vitamin D receptor gene FokI polymorphism may be correlated with the risk of developing a lumbar degenerative disc disorder and disc herniation. However, the small sample population studied and the lack of an evaluation of environmental factors must be taken as limitations in the present meta-analysis.

Associations between vitamin D receptor gene polymorphisms and spinal degenerative disease: evidence from a meta-analysis based on 35 case-control studies

OBJECTIVE

Dozens of reports on the associations of vitamin D receptor (VDR) gene polymorphisms and susceptibility to spinal degenerative disease (SDD) were conducted with inconsistent findings. This study aimed to elucidate the associations through a meta-analysis approach.

METHODS

Databases of PubMed, EMBASE, Web of Science, CNKI, and Wanfang were searched until July 10, 2020. Study quality was evaluated by using Newcastle-Ottawa Scale (NOS). Odds ratios (ORs) and 95% confidence intervals (95%CIs) were calculated to evaluate the associations under allelic model (1 vs. 2), homozygous model (11 vs. 22), heterozygous model (12 vs. 22), dominant model (11 + 12 vs. 22), and recessive model (11 vs. 12 + 22).

RESULTS

A total of 5021 cases and 5746 controls from 35 studies were eligible to this meta-analysis. According to NOS, the included studies were in excellent quality. In the overall population, the pooled data indicated that ApaI was associated with a reduced SDD susceptibility (AA vs. Aa + aa, OR = 0.83, 95%CI 0.71 - 0.96, P = 0.010). But the association was not observed in FokI, TaqI, and BsmI polymorphisms. Subgroup analysis suggested that TaqI polymorphism was correlated to an elevated SDD risk in Asians (TT + Tt vs. tt, OR = 2.55, 95%CI 1.90 - 3.44, P < 0.001).

CONCLUSION

The present study indicates that ApaI polymorphism may contribute to a reduced risk to SDD in the overall population, and TaqI polymorphism confers an elevated susceptibility to SDD in Asians. While, BsmI and FokI polymorphisms appear to have no significant association with SDD.