Interplay between low plasma RANKL and VDR-FokI polymorphism in lumbar disc herniation independently from age, body mass, and environmental factors: a case-control study in the Italian population

Patient-related risk factors and lifestyle factors for lumbar degenerative disc disease: a systematic review

OBJECTIVE

Back pain is a very widespread disease pattern and is one of the most frequent causes for consultation of a physician in general. In most cases, discogenic changes are the pathomorphological correlate of back pain. Numerous risk factors have been identified for these degenerative changes, but the influence and significance of the risk factors remain unclear, which was the aim of this systematic review.

METHODS

A systematic literature search of the commonly used Pubmed database was performed using specific MESH terms. Further selection of the included studies was performed according to the PRISMA scheme, taking into account scientific merit as well as the relation to the research question.

RESULTS

A total of 111 studies out of 1035 found were finally included in the literature search. 134 risk factors for disc degeneration and disc herniation were identified. These were divided into (1) patient-specific risk factors (n░=░34), (2) radiological risk factors (n░=░31), (3) lifestyle risk factors (n░=░6), (4) workplace-related risk factors (n░=░12), (5) genetic risk factors (n░=░50), and (6) other risk factors (n░=░1). Non-adjustable risk factors were age >50 years (OR 1.7/year), female gender (OR 1.41), family disposition (OR 4.0), comorbidities like atherosclerosis (OR 2.24), arthritic changes in other joints (OR 3.1) and history of injuries of the back (OR 3.1). Adjustable factors were elevated BMI (OR 2.77), comorbidities like hypertension (OR 1.25), dyslipidemia (OR 1.26) and diabetes mellitus (OR 6.8), as well as lifestyle habits like smoking (OR 3.8).

DISCUSSION

In summary, intervertebral disc degenerations and herniations represent multifactorial events whose risk factors can be partly influenced and partly not influenced. This systematic review highlights the current state of knowledge as a basis for creating patient-specific algorithms to calculate risk for the development or progression of degenerative disc changes and disc herniations.

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.

Association of Polymorphisms in RANK and RANKL Genes with Osteopenia in Arab Postmenopausal Women

The RANKL/RANK/OPG pathway regulates bone remodelling and turnover. However, the genetic background of bone mineral density (BMD) and osteopenia in Saudi postmenopausal women is yet to be studied. We studied the genetic polymorphism of RANKL/RANK/OPG with BMD and other associated factors in Saudi postmenopausal osteopenic women. A total of 439 (223 osteopenia and 216 control) postmenopausal women were recruited from the orthopaedic department of the King Khalid University Hospital, Riyadh, KSA. Genetic variants of RANK (rs1805034 and rs35211496), RANKL (rs2277438 and rs9533156), and OPG (rs2073618 and rs3102735) were genotyped using RT-PCR. Anthropometrics, bone mineral density, and other bone markers were measured. The levels of bone turnover markers, PTH, and RANKL were found to be significantly different between control and the osteopenia group. The odds ratio of 2.37 (1.00-5.69) for RANK SNP (rs1805034) indicates that subjects with CC genotype are more vulnerable to developing osteopenia as compared to subjects with TT genotype. Similarly, for RANKL SNP (rs2277438), the significant odds ratio of 20.56 (9.82-43.06) indicates that the subjects with GG genotype are at significantly higher risk of having osteopenia compared with the AA genotype subjects. In addition, G allele in rs2277438 also found to be a risk factor for osteopenia 4.54 (3.18-6.49) compared with A allele. However, none of the OPG genotypes shows association with osteopenia. The association of RANK polymorphisms with osteopenia shows its clinical importance in the diagnosis and prognosis of the bone diseases; here, we suggest that the subjects with RANK and RANKL polymorphisms may develop osteoporosis.

Is there a link between vitamin D status, SARS-CoV-2 infection risk and COVID-19 severity?

The outbreak of COVID-19 emerged in December 2019 rapidly spread across the globe and has become pandemic. Little is known about the protective factors of this infection, which is equally distributed between genders and different ages while severe and poor prognosis cases are strongly associated to old males and the presence of comorbidities. Thus, preventive measures aiming at reducing the number of infection and/or their severity are strongly needed. Vitamin D has got great attention and has been claimed as potentially protective against the infection since it may be associated with immunocompetence, inflammation, aging, and those diseases involved in determining the outcomes of COVID-19. This narrative review aims at collecting the literature available on the involvement of the vitamin D status in the pathogenesis of COVID-19 and the putative utility of vitamin D supplementation in the therapeutics. It emerges that a poor vitamin D status seems to associate with an increased risk of infection whereas age, gender and comorbidities seem to play a more important role in COVID-19 severity and mortality. While randomized control trials are needed to better inquire into this topic, vitamin D supplementation may be useful beside its potential effects on SARS-CoV-2 infection and COVID-19.

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.

Vitamin D Receptor gene polymorphisms and plasma levels are associated with lumbar disc degeneration

The purpose of this study was to investigate the association of Vitamin D Receptor (VDR) gene polymorphisms and VDR levels with lumbar disc degeneration (LDD). TaqMan SNP Genotyping Assay was utilized to probe VDR gene polymorphisms including the FokI (rs2228570), ApaI (rs7975232) and TaqI (rs731236) in 454 patients with LDD and 485 controls. Enzyme-Linked Immunosorbent Assay (ELISA) was used to detect plasma VDR levels. The patients with LDD were divided into three subgroups (subgroup 1: lumbar disc herniation; subgroup 2: lumbar spinal stenosis; subgroup 3: lumbar spondylolisthesis) to further probe the association of plasma VDR levels and VDR gene polymorphisms and LDD. Moreover, immunohistochemistry (IHC) was implemented to evaluate VDR expression in lumbar degenerated disc and normal disc. Allele and genotype frequency of TaqI (rs731236) were significantly different in patients with LDD and controls (all P < 0.05). For TaqI polymorphism, the frequencies of T allele were significantly higher in the LDD patients compared with controls (OR = 1.319; 95%CI 1.091 to 1.595; P = 0.004, adjusted (OR = 1.319; 95%CI 1.091 to 1.595; P = 0.004, adjusted OR = 1.383; 95%CI 1.135 to 1.684; P = 0.016). Furthermore, the allele distribution showed a higher frequency of the T allele in the patients with lumbar disc herniation in subgroup 1 (OR = 1.384; 95% CI 1.105 to 1.732; P = 0.004, adjusted OR = 1.319; 95%CI 1.091 to 1.595; P = 0.016). Plasma VDR levels and VDR expression were significantly lower in patients with LDD compared with controls (all P < 0.05). Moreover, the TT genotype of TaqI polymorphism was significantly associated with lower plasma VDR levels in patients with LDD (P = 0.002). TaqI (rs731236) polymorphism was associated with a predisposition to LDD. Plasma VDR and VDR expression levels may be the marker for the occurrence and development of LDD.

Expression and Mechanism of Interleukin 1 (IL-1), Interleukin 2 (IL-2), Interleukin 8 (IL-8), BMP, Fibroblast Growth Factor 1 (FGF1), and Insulin-Like Growth Factor (IGF-1) in Lumbar Disc Herniation

BACKGROUND The expression and mechanism of IL-1, IL-2, IL-8, BMP, FGF1, and IGF-1 in Sprague-Dawley (SD) rats with lumbar disc herniation were investigated. MATERIAL AND METHODS Immunohistochemical methods were applied to identify IL-1, IL-2, IL-8, BMP, FGF1, and IGF-1. PI3K, AKT protein, and mRNA expression were detected and analyzed by Western blot analysis. We selected 30 healthy SD rats and divided them into 2 groups to construct an animal model that was validated by immediate CT scanning. Cartilage tissues from the lumbar disc herniation (experimental) group and control group were obtained and compared. RESULTS The expression of BMP was not significantly different between the control group and the experimental group (P>0.05). FGF1: There was no significant difference in the expression of FGF1 (P>0.05) between the control group and the experimental group. Compared with the control group, the expression of IGF-1 in the experimental group was significantly higher (P<0.05); the expression of IL-1 in the experimental group was significantly higher (P<0.05); and the expression of IL-2 in the experimental group was also significantly higher (P<0.05). There was no significant difference in IL-8 between the experimental group and the control group (P>0.05). The expression levels of PI3K and AKT protein and mRNA were significantly higher than those in healthy controls (P<0.05). CONCLUSIONS After lumbar disc herniation occurred, the IGF-1 was first activated; the PI3K/AKT signaling pathway was later activated, which resulted in the expression of IL-1 and IL-2 inflammation-related factors being increased.

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

Background

Association of Vitamin D receptor (VDR) polymorphisms with lumbar disc herniation (LDH) have been identified in several ethnic groups globally. Despite abundant sunlight, vitamin D deficiency is reported in many tropical countries. As vitamin D is a key modulator for intestinal calcium absorption, low vitamin D could contribute to low serum calcium leading to abnormalities of skeletal homeostasis. Therefore, present study was aimed to study the association of serum 25-hydroxyvitamin D (25(OH)D), serum calcium and VDR polymorphisms in a selected Sri Lankan population.

Materials & methods

A case control study was conducted in 119 participants (cases = 51: controls = 68). Serum 25(OH)D levels were measured using ELISA. The VDR polymorphisms (Fok I and Taq I) were detected by polymerase chain reaction followed by restriction fragment length polymorphism.

Results

Findings indicated a significantly low (p = 0.000) 25(OH)D levels in cases (18.7±3.7 ng/mL) compared to controls(25.5±9.8 ng/mL) while 25(OH)D in both groups were below the reference range. Mean serum calcium levels in both groups were within normal reference range and was not significantly different among groups. Statistically significant association was not observed between VDR Fok I polymorphisms among cases and controls. Although Fok I polymorphism genotypes were in Hardy-Weinberg equilibrium (HWE), Taq I genotypes in controls violated HWE.

Conclusion

Present study confirms that insufficient serum 25(OH)D levels in cases have major contribution to LDH. VDR Fok I polymorphisms did not have any significant association with LDH in Sri Lankan ethnicity.

Association of SNP-SNP Interactions Between RANKL, OPG, CHI3L1, and VDR Genes With Breast Cancer Risk in Egyptian Women

BACKGROUND

Genetic susceptibility for breast cancer (BC) is still poorly understood. A combination of multiple low-penetrant alleles of cancer-related genes and gene-gene interactions (epistasis) contributes to BC risk. Genetic variants in receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), chitinase-3-like protein 1 (CHI3L1), and vitamin D receptor (VDR) genes are implicated in breast carcinogenesis; however, the influence of their epistatic effects on BC susceptibility has not yet been studied. We investigated the association of single nucleotide polymorphism (SNP)-SNP interactions and haplotypes of 6 SNPs in these 4 genes with the genetic predisposition of BC in Egyptian women.

PATIENTS AND METHODS

Data of 115 BC patients and 120 cancer-free controls were studied. Association tests were conducted using logistic regression models.

RESULTS

Individual SNPs showed weak statistical significance with BC susceptibility. The interactions between RANKL-rs9533156 and OPG-rs2073618; OPG-rs2073618 with CHI3L1-rs4950928, VDR-rs2228570 and VDR-rs1544410; OPG-rs2073617 and VDR-rs1544410; VDR-rs2228570 and VDR-rs1544410 were strongly associated with increased BC risk after adjustment for multiple comparisons. No SNPs were in strong linkage disequilibrium. The TCTCTG-rs9533156-rs2073618-rs2073617-rs4950928-rs2228570-rs1544410 haplotype was significantly associated with increased BC risk (adjusted odds ratio = 8.33; 95% confidence interval, 1.32-52.46; P = .025) compared with controls. TCCCTG haplotype stratified BC patients according to estrogen receptor/progesterone receptor status. TCTCTA was positively associated, and TCTCTG and TGTCTG haplotypes inversely correlated with bone metastasis. Bioinformatic analysis revealed 13 proteins commonly interacting with our 4 genes; the most significant was signal transducer and activator of transcription 5B.

CONCLUSION

Our results suggested that a stronger combined effect of SNPs in RANKL, OPG, CHI3L1, and VDR genes via gene-gene interaction may help predict BC risk and prognosis.

A genetic variant in COL11A1 is functionally associated with lumbar disc herniation in Chinese population

This study aimed to explore whether the genetic variant of COL11A1 is functionally associated with the development of lumbar disc herniation (LDH) in Chinese population. SNP rs1676486 of COL11A1 was genotyped in 647 patients and 532 healthy controls. The differences of genotype and allele distributions between LDH patients and healthy controls were evaluated using the χ² test. One-way ANOVA test was used to compare the relationship between genotypes and clinical features including tissue expression of COL11A1 and the degree of disc degeneration. Patients were found to have a significantly higher frequency of TT than the controls (10.2% versus 7.3%, P = 0.004). Besides, the frequency of allele T was found to be remarkably higher in the patients than the controls (34.8% versus 28.1%, P < 0.001) with an odds ratio of 1.36 (95% confidential interval=1.14-1.63). Patients with genotype TT were found to have remarkably more severe disc degeneration (P = 0.02). Besides, the expression of COL11A1 in the lumbar disc was significantly lower in the patients with genotype TT than in those with genotype CT or CC (P < 0.001). Moreover, the expression level was inversely correlated with the severity of disc degeneration (P < 0.001). We confirmed that the rs1676486 of COL11A may be functionally associated with LDH in the Chinese population. Extracellular matrix related proteins may play an important role in the pathogenesis of LDH. Our findings shed light on a better understanding of the pathogenesis of LDH, which could be a promising target for a novel treatment modality of LDH.

Genetic background of degenerative disc disease in the lumbar spine

This is a review paper on the topic of genetic background of degenerative disc diseases in the lumbar spine. Lumbar disc diseases (LDDs), such as lumbar disc degeneration and lumbar disc herniation, are the main cause of low back pain. There are a lot of studies that tried to identify the causes of LDDs. The causes have been categorized into environmental factors and genetic factors. Recent studies revealed that LDDs are mainly caused by genetic factors. Numerous studies have been carried out using the genetic approach for LDDs. The history of these studies is divided into three periods: (1) era of epidemiological research using familial background and twins, (2) era of genomic research using DNA polymorphisms to identify susceptible genes for LDDs, and (3) era of functional research to determine how the genes cause LDDs. This review article was undertaken to present the history of genetic approach to LDDs and to discuss the current issues and future perspectives.

VDR, RANKL and OPG polymorphisms as possible predisposing cofactors of postmenopausal osteoporosis: explorative study in Italian population

Postmenopausal osteoporosis (PO) has a strong genetic component. Presently, the published evidence on the association between the main single-nucleotide polymorphisms (SNPs) of the receptor activator of nuclear factor-kb ligand (RANKL), osteoprotegerin (OPG) and vitamin D receptor (VDR) and bone mass density (BMD) are scarce, mostly considering Italian population. This study sought to determine whether OPG (rs2073618), RANKL (rs9525641) and the VDR (rs2228570) SNPs were associated with BMD in a sample of 139 North-Italian postmenopausal women. The allelic distribution of rs9525641 in women with PO or osteopenia (OP + OPE group) differed from controls (p < 0.05), suggesting that this allele might confer a greater susceptibility to bone resorption. Concerning rs2228570, CC genotype was associated with OP + OPE women, with a worst total hip BMD. Notably, the combined genotype RANK (CT)-VDR (TT) was significantly associated to spine BMD (p < 0.05). In conclusion, this pilot study showed that rs9525641 and rs2228570 polymorphisms might contribute, separately or in combination, in determining BMD phenotype in selected postmenopausal populations.

Genetic analysis of the Vitamin D receptor start codon polymorphism (FokI) in cervical vertebra and lumbar spine pathologies: a meta-analysis

BACKGROUND

Vitamin D receptor (VDR) FokI polymorphism has been reported to influence the risk of spinal diseases. However, several studies suggest inconsistent results. Therefore, we performed this analysis to reveal the accurate relationship between VDR FokI polymorphism and spinal diseases.

MATERIALS AND METHODS

8 articles accord with the strict inclusion and exclusion criteria. 1116 cases and 1263 controls are entered into this analysis. The pooled odds ratios (ORs) and 95% confidence intervals (CI) are calculated to evaluate the association between VDR gene polymorphism and spinal diseases.

RESULT

The results suggest that allele F is a risk factor for spinal diseases and the difference is significant (F vs. f: OR = 1.151, 95% CI, 1.020-1.300). For the genotype analysis of VDR FokI, no statistical differences exist in the models of heterozygote comparison (Ff vs. ff), homozygote comparison (FF vs. ff) and dominant model (FF + Ff vs. ff) (p > 0.05). However, in recessive model (FF vs. Ff + ff), there is a significant association between VDR polymorphism and spinal diseases (OR = 1.209, 95% CI, 1.017-1.436). In subgroup analysis, the results show that allele F is a risk factor for spinal diseases in each estimation. In hospital-based subgroup, the significant differences exist in FF vs. ff and FF vs. Ff + FF models. In degenerative spine diseases group, the results are consistent with that of overall studies.

CONCLUSIONS

According to results of this meta-analysis, allele F is associated with the increased risk of spinal diseases. FF genotype may contribute to the susceptibility of spinal diseases. Therefore, VDR FokI polymorphism is related with spinal diseases.

Plasma vitamin D and osteo-cartilaginous markers in Italian males affected by intervertebral disc degeneration: Focus on seasonal and pathological trend of type II collagen degradation

OBJECTIVE

To evaluate plasma vitamin D and cross-linked C-telopeptides of type I (CTx-I) and type II (CTx-II) collagen concentrations in males with lumbar intervertebral disc degeneration (IVD) compared to healthy controls. Improved knowledge might suggest to optimize the vitamin D status of IVD patients and contribute to clarify mechanisms of cartilage degradation.

METHODS

79 Italian males with lumbar IVD assessed by Magnetic Resonance Imaging (MRI) and 79 age, sex and BMI-matched healthy controls were enrolled. Plasma 25hydroxyvitamin D (25(OH)D), CTx-I and CTx-II were measured by immunoassays. Circannual seasonality, correlation between biomarkers concentrations and clinical variables were assessed.

RESULTS

Overall subjects 25(OH)D and CTx-II showed month rhythmicity with acrophase in August/September and October/November, and nadir in February/March and April/May, respectively. An inverse correlation between 25(OH)D and CTx-I, and a direct correlation between CTx-II and CTx-I were observed. IVD patients, particularly with osteochondrosis, showed higher CTx-II than healthy controls.

CONCLUSIONS

Month of sampling may affect plasma 25(OH)D and CTx-II concentrations. The correlation between CTx-I and CTx-II suggests an interplay between the osteo-cartilaginous endplate and the fibro-cartilaginous disc. The results of this study highlighted that osteochondrosis associates with increased cartilaginous catabolism. Vitamin D supplementation seems more necessary in winter for lumbar IVD patients.

Association between vitamin D receptor gene polymorphisms and intervertebral disc degeneration: A meta-analysis

BACKGROUND

Studies that have investigated the association between vitamin D receptor (VDR) gene polymorphisms and intervertebral disc degeneration (IDD) have yielded inconsistent results.

METHODS

To investigate the association between VDR gene polymorphisms and IDD, a systematic literature search for relevant published studies was performed on PubMed, Embase, Web of Science, Cochrane library, Wan-Fang, and CNKI databases. A random effects model was used for heterogeneous data; while a fixed effect model was used for homogenous data. Odds ratios (OR) and 95% confidence intervals (CI) were calculated to evaluate the strength of the association.

RESULTS

We observed no association between VDR FokI, TaqI-ApaI polymorphisms and IDD. However, on subgroup analysis by ethnicity, VDR FokI mutation was associated with a significantly lower risk for IDD [dominant model: OR = 0.78, 95% CI = 0.65-0.93; heterozygote model: OR = 0.76, 95% CI = 0.63-0.92; allele model: OR = 0.86, 95% CI = 0.75-0.98] among Caucasians.

CONCLUSION

These results suggest that the VDR FokI polymorphism may be associated with IDD among Caucasians. However, the association between VDR TaqI-ApaI polymorphisms and IDD in Asians is still not clear. Further well-designed studies are needed to arrive at a definitive conclusion.

Associations of Caspase-3 gene polymorphism with lumbar disc herniation

To investigate Caspase-3 gene polymorphisms (rs4647693 G/A, rs4647610 A/G, and rs12108497 T/C) and susceptibility to lumbar intervertebral disc herniation (LDH). The genotype frequency distributions of the polymorphisms were detected by polymerase chain reaction-restriction fragment length polymorphism in 107 LDH patients (case group) and 121 healthy individuals (control group). SHEsis software was used to conduct gene linkage disequilibrium and haplotype analysis. Regression analysis was used to analyze possible risk factors for LDH. Statistically significant differences in family history of LDH, amateur sports, leisure activities, bed types, and spine load grade were found between the case and control groups. The distribution of allele and genotype frequencies of rs4647693 G/A, rs4647610 A/G, and rs12108497 T/C polymorphisms of Caspase-3 were significantly different between the case and control groups. Haplotype analysis showed that the G-G-C (rs4647693-rs4647610-rs12108497) haplotype might be a risk factor for LDH, whereas the A-A-T haplotype might be a protective factor (p < 0.05). Binary logistic regression analysis showed that the GA+AA genotype of rs4647693 was negatively associated with the risk of LDH, whereas high spine load grade was positively associated with the risk of LDH. These findings revealed that rs4647693 G/A, rs4647610 A/G, and rs12108497 T/C polymorphisms of Caspase-3 may be associated with susceptibility to LDH and that interaction and modification effects may exist between Caspase-3 polymorphisms.

Vitamin D receptor gene polymorphisms and lumbar disc degeneration: a systematic review and meta-analysis

PURPOSE

To examine the association between Vitamin D receptor (VDR) gene polymorphisms and lumbar disc degeneration (LDD) predisposition.

METHODS

A comprehensive literature search was conducted to identify all the relevant studies. The allele/genotype frequencies were extracted from each study. We calculated the pooled odds ratios (ORs) and 95 % confidence intervals (CI) to assess the strength of the association between the VDR gene polymorphisms and LDD risk. Statistical analysis was performed using RevMan 5.31 software.

RESULTS

A total of 23 case-control studies (1835 cases and 1923 controls) were included in this systematic review. For the TaqI (rs731236), FokI (rs2228570) and ApaI (rs7975232) polymorphisms of VDR gene, nine studies, seven studies, and five studies, were eventually included in the meta-analysis, respectively. There was no evidence that the VDR gene polymorphisms (TaqI, FokI, ApaI) had significant associations with LDD risk.(for TaqI allelic comparison, OR = 1.07, 95 % CI 0.81-1.40, p = 0.64; for FokI allelic comparison, OR = 1.23, 95 % CI 0.83-1.82, p = 0.31; for ApaI allelic comparison, OR = 0.79, 95 % CI 0.55-1.14, p = 0.20). For stratified analyses by ethnicity and study design, no significant associations were found in Caucasian population and Asian population, as well as the population-based studies and hospital-based studies under all genetic models.

CONCLUSIONS

TaqI, FokI, and ApaI polymorphisms of VDR gene were not significantly associated with the predisposition of LDD. Large-scale and well-designed international studies are needed to further analyze this field.

BsmI, ApaI and TaqI Polymorphisms in the Vitamin D Receptor Gene (VDR) and Association with Lumbar Spine Pathologies: An Italian Case-Control Study

Three adjacent single nucleotide polymorphisms of the vitamin D receptor gene (VDR) BsmI (rs1544410), ApaI (rs7975232), and TaqI (rs731236) are commonly studied in several pathologies. We aimed to evaluate the distribution of VDR BsmI, ApaI, and TaqI allele, genotype, and haplotype frequencies in an Italian cohort of 266 patients with lumbar spine disorders assessed by Magnetic Resonance Imaging and 252 asymptomatic controls. The exposure to putative risk factors was evaluated by a questionnaire. Polymorphisms were detected by PCR-RFLP and TaqMan^® SNP Genotyping Assay. The results were statistically adjusted for the identified conventional risk factors. The three SNPs were in linkage disequilibrium. For all cases BbAaTT was a 3-fold risk factor OR = 3.38), whereas bbAATT (OR = 0.22), and bbaaTT (OR = 0.47) genotypes were found to be protective. Specifically, for patients affected by disc herniation only (n = 88) and all lumbar pathologies excluding stenosis and/or spondylolistesis (n = 215) B allele, Bb, Aa, and BbAaTT genotypes were risky, whereas b allele, bb, aa, and bbaaTT genotypes were protective. In patients affected by osteochondrosis with or without disc hernation (n = 50), T allele, Aa, and bbAaTT genotypes were risky, whereas t allele, AA, tt genotypes were protective. In patients affected by stenosis and/or spondylolistesis (n = 51) no significant associations were found. This is the first study showing an association of the three genetic VDR variants BsmI, ApaI, and TaqI and lumbar spine pathologies. Our study contributes to delineate genetic risk factors for specific subgroups of patients with lumbar spine pathologies highlighting the importance of haplotype analysis, and of detailed clinical evaluation of the patients for identification of genetic biomarkers.