Interaction between vitamin D receptor genotype and estrogen receptor alpha genotype influences vertebral fracture risk

ESR1 Gene Variants Are Predictive of Osteoporosis in Female Patients with Crohn's Disease

Decreased bone mass in patients with inflammatory bowel diseases (IBD) is a clinical problem with extremely severe consequences of osteoporotic fractures. Despite its increasing prevalence and the need for mandatory intervention and monitoring, it is often ignored in IBD patients’ care. Determining the biomarkers of susceptibility to bone mineral density disorder in IBD patients appears to be indispensable. We aim to investigate the impact of estrogen receptor gene (ESR1) gene polymorphisms on bone mineral density (BMD) in patients with ulcerative colitis (UC) and Crohn’s disease (CD), as they may contribute both, to osteoporosis and inflammatory processes. We characterised 197 patients with IBD (97 with UC, 100 with CD), and 41 controls carrying out vitamin D, calcium and phosphorus serum levels, and bone mineral density assessment at the lumbar spine and the femoral neck by dual-energy X-ray absorptiometry (DXA), ESR1 genotyping and haplotype analysis. We observed that women with CD showed the lowest bone density parameters, which corresponded to the ESR1 c.454-397T and c.454-351A allele dose. The ESR1 gene PvuII and XbaI TA (px) haplotype correlated with decreased femoral neck T-score (OR = 2.75, CI = [1.21–6.27], P-value = 0.016) and may be predictive of osteoporosis in female patients with CD.

Genetic Predisposition for Osteoporosis and Fractures in Postmenopausal Women

Osteoporosis is a disease with complex etiology where the genetic factors may account for as much as 50-85% of the risk of its development in postmenopausal women. The polymorphism of estrogen receptor genes (ESR1, ESR2) seems essential among the genetic factors. The goal of this study was to analyze polymorphisms of selected genes in a population of postmenopausal women treated for osteoporosis and to evaluate the influence of genetic and nongenetic factors on the estimated 10-year risk of fracture. The study group consisted of 214 women hospitalized for treatment of postmenopausal osteoporosis. We investigated the presence of ESR1, ESR2, LRP5, and WNT16 genetic polymorphisms and the risk of fracture in each woman. The main finding was that of significant differences in the polymorphisms of the WNT16 rs2908004 genetic variant, notably, the less frequent presence of TC allele in women with a greater risk of osteoporotic fractures. We conclude that the polymorphism of the WNT16 gene seems highly relevant in the pathogenesis of osteoporosis, which makes it a promising object for further research on the genetic background of fracture risk.

Association of Calcium and Phosphate Balance, Vitamin D, PTH, and Calcitonin in Patients With Adolescent Idiopathic Scoliosis

STUDY DESIGN

A cross-sectional study of 2 groups of patients with scoliosis, and an age-matched control group was conducted. Each of the groups such as patients with adolescent idiopathic scoliosis (AIS) as well as control group were divided additionally into 2 groups: premenarcheal and postmenarcheal girls.

OBJECTIVE

The aim of the study was to determine the levels of 25-OH-vitamin D3, calcium and phosphate, parathyroid hormone (PTH), and calcitonin in serum of pre- and postmenarcheal girls with AIS and corresponding groups of scoliosis-free controls.

SUMMARY OF BACKGROUND DATA

The primary etiology and pathogenesis of AIS remains unknown. It is assumed that vitamin D deficiency and genetic predisposition, for example, polymorphisms of vitamin D receptor, have a great significance. Vitamin D plays a key role in skeletal development and prevents bone atrophy, affects the absorption of calcium, maintains calcium-phosphate homeostasis, and the bone matrix mineralization. Its deficiency can result in a wide variety of skeletal deformities, low bone mass, and then leads to the disappearance of bone. Defects in trabecular bone structure and/or bone mineralization are the main features of scoliosis. Some studies have reported that Vitamin D deficiency is common among patients with AIS. The mechanism of Vitamin D action on scoliosis development is still unclear.

METHODS

Determination of serum 25-OH-D3 levels was performed using high-performance liquid chromatography chromatography; concentrations of calcium and phosphate were measured using colorimetric methods, and concentration of PTH and calcitonin was measured using ELISA system.

RESULTS

Reduction in the serum levels of 25-OH-D3 and calcitonin in girls with AIS compared with healthy girls was demonstrated.

CONCLUSION

The phosphate-calcium balance and PTH level seem to be normal in patients with AIS. The calcitonin level in girls with AIS is 2-fold lower than in healthy subjects. It is possible that the deficiency of vitamin D can be involved in AIS.

LEVEL OF EVIDENCE

4.

Vitamin D receptor (VDR) gene polymorphism influences the risk of osteoporosis in postmenopausal women of Northwest India

SUMMARY

The influence of VDR gene for the risk of osteoporosis has remained inconclusive. VDR gene polymorphism in relation to BMD in postmenopausal women of Northwest India revealed a susceptibility haplotype AGT. Possession of this haplotype exacerbates the risk of osteoporosis by 2.8 times, which manifests in recessive mode of inheritance.

PURPOSE

The purpose of this study is to understand the influence of coordinated effect of various single nucleotide polymorphisms (SNPs) within vitamin D receptor (VDR) gene for the risk of osteoporosis, which has remained undefined so far.

METHODS

Four pertinent SNPs of VDR gene, i.e., rs2228570, rs1544410, rs17879735, and rs731236 were examined with polymerase chain reaction-restriction fragment length polymorphism in dual energy X-ray absorptiometry verified 188 osteoporotics, 115 osteopenics, and 147 normal postmenopausal women of Northwest India.

RESULTS

Minor allele 'T' of rs2228570 showed significant influence for the risk of osteoporosis (OR 1.60, 95%CI 1.16-2.20, P=0.004) and also in dominant (OR 2.32, 95%CI 1.47-3.64, P=0.0006) and additive model (OR 2.41, 95%CI 1.49-3.87, P=0.0006) after Bonferroni correction. Minor allele (T) of rs2228570 showed an allele dose effect with BMD of L1-L4 (P=0.009) and FN (P=0.036). Disease association analysis exposed a susceptibility haplotype AGT which influences the risk of osteopenia (OR 2.04, 95%CI 1.03-4.08, P=0.036) and osteoporosis (OR 2.90, 95%CI 1.61-5.38, P=0.00005) after adjusting the effects of age, BMI and years since menopause. This haplotype is significantly associated with BMDs at lumbar spine (P=0.0001) and femoral neck (P=0.016).

CONCLUSION

In-depth analysis of this haplotype with other methods of Wald statistics and Akaike information criterion confirmed that carriers of each unit of this haplotype AGT increases the risk of osteoporosis by a factor of 2.80±0.34 (β±SE) which manifests (P=0.1 × 10⁻⁶) in its recessive mode of inheritance.

Gene-gene interaction between RBMS3 and ZNF516 influences bone mineral density

Osteoporosis is characterized by low bone mineral density (BMD), a highly heritable trait that is determined, in part, by the actions and interactions of multiple genes. Although an increasing number of genes have been identified to have independent effects on BMD, few studies have been performed to identify genes that interact with one another to affect BMD. In this study, we performed gene-gene interaction analyses in selected candidate genes in individuals with extremely high versus low hip BMD (20% tails of the distributions), in two independent U.S. Caucasian samples. The first sample contained 916 unrelated subjects with extreme hip BMD Z-scores selected from a population composed of 2286 subjects. The second sample consisted of 400 unrelated subjects with extreme hip BMD Z-scores selected from a population composed of 1000 subjects. Combining results from these two samples, we found one interacting gene pair (RBMS3 versus ZNF516) which, even after Bonferroni correction for multiple testing, showed consistently significant effects on hip BMD. RMBS3 harbored two single-nucleotide polymorphisms (SNPs), rs6549904 and rs7640046, both of which had significant interactions with an SNP, rs4891159, located on ZNF516 (p = 7.04 × 10(-11) and 1.03 × 10(-10) ). We further validated these results in two additional samples of Caucasian and African descent. The gene pair, RBMS3 versus ZNF516, was successfully replicated in the Caucasian sample (p = 8.07 × 10(-3) and 2.91 × 10(-3) ). For the African sample, a significant interaction was also detected (p = 0.031 and 0.043), but the direction of the effect was opposite to that observed in the three Caucasian samples. By providing evidence for genetic interactions underlying BMD, this study further delineates the genetic architecture of osteoporosis.

Vitamin D receptor gene (VDR) transcripts in bone, cartilage, muscles and blood and microarray analysis of vitamin D responsive genes expression in paravertebral muscles of juvenile and adolescent idiopathic scoliosis patients

BACKGROUND

VDR may be considered as a candidate gene potentially related to idiopathic scoliosis susceptibility and natural history. Transcriptional profile of VDR mRNA isoforms might be changed in the structural tissues of the scoliotic spine and potentially influence the expression of VDR responsive genes. The purpose of the study was to determine differences in mRNA abundance of VDR isoforms in bone, cartilage and paravertebral muscles between tissues from curve concavity and convexity, between JIS and AIS and to identify VDR responsive genes differentiating juvenile and adolescent idiopathic scoliosis in paravertebral muscles.

METHODS

In a group of 29 patients with JIS and AIS, specimens of bone, cartilage, paravertebral muscles were harvested at the both sides of the curve apex together with peripheral blood samples. Extracted total RNA served as a matrix for VDRs and VDRl mRNA quantification by QRT PCR. Subsequent microarray analysis of paravertebral muscular tissue samples was performed with HG U133A chips (Affymetrix). Quantitative data were compared by a nonparametric Mann Whitney U test. Microarray results were analyzed with GeneSpring 11GX application. Matrix plot of normalized log-intensities visualized the degree of differentiation between muscular tissue transcriptomes of JIS and AIS group. Fold Change Analysis with cutoff of Fold Change ≥2 identified differentially expressed VDR responsive genes in paravertebral muscles of JIS and AIS.

RESULTS

No significant differences in transcript abundance of VDR isoforms between tissues of the curve concavity and convexity were found. Statistically significant difference between JIS and AIS group in mRNA abundance of VDRl isoform was found in paravertebral muscles of curve concavity. Higher degree of muscular transcriptome differentiation between curve concavity and convexity was visualized in JIS group. In paravertebral muscles Tob2 and MED13 were selected as genes differentially expressed in JIS and AIS group.

CONCLUSIONS

In Idiopathic Scolioses transcriptional activity and alternative splicing of VDR mRNA in osseous, cartilaginous, and paravertebral muscular tissues are tissue specific and equal on both sides of the curve. The number of mRNA copies of VDRl izoform in concave paravertebral muscles might be one of the factors differentiating JIS and AIS. In paravertebral muscles Tob2 and Med13 genes differentiate Adolescent and Juvenile type of Idiopathic Scoliosis.

Oestrogen receptor-alpha polymorphism and risk of fracture: a meta-analysis of 13 studies including 1279 cases and 6069 controls

A meta-analysis was performed to evaluate the effect of oestrogen receptor-alpha (ESR1) gene PvuII polymorphism on fracture risk. It included published data from relevant studies (up to May 2010) identified from Medline, Embase and Current Contents. The 13 included studies contained 1279 fracture cases and 6069 controls. The combined results based on these studies showed no relationship between ESR1 gene PvuII polymorphism and fracture risk. No significant difference in genotype distribution was found when stratifying by race. When stratifying by fracture type, it was found that vertebral fracture cases had a significantly higher frequency of the PvuII pp genotype than controls in five studies (552 cases and 2350 controls). This meta-analysis suggests a modest but statistically significant association between the ESR1 PvuII pp genotype and vertebral fracture.

BsmI, TaqI, ApaI and FokI polymorphisms in the vitamin D receptor (VDR) gene and risk of fracture in Caucasians: a meta-analysis

CONTEXT

Vitamin D receptor (VDR) gene polymorphisms have been strongly associated with bone mineral density in some studies. However, in a recent meta-analysis, no relationship of the VDR BsmI or TaqI polymorphism and fracture risk was found in the meta-analysis of published data.

OBJECTIVE AND DESIGN

Our meta-analysis studied whether a relationship exists between BsmI, TaqI, ApaI and FokI polymorphisms in the VDR gene and risk of fracture.

DATA SOURCES

Relevant studies were identified from the following electronic databases: MEDLINE, EMBASE and Current Contents before January 2010.

DATA SYNTHESIS

This meta-analysis included 17 studies with a total of 21 eligible comparisons, which included 2112 fracture cases and 4521 controls. All of these studies reported on Caucasians. The combined results based on all studies showed that fracture cases had a significantly lower frequency of bb genotype of BsmI [odds ratio (OR) = 0.87, 95% confidence interval (CI)=0.76, 0.98]. When stratifying by fracture type, we found that (1) hip fracture cases had a significantly lower frequency of bb genotype of BsmI (OR=0.82, 95% CI=0.70, 0.97); (2) hip fracture cases had a significantly lower frequency of Tt genotype of TaqI (OR=0.65, 95% CI=0.43, 0.97); (3) hip fracture cases had a significantly higher frequency of tt genotype of TaqI (OR=1.74, 95% CI=1.05, 2.91); (4) vertebral fracture cases had a significantly higher frequency of Aa genotype of ApaI (OR=1.63, 95% CI=1.03, 2.59). No significant difference was found in any genotype of FokI.

CONCLUSION

Our meta-analysis suggests that there is a modest but statistically significant association between the BsmI bb genotypes and fracture.

Genomic and metabolomic patterns segregate with responses to calcium and vitamin D supplementation

Inter-individual response differences to vitamin D and Ca supplementation may be under genetic control through vitamin D and oestrogen receptor genes, which may influence their absorption and/or metabolism. Metabolomic studies on blood and urine from subjects supplemented with Ca and vitamin D reveal different metabolic profiles that segregate with genotype. Genotyping was performed for oestrogen receptor 1 gene (ESR1) and vitamin D receptor gene (VDR) in fifty-six postmenopausal women. Thirty-six women were classified as low bone density as determined by a heel ultrasound scan and twenty women had normal bone density acting as ‘controls’. Those with low bone density (LBD) were supplemented with oral Ca and vitamin D and were classified according to whether they were ‘responders’ or ‘non-responders’ according to biochemical results before and after therapy compared to controls receiving no supplementation. Metabolomic studies on serum and urine were done for the three groups at 0 and 3 months of therapy using NMR spectroscopy with pattern recognition. The ‘non-responder’ group showed a higher frequency of polymorphisms in the ESR1 (codons 10 and 325) and VDR (Bsm1 and Taq1), compared with to the ‘responders’. The wild-type genotype for Fok1 was more frequent in those with LBD (70 %) compared with the control group (10 %). Distinctive patterns of metabolites were displayed by NMR studies at baseline and 3 months of post-treatment, segregating responders from non-responders and controls. Identification of potential ‘non-responders’ to vitamin D and Ca, before therapy, based on a genomic and/or metabolomic profile would allow targeted selection of optimal therapy on an individual basis.

Possible association of combined vitamin D receptor and estrogen receptor genotypes and low bone mineral density in Jordanian postmenopausal women

The genetics of osteoporosis has been extensively studied over the last 20 years. Many of the studies have been aimed at identifying possible risk factors and possible association with low bone mineral density (BMD). Vitamin D receptor (VDR) and estrogen receptor (ER) gene polymorphisms were the first to be studied. Some studies have shown a possible association for individual VDR and ER or combined VDR and ER genotypes in some populations, and others showed lack of such an association. This study is aiming at identification of a possible association with low BMD in Jordanian postmenopausal women. We used restriction fragment length polymorphisms (RFLPs) to study four polymorphisms in the VDR gene and two polymorphisms in the ER gene. Our sample was composed of 100 normal controls and 120 samples from patients with symptomatic vertebral fractures. The results showed a possible association of the ppxx genotype with low BMD in controls and patients and an association of the AaBbTT genotype with high BMD in control subjects. The AABBTT, AABBTTFF, and AABBTTFFPPXX genotypes showed a possible association with low BMD in patients. Further studies are needed to confirm the last finding since it could be an important predictor of low BMD in the Jordanian population.

Polymorphisms in the estrogen receptor genes are associated with hip fractures in Chinese

INTRODUCTION

Hip fractures (HF) are a major cause of public health burden with strong genetic determination. However, the true causal genes remain largely unknown.

MATERIALS AND METHODS

Based on the important biological role of estrogens in bone homeostasis, this study aimed to investigate whether the estrogen receptor genes, ESR1 and ESR2, affect the onset of HF in 700 elderly Chinese subjects (350 with osteoporotic HF and 350 healthy controls). We genotyped 32 SNPs in total and examined their associations both by the single-SNP and haplotype tests.

RESULTS

We identified two novel SNPs of ESR1, rs3020314 and rs1884051, were significantly associated with HF (rs3020314: P=0.0004, OR=1.66, 95%CI: 1.25-2.18; rs1884051: P=0.0004, OR=1.46, 95%CI: 1.19-1.81). We firstly detected significant association of ESR2 with HF (rs960070: P=0.0070, OR=1.43, 95%CI: 1.10-1.86). Haplotype analyses corroborated our single-SNP results.

CONCLUSION

Our findings have important implications for understanding the pathology of osteoporotic fractures. Independent replication studies are needed to validate our results and explore the most possible functional variants for molecular studies.

Serum 25-hydroxyvitamin D concentrations and risk for hip fractures

BACKGROUND

The relationship between serum 25-hydroxyvitamin D [25(OH) vitamin D] concentration and hip fractures is unclear.

OBJECTIVE

To see whether low serum 25(OH) vitamin D concentrations are associated with hip fractures in community-dwelling women.

DESIGN

Nested case-control study.

SETTING

40 clinical centers in the United States.

PARTICIPANTS

400 case-patients with incident hip fracture and 400 control participants matched on the basis of age, race or ethnicity, and date of blood draw. Both groups were selected from 39 795 postmenopausal women who were not using estrogens or other bone-active therapies and who had not had a previous hip fracture.

MEASUREMENTS

Serum 25(OH) vitamin D was measured and patients were followed for a median of 7.1 years (range, 0.7 to 9.3 years) to assess fractures.

RESULTS

Mean serum 25(OH) vitamin D concentrations were lower in case-patients than in control participants (55.95 nmol/L [SD, 20.28] vs. 59.60 nmol/L [SD, 18.05]; P = 0.007), and lower serum 25(OH) vitamin D concentrations increased hip fracture risk (adjusted odds ratio for each 25-nmol/L decrease, 1.33 [95% CI, 1.06 to 1.68]). Women with the lowest 25(OH) vitamin D concentrations (< or =47.5 nmol/L) had a higher fracture risk than did those with the highest concentrations (> or =70.7 nmol/L) (adjusted odds ratio, 1.71 [CI, 1.05 to 2.79]), and the risk increased statistically significantly across quartiles of serum 25(OH) vitamin D concentration (P for trend = 0.016). This association was independent of number of falls, physical function, frailty, renal function, and sex-steroid hormone levels and seemed to be partially mediated by bone resorption.

LIMITATIONS

Few case-patients were nonwhite women. Bone mineral density and parathyroid hormone levels were not accounted for in the analysis.

CONCLUSION

Low serum 25(OH) vitamin D concentrations are associated with a higher risk for hip fracture.

Genotypes and clinical aspects associated with bone mineral density in Argentine postmenopausal women

The aim of this study was to determine genotypes and clinical aspects associated with bone mineral density (BMD) in postmenopausal women from Córdoba, Argentina. Polymorphisms were assessed by RFLP-PCR technique using BsmI and FokI for vitamin D receptor gene (VDR) and XbaI and PvuII for estrogen receptor-alpha gene (ERalpha) as restrictases. Sixty-eight healthy, 54 osteopenic, and 64 osteoporotic postmenopausal women were recruited. Femoral neck and lumbar spine BMD were inversely correlated with age in the entire analyzed population. Height was lower in osteopenic and osteoporotic women as compared to healthy women (P < 0.05). Weight and body mass index (BMI) were the lowest in osteoporotic women (P < 0.01 versus healthy group). Serum procollagen type I Nterminal propeptide (PINP) was higher in osteoporotic women as compared to the other groups. Distribution of VDR and ERalpha genotypes was similar in the three groups. Genotype bb (VDR) was associated with low values of lumbar BMD in the healthy group (P < 0.05 versus genotype Bb), and with low values of femoral BMD (P < 0.05 versus genotype BB) in osteoporotic women. BB*Pp interaction was associated with the highest femoral neck BMD (P < 0.05), whereas the bb*xx interaction was associated with the lowest femoral neck BMD in the total population analyzed (P < 0.05). In conclusion, parameters such as age, height, weight, BMI, serum PINP, VDR genotypes, and interactions between VDR and ERalpha genotypes could be useful to predict a decrease in BMD in Argentine postmenopausal women.

Metabolic bone disease in premature infants and genetic polymorphisms

Koraszülöttekben a csontmineralizációt érintő betegség gyakori jelenség az igen alacsony születési súllyal (születési súly < 1500 g) született újszülöttek körében. Felnőttekben kimutatták, hogy az osteoporosis összefüggésbe hozható a D-vitamin-receptor, az ösztrogénreceptor, valamint a kollagén Iα1-receptor-gének polimorfizmusaival. Célkitűzés: A vizsgálat elsődleges célja annak a tisztázása volt, hogy található-e ilyen jellegű összefüggés a koraszülöttek csontanyagcsere-betegsége és a genetikai polimorfizmusok között. Módszer: 104, igen alacsony születési súllyal született újszülöttet vizsgáltak. Meghatározták a csontképzés (szérum alkalikus foszfatáz, osteocalcin) és a csontreszorpció (vizeletkalcium- és pyridinolinürítés) markereit, mellkasi, valamint hosszú csöves csontröntgenfelvételt készítettek. Eredmények: Harminc koraszülöttben (28,8%) diagnosztizáltak csontmineralizációt érintő betegséget aktív csontképzés és csontreszorpciós paraméterek, valamint pozitív radiológiai jelek alapján. Statisztikailag szignifikáns összefüggést találtak az ösztrogénreceptor-gén thymin-adenin repeat [(TA) n ] allél variánsa és a csontmetabolizmust érintő betegségek között. Csontanyagcsere-betegségben szenvedő koraszülötteknél az alacsonyabb repeatszámok [(TA) n < 19] szignifikánsan gyakrabban fordultak elő [esélyhányados (EH): 5,82; 95%-os megbízhatósági tartomány (MT): 2,26–14,98]. Magasabb számú repeateket [(TA) n > 18] azonban a kontrollcsoportban észleltek (EH: 0,20; 95% MT: 0,05–0,82). A D-vitamin-receptor és kollagén Iα1-receptor ( p = 0,023) egyes genotípusai között találtak szintén szignifikáns interakciót. Lépésenként bővített logisztikus regressziós modellben, mely magában foglalta a klinikai és genetikai jellemzőket, a csontmetabolizmust érintő csontbetegségek szignifikánsan korreláltak a férfinemmel ( p = 0,001), az ápolási napok számával ( p = 0,007), az ösztrogénreceptor- [(TA) n ] variáns magasabb repeatek száma homozigóta formájával ( p = 0,025), ezenkívül a D-vitamin-receptor (Tt) és kollagén Iα1 (CC) genotípusainak ( p = 0,014) és a D-vitamin-receptor (Tt) és ösztrogénreceptor (alacsony repeatszám mindkét allélban) genotípusainak ( p = 0,037) interakcióival. Következtetés: A szerzők eredményei arra mutatnak, hogy genetikai polimorfizmusok összefüggésben állhatnak a koraszülöttek csontanyagcsere-betegségének kialakulásával.

Searching for genes underlying susceptibility to osteoporotic fracture: current progress and future prospect

INTRODUCTION

Osteoporotic fracture (OF) is a public health problem. It is a common practice in the genetics of osteoporosis that bone mineral density (BMD) was studied as a major surrogate phenotype in gene search for risk of OF (ROF) because of their high phenotypic correlation. However, some studies indicate that the genetic correlation between BMD and ROF is very low. This implies that most genes found important for BMD may not be relevant to ROF. Ideally, employing OF per se as a direct study phenotype can directly find the relevant genes underlying ROF.

EVIDENCE

Here, we summarized some evidence supporting ROF under moderate genetic control, and the current progress of molecular genetic studies employing OF as the direct study phenotype, then give our consideration on the future prospects in the genetics of ROF.

Vitamin D and oestrogen receptor polymorphisms in developmental dysplasia of the hip and primary protrusio acetabuli--a preliminary study

We investigated the association of developmental dysplasia of the hip (DDH) and primary protrusion acetabuli (PPA) with Vitamin D receptor polymorphisms Taq I and Fok I and oestrogen receptor polymorphisms Pvu II and Xba I. 45 patients with DDH and 20 patients with PPA were included in the study. Healthy controls (n = 101) aged 18–60 years were recruited from the same geographical area. The control subjects had a normal acetabular morphology based on a recent pelvic radiograph performed for an unrelated cause. DNA was obtained from all the subjects from peripheral blood. Genotype frequencies were compared in the three groups. The relationship between the genotype and morphology of the hip joint, severity of the disease, age at onset of disease and gender were examined. The oestrogen receptor Xba I wild-type genotype (XX, compared with Xx and xx combined) was more common in the DDH group (55.8%) than controls (37.9%), though this just failed to achieve statistical significance (p = 0.053, odds ratio = 2.1, 95% CI = 0.9–4.6). In the DDH group, homozygosity for the mutant Taq I Vitamin D receptor t allele was associated with higher acetabular index (Mann-Whitney U-test, p = 0.03). Pvu II pp oestrogen receptor genotype was associated with low centre edge angle (p = 0.07). This study suggests a possible correlation between gene polymorphism in the oestrogen and vitamin D receptors and susceptibility to, and severity of DDH. The Taq I vitamin D receptor polymorphisms may be associated with abnormal acetabular morphology leading to DDH while the Xba I oestrogen receptor XX genotype may be associated with increased risk of developing DDH. No such correlations were found in the group with PPA.

Association of estrogen receptor alpha gene polymorphisms with bone mineral density in Chinese women: a meta-analysis

INTRODUCTION AND HYPOTHESIS

A large number studies have examined the association between estrogen receptor alpha (ESR-alpha) gene polymorphisms and bone mineral density (BMD) in the Chinese population. We conducted a meta-analysis to assess their pooled effects.

METHODS

We searched for all published articles indexed in MEDLINE, the Chinese Biomedical Database, and the Chinese Journal Full-text Database from January 1994 to April 2006. Any cross-sectional study that tested the association between ESR-alpha PvuII or XbaI genotypes and BMD at the femoral neck or spine in Chinese women was included in the review. Data were extracted independently by two reviewers using a standardized data extraction form. Sixteen eligible studies involving 4,297 Chinese women were identified.

RESULTS

The overall frequencies of X and P alleles were 28% and 40%, respectively. The PvuII polymorphism was statistically significantly associated with BMD at the femoral neck (P = 0.038 for PP = Pp = pp) but not at the lumbar spine in all women. The BMD difference for the contrasts of PP versus Pp/pp genotypes was -0.0105 (95%CI, -0.0202 approximately -0.0008) g/cm(2) (P = 0.036). The XbaI polymorphism was not associated with BMD at the femoral neck or lumbar spine.

CONCLUSION

The PvuII polymorphism had a very weak association with femoral neck BMD whereas XbaI polymorphism was unlikely to be a predictor of femoral neck or spine BMD in Chinese women.

Association analysis of the polymorphisms of the VDR gene with bone mineral density and the occurrence of fractures

Associations of the FokI, BsmI, ApaI, and TaqI polymorphisms of the vitamin D receptor (VDR) gene with the bone mineral density (BMD) of the lumbar part of the spinal column (BMD LS) and the neck of the femur (BMD FN), and with the occurrence of fractures, were studied using the polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis on DNA isolated from peripheral blood of 239 women and 40 men from the region of western Poland. Three polymorphisms of the 3' end of the VDR gene (BsmI, ApaI, TaqI) indicated a strong linkage disequilibrium. Association analysis of the VDR gene FokI polymorphism with BMD LS showed a dose effect of allele f. The association of the bAT haplotype of the BsmI, ApaI, and TaqI polymorphisms of the VDR gene with BMD FN was statistically significant. The association of the ApaI polymorphism with the occurrence of fractures was observed. Associations were also observed between the occurrence of fractures and the baT haplotypes of the VDR gene.

Influence of genetic polymorphisms on bone disease of preterm infants

Bone disease is an important complication among very low birth weight (VLBW, <1500 g) infants. In adults, osteoporosis is associated with polymorphisms of vitamin D receptor (VDR), estrogen receptor (ER), and collagen Ialpha1 (COLIA1) genes. However, limited information is available regarding the role of these polymorphisms in bone disease in premature infants. We have investigated the possible association between bone disease and the allelic polymorphisms of these three genes in 65 VLBW infants. Twenty infants (30.8%) were diagnosed with bone disease based on high activity of bone formation (serum alkaline phosphatase and osteocalcin), bone resorption (urinary excretion of calcium and pyridinium crosslink) markers, and positive radiologic signs. Statistically significant correlation between thymine-adenine repeat [(TA)(n)] allelic variant of ER gene and bone disease was observed. Infants without bone disorder more often carried a high number of repeats [(TA)(n) >18] [odds ratio (OR): 0.17, 95% confidence interval (CI): 0.05-0.55]. A low number of repeats [(TA)(n) <19] was found more frequently in infants suffering from bone disease (OR: 6.00, 95% CI: 1.77-20.31). Significant interaction (p = 0.009) between VDR and COLIA1 genotypes was observed. In a logistic regression model, bone disorder of preterms significantly correlated with male gender (p = 0.002), lower gestational age (p = 0.015), homozygous allelic variants of high number of (TA)(n) repeats (p = 0.006), and interaction between VDR and COLIA1 genotype (p = 0.009).

Vitamin D receptor gene BsmI and TaqI polymorphisms and fracture risk: a meta-analysis

INTRODUCTION

Fracture is the major clinical outcome of osteoporosis. The vitamin D receptor (VDR) gene is thought to be a candidate gene for osteoporosis. Many genetic studies have suggested an association of VDR polymorphisms and osteoporosis, but evidence remains conflicting.

MATERIALS AND METHODS

We searched published studies from 1996 to September 2005 through PubMed and evaluated the genetic effect of the BsmI and TaqI polymorphism of VDR on fracture risk in a meta-analysis. Thirteen studies with a total of 20 eligible comparisons (1632 fracture cases and 5203 controls) were analyzed with fixed and random effects models.

RESULT

No evidence of relationship between the VDR BsmI or TaqI polymorphism and fracture risk was observed with any genetic model. The odds ratio (95% confidence interval) of b-allele versus B-allele was 0.98 (0.86-1.12) with random effects calculations. There was significant between-study heterogeneity. Small studies did not differ significantly from larger ones.

CONCLUSION

No relationship of the VDR BsmI or TaqI polymorphism and fracture risk was found in the meta-analysis of published data.

Genetics of osteoporosis

Osteoporosis is a common disease with a strong genetic component. In recent years, some progress has been made in understanding the genetic basis of osteoporosis. Genetic factors contribute to osteoporosis by influencing not only bone mineral density but also bone size, bone quality, and bone turnover. Meta-analysis has been used to define the role of several candidate genes in osteoporosis. Some quantitative trait loci that regulate bone mass identified by linkage studies in humans and experimental animals have been replicated in multiple populations. Genes that cause monogenic bone diseases also contribute to regulation of bone mass in the normal population. Genome-wide association studies and functional genomics approaches have recently begun to apply to genetic studies of osteoporosis. In the future, not only single gene but also the entire gene networks involved in osteoporosis and regulation of bone mass will systematically be discovered through integrative genomics.

ALDH2 polymorphisms and bone mineral density in an elderly Japanese population

INTRODUCTION

Osteoporosis is a multifactorial genetic disease which greatly increases the risk of bone fracture in elderly persons.

METHODS

Four hundred and three recipients of a community health screening program were examined for the presence/absence of osteoporosis and 11 kinds of gene polymorphisms as a means of determining the relation between these gene polymorphisms and osteoporosis. The gene polymorphisms screened were: alcohol sensitivity-associated polymorphisms of alcohol dehydrogenase (ADH2) Arg47His, aldehyde dehydrogenase (ALDH2) Glu487Lys, smoking sensitivity-associated polymorphisms of glutathione S transferase (GST) M1, (GST)T1, NAD(P)H quinone oxidoreductase 1 (NQO1) C609T, inflammation-associated polymorphisms of interleukin-1beta (IL-1B)T-31C, tumor necrosis factor alpha (TNF-alpha) T-1031C, endothelial constitutive nitric oxide synthase (ecNOS) Glu298Asp, longevity-associated polymorphism of mitochondrial DNA (mtDNA) 5178 A/C, allergy-associated polymorphism of interleukin-4 (IL-4), and immunity-associated polymorphism of CD14.

RESULTS

A significant association was found between the ALDH2Glu478Lys gene polymorphisms and osteoporosis. In the osteoporosis group of patients, a significant difference was noted between the Lys/Lys group and the group comprising Glu/Lys and Glu/Glu groups (namely, the genotypes including Glu alleles). In the Lys/Lys group, after age, sex, BMI, smoking history and alcohol consumption history had been adjusted for, the morbidity rate was significantly elevated [odds ratio (OR): 3.33; 95% confidence interval (95% CI): 1.28-8.71; p=0.014], and the effect was even more evident in the sub-group of women with osteoporosis (OR: 4.31; 95% CI: 1.24-14.92; p=0.021).

CONCLUSIONS

The present results suggest that active prophylactic interventions such as dietary, exercise, and pharmacological therapies should be offered to non-carriers of the Glu allele (Lys/Lys).

Large-scale population-based study shows no evidence of association between common polymorphism of the VDR gene and BMD in British women

The VDR is a candidate gene for osteoporosis. Here we studied five common polymorphisms of VDR in relation to calcium intake and vitamin D status in a population-based cohort of 3100 British women, but found no significant association with bone mass, bone loss, or fracture.

INTRODUCTION

Population studies of vitamin D receptor (VDR) polymorphisms have produced conflicting results. We performed a comprehensive study dealing with all potential confounders in a large population to determine whether polymorphisms in the VDR gene influence bone health.

MATERIALS AND METHODS

We studied 3100 women (50-63 years old) with bone markers, 25-hydroxyvitamin D, calcium, PTH, diet, and physical activity collected in 1998-2000. BMD was measured in 1990-1994 and 1998-2000. Fracture prevalence was assessed in 2002. Women were genotyped for five polymorphisms in the VDR gene: Cdx-2, Fok1, Bsm1, Apa1, and Taq1. The relationship between VDR and BMD, and interactions between VDR genotype, dietary calcium, and 25-hydroxyvitamin D, were examined using analysis of covariance.

RESULTS

Compared with carriers of the G allele, homozygotes for the rare Cdx-2 A polymorphism (n = 136) had less bone loss (-0.5 +/- 1.2 versus -0.7 +/- 1.0%/year [SD]; p = 0.01) and lower PTH (3.0 +/- 1.6 versus 3.4 +/- 2.0 pM; p = 0.03) despite similar vitamin D status. The association was not significant after correction for multiple testing or adjustment for confounders. At low calcium intakes, AA homozygotes had greater femoral neck (FN) BMD compared with carriers of the G allele, but at higher calcium intakes, the association was reversed. At low calcium intake, homozygotes for the b allele of Bsm1 had greater BMD compared with carriers of the B allele, but at higher calcium intakes, there was no difference. Similar results were seen for the Taq1 polymorphism. There was no evidence of gene-nutrient interaction when adjusted for body weight. No interactions between genotypes and vitamin D status on BMD were observed.

CONCLUSIONS

VDR does not seem to influence BMD or bone turnover in early postmenopausal white women with adequate calcium intake. Gene-nutrient interactions on BMD may be an indirect consequence of interactions between genotype and calcium intake on weight.

Bone mineral density and vertebral fracture history are associated with incident and progressive radiographic knee osteoarthritis in elderly men and women: the Rotterdam Study

OBJECTIVE

To study the association between baseline femoral neck and lumbar spine bone mineral density (BMD), prevalent fractures and incident and progressive radiographic osteoarthritis (ROA) of the knee in men and women.

METHODS

A sample of 1403 subjects (829 women and 574 men) was drawn from the Rotterdam Study, a prospective population-based cohort study of the elderly. Incidence and progression of ROA in quartiles of femoral neck (FN) and lumbar spine (LS) BMD were determined using the Kellgren score, and separate analyses were made for men and women. Furthermore, incidence and progression of ROA were compared in subjects with and without a prevalent vertebral or non-vertebral fracture at baseline.

RESULTS

The incidence of knee ROA of subject in the highest FN BMD (10.5%) and LS BMD (14.3%) was significantly higher than of those in the lowest quartiles (3.4% and 3.3% respectively), with corresponding adjusted odds ratios (95% confidence interval) of 2.8 (1.2-6.8) and 4.7 (2.1-10.7). The same trend was seen in the association between LS BMD and the progression of knee ROA, but no association was found between FN BMD and progression of ROA. Separate analyses for men and women both showed significant increased risks in the presence of high baseline BMD, with higher odds ratios in men than in women but larger confidence limits due to lower number of cases in men. Combined incidence and progression of knee ROA in subjects with a prevalent vertebral but not with a prevalent non-vertebral fracture at baseline was 8 times lower than subject without a fracture, independent of baseline BMD.

CONCLUSIONS

High systemic BMD at baseline is associated with increased incidence and progression of knee ROA in both men and women, while a prevalent vertebral fracture has a protective effect.

Genetic polymorphisms of OPG, RANK, and ESR1 and bone mineral density in Korean postmenopausal women

To evaluate the effects of genetic polymorphisms of OPG, RANK, and ESR1, which regulate osteoclastogenesis, on bone mineral density (BMD), a cross-sectional study was conducted in 650 Korean postmenopausal women. BMDs of the distal radius and the calcaneus were measured by dual energy X-ray absorptiometry (DXA). Genetic polymorphisms of OPG 163 A > G, 1181 G > C; RANK 421 C > T, 575 T > C; and ESR1 1335 C > T, 2142 G > A were determined by matrix-assisted laser desorption/ionization-time of flight (MALDI-ToF) mass spectrometry. The differences between the BMDs of the genotypes of OPG, RANK, and ESR1 were analyzed by multiple linear regression model adjusted for age and body mass index. Women with the OPG 1181 CC genotype had higher BMDs at the distal radius (7%) and calcaneus (10%) than those with the GG genotype; and these differences were statistically significant (P = 0.001 and P = 0.007, respectively). A significant association was also observed between RANK 575 T > C and calcaneus BMD (P for trend = 0.017). No significant association was observed between BMDs and the polymorphisms of ESR1. The association between OPG 1181 G > C and BMD was profound in subjects with the RANK 575 TT or ESR1 2142 GG genotypes; women with OPG 1181 CC had higher BMDs at the distal radius (11%) and calcaneus (11%) than those with OPG 1181 GG only in women with RANK 575 TT genotype (P = 0.002 and P = 0.021, respectively). These results suggest that OPG genetic polymorphisms, especially with the RANK 575 TT or ESR1 2142 GG genotypes, are related to low BMD in postmenopausal Korean women.

The influence of a Vitamin D receptor gene polymorphism on the timing of female reproductive functions in humans

OBJECTIVE

To evaluate the association between a common polymorphism of the Vitamin D receptor gene (VDR) and the timing of female reproductive functions in humans.

METHODS

One thousand fifty-eight consecutive women were included in this cross-sectional study. We analyzed the intron 8 Bsm I restriction fragment length polymorphism (RFLP) of VDR on chromosome 12q using a microarray-based system.

RESULTS

The presence of the VDR polymorphism did not influence the timing of menarche and natural menopause and was not associated with the number of spontaneous abortions, full term pregnancies (FTP) as well as the total number of pregnancies. Of note, women with at least one mutant allele of VDR were at a significantly decreased risk for experiencing surgical menopause (odds ratio [OR] 0.65, 95% confidence interval [CI], 0.46-0.92, P = 0.02). Smoking and a body mass index (BMI) > 25 were associated with an earlier natural menopause and an increased risk for surgical menopause, respectively.

CONCLUSIONS

While no association of a common polymorphism of VDR with the timing of menarche and menopause was ascertained, we found the presence of at least one mutant allele of VDR to be associated with a decreased risk of experiencing surgical menopause, i.e., premenopausal hysterectomy, in a large series of Caucasian women.