Association of Thr420Lys polymorphism in DBP gene with fat-soluble vitamins and low radial bone mineral density in postmenopausal Thai women

Vitamin D receptor rs3782905 and vitamin D binding protein rs7041 polymorphisms are associated with hepatocellular carcinoma susceptibility in cirrhotic HCV patients

BACKGROUND

The severity of chronic hepatitis C and susceptibility to hepatocellular carcinoma (HCC) are associated with genetic variations within vitamin D receptor (VDR) in several populations. This study aims to determine the significance of the VDRs (rs2228570, rs3782905, rs11568820) and DBP (rs7041) for the susceptibility to HCC in Egyptian patients with chronic HCV infection and their effect on the progression of liver cirrhosis to carcinogenesis.

METHODS

Single nucleotide polymorphisms (SNPs) VDR (rs2228570, rs3782905), and DBP rs7041 were genotyped using restriction fragment length-PCR (RFLP-PCR) technique and VDR rs11568820 was genotyped using single strand polymorphism PCR (SSP PCR). These SNPs genotypes, haplotypes and linkage disequilibrium analyses were examined in 299 Egyptian individuals (100 HCV-cirrhotic patients, 99 HCC- HCV patients, and 100 healthy controls).

RESULT

The VDR rs2228570 CC genotype, VDR rs3782905 GC and CC genotypes, and DBP rs7041 GG genotype are significantly higher in HCC. It is noteworthy that, VDR rs3782905 CC and DBP rs7041 TG genotypes are higher in HCV induced liver cirrhosis than with HCC progression in HCV infected patients. Furthermore, among patients, the relationship between these SNPs and smoking status, gender, and HCC susceptibility was reported.

CONCLUSION

Among the four investigated SNPs, there are associations between VDR rs3782905 and DBP rs7041 and the HCC progression in Egyptian patients chronically infected with HCV. These SNPs are considered as risk factors in HCV induced liver cirrhosis and HCC. The combinations of these SNPs with smoking status and gender are statistically linked to a high risk of HCC. Future research with a larger sample size of subjects with HCV infection is advised, because chronic liver disease induced by HCV infection is the primary cause of HCC in Egypt. We recommend screening of these SNPs for prediction of LC and HCC development in HCV infected patients, which may improve the used therapeutic protocol. These results suggest that VDR polymorphisms may be potential determinants for HCC susceptibility in Egyptian HCV patients.

Current issues in evaluation and management of osteoporosis in Thailand

Osteoporosis is a major public health issue in Thailand, which increased morbidity, mortality, and health-care utilization. The objective of this review is to provide current perspectives on epidemiology, evaluation and management of osteoporosis in Thailand. According to epidemiologic data, the prevalence of osteoporosis and the incidence of hip fracture were comparable to the rest of the world. However, among Thai postmenopausal women, the prevalence of asymptomatic vertebral fracture was disproportionately high. In addition to established risk factors, conditions that may affect the risk of osteoporosis in the Thai population include certain genetic variants, thalassemia, vitamin D deficiency, and low dietary calcium intake, which requires further investigations to draw conclusions. In 2021, the Thai Osteoporosis Foundation released a new Clinical Practice Guideline that provides up-to-date evidence-based recommendations for evaluation and management of osteoporosis. Nonetheless, more research is required to provide local evidence in a variety of areas to guide management of osteoporosis in Thailand. These include epidemiology of distal radial fracture, the optimal intervention threshold of the Thai-specific Fracture Risk Assessment Tool model, screening for asymptomatic vertebral fracture, and the economic evaluation of osteoporosis management options, including fracture liaison service.

Vitamin D Binding Protein (VDBP) and Its Gene Polymorphisms-The Risk of Malignant Tumors and Other Diseases

Vitamin D is an important component of the endocrine system that controls calcium homeostasis and bone mineralization. Because of the very short half-life of free serum vitamin D it is stabilized and transported to target tissues by being bound to the vitamin D binding protein (VDBP). The most common polymorphisms: rs4588 and rs7041 in the vitamin D binding protein gene may correlate with differences in vitamin D status in the serum. This review presents data that relate to the presence of genetic variants in the VDBP gene in correlation with certain diseases, mostly concerning cancers (breast, prostate, pancreatic, lung, colorectal, basal cell carcinoma cancer and cutaneous melanoma) or other related diseases (thyroid autoimmunity disorders, obesity, diabetes mellitus, bone metabolism, rheumatoid arthritis, ankylosing spondylitis, asthma, chronic obstructive pulmonary disease, tuberculosis and coronary artery diseases).

Prevalence of vitamin D deficiency in women from southern Brazil and association with vitamin D-binding protein levels and GC-DBP gene polymorphisms

Vitamin D deficiency is highly prevalent worldwide, and vitamin D-binding protein (DBP) a major regulator of serum vitamin D levels. The rs4588 and rs7041 polymorphisms of the GC gene constitute the genetic basis of the three major isoforms of circulating DBP (GC1s, GC1f, and GC2), while the rs2282679 variant is located in an important regulatory region of the GC gene. The aim of this study was to assess the prevalence of 25-hydroxyvitamin D [25(OH)D] deficiency and to ascertain whether it is associated with DBP levels and with GC gene variants. Biorepository samples of 443 women aged 20 to 72 years, with no evidence of clinical disease, were analyzed. Circulating levels of 25(OH)D were considered sufficient if ≥20 ng/mL and deficient if <20 ng/mL. Genotype analysis was performed by RT-PCR. Mean age was 53.4±9.4 years; mean BMI was 27.8±5.8 kg/m2. The overall sample had mean 25(OH)D levels of 22.8±8.3 ng/mL; 39.7% of participants had deficient circulating 25(OH)D levels. Higher prevalence ratios (PR) of 25(OH)D deficiency were found for the CC genotype of rs2282679 (PR 1.74; 95%CI 1.30 to 2.24; p<0.001), GC2 isoform (PR 1.66; 95%CI 1.17 to 2.38; p = 0.005), time since menopause (PR 1.02; 95%CI 1.003 to 1.03, p = 0.016), and HOMA-IR (PR 1.02; 95%CI 1.01 to 1.03, p = 0.004). DBP levels (per 30 μg/mL increase in DBP) were associated with lower PR for 25(OH)D deficiency (PR 0.89; 95%CI 0.80;0.99; p = 0.027). Except for HOMA-IR, these prevalence ratios remained significant after adjustment for age and BMI. In conclusion, the rs2282679 polymorphism and the GC2 isoform of DBP were associated with lower serum DBP levels and with susceptibility to 25(OH)D deficiency in Brazilian women with no evidence of clinical disease.

Association of VDR-FokI and VDBP-Thr420Lys polymorphisms with cervical spondylotic myelopathy: A case-control study in the population of China

BACKGROUND

Cervical spondylotic myelopathy (CSM), a common degenerative disorder, is characterized by chronic progressive compression of the cervical spinal cord. The present case-control study aimed to explore the potential role of VDR-FokI and VDBP-Thr420Lys polymorphisms in the susceptibility to CSM in the Chinese population.

METHODS

The study enrolled 318 CSM patients and 282 healthy individuals whose clinical data were retrospectively analyzed. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used to genotype VDR-FokI and VDBP-Thr420Lys polymorphisms. The severity of CSM was assessed using the Japanese Orthopaedic Association (JOA) score with magnetic resonance imaging (MRI) of cervical vertebra. A nonconditional binary logistic regression model was conducted for assessing the risk factors of CSM.

RESULTS

Patients in the CSM group had longer time duration to bend over desk working than the control group. The ff genotype and f allele frequency of VDR-FokI were elevated in CSM patients. Elevated Ff + ff genotype and f allele frequency of VDR-FokI might increase the risk of CSM. The VDR-FokI polymorphism was associated with nucleus pulposus capillary invasion, necrosis, hyaline degeneration and fibrosis, genesis and hyperplasia of cartilage-like cells, and fibrocyst in the fibrous ring. The VDR-FokI and VDBP-Thr420Lys genotypes conformed to Hardy-Weinberg equilibrium which showed that VDR-FokI and VDBP-Thr420Lys had group representation characteristics.

CONCLUSION

Binary logistic regression analysis confirmed that VDR-FokI polymorphism and the time to bend over desk working were risk factors of CSM. Our results indicate that VDR-FokI polymorphism may be closely associated with the risk of CSM.

Correlation of vitamin D binding protein gene polymorphism and protein levels in chronic obstructive pulmonary disease compared with non-chronic obstructive pulmonary disease subjects

AIM

The risk of vitamin D binding protein (DBP) variations in chronic obstructive pulmonary disease (COPD) compared with non-COPD Thai males were investigated.

MATERIALS & METHODS

The rs7041 and rs4588 polymorphisms of the DBP gene and protein level were measured in 136 COPD and 68 non-COPD Thai males.

RESULTS

In the COPD group, GC1-1 gave increased forced expiratory volume at 1 s % predicted compared with GC1-2 but with no significant difference. Significantly lower average DBP serum levels were observed in COPD than non-COPD subjects. Positive correlation between serum DBP and forced expiratory volume at 1 s % predicted was observed in non-COPD subjects.

DISCUSSION & CONCLUSION

DBP variations might be associated with risk factors in COPD caused by both inflammatory and vitamin D circulation processes.

Vitamin D-binding protein and its polymorphisms as a predictor for metabolic syndrome

AIM

To investigate the relationship of vitamin D-binding protein (GC) and genetic variation of GC (rs4588, rs7041 and rs2282679) with metabolic syndrome (MetS) in the Thai population.

MATERIALS & METHODS

GC-globulin concentrations were measured by quantitative western blot analysis in 401 adults. All participants were genotyped using TaqMan allelic discrimination assays.

RESULTS

GC-globulin levels were significatly lower in MetS subjects than in control subjects, in which significant negative correlations of GC-globulin levels with systolic blood pressure, glucose and age were found. Male participants who carried the GT genotype for rs4588 showed an increased risk of MetS compared with the GG wild-type (odds ratio: 3.25; p = 0.004).

CONCLUSION

GC-globulin concentrations and variation in GC rs4588 were supported as a risk factor for MetS in Thais.

Polymorphisms of Vitamin D Signaling Pathway Genes and Calcium-Sensing Receptor Gene in respect to Survival of Hemodialysis Patients: A Prospective Observational Study

We evaluated in the 7-year prospective study whether variants in vitamin D pathway genes and calcium-sensing receptor gene (CASR) are determinants of mortality in hemodialysis (HD) patients (n = 532). HRM analysis was used for GC rs2298849, GC rs1155563, RXRA rs10776909, RXRA rs10881578, and CASR rs7652589 genotyping. GC rs7041, RXRA rs749759, VDR rs2228570, and VDR rs1544410 were genotyped using PCR-RFLP analysis. The minor allele in GC rs2298849 was associated with all-cause mortality in univariate analysis (HR 1.330, 95% CI 1.046-1.692, P = 0.020). Bearers of the minor allele in GC rs2298849 demonstrated higher infection/neoplasm mortality than major allele homozygotes also in multivariate analysis (HR 2.116, 95% CI 1.096-4.087, P = 0.026). Cardiovascular mortality was associated with major homozygosity (CC) in VDR rs2228570 (HR 1.896, 95% CI 1.163-3.091, P = 0.010). CC genotype patients were more often dyslipidemic than TT genotype subjects (46.1% versus 31.9%, P = 0.047). Dyslipidemics showed higher frequency of rs1544410_rs2228570 haplotype AC than nondyslipidemics (26 versus 18%, P corr = 0.005), whereas TT genotype patients were at lower risk of dyslipidemia compared with CC/CT genotype patients (HR 0.59, 95% CI 0.37-0.96, P = 0.04). In conclusion, GC rs2298849 and VDR rs2228570 SNPs are associated with survival on HD. VDR-related cardiovascular mortality may occur due to connections of rs2228570 with dyslipidemia.

Single nucleotide polymorphisms in the Gc gene for vitamin D binding protein in common cancers in Thailand

BACKGROUND

This case-control study aimed to determine if there were any associations between the two single nucleotide polymorphisms (SNPs) in Gc, rs7041 (Asp416Glu) and rs4588 (Thr420Lys) and 3 common cancers (breast, lung and colorectal) in Thai patients.

MATERIALS AND METHODS

Two hundred and eighty two colorectal, 101 breast and 113 lung cancer patients were recruited from one institute during 2011-2013. The controls were age-matched volunteers who had a negative history of index cancers. In addition, vitamin D levels were compared among different genotypes in the 2 SNPs.

RESULTS

The minor allele frequencies of rs7041 (G) and rs4588 (A) were 0.32 and 0.24, respectively. Under the dominant model, the study found significant associations between minor-allele genotypes of the SNP rs7041 (TG/GG) and lung cancer (odds ratio [OR] 1.78, 95% CI 1.05-3.03). When subgroup analysis was performed according to sex and age at diagnosis, the study found that the minor- allele genotypes of rs7041 (TG/GG) were significantly associated with colorectal cancer in patients whose age at diagnosis was more than 60 years (OR 1.67, 95%CI 1.06-2.61) and the minor-allele genotypes of rs4588 (CA/AA) were significantly associated with colorectal cancer in males aged 60 years or less (OR 2.34, 95%CI 1.25-4.37). When SNP combinations (rs7041-rs4588) were examined, the TT-CA combination had a significant protective association with lung cancer (OR 0.44, 95% CI 0.22-0.85). On evaluation of serum 25(OH)D levels in 205 individuals without cancer (males 144, females 61), the proportion of subjects with low serum vitamin D (< 20 ng/ml) in those harboring CA or AA genotypes of rs4588 (41.7%) was significantly higher than the CC genotype (15.5%, p-value < 0.01).

CONCLUSIONS

Genetic polymorphisms in Gc were associated with lung and colorectal cancers in Thai patients. Lower serum 25(OH)D in minor variants of rs4588 may explain this association.

Overview of research studies on osteoporosis in menopausal women since the last decade

Purpose/Introduction:

Osteoporosis is a multifactorial and slowly emerging global health problem. The lifetime risk of dying from hip fracture is same as that from breast cancer. One out of three women between age group of 50-60 years in India suffers from osteoporosis. Indian women have an early age of onset of osteoporosis as compared to western counterparts. There is need for early diagnosis, identification of high-risk groups and prevention and treatment of osteoporosis in the Indian context. The aim of this study was to review the literature published in last decade and compare the research in India with that in rest of the world.

Materials and Methods:

Research articles with key words menopausal, osteoporosis and bone mineral density were searched in Pubmed from January 2004 to December 2013. Articles were categorized according to year, place and objective of the studies.

Results:

In India more articles were published in year 2010-11 (53.3%), while outside the country a uniform distribution of studies was observed throughout the last decade. Objective of research was screening and diagnosis (36.7%) and risk factor identification (40%) in most of the Indian studies as compared to rest of the world. Research publications on prevention and treatment of osteoporosis are less in India (20%).

Conclusion:

Research focusing on diagnosis, prognosis, prevention and treatment are needed in India.

An insight into rheumatology in Thailand

Despite the fact that rheumatic diseases constitute a common health care problem in Thailand, improvements in rheumatology education, research and health care are still required. Low numbers of rheumatologists, their uneven distribution, lack of time to perform both clinical and basic research, lack of patient compliance and restricted access to effective medication comprise some of the barriers that need to be overcome to establish rheumatology education, research and care with a Western-country benchmark. The annual academic activities provided by the Thai Rheumatism Association for rheumatologists, general practitioners, allied health professionals and patients can advance only some forms of education and health care. Better cooperation between the Thai Rheumatism Association, the Royal College of Physicians of Thailand, the Ministry of Public Health and the Thai government is needed to improve rheumatology training, care and research in the country.

Associations between vitamin D-binding protein (DBP) gene polymorphism (TAAA)n and development of osteoporosis in the Volga-Ural region of Russia

Study of DBP gene (TAAA) n polymorphism in women of postmenopausal age revealed a significantly lower incidence of DBP(*) 10 allele and a higher incidence of DBP(*) 11 allele in Russian women with bone fractures in comparison with the relevant controls (χ(2) = 4.47, p = 0.034 and χ(2) = 4.28, p = 0.038, respectively). Allele DBP(*) 11 is a high risk marker (OR = 1.93; 95%CI 1.06-3.48), while allele DBP(*)10 a marker of low risk of bone fractures (OR = 0.59; 95%CI 0.37-0.94). A trend to a reduction of mineral density of the femoral neck and of the lumbar vertebrae in women with DBP(*) 10(*) 8 genotype of DBP gene polymorphic locus (TAAA) n in comparison with DBP(*) 10(*) 10 and DBP(*) 10(*) 11 genotype carriers is traced.

Vitamin D binding protein: a multifunctional protein of clinical importance

Since the discovery of group-specific component and its polymorphism by Hirschfeld in 1959, research has put spotlight on this multifunctional transport protein (vitamin D binding protein, DBP). Besides the transport of vitamin D metabolites, DBP is a plasma glycoprotein with many important functions, including sequestration of actin, modulation of immune and inflammatory responses, binding of fatty acids, and control of bone development. A considerable DBP polymorphism has been described with a specific allele distribution in different geographic area. Multiple studies have shed light on the interesting relationship between polymorphisms of the DBP gene and the susceptibility to diseases. In this review, we give an overview of the multifunctional character of DBP and describe the clinical importance of DBP and its polymorphisms. Finally, we discuss the possibilities to use DBP as a novel therapeutic agent.