1.
Association between vitamin D receptor BsmI polymorphism and bone mineral density in pediatric patients: A meta-analysis and systematic review of observational studies.
Bao, L, Chen, M, Lei, Y, Zhou, Z, Shen, H, Le, F
Medicine. 2017;(17):e6718
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Abstract
BACKGROUND Vitamin D and the vitamin D receptor (VDR) are important in the metabolic processes that affect bone mineral density (BMD). However, the effect of VDR BsmI polymorphism on BMD in pediatric patients is still unclear. METHODS Eligible studies were identified from the following electronic databases: PubMed, Embase, the Cochrane Library, and the Chinese CNKI and Wanfang databases before October 1, 2016. Data were extracted from the eligible studies, and associations between VDR BsmI polymorphism and BMD in pediatric patients were estimated with weighted mean differences (WMDs) and 95% confidence intervals (CIs). Subgroup analysis of ethnicity and sensitivity analyses were used to identify sources of heterogeneity. RESULTS A significant difference was observed between VDR BsmI polymorphism and pediatric BMD levels of the lumbar spine (LS) in the corecessive model (bb vs BB + Bb: WMD = -0.23, 95% CI [-0.35, -0.11], P < 0.01). No significant relationship was found in the dominant, recessive, or codominant models for LS BMD (BB vs Bb: WMD = -0.56, 95% CI [-1.58, 0.46], P = 0.29; BB vs bb: WMD = -0.54, 95% CI [-1.49, 0.41], P = 0.27; and BB vs Bb + bb: WMD = -0.45, 95% CI [-1.71, 0.26], P = 0.22). In addition, we found no remarkable association between the BsmI polymorphism and BMD levels of the femoral neck (FN) in children (BB vs Bb: WMD = -1.08, 95% CI [-3.13, 0.96], P = 0.30; BB vs bb: WMD = 0.98, 95% CI [-0.89, 2.85], P = 0.31; BB vs Bb + bb: WMD = -0.061, 95% CI [-0.30, 0.17], P = 0.61; and bb vs BB + Bb: WMD = 0.82, 95% CI [-0.59, 2.32], P = 0.25). CONCLUSION Our meta-analysis found that the VDR BsmI genetic polymorphism was correlated with LS BMD level in pediatric patients: compared with those with the B allele, children with the bb genotype were less likely to have lower BMD levels. No significant difference was identified in the pediatric FN BMD levels.
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Vitamin D receptor gene and risk of fracture in postmenopausal women: a meta-analysis.
Shen, H, Xie, J, Lu, H
Climacteric : the journal of the International Menopause Society. 2014;(4):319-24
Abstract
OBJECTIVE 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 fracture risk, but evidence remains conflicting. The aim of this study was to evaluate the genetic effect of the BsmI, TaqI, ApaI and FokI polymorphisms in the VDR gene on fracture risk in postmenopausal women. METHODS Relevant studies were identified from the following electronic databases: PubMed, Embase, and Web of Science before September 2013. Statistical analysis was performed by using the software STATA 12.0. A total 1975 fracture cases and 4565 controls in 14 studies with a total of 16 eligible comparisons were identified for data analysis. RESULTS No evidence of relationship between the VDR BsmI, TaqI, ApaI or FokI polymorphisms and fracture risk was observed with any genetic model in postmenopausal women (BsmI: b vs. B: odds ratio (OR) 1.07, 95% confidence interval (CI) 0.90-1.29; TaqI: T vs. t: OR 0.89, 95% CI 0.68-1.15; ApaI: A vs. a: OR 0.91, 95% CI 0.76-1.08; FokI: F vs. f: OR 1.20, 95% CI 0.76-1.90). CONCLUSION This meta-analysis suggests that ApaI, BsmI, TaqI and FokI polymorphisms may be not associated with the risk of fracture in postmenopausal women. Further studies in a larger sample population are required to confirm this finding.