title: Quantitative assessment of the associations between MTHFR C677T and A1298C polymorphisms and risk of fractures: a meta-analysis.
abstract: Many studies have investigated the associations between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and risk of fractures, but the impact of MTHFR polymorphisms on fractures risk is unclear owing to the obvious inconsistence among those studies. This study aims to quantify the strength of association between MTHFR C677T and A1298C polymorphisms and risk of fractures. We searched the PubMed, Embase and Wanfang databases for articles relating the association between MTHFR C677T and A1298C polymorphisms and risk of fractures in humans. We estimated summary odds ratios (ORs) with their confidence intervals (CIs) to assess the associations. Meta-analyses suggested MTHFR C677T polymorphism was associated with increased risk of any site fractures (for T vs. C, OR = 1.17, 95 % CI 1.03-1.32; for TT vs. CC, OR = 1. 31, 95 % CI 1.11-1.54; for TT vs. CT, OR = 1.22, 95 % CI 1.04-1.43; for TT vs. CT/CC, OR = 1.31, 95 % CI 1.13-1.51). Besides, MTHFR A1298C polymorphism was also associated with increased risk of any site fractures. Subgroup meta-analyses suggested MTHFR C677T polymorphism was associated with increased risk of vertebral fractures under three genetic contrast modes (for TT vs. CC, OR = 1.43, 95 % CI 1.05-1.95; for TT vs. CT, OR = 1.36, 95 % CI 1.01-1.85; for TT vs. CT/CC, OR = 1.50, 95 % CI 1.17-1.91), but there was no association between MTHFR C677T polymorphism and risk of hip fractures and non-vertebral fractures (all P values were more than 0.05). Thus, individuals with homozygote genotype TT of MTHFR C677T have obviously increased risk of vertebral fractures compared those with heterozygote genotype CT or homozygote genotype CC. There is no association between MTHFR C677T polymorphism and risk of hip fractures and non-vertebral fractures.
authors.affiliation: Department of Pediatric Orthopaedics, The Second Affiliated Hospital of Inner Mongolia Medical University, Hohhot, 010055, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Bai
authors.forename: Wanlin
authors.initials: W
authors.lastname: Liu
authors.forename: Aiqing
authors.initials: A
authors.lastname: Zhao
authors.forename: Zhenqun
authors.initials: Z
authors.lastname: Zhao
authors.forename: Dianming
authors.initials: D
authors.lastname: Jiang
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D016022:Case-Control Studies; D050723:Fractures, Bone / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006620:Hip Fractures / Q000235:genetics; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D017594:Publication Bias; D012306:Risk; D013124:Spinal Injuries / Q000235:genetics
chemical_list: D042965:Methylenetetrahydrofolate Reductase (NADPH2)