The genetic association between osteoprotegerin gene polymorphisms and fracture risk in Chinese Han population

Associations of osteoprotegerin (OPG) TNFRSF11B gene polymorphisms with risk of fractures in older adult populations: meta-analysis of genetic and genome-wide association studies

The meta-analysis of osteoprotegerin (OPG) (TNFRSF11B) polymorphisms from genetic association studies and genome-wide association studies was performed in order to test the hypothesis of association between OPG polymorphisms and fracture. The findings showed a significant 13% to 37% protective effect of OPG on fractures in postmenopausal women (PSM) (rs2073618), overall, ≥ 60y and Western subjects (rs3134069 and rs3134070).

PURPOSE

Fractures in older people usually result from compromised bone integrity. The multifactorial aetiology of fractures includes both genetic and environmental factors. Inconsistency of reported associations of osteoprotegerin (OPG) (TNFRSF11B) polymorphisms with fracture in the older adult population warranted a meta-analysis to determine more precise estimates.

METHODS

We searched for all available literature on OPG (TNFRSF11B) and fracture. Four polymorphisms were examined, one exonic (rs2073618) and three intronic (rs3134069, rs3134070 and rs3102735). The first two intron polymorphisms were combined (OPGI: osteoprotegerin intron) on account of complete linkage disequilibrium. Risks were estimated with odds ratios (ORs) and 95% confidence intervals (CIs) using the allele-genotype model that included variant (var), wild-type (wt) and heterozygote (het). Multiple comparisons were Bonferroni-corrected. We used meta-regression to examine sources of heterogeneity. Zero heterogeneity (homogeneity: I² = 0%) and high significance (P^a < 0.00001) were the criteria for strength of evidence. Significant outcomes were subjected to sensitivity analysis and publication bias assessment.

RESULTS

From 13 articles (11 genetic association and two genome-wide), this meta-analysis generated five significant pooled ORs, all indicating reduced risks (ORs 0.44-0.87). Of the five, four highly significant comparisons (P^a ≤ 0.00001-0.002) survived the Bonferroni correction, one in rs2073618 het model of the postmenopausal women (OR 0.87, 95% CI 0.81-0.92, I² = 0%) and the other three in OPGI wt model of the overall analysis, ≥ 60 y and Western subjects (ORs 0.63-0.71, 95% CI 0.47-0.86, I² = 97-99%). These findings were consistent, had high significance and high statistical power and were robust and without evidence of publication bias. Four covariates (year of publication, study quality, fracture type/site and sample size) were the sources of heterogeneity in the OPGI overall outcomes (P^a = 0.0001-0.03).

CONCLUSION

Evidence showed that the OPG (TNFRSF11B) polymorphisms reduced the risk for fracture in older adults, particularly protective among postmenopausal women, ≥ 60 y and Western subjects.

Common Variants of the OPG gene Are Associated with Osteoporosis Risk: A Meta-Analysis

Background: The RANKL/RANK/OPG signaling pathway plays a critical role in osteoclastogenesis and bone remodeling. The associations between sequence variants of the osteoprotegerin (OPG) gene and osteoporosis risk have been widely investigated but remain inconclusive. Objective: We performed a meta-analysis to evaluate the associations between OPG gene variants and osteoporosis risk. Methods: We searched electronic databases and included studies meeting inclusion criteria. The genetic associations of four common OPG variants, A163G, T245G, T950C, and G1181C, with osteoporosis risk were explored. Pooled odds ratios (OR) and 95% confidence intervals (95% CI) were calculated for multiple genetic models. Subgroup analyses including ethnicity, gender, menopausal status, sample size, and control source were also performed. Results: Twenty-six studies comprising 4879 osteoporosis cases and 5708 controls were included. The A163G variant was found to be significantly associated with an increased risk of osteoporosis under both the allelic (G vs. A: OR = 1.45, 95% CI 1.29-1.64, p < 0.001) and dominant models (GG+GA vs. AA: OR = 1.48, 95% CI 1.29-1.70, p < 0.001). Significant associations were also found between the T245G variant and osteoporosis risk. In addition, we observed a reduced risk of osteoporosis in women with the CC genotype at T950C (OR = 0.76, 95% CI 0.64-0.89, p = 0.001) and among Caucasians with the GG or CG genotypes at the G1181C locus (OR = 0.78, 95% CI 0.64-0.94, p = 0.010). In postmenopausal women, only the GG/GA genotypes at the A163G variant were more predisposed to osteoporosis (OR = 1.31, 95% CI 1.00-1.71), whereas CC/CG carriers of G1181C locus may have reduced risk (OR = 0.83, 95% CI 0.66-1.03). Conclusions: Common variants of the OPG gene are associated with osteoporosis risk, especially in the Caucasian population and in the female subgroup. These genetic markers could potentially be used as predictive markers for osteoporosis.

The association of OPG polymorphisms with risk of osteoporotic fractures: A systematic review and meta-analysis

BACKGROUND

Subjects with low bone mineral density and osteoporosis are more likely to suffer osteoporotic fractures during their lifetime. Polymorphisms in osteoprotegerin (OPG) gene are found to be associated with low bone mineral density and osteoporosis risk but their association with fracture risk is inconclusive. Here, we performed a meta-analysis to investigate the relationship between OPG polymorphisms with susceptibility to osteoporotic fractures.

METHODS

Eligible studies investigating the association between common OPG polymorphisms (A164G, T245G, T950C, and G1181C) and risk of osteoporotic fracture were retrieved from PubMed, EMBASE, Web of Science, and the Cochrane Library. Odds ratio (OR) and the 95% confidence interval (CI) were calculated in the allelic, dominant, recessive, and homozygous model. Subgroup analyses of vertebral fractures, Caucasians, and postmenopausal women were also performed.

RESULTS

A total of 14 studies comprising 5459 fracture cases and 9860 non-fracture controls were included. A163G was associated with fracture risk in dominant (OR = 1.29, 95%CI 1.11-1.50), recessive (OR = 1.64, 95%CI 1.10-2.44), and homozygous model (OR = 1.73, 95%CI 1.16-2.59). T245G was significantly correlated with susceptibility to fractures in all genetic models. Subjects with CC genotype of T950C had a reduced risk of fracture compared to those with CT or TT genotypes (OR = 0.81, 95%CI 0.70-0.94, P = .004). Subgroup analysis showed that A163G and T245G but not T950C and G1181C were associated with vertebral fracture risk.

CONCLUSION

OPG A163G and T245G polymorphisms were risk factors of osteoporotic fractures while T950C had a protective role. These polymorphisms can be used as predictive markers of fractures.