Significant Associations Between the A163G and G1181C Polymorphisms of the Osteoprotegerin Gene and Risk of Osteoporosis, Especially in Postmenopausal Women: A Meta-Analysis

Abstract

Whereas some studies have reported that the osteoprotegerin (OPG) gene is associated with osteoporosis risk in some studies, their results have proved inconclusive. We performed a meta-analysis of studies on the associations between OPG A163G and G1181C polymorphisms and the risk of osteoporosis. A literature search in PubMed, Embase, Web of Science, Cochrane Library, and China Biological Medicine (CBM) databases was conducted to identify all eligible case-control studies published before August 15th, 2013. Pooled odds ratios with their corresponding 95% confidence intervals were used to evaluate the strength of the association under either a fixed- or random-effect model according to the heterogeneity test. Ten case-control studies were included with a total of 1673 osteoporosis cases and 1554 healthy controls in this meta-analysis. For the OPG A163G polymorphism, the combined results showed that the G allele of the A163G polymorphism may be associated with an increased risk of osteoporosis. Stratified analyses showed that the magnitude of the effect was similar among the Caucasian and postmenopausal women subgroups. Unlike the A163G polymorphism, the meta-analysis results revealed that the C allele of the G1181C polymorphism may be associated with a decreased risk of osteoporosis, especially in the Asian and postmenopausal women subgroups. No publication bias was detected for either polymorphism. Our findings showed that the G allele of the OPG A163G polymorphism may increase osteoporosis risk, whereas the C allele of the G1181C polymorphism may protect individuals from osteoporosis. Both of these effects were observed in postmenopausal women.