Association between seven common OPG genetic polymorphisms and osteoporosis risk: a meta-analysis

Functional polymorphisms of the osteoprotegerin (OPG) gene are known to be involved in bone mineral density and the development of osteoporosis; however, some conflicting results have been reported. The aim of this meta-analysis is to provide a relatively comprehensive assessment of the relationship between seven common OPG genetic polymorphisms (T149C, A163G, G209A, T245G, T950C, G1181C, and C1217T) and osteoporosis risk. A literature search for eligible studies published before August 1st, 2013 was conducted in PubMed, Embase, Web of Science, Cochrane Library, and CNKI (China National Knowledge Infrastructure) databases. Pooled odds ratios and their corresponding 95% confidence intervals were used to evaluate the strength of the association under fixed- or random-effect models according to a heterogeneity test. All analyses were performed using the STATA software, version 12.0. Fourteen case-control studies with a total of 2383 osteoporosis cases and 2280 healthy controls were included in this meta-analysis. Among the seven polymorphisms, A163G and G1181C revealed significant associations with osteoporosis risk. For A163G (rs3102735), 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 in Caucasian and postmenopausal woman subgroups. For G1181C (rs2073618), however, we found that individuals with the C allele of the G1181C polymorphism had a decreased risk of osteoporosis, especially in Asian and postmenopausal woman subgroups. In summary, this meta-analysis indicated that the G allele of the OPG A163G polymorphism might increase osteoporosis risk in Caucasians, whereas individuals with the C allele of the G1181C polymorphism had a decreased risk of osteoporosis, especially in Asians. Both of these effects were observed in postmenopausal women. These polymorphisms could probably be used with other genetic markers together to identify individuals at a high risk of osteoporosis.