Association of insulin-like growth factor I gene and vitamin D receptor gene polymorphisms with the risk of osteoporosis in a Chinese population

Objective: Osteoporosis is a systemic metabolic disease. The etiology of osteoporosis is involved in many environmental and genetic factors. We investigated the association of IGF-I (rs35767, rs2288377 and rs5742612) and VDR (rs7975232, rs2228570, rs1544410 and rs11568820) polymorphisms with the risk of osteoporosis. We also assessed the effect of gene-environment interactions in the development of this disease. Methods: A total of 320 patients with osteoporosis and 320 controls were recruited. IGF-I (rs35767, rs2288377 and rs5742612) and VDR (rs7975232, rs2228570, rs1544410 and rs11568820) were amplified and genotyped by the polymerase chain reaction-restriction fragment length polymorphism method. Results: The AA genotype of rs2288377 was associated with an elevated risk of osteoporosis compared to the TT genotype (OR=1.90, 95% CI=1.08-3.39). In dominant model, the TA+AA genotype of rs2288377 had an increased risk of developing osteoporosis in comparison to the TT genotype (OR=1.50, 95% CI=1.08-2.08). In recessive model, the AA genotype of rs2288377 revealed a higher risk of developing osteoporosis than the TA+TT genotype (OR=2.19, 95% CI=1.28-3.79). Moreover, IGF-I rs35767 and rs5742612, and VDR rs7975232, rs2228570, rs1544410 and rs11568820 were not significantly associated with the risk of osteoporosis. Conclusions: Our study suggests a significant association between the IGFI rs2288377 polymorphism and the risk of osteoporosis in the Chinese population