Influence of polymorphisms in insulin-like growth factor-1 on the risk of osteoporosis in a Chinese postmenopausal female population

We conducted a case-control study in a Chinese postmenopausal population, and explore the potential role of the promoter region variation of the IGF-1 gene in bone mineral density and osteoporosis risk. 485 postmenopausal women with a primary diagnosis of osteoporosis and 485 age-matched controls were selected between 2012 and 2014. The Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) was used for rs35767, rs2288377 and rs5742612 of IGF-1 genotyping. By conditional regression analysis, individuals carrying TT genotype and CT+TT genotype of rs35767 were found to be correlated with an elevated risk of osteoporosis, with adjusted ORs (95% CI) of 1.90 (1.23-2.93) and 1.35 (1.04-1.76), respectively. Our study found that CT+TT genotype of rs35767 was significantly associated with moderate increased risk of osteoporosis in smokers and drinkers, and the ORs (95% CI) were 2.11 (1.06-4.20) and 2.36 (1.29-4.32), respectively. We found that those carrying CT+TT genotype of rs35767 had a significant lower BMD levels at L1-L4 vertebrae, femoral neck, total hip and trochanter compared to those with CC genotype. Our study suggests that TT genotype and CT+TT genotype of IGF-I rs35767 were associated with risk of osteoporosis and BMD levels.