Objective: Osteoporosis is a common disorder with a strong genetic component. We investigated the correlations between bone mineral density (BMD) and four gene polymorphisms (-308G>A tumor necrosis factor alpha (TNF-alpha), -34T>C CYP 17, *141T>C urokinase, and -627C>A interleukin 10 (IL-10) promoter), and their relationship to osteoporosis in postmenopausal women.
Study design: These polymorphisms were determined using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analysis. BMD of the lumbar spine and proximal femur were measured using dual-energy X-ray absorptiometry.
Results: The prevalence of each genotype was as follows: (1) 79.3% A/A, 16.6% A/G, and 4.1% G/G in -308G>A TNF-alpha; (2) 18.9% T/T, 52.1% T/C, and 29% C/C in -34T>C CYP 17; (3) 86.4% C/C and 13.6% C/T in *141T>C urokinase; (4) 46.2% A/A, 45% A/C, and 8.8% C/C in -627C>A IL-10 promoter. Subjects with genotype C/C in -627C>A IL-10 promoter had lower BMD values and a significantly greater risk for osteoporosis (OR 8.1, 95% CI 1.5-42.8) at the lumbar spine compared with subjects with genotype A/C in -627C>A IL-10 promoter, after adjustment for potential confounders.
Conclusion: The RsaI IL-10 promoter gene polymorphism is associated with reduced BMD and predisposes women to osteoporosis at the lumbar spine.