Is there any relation between IL-6 gene -174 G>C polymorphism and postmenopausal osteoporosis?

Objective: IL-6 gene single nucleotide polymorphisms (SNPs) have been reported to have a protective effect against bone resorption. We aimed to investigate the association between bone mineral density and IL-6 promoter region -174 G>C SNP.

Study design: This study included 356 postmenopausal Turkish women, of whom 201 were osteoporotic (lumbar spine T score<-2.5 SD) and 155 non-osteoporotic (lumbar spine T score>-1.5 SD). Bone mineral density (BMD) measures were obtained using dual-energy X-ray absorptiometry. SNP of the IL-6 gene (-174 G>C) was examined by polymerase chain reaction-restriction fragment length polymorphism.

Results: The frequencies of the variant C allele (24% vs. 30%, p=0.074) and mutant CC genotype (12% vs. 20%, p=0.094) were higher in non-osteoporotic women. Lumbar spine and total hip BMD values were lowest among women with the G/G genotype, intermediate in the heterozygotes, and highest in women with the C/C genotype. The GG (p=0.022) and GC (p=0.037) genotypes were covariates which approached statistical significance in the regression model fitting of BMD.

Conclusion: IL-6 promoter region SNP showed an association with BMD in this postmenopausal Turkish population and these data suggest that the wild GG genotype influences the phenotype.