Endocrine Abstracts

Introduction: The cytokine tumor necrosis factor alpha (TNFα) is encoded by the TNFα gene and stimulates bone resorption. TNFα is involved in the pathogenesis of bone loss associated with estrogen deficiency. Polymorphisms in the TNFα gene have been associated with bone mineral density (BMD) in different populations.

Objectives: The present study aimed to explore the influence of the single-nucleotide polymorphism −857C/T in the promoter of the TNFα gene on BMD and serum levels of osteoprotegerin (OPG), receptor activator of nuclear factor-κB ligand (RANKL) and bone metabolic markers in a Greek female population.

Methods: 200 and 17 peri- and postmenopausal women aged 42–63 years were enrolled. All participants underwent spinal BMD evaluation by dual-energy X-ray absorptiometry (DXA). Genotyping of the −857C/T polymorphism was performed by PCR. Levels of OPG, soluble RANKL (sRANKL) and bone metabolic markers were measured.

Results: The frequencies of the genotypes of the -857C/T polymorphism were 57.1% for CC 40.1% for CT and 2.8% for TT. Due to the small number of women carrying genotype TT, the study population was divided into two genotype groups: CC and CT/TT. The −857C/T polymorphism was significantly associated with spinal BMD. Women carrying CT/TT genotypes had higher spinal BMD than women with the CC genotype (CT/TT 0.830±0.125 g/cm² vs CC 0.800±0.114 g/cm², P=0.03). The association remained significant after adjustment for age, years since menopause and BMI (P=0.046).

Conclusions: These findings demonstrate that the functional −857C/T polymorphism of the TNFα gene may influence BMD at the lumbar spine in peri- and postmenopausal Greek women.