The Influence of Clinical Factors and Genetic Variants of COL1A1 and TNFRSF11B on Bone Mineral Density in Postmenopausal Women

Osteoporosis is a chronic metabolic disease characterised by reduced bone mineral density (BMD) and increased susceptibility to fractures. Its development is influenced by both environmental and genetic factors that regulate bone metabolism. Among the genes involved in bone metabolism, <i>COL1A1</i> and <i>TNFRSF11B</i> (OPG) are particularly important. The <i>COL1A1</i> gene encodes the alpha-1 chain of type I collagen, a major component of the bone matrix, and plays a key role in maintaining bone mechanical strength. The <i>TNFRSF11B</i> gene encodes osteoprotegerin (OPG), a protein that inhibits bone resorption by binding the RANKL ligand and blocking osteoclast activation. Therefore, the aim of this study was to determine the association between the rs1107946 and rs1800012 polymorphisms of the <i>COL1A1</i> gene and the rs2073617 polymorphism of the <i>TNFRSF11B</i> (OPG) gene and bone mineral density in postmenopausal women. The study included 590 postmenopausal women: 350 healthy controls, 105 with osteopenia, and 135 with osteoporosis. Genotyping was performed using real-time PCR and LightSNiP probes. Associations between genetic variables and BMD were assessed, taking into account environmental factors (BMI, smoking). The presence of the T allele of the rs1800012 variant was initially associated with lower BMD and an increased risk of osteopenia, but this association lost significance after adjustment for BMI and smoking. For rs1107946 and rs2073617,no statistically significant associations were observed. These findings suggest that the studied SNPs have, at most, modest effects on BMD, with environmental influences playing a stronger role. Further research in larger and more diverse cohorts, including FRAX-based risk estimation, is warranted.