The RANKL/RANK/OPG signal trail: significance of genetic polymorphisms in the etiology of postmenopausal osteoporosis

Objectives: Recent studies have demonstrated that disorders of bone metabolism, which is regulated by RANK/RANKL/OPG signaling pathway, are the cause of osteoporosis. The aim of the study was to investigate the distribution of genotypes of the RANK 575C>T and RANKL -643C>T polymorphisms and to analyze their relationship with bone parameters in postmenopausal women. Material and methods: A total of 310 postmenopausal Caucasian women ( 139 with osteoporosis, 107 with osteopenia, and 64 healthy postmenopausal controls) were included. Bone mineral density (BMD) at the lumbar region of the spine (L2-L4) was measured by dual energy X-ray absorptiometry (DXA). Genetic analysis was performed using the PCR-RFLP method. Results: Analysis of the frequency of genotypes and alleles of the RANK 575C>T and RANKL -643C>T polymorphisms did not show any statistically significant differences between the study groups ( osteoporosis and osteopenia) and postmenopausal women with normal t-score value (ns). Notably, a significant association between the RANKL -643C>T polymorphism and body mass, such as BMI values in osteoporotic women (p<0.05), was observed. Conclusions: Our results suggest lack of association between the 575C>T RANK polymorphism and the development of osteoporosis. The -643C>T RANKL polymorphism, through its significant influence on body weight and BMI value, may contribute to the development of osteoporosis in postmenopausal women.