Endocrine Abstracts

Objectives: To study the association of Beta-2 adrenergic receptor (ADRB2) gene polymorphism Arg16Gly with bone mineral density and metabolic parameters of bone remodelling.

Materials and methods: BMD (g/cm²) was measured by DEXA in 105 post-menopausal women: 35 with normal BMD (age=58.30±1.33 years; BMI=28.18 [19.13-39.87] kg/m²) and 70 with osteoporosis (age=68.30±1.09 years; BMI=28.90 [20.78-43.86] kg/m²). Metabolic bone remodelling parameters were analysed: LDL, HDL, total cholesterol, HOMA_IR, insulin, glycaemia, alkaline phosphatase, osteocalcin and parathormone. Arg16Gly polymorphism was evaluated by PCR-RFLP. Statistical analysis by SPSS 21.0. Statistical significance for P<0.05.

Results: We found association between Arg16Gly polymorphism and osteoporosis with an increase of homozygous Gly/Gly in women with osteoporosis (P=0.009). They showed a higher risk for the development of osteoporosis (OR=6.517; CI95% [1.663-25.539]). In osteoporosis, we found increased osteocalcin (P=0.030) and decreased insulin (P=0.023) and total cholesterol (P=0.027). In women with normal BMD, we found an association between genotype carriers of allele Arg (Arg/Arg+Arg/Gly) and decreased total cholesterol (P=0.018). We also found an association between carriers of allele Gly (Arg/Gly+Gly/Gly) and decreased of glycaemia (P=0.010). Within women with normal BMD, we also found inverse correlations between HDL and alkaline phosphatase (P=0.030) and HOMA_IR (P=0.018). In women with osteoporosis, we found direct correlations between glycaemia and osteocalcin (P=0.017) and HDL (P=0.049).

Conclusion: Arg6Gly polymorphism of ADRB2 gene is associated with a higher risk for the development of osteoporosis. This polymorphism also appears to modulate directly or indirectly some metabolic parameters associated with bone remodelling.