Polymorphisms in neuropeptide genes and bone mineral density in Korean postmenopausal women

Abstract

Objective: The purpose of this study was to investigate the association between single nucleotide polymorphisms in neuropeptide genes and bone mineral density (BMD) in Korean postmenopausal women. Methods: Twenty polymorphisms in NMU (neuromedin U; two polymorphisms), NMU2R (NMU receptor 2; six polymorphisms), CART (cocaine-and amphetamine-regulated transcript; three polymorphisms), NPY (neuropeptide Y; four polymorphisms), NPY2R (NPY type 2 receptor; two polymorphisms), NOS1 (neuronal nitric oxide synthase; two polymorphisms), and MC4R (melanocortin 4 receptor; one polymorphism) genes were analyzed in 482 Korean postmenopausal women. BMD at the lumbar spine and femoral neck was also examined. Effects of polymorphisms on BMD were evaluated after adjusting for potential confounding factors using analysis of covariance. Odds ratios and 95% CIs for osteoporosis were estimated using chi(2) test or Fisher's exact test. Results: Among the polymorphisms measured, the AG genotype of CART rs2239670 had the highest BMD at the lumbar spine. Furthermore, osteoporosis at the lumbar spine was more frequently observed in the GG genotype of NPY rs17149106 polymorphism and in the CC genotype of NPY rs16123 polymorphism and was less frequently observed in the TT-TT genotype identified by a combined polymorphism in the NPY2R gene, compared with the other genotypes. The AA genotype of NOS1 rs1279104 polymorphism was found to have a 3.68-fold higher prevalence of osteoporosis at the femoral neck compared with the GG genotype (95% CI, 1.29-10.50; P = 0.02). Conclusions: Results suggest that CART rs2239670 polymorphism may be one of the genetic factors affecting lumbar spine BMD in Korean postmenopausal women and that NPY rs17149106, NPY rs16123, NOS1 rs1279104, and combined (rs2880415 and rs6857715) polymorphisms in the NPY2R gene may be useful in identifying women at risk for osteoporosis.