Influence of polymorphisms in VDR and COLIA1 genes on the risk of osteoporotic fractures in aged men.

BACKGROUND: Osteoporosis in chronic renal failure is a common finding caused by several factors, including age. In the last decade, the likely effect of genetic markers related with the appearance and evolution of osteoporosis has been mainly studied in women, with no categorical results. The aim of this study was to assess the influence of polymorphisms of the vitamin D receptor (VDR) and COLIA1 genes on the risk of osteoporotic fractures in men older than 50 years. METHODS: The study population comprised 156 men, aged 64 +/- 9 (50-86), randomly selected from the population list of Oviedo, Spain. Prevalent vertebral fractures and incident non-vertebral fractures were identified, as well as several genetic polymorphisms. Prevalent vertebral fractures were considered according to the Genant grade 2 classifications. The analyzed genetic polymorphisms were located on restriction sites BsmI (B,b), ApaI (A,a), and TaqI (T,t) in the VDR and on Sp1 (S,s) in COLIA1. RESULTS: Although none of the VDR gene polymorphisms separately analyzed showed any differences between fractured and non-fractured men, the utilization of haplotypes could be employed in order to find osteoporotic fractures in men. By contrast, the COLIA1 polymorphism was associated with osteoporotic fractures. The percentage of prevalent vertebral fractures was significantly higher in the "ss" genotype with respect to the other genotypes. These results show that in men, the "ss" genotype of COLIA1 polymorphism could be the best osteoporotic fracture risk genetic predictor, independent of bone mass values.