ABSTRACT
Background: Osteoporotic hip fractures are devastating events in older women. There is a genetic modulation of bone phenotypic parameters including bone density (BMD) and bone fragility fractures. Vitamin D receptor (VDR) gene polymorphisms explain a small part of the genetic influence on BMD, whereas their effect on fractures remains uncertain. Aim: To examine the contributions of VDR genotypes to the susceptibility to hip fracture in elderly Chilean women. Patients and methods: We recruited 126 women (67 with fractures and 59 without) from Bio-Bio Region, Chile, aged 65 to 94 years. Genotyping for Bsm-l, Apa-1, Taq-1 and Fok-1 VDR polymorphisms was performed using polymerase chain reaction methods. All hip fractures were confirmed by X-ray. Results: The alíele frequencies were 0.49 for B, 0.57 for A, 0.60 for T and 0.65 for F in the Bsm-l, Apa-1, Taq-1 and Fok-1 polymorphisms respectively. The prevalence of these VDR gene polymorphisms in women with fractures were 16 percent BB, 69 percent Bb, 15 percent bb for Bsm-l; 30 percent AA, 46 percent Aa, 14 percent aa for Apa-1; 17 percent TT, 34 Tt, 8 percent tt for Taq-1 and 43 percentFF, 41 percent Ff, 16 percent ff for Fok-1. All VDR genotype frequencies did not differ from Hardy- Weinberg expectations. Alíele or genotype frequencies did not differ between women with or without fractures. These results did not change when analysis was adjusted by age weight, height or gynecologic history. Conclusions: The genotype frequencies of the VDR polymorphisms are in accordance with the frequencies of other Hispanic and Caucasian populations. Our results suggest that VDR polymorphisms are not associated with the risk of hip fracture in older women of this Region of Southern Chile.
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Genetic Predisposition to Disease/genetics , Hip Fractures/genetics , Osteoporosis, Postmenopausal/genetics , Polymorphism, Genetic , Receptors, Calcitriol/genetics , Bone Density/genetics , Case-Control Studies , Chile , Gene Frequency/genetics , Genotype , Polymerase Chain Reaction , Risk FactorsABSTRACT
BACKGROUND: We aimed to discuss the risk assessments for both patients with hip fractures due to fall-related, low energy traumas and non-fractured control patients by examining bone mineral density and genetic data, two features associated with femoral strength and hip fracture risk. METHODS: Twenty-one osteoporotic patients with proximal femur fractures and non-fractured, osteoporotic, age- and gender-matched controls were included in the study. Bone mineral density measurements were performed with a Lunar DXA. The COL1A1, ESR, VDR, IL-6, and OPG genes were amplified, and labeling of specific gene sequences was performed in a multiplex polymerase chain reaction using the osteo/check PCR kit from the whole blood of all subjects. RESULTS: The bone mineral density (trochanteric and total bone mineral density values) of the fracture group was significantly decreased relative to the control group. We were not able to conduct statistical tests for the polymorphisms of the COL1A1, ESR, and VDR genes because our results were expressed in terms of frequency. Although they were not significant, we did examine differences in the IL-6 and OPG genes polymorphisms between the two groups. We concluded that increasing the number of cases will allow us to evaluate racial differences in femoral hip fracture risk by genotypes.