Bone mineral density and fractures in postmenopausal women of Maya-Mestizo ethnic origin with different body mass indexes.

BACKGROUND: Obesity protects against bone loss, but it increases the risk of fragility fractures. AIM: To determine if bone mineral density (BMD) and the prevalence of fractures are different in postmenopausal Maya-Mestizo women grouped according to their body mass index (BMI). SUBJECTS AND METHODS: We studied 600 postmenopausal Maya-Mestizo women. A structured questionnaire for risk factors was applied. Body mass index was determined. BMD was assessed at the lumbar spine and total hip by dual-energy X-ray absorptiometry. History of low trauma fracture was determined from medical records. ANOVA was used to compare mean BMD between women with different BMI. To compare the frequency of fractures according to BMI group, we used χ2 test. RESULTS: According to WHO classification of BMI, 16.3% of women had normal BMI, 35.3% were overweight, and 48.4% had obesity. We found that women with obesity had a higher BMD versus women with normal BMI or overweight in all the anatomical sites analysed. The prevalence of history of fractures was 18.2%. We did not find differences between the women of different BMI; the wrist was the most frequent skeletal site of the fracture. CONCLUSION: Obesity in postmenopausal Maya-Mestizo women is not a risk factor for developing fragility fractures.

VDR polymorphisms are associated with bone mineral density in post-menopausal Mayan-Mestizo women.

BACKGROUND: Osteoporosis is characterized by low bone mineral density (BMD), which is determined by an interaction of genetic, metabolic and environmental factors. AIM: To analyse the association between two polymorphisms of VDR as well as their haplotypes with BMD in post-menopausal Maya-Mestizo women. SUBJECTS AND METHODS: This study comprised 600 post-menopausal Maya-Mestizo women. A structured questionnaire for risk factors was applied and BMD was assessed at the lumbar spine (LS) and total hip (TH) by dual-energy X-ray absorptiometry. DNA was extracted from blood leukocytes. Two single-nucleotide polymorphisms of VDR (rs731236 and rs2228570) were studied using real-time PCR allelic discrimination for genotyping. Differences between the means of the BMDs according to the genotype were analysed with covariance. Haplotype analysis was conducted. RESULTS: TT genotype of rs731236 of VDR had higher BMD at total hip and femoral neck (FN), and one haplotype formed by the two polymorphisms was associated with only TH-BMD variations. This difference was statistically significant after adjustment for confounders. The genotype of rs2228570 of VDR analysis showed no significant differences with BMD variations. CONCLUSION: The results showed that the TT genotype of rs731236 of VDR and one haplotype formed by rs731236 and rs2228570 polymorphisms were associated with higher BMD at TH and FN.