Geographic Differences in Bone Mineral Density of Mexican Women

Abstract

The aim of this study was to generate standard curves for normal spinal and femoral neck bone mineral density (BMD) in Mexican women using dual-energy X-ray absorptiometry (DXA), to analyze geographic differences and to compare these with 'Hispanic' reference data to determine its applicability. This was a cross-sectional study of 4460 urban, clinically normal, Mexican women, aged 20-90 years, from 10 different cities in Mexico (5 in the north, 4 in the center and 1 in the southeast) with densitometry centers. Women with suspected medical conditions or who had used drugs affecting bone metabolism, were excluded. Lumbar spine BMD was significantly higher (1.089 +/- 0.18 g/cm2) in women from the northern part of Mexico, with intermediate values in the center (1.065 +/- 0.17 g/cm2) and lower values (1.013 +/- 0.19 g/cm2) in the southeast (p < 0.0001). Similarly, femoral neck BMD was significantly higher in women from the north (0.895 +/- 0.14 g/cm2), intermediate in the center (0.864 +/- 0.14 g/cm2) and lower (0.844 +/- 0.14 g/cm ) in the southeast part of Mexico (p < 0.0001). Northern Mexican women tend to be taller and heavier than women from the center and, even more, than those from the southeast of Mexico (p < 0.0001). However, these differences in BMD remained significant after adjustment for weight (p < 0.0001). A significant loss (p < 0.0001) in BMD was observed from 40 to 69 years of age at the lumbar spine and up to the eighth decade at the femoral neck. Higher and lower lumbar spine values, as compared with the 'Hispanic' population, were observed in Mexican mestizo women from the northern and southeastern regions, respectively. In conclusion, there are geographic differences in weight and height of Mexican women, and in BMD despite adjustment for weight.