Lack of Association Between Estrogen Receptor Genotypes and Bone Mineral Density, Fracture History, or Muscle Strength in Elderly Women

Abstract

The PvuII polymorphism of the estrogen receptor (ESR) gene and its relation to bone mineral density (BMD), fracture history, and muscle strength was studied in 313 postmenopausal (76 +/- 5 years) women of Caucasian origin, of whom 142 had suffered from a fragility fracture after the age of 50 years (14 with fracture of the hip, 38 of the spine, 45 of the wrist, and 85 of other bones). The ESR genotype distribution was similar in women with and without a history of fragility fracture (PP 21%, Pp 43%, pp 36% compared with PP 18%, Pp 47%, pp 35%). We did not find a correlation between the ESR genotypes and BMD at the lumbar spine, the femoral neck, or the proximal forearm. No association was found with grip or quadriceps strength. We further evaluated the relationship between the vitamin D receptor (VDR) and ESR haplotypes and BMD in a random subgroup of 270 elderly women. No differences were found in women with the BBpp versus the bbPP haplotype in the femoral neck (mean difference +/- SD, in Bbpp compared with bbPP groups: -0.05 +/- 0.15 g/cm2), the spine (0.01 +/- 0.13 g/cm2), or the forearm (0.04 +/- 0.08 g/cm2). The significant association of quadriceps strength with VDR genotypes (25% lower in BB compared with bb genotype, p < 0.05) was not influenced by ESR haplotypes. We conclude that in elderly Caucasian women the PvuII ESR polymorphism is not associated with osteoporosis, fracture history, nor muscle strength and does not influence the association of bone density and muscle strength with polymorphism of the VDR.