QUADRICEPS AND GRIP STRENGTH ARE RELATED TO VITAMIN-D-RECEPTOR GENOTYPE IN ELDERLY NONOBESE WOMEN

Osteoporotic fragility fractures are related to bone density and injur y, which are both related to muscle strength, The influence of genetic factors, such as the vitamin D receptor (VDR) polymorphism on bone mi neral density (BMD), is documented but still controversial, and is not known for muscle strength, In the present study, we investigated the association between the VDR BsmI polymorphism and BMD (femoral neck FN ], lumbar spine [LS],and proximal forearm [FA]) and muscle strength (q uadriceps and grip strength) in 501 healthy women older than 70 years. No association was found between the VDR genotypes and BMD in elderly women. However, in nonobese women (body mass index <30 kg/cm(2)), the BMD in the FN was 5% higher in women with the bb BsmI genotype than i n women with the BE genotype (p < 0.05), After correction for muscle s trength, no association was found, A significant association between t he VDR genotypes and quadriceps and grip strength was observed. In non obese women, a 23% difference in quadriceps strength (p < 0.01) and 7% in grip strength (NS) was observed between the bb and BE genotype of the VDR, After correction for confounding factors and BMD, this associ ation was significant for quadriceps and grip strength, These results indicate a major association of an allelic valiant at the VDR locus wi th muscle strength in elderly nonobese women, which could explain a sm all association between VDR polymorphism with BMD in the femoral neck in nonobese women, No such associations were found in obese women, sug gesting that factors related to obesity obscure such an association.