[Polymorphism of the gene of vitamin D receptor and bone mineral density in postmenopausal women].
BACKGROUND
Conflicting results have been reported on the association between restriction fragment length polymorphism at the vitamin D receptor (VDR) gene locus and bone mineral density (BMD). Population differences in environmental factors, such as calcium intake and calcidiol levels which have strong influence in BMD, may alter this association.


METHODS
We analyzed the Bsml RFLP at the eight introm of the VDR gene in a population sample (n = 204) of postmenopausal Spanish women aged 50-65 years being seen clinically and studied calcium intake (dietetic questionnaire) and biochemical parameters (PTH and calcidiol). In parallel bone densitometry were measured in lumbar spine and proximal femur.


RESULTS
We identified low BMD of the proximal femur in the BB group. This effect was not observed at other body locations. The calcium intake was lees than 500 mg/day in 60% of the studied population as calcidiol levels were lower than 10 ng/l in 36% of it. The total group population with normal calcium intake (> 1,000 mg/day) showed higher BMD (proximal femur and spine) than the group with low calcium intake, this variation not being observed in group BB alleles. Interestingly, we observed significant differences in BMD proximal femur between genotype groups BB versus Bb + bb when calcidiol levels were < 10 ng/l. Moreover, within the BB subgroup, those subjects with normal calcidiol levels have higher proximal femur BMD compared with those with low calcidiol levels.


CONCLUSIONS
Our results indicate an effect of the VDR genotype on BMD proximal femur which is clearly influenced by calcium intake and calcidiol serum levels.
Bernad
M
M
Servicio de Reumatología, Hospital Universitario La Paz, Madrid. emarem@jet.es
Jaramillo
G
G
Aguado
P
P
del Campo
T
T
Coya
J
J
Martín Mola
E
E
Gijón Baños
J
J
Saldaña Barrera
H
H
Martínez
M E
ME
D000368:Aged; D000886:Anthropometry; D015519:Bone Density / Q000235:genetics*; D002112:Calcifediol / Q000097:blood; D005260:Female; D005269:Femur / Q000502:physiology; D005796:Genes / Q000235:genetics; D005838:Genotype; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis; D011110:Polymorphism, Genetic / Q000235:genetics*; D017698:Postmenopause / Q000502:physiology*; D018167:Receptors, Calcitriol / Q000235:genetics*; D013030:Spain; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000235:genetics*
D018167:Receptors, Calcitriol; D014807:Vitamin D; D002112:Calcifediol
Polimorfismo del gen del receptor de la vitamina D y densidad mineral ósea en mujeres posmenopáusicas.