title: Association of vitamin D and estrogen receptor gene polymorphism with the effects of longterm hormone replacement therapy on bone mineral density.
abstract: We longitudinally studied whether vitamin D receptor (VDR) and estrogen receptor (ER) gene polymorphisms in Japanese women influenced the effect of longterm hormone replacement therapy (HRT) on bone mineral density (BMD) in the lumbar spine. The 81 subjects were aged 40 to 64 years (mean +/- SEM, 49.5 +/- 0.6 years), and had received sequential or continuous HRT regimens, including 0.625 mg of conjugated equine estrogen and 2.5 to 5 mg of medroxy-progesterone acetate, for at least 3 years. Genomic DNA was extracted from blood cells, and analyzed for restriction fragment length polymorphism, using the restriction endonucleases Taq I, Apa I, and Fok I for VDR, and Pvu II and Xba I for ER. At 1 year, subjects with a Taq I genotype of TT (i.e., site absent) showed a significantly greater increase in BMD with treatment (DeltaBMD) than subjects with the Tt genotype (2.6 +/- 0.5% vs -0.8 +/- 1.4%; P = 0.016). A small difference between genotypes remained at 2 years (3.8 +/- 0.6% vs 0.8 +/- 1.6%; P = 0.069), but no significant difference between genotypes was seen at 3 years. In multiple regression analyses, DeltaBMD at 1 year was significantly affected by VDR- Taq I, Apa I, and ER- Pvu II genotypes and by age at treatment initiation, although at 3 years or more, DeltaBMD was significantly affected only by age. These results indicate that Taq I VDR gene polymorphism predicted the effect on lumbar BMD for the first year of HRT in Japanese women, and that the differences in BMD versus the polymorphism disappeared if the treatment was continued for over 2 years.
authors.affiliation: Department of Obstetrics and Gynecology, Niigata University School of Medicine, 1-757 Asahimachi-dori, Niigata 951-8510, Japan. takumi@med.niigata-u.ac.jp
authors.forename: Takumi
authors.initials: T
authors.lastname: Kurabayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsushita
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Tomita
authors.forename: Nozomi
authors.initials: N
authors.lastname: Kato
authors.forename: Mariko
authors.initials: M
authors.lastname: Kikuchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nagata
authors.forename: Akira
authors.initials: A
authors.lastname: Honda
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Yahata
authors.forename: Kenichi
authors.initials: K
authors.lastname: Tanaka
mesh_terms: D015519:Bone Density / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D015914:Estrogen Replacement Therapy; D005260:Female; D005838:Genotype; D006801:Humans; D007564:Japan; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000187:drug effects / Q000502:physiology; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D018167:Receptors, Calcitriol / Q000235:genetics*; D011960:Receptors, Estrogen / Q000235:genetics*; D013997:Time Factors
chemical_list: D018167:Receptors, Calcitriol; D011960:Receptors, Estrogen