title: The effect of vitamin D receptor BsmI genotype on the response to osteoporosis treatment in postmenopausal women: a pilot study.
abstract: OBJECTIVE
  The purpose of our study was to investigate the possible effect of BsmI vitamin D receptor (VDR's) polymorphism on changes in bone mineral density (BMD) and bone turnover markers in postmenopausal women receiving different treatments.
  
  
  METHODS
  This pilot study included 42 postmenopausal women with elevated fracture risk, randomized into 1-year treatment with weekly oral alendronate or daily subcutaneous teriparatide. Both groups received daily supplements of 1000 mg calcium and 800 IU vitamin D. Blood samples were obtained for biochemical evaluation and genotyping. BMD at the lumbar spine and femoral neck were assessed with dual energy X-ray absorptiometry. Baseline, follow-up BMD and markers of bone turnover were assessed according to the BsmI genotype.
  
  
  RESULTS
  BMD at the lumbar spine increased in patients carrying at least one b allele, while it decreased in patients with the BB genotype (P = 0.041). Whereas no gene-treatment interaction was observed in teriparatide-receiving patients, women with the BB genotype receiving alendronate resulted in negative BMD (-0.056 ± 0.032 g/m(2) ) and T-score (-0.295 ± 0.190) gradient, compared to carriers of the b allele (BMD: +0.020 ± 0.017 g/m(2) , P = 0.054; T-score: +0.217 ± 0.100, P = 0.030). No effect of genotype was apparent with respect to gradients of biochemical bone markers.
  
  
  CONCLUSIONS
  These preliminary results indicate that alendronate has a differential effect on BMD, depending on the VDR genotype. Carriers of the b allele may be more responsive to treatment compared to patients with the BB genotype. The interaction of VDR's BsmI polymorphism with the efficacy of the anti-osteoporotic treatment needs further investigation by larger prospective studies.
authors.affiliation: 2nd Department of Obstetrics and Gynecology, University of Athens, Aretaieion Hospital, Athens, Greece.
authors.forename: Maria
authors.initials: M
authors.lastname: Creatsa
authors.forename: Paraskevi
authors.initials: P
authors.lastname: Pliatsika
authors.forename: George
authors.initials: G
authors.lastname: Kaparos
authors.forename: Aristidis
authors.initials: A
authors.lastname: Antoniou
authors.forename: Eleni
authors.initials: E
authors.lastname: Armeni
authors.forename: Efstratios
authors.initials: E
authors.lastname: Tsakonas
authors.forename: Costantinos
authors.initials: C
authors.lastname: Panoulis
authors.forename: Andreas
authors.initials: A
authors.lastname: Alexandrou
authors.forename: Evangelia
authors.initials: E
authors.lastname: Dimitraki
authors.forename: George
authors.initials: G
authors.lastname: Christodoulakos
authors.forename: Irene
authors.initials: I
authors.lastname: Lambrinoudaki
mesh_terms: D000368:Aged; D019386:Alendronate / Q000494:pharmacology / Q000627:therapeutic use*; D015519:Bone Density / Q000187:drug effects* / Q000235:genetics; D050071:Bone Density Conservation Agents / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000187:drug effects; D005838:Genotype; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000187:drug effects; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000235:genetics*; D010865:Pilot Projects; D020641:Polymorphism, Single Nucleotide; D011446:Prospective Studies; D011859:Radiography; D018167:Receptors, Calcitriol / Q000235:genetics*; D019379:Teriparatide / Q000494:pharmacology / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D050071:Bone Density Conservation Agents; D018167:Receptors, Calcitriol; D019379:Teriparatide; D019386:Alendronate