title: Bsm1 vitamin D receptor polymorphism and calcium homeostasis following bariatric surgery.
abstract: OBJECTIVE
  To evaluate the association between the Bsm1 vitamin D receptor polymorphism and the calcium-vitamin D-parathormone axis following bariatric surgery.
  
  
  METHODS
  This cross-sectional study included 86 morbidly obese patients, who underwent either gastric bypass or sleeve gastrectomy, with a mean follow-up of four years. Calcium metabolism indices and bone turnover markers were assessed according to the presence of secondary hyperparathyroidism and the Bsm1 vitamin D receptor genotypes.
  
  
  RESULTS
  Secondary hyperparathyroidism (42.2% of sample) was associated with lower levels of 25hydroxyvitamin D and elevated markers of bone turnover. In subjects without secondary hyperparathyroidism, presence of the unfavorable B allele resulted in higher levels of parathormone (Bb and BB vs. bb genotype: 50.3 ± 8.2 pg/dl vs. 44.4 ± 10.7 pg/dl, p = .011, adjusted for weight loss, baseline body mass index, 25hydroxyvitamin D, surgical procedure, and duration after surgery). In the whole sample, patients bearing the unfavorable B allele exhibited lower weight loss, a parameter that was negatively associated with markers of bone resorption.
  
  
  CONCLUSIONS
  Secondary hyperparathyroidism is highly prevalent after bariatric surgery. Bsm1 vitamin D receptor polymorphism may have an effect in early stages of calcium metabolism imbalance, while no association is detected in patients who have already developed secondary hyperparathyroidism. Moreover, vitamin D receptor polymorphism is associated with post-surgery weight loss, a process related to bone turnover.
authors.affiliation: 11st Department of Surgery, University of Athens, Laiko Athens General Hospital, Athens, Greece.
authors.forename: Andreas
authors.initials: A
authors.lastname: Alexandrou
authors.forename: Eleni
authors.initials: E
authors.lastname: Armeni
authors.forename: George
authors.initials: G
authors.lastname: Kaparos
authors.forename: Demetrios
authors.initials: D
authors.lastname: Rizos
authors.forename: Evangelia
authors.initials: E
authors.lastname: Tsoka
authors.forename: Efthymios
authors.initials: E
authors.lastname: Deligeoroglou
authors.forename: Maria
authors.initials: M
authors.lastname: Creatsa
authors.forename: Areti
authors.initials: A
authors.lastname: Augoulea
authors.forename: Theodoros
authors.initials: T
authors.lastname: Diamantis
authors.forename: Irene
authors.initials: I
authors.lastname: Lambrinoudaki
mesh_terms: D000328:Adult; D000483:Alleles; D000886:Anthropometry; D001862:Bone Resorption / Q000235:genetics*; D002118:Calcium / Q000378:metabolism*; D015986:Confounding Factors, Epidemiologic; D003430:Cross-Sectional Studies; D015252:Deoxyribonucleases, Type II Site-Specific; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy / Q000379:methods; D015390:Gastric Bypass; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006706:Homeostasis; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000209:etiology / Q000235:genetics* / Q000378:metabolism; D008019:Life Style; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery*; D010281:Parathyroid Hormone / Q000097:blood*; D012150:Polymorphism, Restriction Fragment Length; D011178:Postgastrectomy Syndromes / Q000209:etiology / Q000235:genetics* / Q000378:metabolism; D018167:Receptors, Calcitriol / Q000235:genetics*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D015431:Weight Loss
chemical_list: D010281:Parathyroid Hormone; D018167:Receptors, Calcitriol; D014807:Vitamin D; C104450:25-hydroxyvitamin D; C053864:endodeoxyribonuclease BsmI; D015252:Deoxyribonucleases, Type II Site-Specific; D002118:Calcium
keywords: Bsm1 VDR polymorphism; Roux-en-Y Gastric bypass; bariatric surgery; calcium metabolism; parathormone; sleeve gastrectomy