title: [Bone mass loss after sleeve gastrectomy: a prospective comparative study with gastric bypass].
abstract: BACKGROUND
  Bariatric surgery is the most effective option for the treatment of patients with a high risk of complications due to their obesity. However, it brings about a series of changes in calcium and vitamin D metabolism and an increase in resorption which lead to a loss of bone mass.
  
  
  OBJECTIVE
  The objective of this study is to compare sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) as regards loss of bone mass using bone densitometry and bone remodelling markers.
  
  
  METHODS
  Fifteen women with morbid obesity were included, 8 by SG and 7 by RYGB, with a mean age of 47.8+/-9 and mean body mass index 43.3+/-3.4. Bone mass measurements were made on the lumbar spine, femur and distal radius, and the bone remodelling markers N-telopeptide (NTx) and bone alkaline phosphatase (BALP), as well as vitamin D levels before and 12 months after surgery.
  
  
  RESULTS
  A significant bone mass loss was observed was observed with SG and RYGB, in the lumbar spine and hip, whilst no differences were observed in the radial. The percentage bone mass loss was less in the column and femur after SG than with RYGB, although it did not reach statistical significance, 4.6%+/-4.4 (mean+/-SD) and 6.3%+/-5.4 (mean+/-SD), respectively. At 12 months the Ntx increased for both types of surgery, and the BAP was only increased for SG.
  
  
  CONCLUSIONS
  SG causes less, although not significant, bone mass loss compared to RYGB.
authors.affiliation: Universitat Autónoma de Barcelona, Hospital del Mar, Barcelona, España.
authors.forename: Xavier
authors.initials: X
authors.lastname: Nogués
authors.forename: Albert
authors.initials: A
authors.lastname: Goday
authors.forename: Maria Jesus
authors.initials: MJ
authors.lastname: Peña
authors.forename: David
authors.initials: D
authors.lastname: Benaiges
authors.forename: Marta
authors.initials: M
authors.lastname: de Ramón
authors.forename: Xenia
authors.initials: X
authors.lastname: Crous
authors.forename: Manuel
authors.initials: M
authors.lastname: Vial
authors.forename: Manuel
authors.initials: M
authors.lastname: Pera
authors.forename: Luis
authors.initials: L
authors.lastname: Grande
authors.forename: Adolfo
authors.initials: A
authors.lastname: Díez-Pérez
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: Ramón
mesh_terms: D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000209:etiology*; D005260:Female; D005743:Gastrectomy / Q000009:adverse effects* / Q000379:methods*; D015390:Gastric Bypass / Q000009:adverse effects*; D006801:Humans; D008875:Middle Aged; D009767:Obesity, Morbid / Q000601:surgery*; D010865:Pilot Projects; D011446:Prospective Studies