title: Bone structural changes after gastric bypass surgery evaluated by HR-pQCT: a two-year longitudinal study.
abstract: OBJECTIVE
  Roux-en-Y gastric bypass (RYGB) has proved successful in attaining sustained weight loss but may lead to metabolic bone disease. To assess impact on bone mass and structure, we measured a real bone mineral density at the hip and spine by dual-energy X-ray absorptiometry, and volumetric BMD (vBMD) and bone microarchitecture at the distal radius and tibia by high-resolution peripheral quantitative CT in 25 morbidly obese subjects (15 females, 10 males) at 0, 12 and 24 months after RYGB. Bone turnover markers (BTMs), calciotropic and gut hormones and adipokines were measured at the same time points.
  
  
  RESULTS
  After a 24.1% mean weight loss from baseline to month 12 (P< 0.001), body weight plateaued from month 12 to 24 (-0.9%,P= 0.50). However, cortical and trabecular vBMD and microarchitecture deteriorated through the 24 months, such that there was a 5 and 7% reduction in estimated bone strength at the radius and tibia respectively (bothP< 0.001). The declines observed in the first 12 months were matched or exceeded by declines in the 12- to 24-month period. While a significant increase in BTMs and decrease in leptin and insulin were seen at 24 months, these changes were maximal at month 12 and stabilized from month 12 to 24.
  
  
  CONCLUSIONS
  Despite weight stabilization and maintenance of metabolic parameters, bone loss and deterioration in bone strength continued and were substantial in the second year. The clinical importance of these changes in terms of increased risk of developing osteoporosis and fragility fractures remain an important concern.
authors.affiliation: Department of EndocrinologyOdense University Hospital, Odense C, Denmark.|Institute of Clinical ResearchUniversity of Southern Denmark, Odense C, Denmark.
authors.forename: Vikram V
authors.initials: VV
authors.lastname: Shanbhogue
authors.affiliation: Department of EndocrinologyOdense University Hospital, Odense C, Denmark.|Institute of Clinical ResearchUniversity of Southern Denmark, Odense C, Denmark.|Center for Eating DisordersOdense University Hospital & Psychiatry of Region Southern Denmark, Odense C, Denmark.
authors.forename: René Klinkby
authors.initials: RK
authors.lastname: Støving
authors.affiliation: Department of EndocrinologyOdense University Hospital, Odense C, Denmark.
authors.forename: Katrine Hartmund
authors.initials: KH
authors.lastname: Frederiksen
authors.affiliation: Department of EndocrinologyOdense University Hospital, Odense C, Denmark.
authors.forename: Stine
authors.initials: S
authors.lastname: Hanson
authors.affiliation: Institute of Clinical ResearchUniversity of Southern Denmark, Odense C, Denmark.
authors.forename: Kim
authors.initials: K
authors.lastname: Brixen
authors.affiliation: Department of EndocrinologyHospital of Southwest Denmark, Esbjerg, Denmark.
authors.forename: Jeppe
authors.initials: J
authors.lastname: Gram
authors.affiliation: Department of Clinical BiochemistryResearch Center for Ageing and Osteoporosis, Glostrup, Denmark.|OPENOdense Patient data Explorative Network, Odense University Hospital/Institute of Clinical Research, University of Southern Denmark, Odense, Denmark.
authors.forename: Niklas Rye
authors.initials: NR
authors.lastname: Jørgensen
authors.affiliation: Department of EndocrinologyOdense University Hospital, Odense C, Denmark.|Institute of Clinical ResearchUniversity of Southern Denmark, Odense C, Denmark.
authors.forename: Stinus
authors.initials: S
authors.lastname: Hansen
mesh_terms: D015502:Absorptiometry, Photon; D052242:Adiponectin / Q000378:metabolism; D000328:Adult; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000000981:diagnostic imaging / Q000209:etiology / Q000378:metabolism; D016723:Bone Remodeling; D024042:Collagen Type I / Q000378:metabolism; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D015390:Gastric Bypass / Q000009:adverse effects*; D006621:Hip Joint / Q000000981:diagnostic imaging; D006801:Humans; D007328:Insulin / Q000378:metabolism; D020738:Leptin / Q000378:metabolism; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000601:surgery*; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000378:metabolism; D010281:Parathyroid Hormone / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology* / Q000378:metabolism; D011347:Procollagen / Q000378:metabolism; D011884:Radius / Q000000981:diagnostic imaging; D013977:Tibia / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D014807:Vitamin D / Q000031:analogs & derivatives / Q000378:metabolism; D015431:Weight Loss
chemical_list: D052242:Adiponectin; D024042:Collagen Type I; D007328:Insulin; D020738:Leptin; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; C052929:collagen type I trimeric cross-linked peptide; C047202:procollagen Type I N-terminal peptide; D014807:Vitamin D; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; C104450:25-hydroxyvitamin D