title: Bone strength is preserved following bariatric surgery.
abstract: BACKGROUND
  There is an increasing concern that bariatric surgery results in excessive bone loss as demonstrated by studies that use areal bone mineral density (aBMD) outcomes by dual energy X-ray absorptiometry (DXA). Thus, we explored the effect of bariatric surgery on bone mechanical strength.
  
  
  METHODS
  Bone strength and body composition outcomes were measured in 21 adults (age 45.3 years; BMI 45.7 kg/m(2)) at baseline (pre-surgery) and 3, 6, and 12 months post-surgery. Bone geometry, density and strength were assessed by peripheral quantitative computed tomography (pQCT) at the distal (4 %) sites of the radius and tibia and at the midshaft sites of the tibia (66 %) and radius (50 %). Participants were divided into tertiles (high, medium, and low) of percentage weight loss at 6 months post-surgery.
  
  
  RESULTS
  Participants in all three tertiles lost significant body weight by 6 months post-surgery (mean loss -5 to -30 %, all p < 0.05). At 6 months, all tertiles lost significant fat mass (-9 to -51 %, all p < 0.05), but only the high tertile lost significant fat-free mass (-8 %, p < 0.05). Despite a slight increase in tibia bone strength (SSIp) at 3 months (+1.1 %, p < 0.05), estimates of bone strength at the radius and tibia sites did not change at later post-surgical time points regardless of weight loss.
  
  
  CONCLUSIONS
  Contrary to DXA-based aBMD outcomes in the current literature, these results suggest that bone strength was preserved up to 12 months following bariatric surgery. Future longer-term studies exploring bone strength and geometry are needed to confirm these findings.
authors: School of Kinesiology, University of Minnesota, 1900 University Avenue SE, Minneapolis, MN, USA, 55455, l.scibora@stthomas.edu.
authors: Lesley M
authors: LM
authors: Scibora
authors: Henry
authors: H
authors: Buchwald
authors: Moira A
authors: MA
authors: Petit
authors: Julie
authors: J
authors: Hughes
authors: Sayeed
authors: S
authors: Ikramuddin
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D050110:Bariatric Surgery / Q000009:adverse effects*; D015519:Bone Density; D001851:Bone Diseases, Metabolic / Q000000981:diagnostic imaging* / Q000209:etiology; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000601:surgery*; D011184:Postoperative Period; D011884:Radius / Q000000981:diagnostic imaging*; D013977:Tibia / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed; D055815:Young Adult