title: Weight-loss-associated changes in bone mineral density and bone turnover after partial weight regain with or without aerobic exercise in obese women.
abstract: OBJECTIVE
  Moderate, long-term weight loss results in the loss of bone mass in overweight or obese premenopausal women. However, whether these changes persist during weight maintenance or regain remains to be determined.
  
  
  METHODS
  Overweight or obese (body mass index: 25.8-42.5 kg/m(2)) women (n=40) with at least two risk factors for the metabolic syndrome participated in this 12-month study that examined the effects of prescribed weight loss and regain, with or without exercise, on bone turnover and on bone mineral density (BMD) in a subset of participants (n=24). During the first 6 month, participants lost ≈ 10% of their initial body weight via energy restriction and supervised aerobic exercise. Following weight loss, participants were randomly assigned to either an exercise or a no exercise treatment for the regain (+50% of weight lost) phase. A one-way (time) repeated measures one-factor analysis of variance (RMANOVA) tested the effects of weight loss on BMD and bone turnover, and a two-way RMANOVA (time, exercise) was used to examine the effects of exercise during weight regain.
  
  
  RESULTS
  Hip (P=0.007) and lumbar spine (P=0.05) BMD decreased with weight loss, and remained reduced after weight regain with or without exercise. Likewise, the weight-loss-associated increases in osteocalcin (P<0.001) and C-terminal peptide of type I collagen (P<0.001) persisted following weight regain, independent of exercise.
  
  
  CONCLUSIONS
  The results of the present study, which is the first to examine changes in bone mass and turnover during carefully controlled weight regain, suggest that weight-loss-induced perturbations in bone mass and turnover persist after partial weight regain, regardless of whether regular weight-bearing aerobic exercise was continued.
authors.affiliation: Department of Nutrition and Exercise Physiology, Columbia, MO 65211, USA. hintonp@missouri.edu
authors.forename: P S
authors.initials: PS
authors.lastname: Hinton
authors.forename: R S
authors.initials: RS
authors.lastname: Rector
authors.forename: M A
authors.initials: MA
authors.lastname: Linden
authors.forename: S O
authors.initials: SO
authors.lastname: Warner
authors.forename: K C
authors.initials: KC
authors.lastname: Dellsperger
authors.forename: A
authors.initials: A
authors.lastname: Chockalingam
authors.forename: A T
authors.initials: AT
authors.lastname: Whaley-Connell
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: T R
authors.initials: TR
authors.lastname: Thomas
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D015992:Body Mass Index; D015519:Bone Density; D001862:Bone Resorption / Q000378:metabolism*; D001842:Bone and Bones / Q000378:metabolism*; D031204:Caloric Restriction; D024042:Collagen Type I / Q000097:blood; D004038:Diet, Reducing; D015444:Exercise / Q000502:physiology*; D005260:Female; D006615:Hip; D006801:Humans; D008159:Lumbar Vertebrae; D024821:Metabolic Syndrome / Q000209:etiology; D009765:Obesity / Q000097:blood / Q000378:metabolism*; D015675:Osteocalcin / Q000097:blood; D010455:Peptides / Q000097:blood; D012307:Risk Factors; D015430:Weight Gain / Q000502:physiology*; D015431:Weight Loss / Q000502:physiology*
chemical_list: D024042:Collagen Type I; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D015675:Osteocalcin