title: Postmenopausal weight change and incidence of fracture: post hoc findings from Women's Health Initiative Observational Study and Clinical Trials.
abstract: OBJECTIVE
  To determine associations between postmenopausal change in body weight and incidence of fracture and associations between voluntary and involuntary weight loss and risk of fracture.
  
  
  METHODS
  Post hoc analysis of data from the Women's Health Initiative Observational Study and Clinical Trials.
  
  
  METHODS
  40 clinical centers in the United States.
  
  
  METHODS
  120,566 postmenopausal women, aged 50-79 at baseline (1993-98), followed through 2013 (mean fracture follow-up duration 11 years from baseline).
  
  
  METHODS
  Annualized percentage change in measured body weight from baseline to year 3, classified as stable (<5% change), weight loss (≥ 5%), or weight gain (≥ 5%). Self assessment of whether weight loss was intentional or unintentional. Cox proportional hazards regression models were adjusted for age, race/ethnicity, baseline body mass index (BMI), smoking, alcohol intake, level of physical activity, energy expenditure, calcium and vitamin D intake, physical function score, oophorectomy, hysterectomy, previous fracture, comorbidity score, and drug use.
  
  
  RESULTS
  Incident self reported fractures of the upper limbs, lower limbs, and central body; hip fractures confirmed by medical records.
  
  
  RESULTS
  Mean participant age was 63.3. Mean annualized percent weight change was 0.30% (95% confidence interval 0.28 to 0.32). Overall, 79,279 (65.6%) had stable weight; 18,266 (15.2%) lost weight; and 23,021 (19.0%) gained weight. Compared with stable weight, weight loss was associated with a 65% higher incidence rates of fracture in hip (adjusted hazard ratio 1.65, 95% confidence interval 1.49 to 1.82), upper limb (1.09, 1.03 to 1.16), and central body (1.30, 1.20 to 1.39); weight gain was associated with higher incidence rates of fracture in upper limb (1.10, 1.05 to 1.18) and lower limb (1.18, 1.12 to 1.25). Compared with stable weight, unintentional weight loss was associated with a 33% higher incidence rates of hip fracture (1.33, 1.19 to 1.47) and increased incidence rates of vertebral fracture (1.16, 1.06 to 1.26); intentional weight loss was associated with increased incidence rates of lower limb fracture (1.11, 1.05 to 1.17) and decreased incidence of hip fracture (0.85, 0.76 to 0.95).
  
  
  CONCLUSIONS
  Weight gain, weight loss, and intentional weight loss are associated with increased incidence of fracture, but associations differ by fracture location. Clinicians should be aware of fracture patterns after weight gain and weight loss.
authors: David Geffen School of Medicine at University of California, Los Angeles, Division of General Internal Medicine and Health Services Research, UCLA Medicine/GIM, 911 Broxton Avenue, 1st floor, Los Angeles, CA, 90024, USA ccrandall@mednet.ucla.edu.
authors: Carolyn J
authors: CJ
authors: Crandall
authors: Center for Biostatistics, Ohio State University, 2012 Kenny Road, Columbus, Ohio, USA.
authors: Vedat O
authors: VO
authors: Yildiz
authors: Department of Social and Preventive Medicine, University at Buffalo, State University of New York, 65 Farber Hall, 3435 Main Street, Buffalo, NY 14214-3000 State University of NY at Buffalo, Buffalo, NY, USA.
authors: Jean
authors: J
authors: Wactawski-Wende
authors: Department of Preventive Medicine, University of Tennessee Health Science Center, 66 N. Pauline, Suite 633, Memphis, TN 38163, USA.
authors: Karen C
authors: KC
authors: Johnson
authors: Division of Epidemiology and Biostatistics, University of Arizona, Tucson, Arizona, USA.
authors: Zhao
authors: Z
authors: Chen
authors: Department of Nutritional Sciences, University of Arizona, Tucson, Arizona, USA.
authors: Scott B
authors: SB
authors: Going
authors: Department of Epidemiology, University of Alabama at Birmingham, RPHB 523C, Birmingham, AL, 35294, USA.
authors: Nicole C
authors: NC
authors: Wright
authors: Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
authors: Jane A
authors: JA
authors: Cauley
mesh_terms: D000368:Aged; D015992:Body Mass Index; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000150:complications; D017698:Postmenopause; D016016:Proportional Hazards Models; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D015430:Weight Gain; D015431:Weight Loss
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