title: The relationship between incidence of fractures and anemia in older multiethnic women.
abstract: OBJECTIVE
  To prospectively examine the relationship between anemia and incident fractures of the hip, spine, and all skeletal sites in women from diverse racial and ethnic backgrounds enrolled in the Women's Health Initiative (WHI) Observational Study and Clinical Trials.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Forty WHI clinical centers across the United States.
  
  
  METHODS
  Postmenopausal women (n=160,080), mean age 63.2±7.2, were recruited and followed for an average of 7.8 years.
  
  
  METHODS
  Anemia was defined as hemoglobin levels at baseline less than 12 g/dL. All fractures were self-reported. Trained physicians further confirmed hip fractures using medical records.
  
  
  RESULTS
  Eight thousand seven hundred thirty-nine of the participants (5.5%) were anemic. The age-adjusted incidence rate of hip fractures per 10,000 person-years was 21.4 in women with anemia and 15.0 in women without anemia; higher incidence rates for spine and all fractures were also observed in anemic women. After multiple covariates were included in the Cox proportional hazards models, significantly greater fracture risk associated with anemia still existed, as demonstrated by hazard ratios of fractures associated with anemia of 1.38 (95% confidence interval (CI)=1.13-1.68) for hip, 1.30 (95% CI=1.09-1.55) for spine, and 1.07 (95% CI=1.01-1.14) for all types. No significant racial or ethnic difference was found in these relationships.
  
  
  CONCLUSIONS
  A significantly greater fracture risk was observed in multiethnic postmenopausal women with anemia. Given the high prevalence of anemia in the elderly population, it is important to better understand the relationship and mechanisms linking anemia to fracture risk.
authors.affiliation: Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, Arizona 85724, USA. zchen@email.arizona.edu
authors.forename: Zhao
authors.initials: Z
authors.lastname: Chen
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Thomson
authors.forename: Mikel
authors.initials: M
authors.lastname: Aickin
authors.forename: J Skye
authors.initials: JS
authors.lastname: Nicholas
authors.forename: David
authors.initials: D
authors.lastname: Van Wyck
authors.forename: Cora E
authors.initials: CE
authors.lastname: Lewis
authors.forename: Jane A
authors.initials: JA
authors.lastname: Cauley
authors.forename: Tamsen
authors.initials: T
authors.lastname: Bassford
mesh_terms: D000368:Aged; D000740:Anemia / Q000150:complications / Q000453:epidemiology* / Q000208:ethnology; D015331:Cohort Studies; D016001:Confidence Intervals; D005006:Ethnicity; D005260:Female; D005500:Follow-Up Studies; D050723:Fractures, Bone / Q000150:complications / Q000453:epidemiology* / Q000208:ethnology; D006620:Hip Fractures / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000453:epidemiology* / Q000208:ethnology; D017698:Postmenopause; D015995:Prevalence; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology; D016387:Women's Health