title: Modifiable risk factors associated with bone deficits in childhood cancer survivors.
abstract: BACKGROUND
  To determine the prevalence and severity of bone deficits in a cohort of childhood cancer survivors (CCS) compared to a healthy sibling control group, and the modifiable factors associated with bone deficits in CCS.
  
  
  METHODS
  Cross-sectional study of bone health in 319 CCS and 208 healthy sibling controls. Bone mineral density (BMD) was measured by dual-energy x-ray absorptiometry (DXA). Generalized estimating equations were used to compare measures between CCS and controls. Among CCS, multivariable logistic regression was used to evaluate odds ratios for BMD Z-score ≤ -1.
  
  
  RESULTS
  All subjects were younger than 18 years of age. Average time since treatment was 10.1 years (range 4.3 - 17.8 years). CCS were 3.3 times more likely to have whole body BMD Z-score ≤ -1 than controls (95% CI: 1.4-7.8; p = 0.007) and 1.7 times more likely to have lumbar spine BMD Z-score ≤ -1 than controls (95% CI: 1.0-2.7; p = 0.03). Among CCS, hypogonadism, lower lean body mass, higher daily television/computer screen time, lower physical activity, and higher inflammatory marker IL-6, increased the odds of having a BMD Z-score ≤ -1.
  
  
  CONCLUSIONS
  CCS, less than 18 years of age, have bone deficits compared to a healthy control group. Sedentary lifestyle and inflammation may play a role in bone deficits in CCS. Counseling CCS and their caretakers on decreasing television/computer screen time and increasing activity may improve bone health.
authors.affiliation: Department of Pediatrics, University of Minnesota, Minneapolis, MN, USA. polgr001@umn.edu
authors.forename: Lynda E
authors.initials: LE
authors.lastname: Polgreen
authors.forename: Anna
authors.initials: A
authors.lastname: Petryk
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Dietz
authors.forename: Alan R
authors.initials: AR
authors.lastname: Sinaiko
authors.forename: Wendy
authors.initials: W
authors.lastname: Leisenring
authors.forename: Pam
authors.initials: P
authors.lastname: Goodman
authors.forename: Lyn M
authors.initials: LM
authors.lastname: Steffen
authors.forename: Joanna L
authors.initials: JL
authors.lastname: Perkins
authors.forename: Donald R
authors.initials: DR
authors.lastname: Dengel
authors.forename: K Scott
authors.initials: KS
authors.lastname: Baker
authors.forename: Julia
authors.initials: J
authors.lastname: Steinberger
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D015519:Bone Density / Q000502:physiology*; D001846:Bone Development / Q000502:physiology*; D016022:Case-Control Studies; D002648:Child; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D015999:Multivariate Analysis; D009369:Neoplasms / Q000150:complications / Q000503:physiopathology*; D012044:Regression Analysis; D012307:Risk Factors; D057185:Sedentary Behavior; D035781:Siblings; D017741:Survivors