title: Hip bone geometry in HIV/HCV-co-infected men and healthy controls.
abstract: People with both HIV and hepatitis C are more likely than those with HIV alone to have wrist, hip, and spine fractures. We compared hip strength between HIV/HCV-co-infected men and healthy men and found that HIV/HCV-co-infected men had decreased hip strength due to lower lean body mass.
  
  
  BACKGROUND
  Hepatitis C co-infection is a risk factor for fragility fracture among HIV-infected populations. Whether bone strength is compromised in HIV/HCV-co-infected patients is unknown.
  
  
  METHODS
  We compared dual-energy x-ray absorptiometry (DXA)-derived hip geometry, a measure of bone strength, in 88 HIV/HCV-co-infected men from the Johns Hopkins HIV Clinic to 289 men of similar age and race and without HIV or HCV from the Boston Area Community Health Survey/Bone Survey. Hip geometry was assessed at the narrow neck, intertrochanter, and shaft using hip structural analysis. Lean body mass (LBM), total fat mass (FM), and fat mass ratio (FMR) were measured by whole-body DXA. Linear regression was used to identify body composition parameters that accounted for differences in bone strength between cohorts.
  
  
  RESULTS
  HIV/HCV-co-infected men had lower BMI, LBM, and FM and higher FMR compared to controls (all p < 0.05). At the narrow neck, significant differences were observed between HIV/HCV-co-infected men and controls in bone mineral density, cross-sectional area, section modulus, buckling ratio, and centroid position. After adjustment for race, age, smoking status, height, and weight, only buckling ratio and centroid position remained significantly different between cohorts (all p < 0.05). Substituting LBM, FM, and FMR for weight in the multivariate model revealed that differences in LBM, but not FM or FMR, accounted for differences in all narrow neck parameters between cohorts, except buckling ratio and centroid position.
  
  
  CONCLUSIONS
  HIV/HCV-co-infected men have compromised hip strength at the narrow neck compared to uninfected controls, which is attributable in large part to lower lean body mass.
authors: Johns Hopkins University School of Medicine, Baltimore, MD, USA. vwalker4@jhmi.edu
authors: V
authors: V
authors: Walker Harris
authors: C G
authors: CG
authors: Sutcliffe
authors: A B
authors: AB
authors: Araujo
authors: G R
authors: GR
authors: Chiu
authors: T G
authors: TG
authors: Travison
authors: S
authors: S
authors: Mehta
authors: M S
authors: MS
authors: Sulkowski
authors: Y
authors: Y
authors: Higgins
authors: D L
authors: DL
authors: Thomas
authors: A S
authors: AS
authors: Dobs
authors: T J
authors: TJ
authors: Beck
authors: T T
authors: TT
authors: Brown
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D001823:Body Composition; D015519:Bone Density; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D015658:HIV Infections / Q000150:complications*; D006526:Hepatitis C / Q000150:complications*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies