title: Early cartilage abnormalities at the hip are associated with obesity and body composition measures - a 3.0T MRI community-based study.
abstract: BACKGROUND
  Although obesity is a risk factor for hip osteoarthritis (OA), the role of body composition, if any, is unclear. This study examines whether the body mass index (BMI) and body composition are associated with hip cartilage changes using magnetic resonance imaging (MRI) in community-based adults.
  
  
  METHODS
  141 community-based participants with no clinical hip disease, including OA, had BMI and body composition (fat mass and fat free mass) measured at baseline (1990 to 1994), and BMI measured and 3.0 T MRI performed at follow-up (2009-2010). Femoral head cartilage volume was measured and femoral head cartilage defects were scored in the different hip regions.
  
  
  RESULTS
  For females, baseline BMI (β = -26 mm(3), 95% Confidence interval (CI) -47 to -6 mm(3), p = 0.01) and fat mass (β = -11 mm(3), 95% CI -21 to -1 mm(3), p = 0.03) were negatively associated with femoral head cartilage volume. Also, while increased baseline fat mass was associated with an increased risk of cartilage defects in the central superolateral region of the femoral head (Odds Ratio (OR) = 1.08, 95% CI 1.00-1.15, p = 0.04), increased baseline fat free mass was associated with a reduced risk of cartilage defects in this region (OR = 0.82, 95% CI 0.67-0.99; p = 0.04). For males, baseline fat free mass was associated with increased femoral head cartilage volume (β = 40 mm(3), 95% CI 6 to 74 mm(3), p = 0.02).
  
  
  CONCLUSIONS
  Increased fat mass was associated with adverse hip cartilage changes for females, while increased fat free mass was associated with beneficial cartilage changes for both genders. Further work is required to determine whether modifying body composition alters the development of hip OA.
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. andrew.teichtahl@monash.edu.|Baker IDI Heart and Diabetes Institute, Commercial Road, Melbourne, VIC, 3004, Australia. andrew.teichtahl@monash.edu.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Teichtahl
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. yuanyuan.wang@monash.edu.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. sesmi8@student.monash.edu.au.
authors.forename: Sam
authors.initials: S
authors.lastname: Smith
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. anita.wluka@monash.edu.
authors.forename: Anita E
authors.initials: AE
authors.lastname: Wluka
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. donna.urquhart@monash.edu.
authors.forename: Donna
authors.initials: D
authors.lastname: Urquhart
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. graham.giles@cancervic.org.au.|Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Carlton, VIC, 3053, Australia. graham.giles@cancervic.org.au.|Cancer Epidemiology Centre, Cancer Council Victoria, Melbourne, VIC, 3004, Australia. graham.giles@cancervic.org.au.
authors.forename: Graham G
authors.initials: GG
authors.lastname: Giles
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. monira.hussain@monash.edu.
authors.forename: Sultana Monira
authors.initials: SM
authors.lastname: Hussain
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, VIC, 3004, Australia. Flavia.cicuttini@monash.edu.
authors.forename: Flavia M
authors.initials: FM
authors.lastname: Cicuttini
mesh_terms: D000328:Adult; D000368:Aged; D001315:Australia; D001823:Body Composition; D015992:Body Mass Index; D002358:Cartilage, Articular / Q000473:pathology*; D015331:Cohort Studies; D016001:Confidence Intervals; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D057187:Independent Living; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000150:complications* / Q000175:diagnosis; D016017:Odds Ratio; D015207:Osteoarthritis, Hip / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors