title: The role of fat mass and skeletal muscle mass in knee osteoarthritis is different for men and women: the NEO study.
abstract: OBJECTIVE
  To investigate if the amount of fat mass (FM) or skeletal muscle mass (SMM) is more strongly associated with knee osteoarthritis (OA), in both men and women.
  
  
  METHODS
  The Netherlands Epidemiology of Obesity (NEO) study is a population-based cohort aged 45-65 years, including 5313 participants (53% female, median body mass index (BMI) 29.9 kg/m(2)). FM (kg), fat percentage, SMM (kg) and skeletal muscle (SM) percentage were estimated using bioelectrical impedance analysis (BIA). Clinical OA was defined following the ACR criteria. Structural OA was defined based on magnetic resonance imaging (MRI) in 1142 participants. Logistic regression analyses were used to examine the associations of all body composition measures with clinical and structural knee OA per standard deviation (SD), stratified by sex and adjusted for age and height.
  
  
  RESULTS
  Clinical or structural OA was present in 25% and 14% of women and 12% and 13% of men, respectively. FM and fat percentage were positively associated with clinical knee OA in men and women. SMM was positively associated, while the SM percentage was negatively associated with clinical OA in both men and women. The FM/SMM ratio was positively associated with clinical OA. All determinants showed even stronger ORs for structural knee OA. In men, SMM was more strongly associated with knee OA as compared to FM whereas in women, FM was most strongly associated.
  
  
  CONCLUSIONS
  Especially a high FM/SMM ratio seems to be unfavorable in knee OA. In men, SMM is most strongly associated with knee OA whereas in women FM seems to be of most importance.
authors: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: a.w.visser@lumc.nl.
authors: A W
authors: AW
authors: Visser
authors: Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
authors: R
authors: R
authors: de Mutsert
authors: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.
authors: M
authors: M
authors: Loef
authors: Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
authors: S
authors: S
authors: le Cessie
authors: Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands; Department of Endocrinology, Vrije Universiteit Medical Center, Amsterdam, The Netherlands.
authors: M
authors: M
authors: den Heijer
authors: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
authors: J L
authors: JL
authors: Bloem
authors: Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands.
authors: M
authors: M
authors: Reijnierse
authors: Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
authors: F R
authors: FR
authors: Rosendaal
authors: Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands; Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands.
authors: M
authors: M
authors: Kloppenburg
mesh_terms: D000273:Adipose Tissue / Q000473:pathology*; D000368:Aged; D000886:Anthropometry / Q000379:methods; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology*; D009426:Netherlands / Q000453:epidemiology; D009765:Obesity / Q000150:complications / Q000453:epidemiology / Q000473:pathology; D009929:Organ Size / Q000502:physiology; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology* / Q000503:physiopathology; D011446:Prospective Studies; D012737:Sex Factors
keywords: Fat mass; Knee osteoarthritis; Skeletal muscle mass