title: Association of weight-adjusted body fat and fat distribution with bone mineral density in middle-aged chinese adults: a cross-sectional study.
abstract: BACKGROUND
  Although it is well established that a higher body weight is protective against osteoporosis, the effects of body fat and fat distribution on bone mineral density (BMD) after adjustment for body weight remains uncertain.
  
  
  OBJECTIVE
  To examine the relationship between body fat and fat distribution and BMD beyond its weight-bearing effect in middle-aged Chinese adults.
  
  
  METHODS
  The study had a community-based cross-sectional design and involved 1,767 women and 698 men aged 50-75 years. The BMD of the lumbar spine, total hip, and whole body, and the fat mass (FM) and percentage fat mass (%FM) of the total body and segments of the body were measured by dual-energy X-ray absorptiometry. General information on the participants was collected using structured questionnaire interviews.
  
  
  RESULTS
  After adjusting for potential confounders, an analysis of covariance showed the weight-adjusted (WA-) total FM (or %FM) to be negatively associated with BMD in all of the studied sites (P<0.05) in both women and men. The unfavorable effects of WA-total FM were generally more substantial in men than in women, and the whole body was the most sensitive site related to FM, followed by the total hip and the lumbar spine, in both genders. The mean BMD of the lumbar spine, total hip, and whole body was 3.93%, 3.01%, and 3.65% (in women) and 5.02%, 5.57%, 6.03% (in men) lower in the highest quartile (vs. lowest quartile) according to the WA-total FM (all p<0.05). Similar results were noted among the groups for WA-total FM%. In women, abdominal fat had the most unfavorable association with BMD, whereas in men it was limb fat.
  
  
  CONCLUSIONS
  FM (or %FM) is inversely associated with BMD beyond its weight-bearing effect. Abdominal fat in women and limb fat in men seems to have the greatest effect on BMD.
authors.affiliation: Guangdong Provincial Key Laboratory of Food, Nutrition and Health, School of Public Health, Sun Yat-sen University, Guangzhou, PR China.
authors.forename: Yan-hua
authors.initials: YH
authors.lastname: Liu
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Ya-bin
authors.initials: YB
authors.lastname: Wen
authors.forename: Ke
authors.initials: K
authors.lastname: Guan
authors.forename: Wen-hua
authors.initials: WH
authors.lastname: Ling
authors.forename: Li-ping
authors.initials: LP
authors.lastname: He
authors.forename: Yi-xiang
authors.initials: YX
authors.lastname: Su
authors.forename: Yu-ming
authors.initials: YM
authors.lastname: Chen
mesh_terms: D050153:Abdominal Fat / Q000473:pathology*; D015502:Absorptiometry, Photon; D000368:Aged; D050218:Body Fat Distribution; D015519:Bone Density; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D006615:Hip / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000000981:diagnostic imaging / Q000473:pathology*; D051598:Whole Body Imaging