title: An independent positive relationship between the serum total osteocalcin level and fat-free mass in healthy premenopausal women.
abstract: BACKGROUND
  It is widely reported that osteocalcin is negatively associated with fat mass. However, there are few reports describing its correlation with fat-free mass, particularly in women.
  
  
  OBJECTIVE
  The objective of the current study was to investigate the possible relationship between osteocalcin and fat-free mass in healthy, nonobese women.
  
  
  METHODS
  This study was performed in a tertiary university teaching hospital.
  
  
  METHODS
  A total of 504 healthy women aged 20-75 years were enrolled.
  
  
  METHODS
  Body composition was measured using a bioelectronics impedance analyzer. The serum concentrations of total osteocalcin, estradiol, leptin, osteoprotegerin, the receptor activator of nuclear factor-κB ligand, IGF-I, fasting plasma glucose, and urinary N-terminal telopeptide of type I collagen were tested. The bone mineral densities (BMDs) at the lumbar spine and proximal femoral neck were measured by dual-energy X-ray absorptiometry.
  
  
  RESULTS
  The serum total osteocalcin level had a significant positive association with fat-free mass (r = 0.168, P = .007) after adjusting for age, fat mass, menopausal status, estradiol, fasting glucose, leptin, osteoprotegerin, receptor activator of nuclear factor-κB ligand, IGF-I, N-terminal telopeptide of type I collagen, BMDs, and waist and hip circumference. Analysis in pre- and postmenopausal women demonstrated that this association was only present in premenopausal women (r = 0.190, P = .005). The multiple stepwise regression analysis revealed that hip circumference, femoral neck-BMD, fat mass, leptin, osteocalcin, and age are the contributors to the changes in fat-free mass in premenopausal women (adjusted R(2) = 0.521, P < .001).
  
  
  CONCLUSIONS
  The serum level of total osteocalcin was positively associated with fat-free mass independent of age, fat mass, leptin, and other confounders in premenopausal women.
authors.affiliation: Department of Endocrine and Metabolic Diseases, Rui-jin Hospital, Shanghai Jiao-tong University School of Medicine, 197 Rui-jin Er Road, Shanghai, China 200025.
authors.forename: Jian-min
authors.initials: JM
authors.lastname: Liu
authors.forename: Hong-yan
authors.initials: HY
authors.lastname: Zhao
authors.forename: Lin
authors.initials: L
authors.lastname: Zhao
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Lian-zhen
authors.initials: LZ
authors.lastname: Zhang
authors.forename: Bei
authors.initials: B
authors.lastname: Tao
authors.forename: Li-hao
authors.initials: LH
authors.lastname: Sun
authors.forename: Yong-ju
authors.initials: YJ
authors.lastname: Zhao
authors.forename: Wei-qing
authors.initials: WQ
authors.lastname: Wang
authors.forename: Man-yin
authors.initials: MY
authors.lastname: Xu
authors.forename: Jia-lun
authors.initials: JL
authors.lastname: Chen
authors.forename: Guang
authors.initials: G
authors.lastname: Ning
mesh_terms: D050154:Adiposity; D000328:Adult; D000367:Age Factors; D000368:Aged; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001823:Body Composition; D015519:Bone Density; D001846:Bone Development; D015331:Cohort Studies; D005260:Female; D005498:Follicular Phase / Q000097:blood* / Q000652:urine; D006801:Humans; D020738:Leptin / Q000097:blood; D008875:Middle Aged; D024510:Muscle Development; D015675:Osteocalcin / Q000097:blood*; D017698:Postmenopause; D017697:Premenopause; D055815:Young Adult
chemical_list: D015415:Biomarkers; D020738:Leptin; D015675:Osteocalcin