title: Correlation of serum leptin level with bone mineral density and bone turnover markers in Chinese adolescent dancers.
abstract: OBJECTIVE
  To investigate plasma leptin concentrations in adolescent female dancers and to determine whether leptin has some effects on their bone mineral density (BMD) and bone turnover markers.
  
  
  METHODS
  Sixty dancers aged 15-17 years and 77 healthy controls were enrolled in the study. Bone mineral density (BMD) and body composition were detected by dual energy X-ray absorptiometry. Serum leptin concentrations were measured by radioimmunoassay (RIA). Two bone turnover markers, bone-specific alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase(TRACP), were determined by ELISA.
  
  
  RESULTS
  The dancers had a lower fat mass and a lower leptin level than the controls, while they had a relatively higher BMD of the total body and legs after adjustment for BMI and age. The levels of bone resorption and formation of markers were higher in the dancers than in the controls. Leptin was positively correlated with BMI, body weight, fat mass, and percentage of body fat. In dancers, Leptin was positively correlated with the BMD of the total body and the left leg. However, after adjustment for BMI, no correlation of serum leptin concentrations with BMD values was found in either dancers or controls. Nor correlation was found between leptin and bone turnover markers after adjustment for BMI.
  
  
  CONCLUSIONS
  The leptin profile is different between the controls and the dancers with a lower BMI and a lower fat mass. Circulating plasma leptin level depends on BMI and is not a direct determinant of BMD in Chinese adolescent dancers.
authors.affiliation: Institute for Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing 100050, China. Lichen_yang@yahoo.com.cn
authors.forename: Li-Chen
authors.initials: LC
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Lan
authors.forename: Jing
authors.initials: J
authors.lastname: Hu
authors.forename: Yan-Hua
authors.initials: YH
authors.lastname: Yang
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Piao
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D015519:Bone Density / Q000502:physiology*; D003615:Dancing; D005260:Female; D006801:Humans; D020738:Leptin / Q000097:blood*
chemical_list: D015415:Biomarkers; D020738:Leptin