title: [Association of body mass index and male primary osteoporosis].
abstract: OBJECTIVE
  To explore the association between body mass index (BMI) and male primary osteoporosis (OP) in a Chinese Han population.
  
  
  METHODS
  The association of BMI with OP was assessed in 276 Chinese healthy aged males for physical examination. They were classified into OP, osteopenia and normal groups according to the World Health Organization (WHO) criteria, i.e. OP was defined arbitrarily when any T-score was -2.5 standard deviations or less at femoral neck, total hip or lumbar spine (L1-4) site. We also classified the subjects as different BMI groups of low weight, normal weight, overweight and obesity. The prevalence of OP was compared among different BMI groups. We determined the sensitivity, specificity and area under the curve of receiver operating characteristic (ROC) for validating the valuation of BMI to predict male primary OP.
  
  
  RESULTS
  Among them, 6/12 had OP in the low weight group, 17.36% (21/121) in the normal group and 12.59% (18/143) in the overweight and obesity group. And the difference was significant. The analysis of ROC curve showed that BMI was of limited value in predicting OP (P > 0.05).
  
  
  CONCLUSIONS
  BMI has a positive correlation with male OP. The value of BMI is limited for predicting OP in males. And the relevant factors associated with male OP should to be further studied.
authors.affiliation: Department of Orthopedics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Jisheng
authors.initials: J
authors.lastname: Lin
authors.affiliation: Department of Orthopedics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Zhao
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Department of Orthopedics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China. Email: feiqi@medmail.com.cn.
authors.forename: Qi
authors.initials: Q
authors.lastname: Fei
authors.affiliation: Department of Orthopedics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Bingqiang
authors.initials: B
authors.lastname: Wang
authors.affiliation: Department of Orthopedics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Orthopedics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Zhao
authors.affiliation: Department of Orthopedics, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
mesh_terms: D044466:Asian People; D015992:Body Mass Index; D006801:Humans; D008159:Lumbar Vertebrae; D008297:Male; D009765:Obesity; D010024:Osteoporosis; D015995:Prevalence; D012372:ROC Curve