title: [Prospective investigation of annual bone loss rate in females in Changsha city, Hunan province].
abstract: OBJECTIVE
  To investigate prospectively the annual bone loss rate at spine, proximal femur and distal radius in females and its relationship to relevant factors.
  
  
  METHODS
  The bone mineral density (BMD) at anteroposterior lumber, proximal femur and distal radius in 220 women of Mawangdui Township, aged 36 - 60, was measured twice, March to April 2000 and March to April 2004, using a Hologic QDR 4500A fan beam X-ray bone densitometer.
  
  
  RESULTS
  The annual bone loss rate was the highest during the period of 1 to 5 years since menopause, showing an annual bone loss of 1.70% at the anteroposterior spine, and 2.21%, 1.92%, and 1.56% at the femoral neck, greater trochanter, and distal radius respectively. Even before menopause bone loss was found at the femoral neck and distal radius. BMD loss at the anteroposterior spine and greater trochanter was found in the peri-menopause group. The bone loss rate was the highest in the early menopause group (1.56%/year, P < 0.01), and became lower, however, not significantly in the late menopause group (0.38%/year, P > 0.05). Age was positively correlated with the annual bone loss rates at the anteroposterior spine, greater trochanter, and distal radius (gamma = 0.223 - 0.547, P < 0.05 - 0.01), and the number of year since menopause was also positively correlated with the annual bone loss rate at anteroposterior spine and greater trochanter (gamma = 0.432 - 0.569 P < 0.05 - 0.01). However, body weight and body mass index were negatively correlated with the annual bone loss rates at the anteroposterior spine, femoral neck, and greater trochanter (gamma = 0.239 - 0.466, P < 0.05 - 0.01).
  
  
  CONCLUSIONS
  Annual bone loss varies at different skeletal region. Age, years since menopause, and body weight influence the bone loss at different skeletal regions in females.
authors.affiliation: Institute of Metabolism and Endocrinology, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Peng-fei
authors.initials: PF
authors.lastname: Shan
authors.forename: Xiang-hang
authors.initials: XH
authors.lastname: Luo
authors.forename: Xian-ping
authors.initials: XP
authors.lastname: Wu
authors.forename: Er-yuan
authors.initials: EY
authors.lastname: Liao
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D015519:Bone Density; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008593:Menopause / Q000378:metabolism; D008875:Middle Aged; D010024:Osteoporosis / Q000453:epidemiology* / Q000378:metabolism; D015663:Osteoporosis, Postmenopausal / Q000453:epidemiology* / Q000378:metabolism; D011446:Prospective Studies