title: A randomized, prospective study of the effects of Tai Chi Chun exercise on bone mineral density in postmenopausal women.
abstract: OBJECTIVE
  To evaluate the potential benefits of programmed Tai Chi Chun (TCC) exercise on the weight-bearing bones of early postmenopausal women.
  
  
  METHODS
  Age-matched and randomized prospective intervention.
  
  
  METHODS
  University medical school.
  
  
  METHODS
  One hundred thirty-two healthy postmenopausal women (mean age, 54.0+/-3.5y) within 10 years of menopause onset were recruited and randomized into the TCC exercise group (n=67) or the sedentary control group (n=65).
  
  
  METHODS
  Supervised TCC exercise was performed by the TCC group for 45 minutes a day, 5 days a week, for 12 months; control subjects retained a sedentary life style. Main outcome measures Bone mineral density (BMD) was measured in the lumbar spine and proximal femur by using dual-energy x-ray absorptiometry and in the distal tibia by using multislice peripheral quantitative computed tomography (pQCT). All BMD measurements were repeated after 12 months in both groups. Fracture rate was also documented.
  
  
  RESULTS
  Baseline measurements showed homogeneity in age, anthropometric variables, and menstruation status between the TCC and control groups. Exactly 81.6% of the subjects in the TCC group and 83.1% of subjects in the control group completed the 12-month follow-up study. BMD measurements revealed a general bone loss in both TCC and sedentary control subjects at all measured skeletal sites, but with a reportedly slower rate in the TCC group. A significant 2.6- to 3.6-fold retardation of bone loss (P<.01) was found in both trabecular and cortical compartments of the distal tibia in the TCC group as compared with the controls, as measured by pQCT. A total of 4 fracture cases were documented during follow-up, including 3 subjects in the control group and 1 in the TCC group.
  
  
  CONCLUSIONS
  This is the first prospective and randomized study to show that a programmed TCC exercise intervention is beneficial for retarding bone loss in weight-bearing bones in early postmenopausal women. Long-term follow-up is needed to substantiate the role of TCC exercise in the prevention of osteoporosis and its related fracture.
authors.affiliation: Department of Orthopaedics and Traumatology, Chinese University of Hong Kong, Hong Kong.
authors.forename: Kaiming
authors.initials: K
authors.lastname: Chan
authors.forename: Ling
authors.initials: L
authors.lastname: Qin
authors.forename: Mingchu
authors.initials: M
authors.lastname: Lau
authors.forename: Jean
authors.initials: J
authors.lastname: Woo
authors.forename: Szeki
authors.initials: S
authors.lastname: Au
authors.forename: Wingyee
authors.initials: W
authors.lastname: Choy
authors.forename: Kwongman
authors.initials: K
authors.lastname: Lee
authors.forename: Shiuhung
authors.initials: S
authors.lastname: Lee
mesh_terms: D044466:Asian People; D015519:Bone Density; D005260:Female; D050723:Fractures, Bone / Q000453:epidemiology; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000517:prevention & control*; D017063:Outcome Assessment, Health Care; D011446:Prospective Studies; D026302:Tai Ji