title: Fracture prediction from bone mineral density in Japanese men and women.
abstract: In a cohort of 2356 Japanese elderly, after adjusting for age and prevalent vertebral fracture, baseline BMD predicted the risk of spine and hip fracture with similar RR to that obtained from previous reports in whites. The RR per SD decrease in BMD for fracture declined with age.
  
  
  BACKGROUND
  Low bone mineral density (BMD) is one of the most important predictors of a future fracture. However, we are not aware of any reports among Japanese in Japan.
  
  
  METHODS
  We examined the association of BMD with risk of fracture of the spine or hip among a cohort of 2356 men and women aged 47-95 years, who were followed up by biennial health examinations. Follow-up averaged 4 years after baseline measurements of BMD that were taken with the use of DXA. Vertebral fracture was assessed using semiquantitative methods, and the diagnosis of hip fracture was based on medical records. Poisson and Cox regression analysis were used.
  
  
  RESULTS
  The incidence was twice as high in women as in men, after adjusting for age. After adjusting for baseline BMD and prevalent vertebral fracture, however, the gender difference was no longer significant. Age, baseline BMD of spine and femoral neck, and prior vertebral fracture predicted vertebral fracture and hip fracture. Loss of absolute BMD of the femoral neck predicted spine fracture, after adjusting for baseline BMD; rates of change in percent BMD, weight, height, body mass index, and age at menopause did not. The predictive value of baseline BMD for vertebral fracture risk was similar in men and women. The relative risk (RR) for vertebral fracture and hip fracture per SD decrease in BMD declined with age, after adjustment for prevalent vertebral fractures.
  
  
  CONCLUSIONS
  Baseline BMD, loss of femoral neck BMD, and prior vertebral fracture predict the risk of spine and hip fracture in Japanese with similar RR to that obtained from previous reports in whites. The RR per SD decrease in BMD for fracture declined with age, suggesting that factors other than BMD might play a greater role in the elderly.
authors.affiliation: Department of Clinical Studies, Radiation Effects Research Foundation, Hiroshima, Japan. fujiwara@rerf.or.jp
authors.forename: Saeko
authors.initials: S
authors.lastname: Fujiwara
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Kasagi
authors.forename: Naomi
authors.initials: N
authors.lastname: Masunari
authors.forename: Kumiko
authors.initials: K
authors.lastname: Naito
authors.forename: Gen
authors.initials: G
authors.lastname: Suzuki
authors.forename: Masao
authors.initials: M
authors.lastname: Fukunaga
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000502:physiology*; D005260:Female; D006620:Hip Fractures / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000293:injuries; D008297:Male; D008875:Middle Aged; D012306:Risk; D012737:Sex Factors; D016103:Spinal Fractures / Q000453:epidemiology*