Osteoporosis International

, Volume 12, Issue 7, pp 529–537

Bone Mineral Density of the Spine, Hip and Distal Forearm in Representative Samples of the Japanese Female Population: Japanese Population-Based Osteoporosis (JPOS) Study

  • M. Iki
  • S. Kagamimori
  • Y. Kagawa
  • T. Matsuzaki
  • H. Yoneshima
  • F. Marumo
  • for JPOS Study Group
Original Article

DOI: 10.1007/s001980170073

Cite this article as:
Iki, M., Kagamimori, S., Kagawa, Y. et al. Osteoporos Int (2001) 12: 529. doi:10.1007/s001980170073

Abstract:

Low bone mineral density (BMD) is one of the most important elements for the diagnosis of osteoporosis and screening people with higher risk of fractures. To establish the criterion value of BMD for the diagnosis of osteoporosis and to estimate the prevalence rate of osteoporosis in Japanese women, we performed a Japanese population-based osteoporosis (JPOS) study. The subjects were 4550 women aged 15 through 79 years randomly selected from seven municipalities throughout Japan. The sample size was determined to ensure that the observed mean BMD would remain within 2.5% from the real value with a probability of 0.95 in each of the 5-year age groups. The study comprised bone mass measurements by dual-energy X-ray absorptiometry at the spine (L2–4), hip and distal forearm, body size measurements and detailed interviews on medical and gynecologic history. After excluding those subjects with apparent or suggested abnormalities affecting bone mass from 3985 women (87.6%) who completed the study, 3465 women remained and served as the subjects. We present 5-year age-specific mean values of BMD and cut-off values for the diagnosis of osteoporosis according to World Health Organization (WHO) and the Japanese Society of Bone and Mineral Research (JSBMR) criteria. The cut-off levels at the spine and the distal radius proposed in this study were similar to those proposed by the JSBMR but the cut-off level at the femoral neck in this study was 4.7% higher than that of the JSBMR. The prevalence rates of osteoporosis according to WHO criteria in the present subjects aged 50 through 79 years were calculated as 38.0% at the spine, 11.6% at the femoral neck and 56.8% at the distal one-third site of the radius, and those in the Japanese female population of the same age were estimated to be 35.1%, 9.4% and 51.2%, respectively. A fivefold difference was observed among the prevalence rates at different skeletal sites, which suggests that the different definitions of osteoporosis should be established for the different skeletal sites. The prevalence rate diagnosed at the femoral neck seemed to be lower in the present study than those reported for Caucasians. This might account for a lower incidence rate of hip fracture in Japanese women.

Key words:Bone mineral density – Diagnostic criteria for osteoporosis – DXA – Japanese women – Population-based epidemiologic study – Prevalence rate of osteoporosis

Copyright information

© International Osteoporosis Foundation and National Osteoporosis Foundation 2001

Authors and Affiliations

  • M. Iki
    • 1
  • S. Kagamimori
    • 2
  • Y. Kagawa
    • 3
  • T. Matsuzaki
    • 4
  • H. Yoneshima
    • 5
  • F. Marumo
    • 6
  • for JPOS Study Group
  1. 1.Department of Public Health, Kinki University School of Medicine, Osaka-Sayama, JapanJP
  2. 2.Department of Welfare Promotion and Epidemiology, Toyama Medical and Pharmaceutical University, Toyama, JapanJP
  3. 3.Kagawa Nutrition University, Tokyo, JapanJP
  4. 4.Institute of Comprehensive Community Care, Tokyo, JapanJP
  5. 5.Kasukabe Shuuwa Hospital, Kasukabe, JapanJP
  6. 6.Department of Homeostasis Medicine and Nephrology, Graduate School of Tokyo Medical and Dental University, Tokyo JapanJP