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

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.

The prevalence of osteoporosis in Korean adults aged 50 years or older and the higher diagnosis rates in women who were beneficiaries of a national screening program: The Korea National Health and Nutrition Examination Survey 2008–2009

“…Although the prevalence of osteoporosis in Asian countries is not clear, because there are only a few studies in these populations, the osteoporosis prevalence in women aged from 50 to 79 years was reported as about 38% in China (19) and 31.0% in Japan. (20) The prevalence in East Asian countries was quite similar to our data. The prevalence of osteoporosis among these older than 50 years of age in the United States was reported as 10% in women and 2% in men from the National Health and Nutrition Examination Survey (NHANES) 2005-2006, (11) which was a lower prevalence compared to our study.…”

Geographic variation of bone mineral density and selected risk factors for prediction of incident fracture among Canadians 50 and older

“…The variation was larger than regional variation found in the U.S. [18], but smaller than geographic variation found within Norway, Mexico, Japan [19][20][21] or across Europe [22]. As expected, regional variation in the prevalence of osteoporosis (as defined by BMD T-scores≤−2.5) was related to underlying differences in the distribution of BMD.…”

Localization of Quantitative Trait Loci for Bone Mineral Density on Chromosome 13 in the Mongolian Population

“…This prevalence was lower than that reported in the Japanese Population Osteoporosis Study (Iki et al, 2001) of females over 50 with a 36.3% prevalence in the distal radius. On the other hand, the prevalence in our study was higher than that of other ethnicities with 10.0%, 5.0%, 13.3%, 15.6% and 15.1% in European, African, Asian, Hispanic, and native American origins, respectively, over 50 years measured in the distal forearm using DEXA (Barrett-Connor et al, 2005).…”