ABSTRACT
A number of studies investigated the distribution of BMD values and the prevalence of osteoporosis in China, but their findings varied. Until now, a BMD reference database based on uniform measurements in a large-scale Chinese population has been lacking. A total of 75,321 Chinese adults aged 20 years and older were recruited from seven centers between 2008 and 2018. BMD values at the lumbar spine (L1 -L4 ), femoral neck, and total femur were measured by GE Lunar dual-energy X-ray absorptiometry systems. BMD values measured in each center were cross-calibrated by regression equations that were generated by scanning the same European spine phantom 10 times at every center. Cubic and multivariate linear regression were performed to assess associations between BMD values and demographic variables. Sex-specific prevalence of osteoporosis was age-standardized based on the year 2010 national census data for the Chinese population. The sex-specific BMD values at each site were negatively associated with age, positively associated with body mass index levels, and lower in the participants from southwest China than in those from other geographic regions after multivariate adjustment. Furthermore, BMD values at the femoral neck and total femur decreased with the year of BMD measurement. The peak BMD values at the lumbar spine, femoral neck, and total femur were 1.088 g/cm2 , 0.966 g/cm2 , and 0.973 g/cm2 , respectively, for men, and 1.114 g/cm2 , 0.843 g/cm2 , and 0.884 g/cm2 , respectively, for women. The age-standardized prevalence of osteoporosis at the spine or hip was 6.46% and 29.13% for men and women aged 50 years and older, respectively. Currently a total of 10.9 million men and 49.3 million women in China are estimated to have osteoporosis. In our national examination of BMD, we found that BMD values differed by demographic characteristics. We estimated the age-standardize prevalence of osteoporosis in China to be 6.46% and 29.13% respectively, for men and women aged 50 years and older.
