Normal changes in spinal bone mineral density in a Chinese population: Assessment by quantitative computed tomography and dual-energy X-ray absorptiometry

This study was designed to determine age- and gender-based normative values for spinal bone mineral density (BMD) in a Chinese population. In addition , we compared our data with those of other countries and populations. Four hundred and forty-three healthy Chinese subjects, aged 10-79 years (189 mal es, mean age 46.9 years; 254 females, mean age 45.7 years) were recruited f or BMD assessment. BMD was measured by quantitative computed tomography (QC T) and dual-energy X-ray absorptiometry (DXA), including posteroanterior DX A (PA-DXA), lateral DXA (L-DXA) and midlateral DXA (mL-DXA). For both gende rs, BMD values peaked in the 10-19 year age group when measured by QCT, and in the 30-39 year age group when measured by PA-DXA. BMD values decreased with age after reaching peak bone density in males and females for all meas urements, except for PA-DXA in males. Male BMD values by DXA tended to incr ease beginning with the 60-69 age group through the 70-79 age group whether by PA-DXA, or L-DXA and mL-DXA. However, male QCT data showed stable BMD v alues among these two older groups. Comparative results showed female QCT d ata were higher in the 20-39 age group and lower after the 40-49 age group compared with American females. The peak BMD value by PA-DXA in Chinese fem ales was reached in the same age group as American and European females and was similar in magnitude (p > 0.05). However, the peak BMD value for Chine se females was reached earlier and was significantly higher than that obser ved in Japanese females (p < 0.001). We conclude that the age group in whic h the peak BMD values are reached is different depending on the technique u sed, as is the calculated age-related rate of bone loss. It can be speculat ed that such differences reflect different timing for bone maturation in ca ncellous and cortical bone.