[The relationship between obesity, intra-abdominal fat area and bone mineral density and bone strength]

Recently some studies have showed that bone strength may avoid the misdiagnosis and missed diagnosis of osteoporosis(OP) by bone mineral density (BMD) alone. It was found that corrected bone mineral content (cBMC) was well correlated with bone strength. In this study bone strength was replaced by cBMC to compare it with BMD, and evaluate whether BMD has limitations in the diagnosis of OP in obese individuals. one hundred and two healthy subjects in the community with the body mass index (BMI) between 25 and 39 kg/m2 were enrolled. There were 31 males and 71 females with a mean age of 37.2 +/- 9.4 years. Their BMD and BMC of lower limbs, trunk and the whole body were measured with dual energy X-ray absorptiometry (DEXA). cBMC was expressed by BMC divided by weight. Intra abdominal fat area (IAFA) was measured by CT scan at the level between 4th-5th lumbar vertebra. Linear correlation analysis with SPSS 10.0 soft pack was used for statistics. The results showed that there was a positive correlation and tendency between body weight, BMI and BMD values of lower limbs, trunk and the whole body. However, negative correlation and tendency were demonstrated between body weight, BMI and cBMC, between IAFA and BMD of lower limbs, trunk and the whole body and between IAFA and cBMC as well. We found that the tendency of changes of cBMC and bone strength was similar. So we suggest in certain extent that cBMC could replace bone strength in the diagnosis of OP in obese individuals.