[Effect of body composition on bone mineral density in males with different glucose tolerance]

To investigate the effect of body composition on bone mineral density (BMD) in males with different glucose tolerance.

A total of 87 male subjects aged 35~64 years were divided into 2 groups by glucose tolerance test, 57 diagnosed T2DM and 30 with normal glucose tolerance(NGT). BMDs of anteroposterior lumbar vertebrae (AP), left femur neck (FN), total hip (T-hip), and total bone mineral density(TBMD)were measured by dual-energy-X-ray absorptiometry (DEXA). Body composition was also measured by DEXA, while fat tissue mass(FTM), lean tissue mass(LTM), percentage of truncal fat (Tru-fat%) and total fat (Fat%) were computed. The effect of body composition on the BMD of the 2 groups was analyzed.

LTM and FN-BMD had a positive correlation in the NGT group, but no correlation in the T2DM group. The percentage of fat showed a negative relationship with the BMD of AP in the T2DM group, but not in the NGT group. The percentage of fat and total BMD had a negative association in both the NGT and the T2DM groups. In the NGT group, LTM was the independent predictor of BMD of AP,FN and hip (b=0.509, 0.411, and 0.585; P<0.01 or 0.05; R2=0.169~0.342). In the T2DM group, LTM was the independent predictor of BMD of AP (b=0.330, P<0.05, R2=0.109) and hip (b=0.462, P<0.01,R2=0.213), but not FN.

LTM has an attenuated effect on the BMD in male patients with T2DM compared with patients with NGT. An increased percent of fat percent is harmful to preserve bone mass in male adults, regardless of normal glucose tolerance or T2DM.