Relationship Of Body Composition With Bone Mineral Density In Northern Chinese Male

ObjectiveThis study aims to investigate the associations between body composition and bone mineral density (BMD) for different age and body mass index (BMI) on the basis of collecting male clinical cases in North China. Thus provide scientific basis for prevention and management of male osteoporosis.MethodsA cross-sectional study was conducted on five hundred and thirty-two northern Chinese men, divided on the basis of BMI and age. BMD (total body, hip, neck femur, shaft femur, lumbar spine at L1-L4, lean mass (LM), Fat mass(FM), percent body fat (%BF), were measured using dual-energy X-ray absorptiometry. SPSS (version 13.0) was used for analysis.Results1. For the whole, age was negatively correlated with BMD of total body, hip, neck femur and shaft femur (r<-0.2, p<0.01), weight was positively correlated with BMD in all regions (r>0.2, p<0.01), fat mass and lean mass were also positively correlated with BMD in all body regions, percent body fat (%BF) was not correlated with total and any regional BMD, age was negatively correlated with lean mass (r=-0.403, p<0.01)2. Compared to young group, lean mass, BMD of total body, hip, neck femur and shaft femur in old group were lower (p<0.01)3. In young group, lean mass was significantly positive with BMD in all body regions (r >0.3, all p<0.01) while fat mass only had significant associations with BMD of total body and hip (r>0.3, p<0.01). In old group both fat mass and lean mass were significantly positive with BMD in all body regions (r>0.2, p<0.01)4. In the results of multiple regression analysis,in old group both fat mass and lean mass were significantly positive with BMD in all body regions (p<0.01), but only lean mass had significant associations with BMD in young group (p<0.05)5. Comparison of fat mass, lean mass,%BF among control group, overweight group and obesity group were significantly different (p<0.01). Compared to control group, BMD of overweight group and obesity group were significantly higher (p<0.01)6. In control group, lean mass was significantly positive with BMD in all body regions (r>0.2, all p<0.01), fat mass only had a significant association with hip BMD (r =0.251, p<0.01). Lean mass had significant associations with BMD of total body, hip, shaft femur and neck femur (r<0.2, p>0.05) while there was no statistical significance between fat mass and BMD in overweight group. In obesity group, lean mass was significantly positive with BMD in all body regions (r>0.3, all p<0.01) and %BF was negatively associated with total body, hip,neck femur and shaft femur BMD (r<-0.3, p<0.01)7. In the results of multiple regression analysis, fat mass was significantly positive with total body, hip,neck femur and shaft femur BMD (p<0.01) in cntrol group while in both overweight group and obesity group fat mass had no significant associations with BMD (p>0.05)Conclusions1. Age had a negative association with BMD in old men.2. Weight was a good predictor of BMD.3. Lean mass had a positive association with BMD in men.4. Fat mass had a positive association with BMD in old men.5. In overweight and obesity group (BMI≥24 kg/m2), fat mass was not correlated with total and any regional BMD and% BF was negatively associated with BMD.