Endocrine Abstracts

Objective: To examine different methods of analysing bone health and body composition in children and examine the relationships between these methods.

Method: In a LREC approved cross-sectional study, DXA was used to assess bone mineral content (BMC) (at total body (TB), lumbar spine (LS), femur (F) and femoral neck (FN)), cross-sectional moment of inertia (CSMI) at the proximal femur and body composition (defined as Lean mass (LM) and Fat mass (FM)) in 60 healthy Glasgow school children (30M:30F) aged between 5–16 years (median age:10.5 yrs, 10th, 90th centiles:6.1,14.4). Speed of Sound Quantitative Ultrasound (QUS) was used for assessment of tibia (t) and radius (r), and Maximal Isometric Grip Force (MIGF) of the dominant hand as a surrogate marker of muscle strength. All children were measured for routine anthropometry, hip and waist circumferences.

Results: BMC(TB), BMC(LS) and BMC(F) were correlated with LM (r,0.9, P=0.0001; r,0.6, P=0.0001; r,0.9, P=0.0001 respectively). BMC(TB) and BMC(F) were also independently correlated with FM (r,0.5, P=0.001; r,0.5, P=0.008 respectively). FM was inversely correlated to Hip/Waist ratio (r,−0.5, P=0.001). BMC(TB) and BMC(LS) were correlated with QUS(t) (r,0.3, P=0.04; r,0.4, P=0.007 respectively) and with QUS(r) (r,0.3, P=0.03; r,0.4, P=0.04 respectively). BMC(TB) and BMC(LS) were correlated with MIGF (r,0.8, P=0.0001; r,0.4, P=0.004 respectively). LM was correlated to QUS (t&r), MIGF and CSMI (r,0.4, P=0.04; r,0.4, P=0.02; r,0.8, P=0.0001; r,0.9, P=0.001 respectively). MIGF was correlated with CSMI and QUS (r) (r,0.8, P=0.0001, r,0.5, P=0.03). There were no correlations between BMC(F) and BMC(FN) with QUS and MIGF.

Conclusions: BMC is associated with both LM and FM at multiple skeletal sites. Hip/waist ratio is a good marker of FM as measured by DXA. BMC and LM measured by DXA are correlated with both QUS and MIGF. DXA, QUS and MIGF are important modalities in the assessment of bone health and body composition in children.