Bone mineral density and body composition in boys with distal forearm fractures: a dual-energy x-ray absorptiometry study.

OBJECTIVE: To determine whether boys with distal forearm fractures differ from fracture-free control subjects in bone mineral density (BMD) or body composition.

STUDY DESIGN: A case-control study of 100 patients with fractures (aged 3 to 19 years) and l00 age-matched fracture-free control subjects was conducted. Weight, height, and body mass index were measured anthropometrically. BMD values and body composition were determined by dual-energy x-ray absorptiometry.

RESULTS: More patients than control subjects (36 vs l4) were overweight (body mass index >85th percentile for age, P <.001). Patients had lower areal (aBMD) and volumetric (BMAD) bone mineral density values and lower bone mineral content but more fat and less lean tissue than fracture-free control subjects. The ratios (95% CIs) for all case patients/control subjects in age and weight-adjusted data were ultradistal radius aBMD 0.94 (0.91-0.97); 33% radius aBMD 0.96 (0.93-0.98) and BMAD 0.95 (0.91-0.99); spinal L2-4 BMD 0.92 (0.89-0.95) and BMAD 0.92 (0.89-0.94); femoral neck aBMD 0.95 (0.92-0.98) and BMAD 0.95 (0.91-0.98); total body aBMD 0.97 (0.96-0.99), fat mass 1.14 (1.04-1.24), lean mass 0.96 (0.93-0.99), and total body bone mineral content 0.94 (0.91-0.97).

CONCLUSIONS: Our results support the view that low BMC, aBMD, and BMAD values and high adiposity are associated with increased risk of distal forearm fracture in boys. This is a concern, given the increasing levels of obesity in children today.