[Bone mineral density, milk intake and physical activity in boys who suffered forearm fractures]. / Densidade mineral óssea, ingestão de leite e atividade física de meninos que sofreram fraturas no antebraço.

OBJECTIVE: To compare boys with and without forearm fracture in terms of their bone mineral density, intake of milk and dairy products, and physical activity. METHODS: There were 23 boys in each group (aged between 7 and 13 years). They were submitted to bone densitometry with dual-energy x-ray absorptiometry (DEXA) of the forearm (opposite side of the fracture). Participants answered questionnaires about their intake of milk and dairy products, and about their physical activity. RESULTS: The mean+/-SD of the bone mineral density of the radial and ulnar distal diaphysis in the case group (0.430+/-0.038 g.cm(-2)) was significantly lower (p = 0.018) than that of the control group (0.458+/-0.039 g.cm(-2)). Likewise, the mean of the distal metaphysis of the forearm was 0.309+/-0.033 g.cm(-2) in the case group and 0.349+/-0.054 g.cm(-2) in the control group (p = 0.004). Milk intake (1.5+/-1.2 cups a day) was significantly lower in the case group (p = 0.001) than in the control group (2.7+/-1.2 cups a day). The number of boys who practiced after-school physical activity was significantly lower (p = 0.017) in the case group (six boys = 26%) than in the control group (15 boys = 53%). CONCLUSION: Boys who suffered forearm fracture showed lower bone mineral density compared with the control group. In the case group, milk intake and physical activity were lower than in the control group.