Physical activity and bone mineral acquisition in peripubertal girls

The association of the amount and type of physical activity dth bone minera l acquisition was studied in 191 peripubertal Caucasian girls aged 9-16 yea rs (66 gymnasts, 65 runners, and 60 nonathletic controls). Weight, height, stage of puberty, the amount of leisure-time physical activity, and years o f training were recorded, and dietary calcium and vitamin D were assessed b y a semi-quantitative questionnaire. The bone area, the bone mineral densit y (BMD), and the bone mineral content (BMC) of the femoral neck, lumbar spi ne and antebrachium were measured by dual-energy x-ray absorptiometry. The unadjusted mean values of BMD at the femoral neck were 15.2% higher in the pubertal gymnasts than in the controls (P<0.001). Compared with the control s, the mean BMC adjusted for bone area of the pubertal gymnasts at the femo ral neck and lumbar spine was 16.4% and 10.8% higher, respectively. When co mparing the association of the type of physical activity among the pubertal athletics by multiple regression analysis, height, physical activity, gymn astics, and Tanner stage emerged as significant variables and accounted for 54.7% and 63.4% of the total variation in BMD of the femoral neck and lumb ar spine, respectively. These results indicate that physical activity is as sociated with bone mineral acquisition in peripubertal girls and that high- impact weight-bearing exercise seems to be particularly associated with the increase of the BMD at the femoral neck.