BONE-MINERAL DENSITY IN PROFESSIONAL BALLET DANCERS

We studied the effect of physical training on the bone mineral content and soft tissue composition in 42 professional ballet dancers (17 men and 25 women). Twenty-eight of them were still actively performing an d 14 had retired from professional dancing. Forty-two healthy age- and sex-matched volunteers served as controls. The bone mineral density ( BMD) (g/cm2) in total body, spine, hip, arms, legs, and the proximal t ibia metaphysis was measured with a Lunar DPX apparatus and the BMD of the distal forearm was measured with single-photon absorptiometry (SP A). Twelve of the now retired dancers had earlier been measured with S PA in the tibia condyle during their active career in 1975. There was no significant difference in BMD value, between dancers and controls w ith the exception of a lower BMD i, th, head of the male dancers and a lower BMD in the arms of female dancers. After correcting for differe nce in body mass index (BMI), using analysis of covariance we found si gnificant higher BMD in the lower extremities of female dancers and in the hip of male dancers. No correlation was found between the SPA mea surements from 1975 and the corresponding measurements 15 years later. The dancers were on average 9 kg lighter but of the same height as th e controls. The dancers had lower body mass index and fat content but their lean body mass was the same as the controls.