Sport-specific differences in DXA-derived bone outcomes persist after adjustment for lean mass in competitive female athletes

Abstract Bone mineral density (BMD) contributes to skeletal strength, and mechanical loading influences skeletal adaptation. This cross-sectional study compared total-body BMD, BMD Z-scores, and bone mineral content (BMC) between Finnish female athletes ( n = 207) and non-athlete controls ( n = 307) and across endurance, antigravitation, ball game and power sports. Outcomes were assessed using dual-energy X-ray absorptiometry (DXA). Analyses were adjusted for age and total lean mass. Athletes had higher total-body BMD, BMD Z-scores, and BMC than controls in unadjusted comparisons (all p < .001). After adjustment, differences in BMD and BMD Z-scores remained, whereas the BMC difference was no longer significant. Lean mass was positively associated with all bone outcomes, with the strongest association observed for BMC. Bone outcomes also differed by sport category, with power athletes having the highest and endurance athletes the lowest mean values. Sport-category effects remained significant after adjustment for age and total lean mass. Although mechanical loading was not directly measured, sport-specific loading characteristics may provide useful context when interpreting DXA-derived measures in athletes.