Bone size and sex are key determinants of the longitudinal bone phenotype trajectory in aging males and females

We investigated the longitudinal progression of bone phenotypes, categorized as healthy, low volume, and low density, in adult males and females. Phenotype transitions were analyzed by age, sex, and average bone size. Most individuals followed an average trajectory from healthy to low volume to low density, with fracture risk increasing most notably from low volume to low density. Larger bones tended to skip the low volume stage, transitioning directly to low density. Findings demonstrate the potential of bone phenotypes for individualized bone health assessment.