Laakso S, et al. - This study determined the impacts of severe childhood-onset obesity on the cross talk between metabolic state, testes, and skeleton at late puberty. For testicular hormones and X-ray absorptiometry-derived bone mass, a cohort of adolescent and young adult males with severe childhood-onset obesity and an age-matched control group were evaluated. In young men, severe childhood-onset obesity was correlated with impaired Leydig cell function. The findings from the present study suggested that lower free testosterone could contribute to impaired skeletal characteristics.