Total osteocalcin levels are independently associated with worse testicular function and a higher degree of hypothalamic–pituitary–gonadal axis activation in Klinefelter syndrome

F. Carlomagno, V. Hasenmajer, M. Spaziani, M. Tenuta, F. Sesti, C. Tarantino, C. Pozza, A. M. Isidori & D. Gianfrill