The present work describes bibliographic analysis of ontogenetic changes in hormonal regulation of sleep and circadian biorhythms. It is suggested that two-stage, age-related dynamics of such changes may be related to differential occurrence registered by us earlier, of maxima of morbidity and mortality caused by a number of disorders, in middle-age and in senile period. It is proposed to concentrate future efforts on elaboration of mathematical models of ontogenetic regulation, on the basis of systems biomedicine.