[Interpretation of a vitality model from the clinico-experimental viewpoint].

The vitality model conceived by Beier from a theoretical point of view is corroborated by clinical and experimental investigations of the authors. From a randomized study on the biological age of a statistically representative population group it can be concluded that the speed of ageing of this group is not linear in its course and hardly displays any differences between the sexes. Besides, distinct selection effects in advanced age suggest that the human population might consist of two sub-populations (the potentially long-lived and the potentially short-lived) who differ from one another with regard to the speed of ageing, morbidity and to the duration of life. Furthermore, similarities of the sex-specific change in vitality as occurs in the course of life, and the significance of this change for a possible reduction of male over-mortality are pointed out.