[Circadian rhythms of various components of the blood in the aged]

Chronobiological modifications in advanced age were already observed for several biochemical parameters and biological functions. Within a review about the circadian rhythms of some blood constituents in the aged, personal results about blood picture, antithrombin III, serum iron and transferrin, immunoglobulins and some enzymes are reported. A circadian rhythm was evident for almost all parameters considered. Differences with respect to young persons were evidenced for IgA, IgG and antithrombin III. The circadian system in the aged is, in general, similar to that of the adult in the middle life.