[Vascular changes in the lower extremities and their significance for tissue oxygen supply in middle and old age]

The studies involved practically healthy subjects aged 20-102. The oscillogram and rheogram were recorded in the upper and lower extremities. Measurements on the pulse wave progagation velocity and the skin capillary blood circulation were taken. The oxygen tension in subcutaneous cellular tissue was determined by the polarographic method. It was found that the values of systolic pressure, pulse pressure, and mean dynamic pressure increased, whereas the oscillographic index decreased with aging. In older people the rheogram was characterized by a slow elevation, rounded peak, frequently arch-shaped, flattening or absence of diastolic wave, shortening of Q-X-interval, and decrease of rheographic index. These age-associated changes reflecting decrease in elasticity and increase in rigidity of peripheral arteries as well as decrease in blood filling of tissues were more pronounced in the lower extremities. In older people the oxygen supply and the intensity of tissue respiration in subcutaneous cell tissue of legs were lower as compared with the upper extremities. In young adults no differences were found in oscillographic, rheographic, and polarographic values as well as in capillaroscopic pictures between upper and lower extremities.