Influence of age on postischaemic reactive hyperaemia

This work was carried out to evaluate the response of skin microcirculation to ischaemia in younger and older subjects, to determine if there were functional changes in microcirculation in the older skin. Skin perfusion during reactive hyperaemia was measured at volar sites on the forearms in five younger (mean age: 25.2 years) and five older normal subjects (mean age: 64.6 years). Ischaemia was produced by the application of loads of 22.3 N (24.5 kPa) and 44.5 N (49.0 kPa) applied to the skin surface for 3 min by means of a hollow cylindrical indentor. The skin perfusion within the area indented was continuously monitored by a laser Doppler flowmeter before, during and after loading. In the pre-loaded condition, there was no difference in skin perfusion between the younger and the older groups. Following loading with 22.3 N a significantly lower value of the peak perfusion relative to the pre-loaded value was observed in the older group (P less than 0.05). The perfusion in the older group following loading with 44.5 N was significantly reduced compared to the younger group (P less than 0.05). It is concluded that postischaemic reactive hyperaemia in the older skin was reduced compared with the younger skin.