IMPAIRMENT OF THE POSTURAL VENOARTERIOLAR REFLEX IN AGED INDIVIDUALS

The venoarteriolar vasoconstriction reflex plays a major role in the p revention of leg oedema in the upright position in man. We studied the venoarteriolar vasoconstriction reflex with laser Doppler flowmetry i n young (21 subjects, age 17-27) and very old (20 subjects, age 75-100 ) healthy volunteers. In the group of young volunteers, after lowering of the lower extremity 50 cm below the heart level, cutaneous blood f lux decreased to 16.6% of the baseline, whereas in the group of old pe rsons the venoarteriolar relies was impaired and the flux decreased on ly to 29.2%. The difference between the two groups was statistically s ignificant (p < 0.001). These results may explain the increased preval ence of postural oedema in old people.