Laser Doppler flux characteristics at the skin of the dorsum of the foot in young and in elderly healthy human subjects.
In aged human subjects the cutaneous circulation has shown reduced vasoreactive capacity when stimulated by heat or ischemia, and autonomic dysfunction developing in the elderly was suggested. Should this autonomic dysfunction affect the arteriolar vasomotional activity, it might be demonstrated by laser Doppler fluxmetry (LDF) at rest. LDF flow motion characteristics at the dorsal foot skin were investigated under resting conditions in two subject groups differing in age. The younger group (n = 27, aged 25-29 years) showed a resting flux of 3.0 +/- 1.0 Arbitrary Units (AU) and a flux amplitude of 0.34 +/- 0.13 AU. In the elderly group (n = 22, aged 60-92 years) both these values were significantly (P < 0.05) lower (2.4 +/- 0.5 and 0.18 +/- 0.05 AU, respectively). The flux frequency, on the contrary, was similar in both age groups: 4.9 cycles min-1. We conclude that the mean resting flux and the mean flow motion amplitude under resting conditions at the skin of the dorsum of the foot are significantly reduced in an old-age group. The latter finding might be an aging phenomenon affecting the microvascular tone and reactivity, and might be one of the elements responsible for the attenuated cutaneous vasoreactivity described in elderly humans in response to heat and ischemic stress.
Van den Brande
P
P
Department of Vascular Surgery, Academic Hospital, Vrije Universiteit Brussel, Belgium.
von Kemp
K
K
De Coninck
A
A
Debing
E
E
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D005260:Female; D005528:Foot / Q000098:blood supply*; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D012016:Reference Values; D012867:Skin / Q000098:blood supply*; D018709:Statistics, Nonparametric; D014666:Vasomotor System / Q000502:physiology