Attenuation of the cutaneous vasoconstrictor response to cold in elderly men

This study tested the hypothesis that the cutaneous vasoconstrictor response to cold is reduced in elderly individuals. We measured laser Doppler flux (LDF) in the fingertip and blood cell velocity (CBV), via videodensitometry, in individual capillaries of the finger nailfold both before and during submersion of the contralateral arm in a 15 degrees C water bath. Subjects were 10 young (M = 25 years) and 10 old (M = 71 years) male adults. During the first minute of cooling, both the young (Y) and old (O) groups experienced a significant (p < .004) decrease in LDF. Over the subsequent 4 minutes of cold stress, LDF remained significantly depressed in the Y group, whereas LDF returned to values not significantly different from pre-cooling control in the O subjects. During the cold stress, CBV significantly decreased in the Y (p < .03) subjects; however, the degree of change was much less than that of LDF (49% decrease in LDF versus 14% decrease for CBV). In contrast to the Y subjects, the O group showed no significant change in CBV during cooling (p > .28). These results indicate that indirect cooling elicits a reflex decrease in cutaneous bloodflow, which is more pronounced in the deep vessels than in the superficial capillaries, and that these effects are attenuated with advancing age.