Cutaneous vascular responses and thermoregulation in relation to age

Abstract

1. Sympathetic vasoconstrictor responses to inspiratory gasp and contralateral arm cold challenge were assessed in fingertip skin in relation to age and were correlated with vasoconstrictor ability during body cooling. The above relationship was also examined in diabetic patients in whom vasoconstrictor responses to inspiratory gasp and contralateral arm cold challenge had been shown previously to be markedly impaired. 2. Vasoconstrictor responses to inspiratory gasp and contralateral arm cold challenge, measured by laser Doppler flowmetry, were significantly reduced in the elderly group, although individual responses varied from normal to absent, and they also had a considerably greater variability as measured on three separate occasions than seen in young subjects. Discriminant analysis showed that, from each of three occasions, 65% of vasoconstrictor responses were abnormal in the elderly group. 3. Body cooling was performed by reducing the environmental temperature from 40 degrees C to 12 degrees C, and the time taken for blood flow to fall to 75%, 50% and 25% of the pre-cooling level (VC75, VC50, VC25, respectively) was calculated. Vasoconstriction was rapid in young subjects and was consistent with good vasoconstrictor responses to inspiratory gasp and contralateral arm cold challenge. In the elderly group, vasoconstriction was slower, but only the VC25 value differed significantly [elderly group, 13.3 (7.9-31.0) min, young group, 5.7 (2.7-15.5) min; median (interquartile range); P less than 0.05].(ABSTRACT TRUNCATED AT 250 WORDS)

Association Between Atmospheric Conditions and Occurrence of Out-of-Hospital Cardiac Arrest

“…Elderly people are more susceptible to changes in weather conditions than the young. 19 The low temperature-related higher incidence of OHCA in the elderly might be partly explained by the age-dependent decline in homeostasis, as reported by Khan et al 34 The higher incidence of arterial disease in the elderly may also make them more susceptible to thrombosis. 33 The Eurowinter Group noted that winter mortality from heart disease could be reduced by wearing warmer clothes.…”

Effect of age on cutaneous vasoconstrictor responses to norepinephrine in humans

“…Venous occlusion plethysmography measurements of forearm blood flow are more dependent on muscle blood flow than skin blood flow during normothermic conditions (3). Therefore, it is unknown whether similar agerelated alterations in vasoconstriction occur in the cutaneous vasculature.Previous studies have observed increased convective heat loss and higher skin temperatures in the elderly during cold stress (15,18,31). This greater heat loss is not attributed to decreases in fitness but rather to the inability to reduce skin temperatures to the same degree in older compared with young subjects (1, 6).…”

“…Previous studies have observed increased convective heat loss and higher skin temperatures in the elderly during cold stress (15,18,31). This greater heat loss is not attributed to decreases in fitness but rather to the inability to reduce skin temperatures to the same degree in older compared with young subjects (1, 6).…”

Effects of Dăoyĭn Qìgōng in postpolio syndrome patients with cold intolerance

“…Vasoconstriction and shivering, which are the primary means of maintaining body temperature during exposure to cold, are less efficient with this decline in vitality 29,30 . In normal aging, such changes are part of the overall framework of physiological changes.…”