Reflex peripheral vasoconstriction is diminished in older men

William Lawrence Kenney, Jr., C. Glenn Armstrong

Research output: Contribution to journalArticle

70 Citations (Scopus)

Abstract

The purpose of this study was to compare reflex control of limb blood flow in healthy young (Y; 26 ± 2 yr) and older (O; 61 ± 2 yr) men during whole body cooling under resting conditions. To better isolate the effect of chronological age, the two age groups (n = 6 per group) were closely matched for maximal oxygen uptake, body surface area, skinfold thickness, and fat- free weight. Subjects sat in an environmentally controlled chamber clad in standardized (0.6-clo) light cotton clothing at a dry-bulb temperature (T(db)) of 28°C. After 30 min, T(db) was decreased by 2°C every 5 min until T(db) - 10°C, where it was held constant for the remainder of the 120-min session. Esophageal and mean skin temperatures were monitored continuously. Forearm blood flow (FBF) was measured every 5 min by venous occlusion plethysmography by using a mercury-in Silastic strain gauge while arm temperature between the wrist and elbow was clamped at 37.2 ± 0.1°C by localized warm air beating. In this way, limb vasoconstriction was driven solely by thermoregulatory reflexes and not by direct effects of localized cooling. Mean skin temperature decreased at a similar rate and to a similar extent (by ~6°C over a 2-h period) in both age groups, whereas esophageal temperature was relatively unaffected. In response to the local heating, the Y group maintained a significantly higher FBF than did the O group during the initial 30 min but decreased FBF during the cooling phase at a greater rate and to a greater extent than did the O group, leading to a significantly lower FBF during the final 30 min (at T(db) 10°C). Because there was no age difference in the mean arterial pressure response, similar effects of age were seen on forearm vascular conductance (FBF/mean arterial pressure). It was concluded that older men have a diminished reflex limb vasoconstrictor response to skin cooling. Furthermore, this difference in control of peripheral blood flow appears to be related to age per se; i.e., it is not a reflection of age-related differences in maximal oxygen uptake or body composition.

Original languageEnglish (US)
Pages (from-to)512-515
Number of pages4
JournalJournal of Applied Physiology
Volume80
Issue number2
DOIs
StatePublished - Jan 1 1996

Fingerprint

Vasoconstriction
Reflex
Forearm
Extremities
Skin Temperature
Temperature
Arterial Pressure
Age Groups
Oxygen
Skinfold Thickness
Clothing
Plethysmography
Body Surface Area
Vasoconstrictor Agents
Elbow
Body Composition
Wrist
Mercury
Heating
Blood Vessels

All Science Journal Classification (ASJC) codes

  • Physiology
  • Physiology (medical)

Cite this

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abstract = "The purpose of this study was to compare reflex control of limb blood flow in healthy young (Y; 26 ± 2 yr) and older (O; 61 ± 2 yr) men during whole body cooling under resting conditions. To better isolate the effect of chronological age, the two age groups (n = 6 per group) were closely matched for maximal oxygen uptake, body surface area, skinfold thickness, and fat- free weight. Subjects sat in an environmentally controlled chamber clad in standardized (0.6-clo) light cotton clothing at a dry-bulb temperature (T(db)) of 28°C. After 30 min, T(db) was decreased by 2°C every 5 min until T(db) - 10°C, where it was held constant for the remainder of the 120-min session. Esophageal and mean skin temperatures were monitored continuously. Forearm blood flow (FBF) was measured every 5 min by venous occlusion plethysmography by using a mercury-in Silastic strain gauge while arm temperature between the wrist and elbow was clamped at 37.2 ± 0.1°C by localized warm air beating. In this way, limb vasoconstriction was driven solely by thermoregulatory reflexes and not by direct effects of localized cooling. Mean skin temperature decreased at a similar rate and to a similar extent (by ~6°C over a 2-h period) in both age groups, whereas esophageal temperature was relatively unaffected. In response to the local heating, the Y group maintained a significantly higher FBF than did the O group during the initial 30 min but decreased FBF during the cooling phase at a greater rate and to a greater extent than did the O group, leading to a significantly lower FBF during the final 30 min (at T(db) 10°C). Because there was no age difference in the mean arterial pressure response, similar effects of age were seen on forearm vascular conductance (FBF/mean arterial pressure). It was concluded that older men have a diminished reflex limb vasoconstrictor response to skin cooling. Furthermore, this difference in control of peripheral blood flow appears to be related to age per se; i.e., it is not a reflection of age-related differences in maximal oxygen uptake or body composition.",
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Reflex peripheral vasoconstriction is diminished in older men. / Kenney, Jr., William Lawrence; Armstrong, C. Glenn.

In: Journal of Applied Physiology, Vol. 80, No. 2, 01.01.1996, p. 512-515.

Research output: Contribution to journalArticle

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