Non-Uniform, Age-Related Decrements in Regional Sweating and Skin Blood Flow.
ABSTRACT Aging is associated with attenuated thermoregulatory function which varies regionally over the body. Decrements in vasodilation and sweating are well documented with age yet limited data are available concerning the regional relation between these responses. We aimed to examine age-related alterations in the relation between regional sweating (RSR) and skin blood flow (SkBF) to thermal and pharmacological stimuli. Four microdialysis fibers were inserted in the ventral forearm, abdomen, thigh, and lower back of eight healthy aged subjects (64±7 years) and nine young (23±3 years) during 1) acetylcholine dose response (ACh 1x10(-7) - 0.1 M, mean skin temperature 34°C) and 2) passive whole body heating to Δ1°C rise in oral temperature (Tor). RSR and SkBF were measured over each microdialysis membrane using ventilated capsules and laser-Doppler flowmetry. Maximal SkBF was measured at the end of both protocols (50mM SNP). Regional sweating thresholds and RSR were attenuated in aged versus young at all sites (p<0.0001) during whole body heating. Vasodilation thresholds were similar between groups (p>0.05). Attenuated SkBF were observed at the arm and back in the aged, representing 56% and 82% of those in the young at these sites, respectively (0.5 ΔTor). During ACh perfusion SkBF (p=0.137) and RSR were similar between groups (p= 0.326). Together these findings suggest regional age-related decrements in heat-activated sweat gland function but not cholinergic sensitivity. Functional consequences of such thermoregulatory impairment include the compromised ability of older individuals to defend core temperature during heat exposure, and a subsequently greater susceptibility to heat-related illness and injury.
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ABSTRACT: The influence of peripheral factors on the control of heat loss responses (i.e., sweating and skin blood flow) in the postexercise period remains unknown in young and older adults. Therefore, in eight young (22 ± 3 years) and eight older (65 ± 3 years) males, we examined dose-dependent responses to the administration of acetylcholine (ACh) and methacholine (MCh) for sweating (ventilated capsule), as well as to ACh and sodium nitroprusside (SNP) for cutaneous vascular conductance (CVC, laser-Doppler flowmetry, % of max). In order to assess if peripheral factors are involved in the modulation of thermoeffector activity postexercise, pharmacological agonists were perfused via intradermal microdialysis on two separate days: (1) at rest (DOSE) and (2) following a 30-min bout of exercise (Ex+DOSE). No differences in sweat rate between the DOSE and Ex+DOSE conditions at either ACh or MCh were observed for the young (ACh: P = 0.992 and MCh: P = 0.710) or older (ACh: P = 0.775 and MCh: P = 0.738) adults. Similarly, CVC was not different between the DOSE and Ex+DOSE conditions for the young (ACh: P = 0.123 and SNP: P = 0.893) or older (ACh: P = 0.113 and SNP: P = 0.068) adults. Older adults had a lower sweating response for both the DOSE (ACh: P = 0.049 and MCh: P = 0.006) and Ex+DOSE (ACh: P = 0.050 and MCh: P = 0.029) conditions compared to their younger counterparts. These findings suggest that peripheral factors do not modulate postexercise sweating and skin blood flow in both young and older adults. Additionally, sweat gland function is impaired in older adults, albeit the impairments were not exacerbated during postexercise recovery.Physiological Reports. 07/2014; 2(7).
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ABSTRACT: The literature survey 2013 is based on 1063 papers found in Scopus and the journal “Thermology international, Vol.23” with the keywords “thermography” or “thermometry” “temperature measurement” or ‘skin temperature’ or ‘core temperature’ and restricted to “human” and “published in 2013”. 41 percent of papers of this review are originated from Europe and 94.9 percent of all papers are written in English. 315 controlled studies using some kind of temperature measurement were included in this survey. Physiology and Endocrinology, Surgery, Cancer and Neurology&Psychiatry were the predominant fields of applications of temperature measurement in medicine. As in previous years, therapeutic hypothermia and hyperthermia treatment was the topic of many papers. Fever attracted also a high number of publications. Although the terms" breast" or “breast cancer” appeared in 101 publications, only a minority of those were related to breast thermography. Some articles were found for the complex regional pain syndrome and Raynaud´s phenomenon THERMOLOGIE 2013 – EINE COMPUTER-GESTÜTZTE LITERATURSUCHE Die Literatursuche für 2013 basiert auf 1063 Arbeiten, die unter den Schlüsselwörtern “Thermographie” oder “Thermometrie” oder “Temperaturmessung” oder ‘Hauttemperatur’ oder ‘Kerntemperatur” und der Einschränkung “Mensch” und “2013 publiziert” in der Datenbank Scopus und im 23. Jahrgang der Zeitschrift “Thermology international” gefunden wurden. Die Autoren thermologischer Publikationen kommen in 41 Prozent aus Europa, und 94,9 Prozent aller Arbeiten wurden in Englisch publiziert. 315 kontrollierte Studien, die irgendeine Form von Temperaturmessung einsetzten, wurden in diese Übersicht aufgenommen. Pharmakologie, Innere Medizin, Krebserkrankungen und Neurologie & Psychiatrie waren die vorherrschenden Anwendungsgebiete für Temperaturmessung in der Medizin. Wie in früheren Literaturübersichten, war die therapeutische Hypothermie und die Behandlung mit Hyperthermie das Thema vieler Veröffentlichungen. Auch Fieber erzielte eine große Zahl von Publikationen. Obwohl der Begriff “Brust” bzw. “Brustkrebs” in 101 Publikationen erwähnt wurde, berichtete nur eine Minorität davon über Brustthermographie. Einige Publikationen wurden zum komplexen regionalen Schmerzsyndrom (CRPS) und über das Raynaud-Phänomen gefunden und neue Anwendungen der medizinischen Thermographie wurden berichtet.Thermology International 09/2014; 24(3):93-130.
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ABSTRACT: Reflex syncope is classified based on the efferent autonomic system as vasodepressant type, cardioinhibitory type and mixed type. We employed quantitative sweat testing to assess differences in sudomotor sympathetic activity in relation to the type of reflex syncope. In cardioinhibitory type sweating started in 7/9 patients after and in vasodepressor type in 11/12 patients before syncope. In mixed type sweating in 21 patients started before and in 9 after syncope. Onset of sweating correlated significantly with onset of syncope symptoms. These results possibly reflect different onsets of emotional sweating.Autonomic Neuroscience. 01/2014;