Effects of low-dose aspirin therapy on thermoregulation in firefighters

Serina J. McEntire, Steven E. Reis, Oscar Suman, David Hostler

Research output: Contribution to journalArticle

Abstract

Background Heart attack is the most common cause of line-of-duty death in the fire service. Daily aspirin therapy is a preventative measure used to reduce the morbidity of heart attacks but may decrease the ability to dissipate heat by reducing skin blood flow. Methods In this double-blind, placebo-controlled, crossover study, firefighters were randomized to receive 14 days of therapy (81-mg aspirin or placebo) before performing treadmill exercise in thermal-protective clothing in a hot room [38.8 ± 2.1°C, 24.9 ± 9.1% relative humidity (RH)]. Three weeks without therapy was provided before crossing to the other arm. Firefighters completed a baseline skin blood-flow assessment via laser Doppler flowmetry; skin was heated to 44°C to achieve maximal cutaneous vasodilation. Skin blood flow was measured before and after exercise in a hot room, and at 0 minutes, 10 minutes, 20 minutes, and 30 minutes of recovery under temperature conditions (25.3 ± 1.2°C, 40.3 ± 13.7% RH). Platelet clotting time was assessed before drug administration, and before and after exercise. Results Fifteen firefighters completed the study. Aspirin increased clotting time before and after exercise compared with placebo (p = 0.003). There were no differences in absolute skin blood flow between groups (p = 0.35). Following exercise, cutaneous vascular conductance (CVC) was 85 ± 42% of maximum in the aspirin and 76 ± 37% in the placebo groups. The percentage of maximal CVC did not differ by treatment before or after recovery. Neither maximal core body temperature nor heart rate responses to exercise differed between trials. Conclusion There were no differences in skin blood flow during uncompensable heat stress following exercise after aspirin or placebo therapy.

Original languageEnglish (US)
Pages (from-to)256-262
Number of pages7
JournalSafety and Health at Work
Volume6
Issue number3
DOIs
StatePublished - Sep 1 2015

Fingerprint

Firefighters
Body Temperature Regulation
Aspirin
Skin
heart attack
Blood
Exercise
heat
Placebos
Atmospheric humidity
Therapeutics
clothing
Hot Temperature
morbidity
Humidity
Recovery
Protective clothing
Exercise equipment
Blood Vessels
Group

Keywords

  • aspirin
  • exertion
  • firefighter
  • heat stress
  • skin blood flow

ASJC Scopus subject areas

  • Public Health, Environmental and Occupational Health
  • Chemical Health and Safety
  • Safety, Risk, Reliability and Quality
  • Safety Research

Cite this

Effects of low-dose aspirin therapy on thermoregulation in firefighters. / McEntire, Serina J.; Reis, Steven E.; Suman, Oscar; Hostler, David.

In: Safety and Health at Work, Vol. 6, No. 3, 01.09.2015, p. 256-262.

Research output: Contribution to journalArticle

McEntire, Serina J. ; Reis, Steven E. ; Suman, Oscar ; Hostler, David. / Effects of low-dose aspirin therapy on thermoregulation in firefighters. In: Safety and Health at Work. 2015 ; Vol. 6, No. 3. pp. 256-262.
@article{4e596f53ab344c9894521d67b84c79e4,
title = "Effects of low-dose aspirin therapy on thermoregulation in firefighters",
abstract = "Background Heart attack is the most common cause of line-of-duty death in the fire service. Daily aspirin therapy is a preventative measure used to reduce the morbidity of heart attacks but may decrease the ability to dissipate heat by reducing skin blood flow. Methods In this double-blind, placebo-controlled, crossover study, firefighters were randomized to receive 14 days of therapy (81-mg aspirin or placebo) before performing treadmill exercise in thermal-protective clothing in a hot room [38.8 ± 2.1°C, 24.9 ± 9.1{\%} relative humidity (RH)]. Three weeks without therapy was provided before crossing to the other arm. Firefighters completed a baseline skin blood-flow assessment via laser Doppler flowmetry; skin was heated to 44°C to achieve maximal cutaneous vasodilation. Skin blood flow was measured before and after exercise in a hot room, and at 0 minutes, 10 minutes, 20 minutes, and 30 minutes of recovery under temperature conditions (25.3 ± 1.2°C, 40.3 ± 13.7{\%} RH). Platelet clotting time was assessed before drug administration, and before and after exercise. Results Fifteen firefighters completed the study. Aspirin increased clotting time before and after exercise compared with placebo (p = 0.003). There were no differences in absolute skin blood flow between groups (p = 0.35). Following exercise, cutaneous vascular conductance (CVC) was 85 ± 42{\%} of maximum in the aspirin and 76 ± 37{\%} in the placebo groups. The percentage of maximal CVC did not differ by treatment before or after recovery. Neither maximal core body temperature nor heart rate responses to exercise differed between trials. Conclusion There were no differences in skin blood flow during uncompensable heat stress following exercise after aspirin or placebo therapy.",
keywords = "aspirin, exertion, firefighter, heat stress, skin blood flow",
author = "McEntire, {Serina J.} and Reis, {Steven E.} and Oscar Suman and David Hostler",
year = "2015",
month = "9",
day = "1",
doi = "10.1016/j.shaw.2015.06.003",
language = "English (US)",
volume = "6",
pages = "256--262",
journal = "Safety and Health at Work",
issn = "2093-7911",
publisher = "Occupational Safety and Health Research Institute.(OSHRI)",
number = "3",

}

TY - JOUR

T1 - Effects of low-dose aspirin therapy on thermoregulation in firefighters

AU - McEntire, Serina J.

AU - Reis, Steven E.

AU - Suman, Oscar

AU - Hostler, David

PY - 2015/9/1

Y1 - 2015/9/1

N2 - Background Heart attack is the most common cause of line-of-duty death in the fire service. Daily aspirin therapy is a preventative measure used to reduce the morbidity of heart attacks but may decrease the ability to dissipate heat by reducing skin blood flow. Methods In this double-blind, placebo-controlled, crossover study, firefighters were randomized to receive 14 days of therapy (81-mg aspirin or placebo) before performing treadmill exercise in thermal-protective clothing in a hot room [38.8 ± 2.1°C, 24.9 ± 9.1% relative humidity (RH)]. Three weeks without therapy was provided before crossing to the other arm. Firefighters completed a baseline skin blood-flow assessment via laser Doppler flowmetry; skin was heated to 44°C to achieve maximal cutaneous vasodilation. Skin blood flow was measured before and after exercise in a hot room, and at 0 minutes, 10 minutes, 20 minutes, and 30 minutes of recovery under temperature conditions (25.3 ± 1.2°C, 40.3 ± 13.7% RH). Platelet clotting time was assessed before drug administration, and before and after exercise. Results Fifteen firefighters completed the study. Aspirin increased clotting time before and after exercise compared with placebo (p = 0.003). There were no differences in absolute skin blood flow between groups (p = 0.35). Following exercise, cutaneous vascular conductance (CVC) was 85 ± 42% of maximum in the aspirin and 76 ± 37% in the placebo groups. The percentage of maximal CVC did not differ by treatment before or after recovery. Neither maximal core body temperature nor heart rate responses to exercise differed between trials. Conclusion There were no differences in skin blood flow during uncompensable heat stress following exercise after aspirin or placebo therapy.

AB - Background Heart attack is the most common cause of line-of-duty death in the fire service. Daily aspirin therapy is a preventative measure used to reduce the morbidity of heart attacks but may decrease the ability to dissipate heat by reducing skin blood flow. Methods In this double-blind, placebo-controlled, crossover study, firefighters were randomized to receive 14 days of therapy (81-mg aspirin or placebo) before performing treadmill exercise in thermal-protective clothing in a hot room [38.8 ± 2.1°C, 24.9 ± 9.1% relative humidity (RH)]. Three weeks without therapy was provided before crossing to the other arm. Firefighters completed a baseline skin blood-flow assessment via laser Doppler flowmetry; skin was heated to 44°C to achieve maximal cutaneous vasodilation. Skin blood flow was measured before and after exercise in a hot room, and at 0 minutes, 10 minutes, 20 minutes, and 30 minutes of recovery under temperature conditions (25.3 ± 1.2°C, 40.3 ± 13.7% RH). Platelet clotting time was assessed before drug administration, and before and after exercise. Results Fifteen firefighters completed the study. Aspirin increased clotting time before and after exercise compared with placebo (p = 0.003). There were no differences in absolute skin blood flow between groups (p = 0.35). Following exercise, cutaneous vascular conductance (CVC) was 85 ± 42% of maximum in the aspirin and 76 ± 37% in the placebo groups. The percentage of maximal CVC did not differ by treatment before or after recovery. Neither maximal core body temperature nor heart rate responses to exercise differed between trials. Conclusion There were no differences in skin blood flow during uncompensable heat stress following exercise after aspirin or placebo therapy.

KW - aspirin

KW - exertion

KW - firefighter

KW - heat stress

KW - skin blood flow

UR - http://www.scopus.com/inward/record.url?scp=84942294404&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84942294404&partnerID=8YFLogxK

U2 - 10.1016/j.shaw.2015.06.003

DO - 10.1016/j.shaw.2015.06.003

M3 - Article

VL - 6

SP - 256

EP - 262

JO - Safety and Health at Work

JF - Safety and Health at Work

SN - 2093-7911

IS - 3

ER -