Journal article
Heat Stress and Cardiovascular, Hormonal, and Heat Shock Proteins in Humans
Journal of athletic training, Vol.47(2), pp.184-190
03/01/2012
DOI: 10.4085/1062-6050-47.2.184
PMID: 22488284
Abstract
Context: Conditions such as osteoarthritis, obesity, and spinal cord injury limit the ability of patients to exercise, preventing them from experiencing many well-documented physiologic stressors. Recent evidence indicates that some of these stressors might derive from exercise-induced body temperature increases. Objective: To determine whether whole-body heat stress without exercise triggers cardiovascular, hormonal, and extra-cellular protein responses of exercise. Design: Randomized controlled trial. Setting: University research laboratory. Patients or Other Participants: Twenty-five young, healthy adults (13 men, 12 women; age = 22.1 ± 2.4 years, height = 175.2 ± 11.6 cm, mass = 69.4 ± 14.8 kg, body mass index = 22.6 ± 4.0) volunteered. Intervention(s): Participants sat in a heat stress chamber with heat (73°C) and without heat (26°C) stress for 30 minutes on separate days. We obtained blood samples from a subset of 13 participants (7 men, 6 women) before and after exposure to heat stress. Main Outcome Measure(s): Extracellular heat shock protein (HSP72) and catecholamine plasma concentration, heart rate, blood pressure, and heat perception. Results: After 30 minutes of heat stress, body temperature measured via rectal sensor increased by 0.8°C. Heart rate increased linearly to 131.4 ± 22.4 beats per minute (F6,24 = 186, P < .001) and systolic and diastolic blood pressure decreased by 16 mm Hg (F6,24 = 10.1, P < .001) and 5 mm Hg (F6,24 = 5.4, P < .001), respectively. Norepinephrine (F1,12 = 12.1, P = .004) and prolactin (F1,12 = 30.2, P < .001) increased in the plasma (58% and 285%, respectively) (P < .05). The HSP72 (F1,12 = 44.7, P < .001) level increased with heat stress by 48.7% ± 53.9%. No cardiovascular or blood variables showed changes during the control trials (quiet sitting in the heat chamber with no heat stress), resulting in differences between heat and control trials. Conclusions: We found that whole-body heat stress triggers some of the physiologic responses observed with exercise. Future studies are necessary to investigate whether carefully prescribed heat stress constitutes a method to augment or supplement exercise.
Details
- Title: Subtitle
- Heat Stress and Cardiovascular, Hormonal, and Heat Shock Proteins in Humans
- Creators
- Masaki Iguchi - Physical Therapy and Rehabilitation Science Department, University of Iowa, Iowa CityAndrew E Littmann - Physical Therapy and Rehabilitation Science Department, University of Iowa, Iowa CityShuo-Hsiu Chang - Department of Physical Medicine and Rehabilitation, University of Texas Health Science Center at Houston, HoustonLydia A Wester - Department of Integrative Physiology, University of Iowa, Iowa CityJane S Knipper - Pulmonary Rehabilitation, University of Iowa Hospitals and Clinics, Iowa CityRichard K Shields - Physical Therapy and Rehabilitation Science Department, University of Iowa, Iowa City
- Resource Type
- Journal article
- Publication Details
- Journal of athletic training, Vol.47(2), pp.184-190
- DOI
- 10.4085/1062-6050-47.2.184
- PMID
- 22488284
- NLM abbreviation
- J Athl Train
- ISSN
- 1062-6050
- eISSN
- 1938-162X
- Language
- English
- Date published
- 03/01/2012
- Academic Unit
- Orthopedics and Rehabilitation; Physical Therapy and Rehabilitation Science
- Record Identifier
- 9984047782702771
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