Age‐related circulatory responses to whole body cooling: observations by heart rate variability

Authors

• Jarmo Alametsä Tampere University of Applied Science, Tampere
• Kalev Kuklane The Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, Lund
• Juhani Smolander The Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, Lund
• Leif Vanggaard Danish Arctic Institute, Copenhagen K
• Amitava Halder The Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, Lund
• Karin Lundgren The Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, Lund
• Chuansi Gao The Thermal Environment Laboratory, Division of Ergonomics and Aerosol Technology, Department of Design Sciences, Faculty of Engineering, Lund University, Lund
• Jari Viik Tampere University of Technology, BioMediTech, Tampere

Keywords:

ECG, heart rate variability, elderly, thermal balance, mild whole‐body cooling, blood pressure

Abstract

The purpose was to study potential age ‐ related changes in the circulatory system via heart rate variability (HRV) by gradually lowering ambient temperature (0.2°C/min) from thermoneutral (32 C°) towards cold (18 C°). ECG was recorded from a young (31 years) and from an older subject (78 years), both males. During the tests, brachium blood pressure (BP) was recorded.

During the cooling, BP increased in both subjects (young from 95/69 to 132/75 mmHg, old from 125/68 to 176/101 mmHg), the latter exhibiting a prominent rise in diastolic values after cooling. HRV parameters increased in both subjects during the cold exposure being modest in the younger subject as compared to the older one. Also, recovery from the cold in terms of HRV was faster in the younger subject. The present preliminary observations indicate that older age is coupled with altered HRV response to a mild whole‐body skin cooling.