Altered core and skin temperature responses to endurance exercise in heart failure patients and healthy controls.
BACKGROUND
Exercise training represents a central aspect of rehabilitation of heart failure patients. Previous work on passive heating suggests impaired thermoregulatory responses in heart failure patients. However, no previous study directly examined thermoregulatory responses to an exercise bout, that is, active heating, as typically applied in rehabilitation settings in heart failure.


METHODS
Cross-sectional observational study to compare changes in core body temperature (Tcore) and skin temperature (Tskin) during exercise between heart failure patients and controls.


METHODS
Fourteen heart failure subjects (65 ± 7 years, 13:1 male:female) and 14 healthy controls (61 ± 5 years, 12:2 male:female) were included. Tcore (telemetric temperature pill) and Tskin (skin thermistors) were measured continuously during a 45-min cycle exercise at comparable relative exercise intensity.


RESULTS
Tcore increased to a similar extent in both groups (controls 1.1 ± 0.4℃, heart failure patients 0.9 ± 0.3℃, 'time*group': p = 0.15). Tskin decreased during the initial phase of exercise in both groups, followed by an increase in Tskin in controls (1.2 ± 1.0℃), whilst Tskin remained low in HF patients (-0.3 ± 1.4℃) ('time*group': p < 0.001). Furthermore, we found that a given change in Tcore was associated with a smaller increase in Tskin in heart failure patients compared with controls. When comparing heart failure patients and controls who performed exercise at similar absolute workload, between-group differences disappeared (p-values > 0.05).


CONCLUSIONS
Heart failure patients and controls show comparable exercise-induced increase in Tcore, whilst heart failure patients demonstrate altered Tskin responses to exercise and attenuated elevation in Tskin per increase in Tcore. These impaired thermoregulatory responses to exercise are, at least partly, explained by the lower absolute workload and lower physical fitness level in heart failure patients.
Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands.
Nathalie M M
NM
Benda
Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands Division of Cardiology, Hartford Hospital, USA.
Thijs M H
TM
Eijsvogels
Department of Cardiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands.
Arie P J
AP
Van Dijk
Department of Cardiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands.
Louise
L
Bellersen
Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, UK.
Dick H J
DH
Thijssen
Department of Physiology, Radboud University Medical Center, Radboud Institute for Health Sciences, Nijmegen, The Netherlands maria.hopman@radboudumc.nl.
Maria T E
MT
Hopman
D000368:Aged; D001831:Body Temperature / Q000502:physiology*; D001833:Body Temperature Regulation / Q000502:physiology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010807:Physical Endurance / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology; D012881:Skin Temperature / Q000502:physiology*
Body temperature; body temperature regulation; exercise; heart failure; skin temperature