Exacerbation of circadian rhythms of core body temperature and sepsis in trauma patients

Spaceflight can be associated with sleep loss and circadian misalignment as a result of non-24 h light-dark cycles, operational shifts in work/rest cycles, high workload under pressure, and psychological factors. Head-down tilt bed rest (HDBR) is an established model to mimic some of the physiological and psychological adaptions observed in spaceflight. Data on the effects of HDBR on circadian rhythms are scarce. To address this gap, we analyzed the change in the circadian rhythm of core body temperature (CBT) in two 60-day HDBR studies sponsored by the European Space Agency [n = 13 men, age: 31.1 ± 8.2 years (M ± SD)]. CBT was recorded for 36 h using a non-invasive and validated dual-sensor heatflux technology during the 3rd and the 8th week of HDBR. Bed rest induced a significant phase delay from the 3rd to the 8th week of HDBR (16.23 vs. 16.68 h, p = 0.005, g = 0.85) irrespective of the study site (p = 0.416, g = −0.46), corresponding to an average phase delay of about 0.9 min per day of HDBR. In conclusion, long-term bed rest weakens the entrainment of the circadian system to the 24-h day. We attribute this effect to the immobilization and reduced physical activity levels associated with HDBR. Given the critical role of diurnal rhythms for various physiological functions and behavior, our findings highlight the importance of monitoring circadian rhythms in circumstances in which gravity or physical activity levels are altered.

Download Full-text

Circadian desynchronization of core body temperature and sleep stages in the rat

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0702424104 ◽

2007 ◽

Vol 104 (18) ◽

pp. 7634-7639 ◽

Cited By ~ 74

Author(s):

Trinitat Cambras ◽

John R. Weller ◽

Montserrat Anglès-Pujoràs ◽

Michael L. Lee ◽

Andrea Christopher ◽

...

Keyword(s):

Body Temperature ◽

Circadian Rhythms ◽

Slow Wave Sleep ◽

Paradoxical Sleep ◽

Core Body Temperature ◽

The Other ◽

Sleep Stages ◽

Physical And Mental Health ◽

Free Running ◽

Core Body

Proper functioning of the human circadian timing system is crucial to physical and mental health. Much of what we know about this system is based on experimental protocols that induce the desynchronization of behavioral and physiological rhythms within individual subjects, but the neural (or extraneural) substrates for such desynchronization are unknown. We have developed an animal model of human internal desynchrony in which rats are exposed to artificially short (22-h) light–dark cycles. Under these conditions, locomotor activity, sleep–wake, and slow-wave sleep (SWS) exhibit two rhythms within individual animals, one entrained to the 22-h light–dark cycle and the other free-running with a period >24 h (τ>24 h). Whereas core body temperature showed two rhythms as well, further analysis indicates this variable oscillates more according to the τ>24 h rhythm than to the 22-h rhythm, and that this oscillation is due to an activity-independent circadian regulation. Paradoxical sleep (PS), on the other hand, shows only one free-running rhythm. Our results show that, similarly to humans, (i) circadian rhythms can be internally dissociated in a controlled and predictable manner in the rat and (ii) the circadian rhythms of sleep–wake and SWS can be desynchronized from the rhythms of PS and core body temperature within individual animals. This model now allows for a deeper understanding of the human timekeeping mechanism, for testing potential therapies for circadian dysrhythmias, and for studying the biology of PS and SWS states in a neurologically intact model.

Download Full-text

Temporal phasing of locomotor activity, heart rate rhythmicity, and core body temperature is disrupted in VIP receptor 2-deficient mice

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00599.2010 ◽

2011 ◽

Vol 300 (3) ◽

pp. R519-R530 ◽

Cited By ~ 30

Author(s):

Jens Hannibal ◽

Hansen M. Hsiung ◽

Jan Fahrenkrug

Keyword(s):

Heart Rate ◽

Locomotor Activity ◽

Body Temperature ◽

Circadian Rhythms ◽

Wheel Running ◽

Core Body Temperature ◽

Running Activity ◽

Wheel Running Activity ◽

Core Body ◽

Deficient Mice

Neurons of the brain's biological clock located in the hypothalamic suprachiasmatic nucleus (SCN) generate circadian rhythms of physiology (core body temperature, hormone secretion, locomotor activity, sleep/wake, and heart rate) with distinct temporal phasing when entrained by the light/dark (LD) cycle. The neuropeptide vasoactive intestinal polypetide (VIP) and its receptor (VPAC2) are highly expressed in the SCN. Recent studies indicate that VIPergic signaling plays an essential role in the maintenance of ongoing circadian rhythmicity by synchronizing SCN cells and by maintaining rhythmicity within individual neurons. To further increase the understanding of the role of VPAC2 signaling in circadian regulation, we implanted telemetric devices and simultaneously measured core body temperature, spontaneous activity, and heart rate in a strain of VPAC2-deficient mice and compared these observations with observations made from mice examined by wheel-running activity. The study demonstrates that VPAC2 signaling is necessary for a functional circadian clock driving locomotor activity, core body temperature, and heart rate rhythmicity, since VPAC2-deficient mice lose the rhythms in all three parameters when placed under constant conditions (of either light or darkness). Furthermore, although 24-h rhythms for three parameters are retained in VPAC2-deficient mice during the LD cycle, the temperature rhythm displays markedly altered time course and profile, rising earlier and peaking ∼4–6 h prior to that of wild-type mice. The use of telemetric devices to measure circadian locomotor activity, temperature, and heart rate, together with the classical determination of circadian rhythms of wheel-running activity, raises questions about how representative wheel-running activity may be of other behavioral parameters, especially when animals have altered circadian phenotype.

Download Full-text

Circadian rhythms in bed rest: Monitoring core body temperature via heat-flux approach is superior to skin surface temperature

Chronobiology International ◽

10.1080/07420528.2016.1224241 ◽

2016 ◽

Vol 34 (5) ◽

pp. 666-676 ◽

Cited By ~ 16

Author(s):

Stefan Mendt ◽

Martina Anna Maggioni ◽

Michael Nordine ◽

Mathias Steinach ◽

Oliver Opatz ◽

...

Keyword(s):

Heat Flux ◽

Body Temperature ◽

Circadian Rhythms ◽

Surface Temperature ◽

Core Body Temperature ◽

Bed Rest ◽

Skin Surface ◽

Skin Surface Temperature ◽

Core Body

Download Full-text

Acute dim light at night increases body mass, alters metabolism, and shifts core body temperature circadian rhythms

Chronobiology International ◽

10.3109/07420528.2014.926911 ◽

2014 ◽

Vol 31 (8) ◽

pp. 917-925 ◽

Cited By ~ 33

Author(s):

Jeremy C. Borniger ◽

Santosh K. Maurya ◽

Muthu Periasamy ◽

Randy J. Nelson

Keyword(s):

Body Temperature ◽

Circadian Rhythms ◽

Body Mass ◽

Core Body Temperature ◽

Light At Night ◽

Dim Light ◽

And Shifts ◽

Core Body

Download Full-text

Circadian disruption of core body temperature in trauma patients: a single-center retrospective observational study

Journal of Intensive Care ◽

10.1186/s40560-019-0425-x ◽

2020 ◽

Vol 8 (1) ◽

Cited By ~ 3

Author(s):

Aurélien Culver ◽

Benjamin Coiffard ◽

François Antonini ◽

Gary Duclos ◽

Emmanuelle Hammad ◽

...

Keyword(s):

Risk Factors ◽

Intensive Care Unit ◽

Body Temperature ◽

Mortality Rate ◽

Head Trauma ◽

Core Body Temperature ◽

Trauma Patients ◽

Single Center ◽

Independent Risk Factors ◽

Core Body

Abstract Background Circadian clock alterations were poorly reported in trauma patients, although they have a critical role in human physiology. Core body temperature is a clinical variable regulated by the circadian clock. Our objective was to identify the circadian temperature disruption in trauma patients and to determine whether these disruptions were associated with the 28-day mortality rate. Methods A retrospective and observational single-center cohort study was conducted. All adult severe trauma patients admitted to the intensive care unit of Aix Marseille University, North Hospital, from November 2013 to February 2018, were evaluated. The variations of core body temperature for each patient were analyzed between days 2 and 3 after intensive care unit admission. Core body temperature variations were defined by three parameters: mesor, amplitude, and period. A logistic regression model was used to determine the variables influencing these three parameters. A survival analysis was performed assessing the association between core body temperature rhythm disruption and 28-day mortality rate. A post hoc subgroup analysis focused on the patients with head trauma. Results Among the 1584 screened patients, 248 were included in this study. The period differed from 24 h in 177 (71%) patients. The mesor value (°C) was associated with body mass index and ketamine use. Amplitude (°C) was associated with ketamine use only. The 28-day mortality rate was 18%. For all trauma patients, age, body mass index, intracranial hypertension, and amplitude were independent risk factors. The patients with a mesor value < 36.9 °C (p < 0.001) and an amplitude > 0.6 °C (p < 0.001) had a higher 28-day mortality rate. Among the patients with head trauma, mesor and amplitude were identified as independent risk factors (HR = 0.40, 95% CI [0.23–0.70], p = 0.001 and HR = 4.73, 95% CI [1.38–16.22], p = 0.01). Conclusions Our results highlight an association between core body temperature circadian alteration and 28-day mortality rate. This association was more pronounced in the head trauma patients than in the non-head trauma patients. Further studies are needed to show a causal link and consider possible interventions.

Download Full-text