Whole-body repeated hyperthermia increases irisin and brain-derived neurotrophic factor: A randomized controlled trial

CONTEXT

Hyperthermia is known to be beneficial to patients affected by various diseases. Irisin is a key regulators of fat metabolism known to be released as response to cold. Brain Derived Neurotrophic Factor (BDNF) is a marker of neuroplasticity usually increased as response to acute exposure to human body stressors.

OBJECTIVE

Effect of a repeated hyperthermia exposure programme on changes in circulating irisin and serum BDNF in healthy humans.

DESIGN

Setting, Participants: Randomized, single-blind, cross-over trial in healthy humans conducted at Sechenov University Physiology Laboratory from April 2019. The treatment period was 2 weeks (wash-out 3 weeks). Researchers analysing serum biomarkers and questionnaires data were blinded to participants allocation. Participants were 20 healthy male (age 21.5 ± 2.1 years).

INTERVENTION

Hyperthermia exposure programme (WBPH) versus sham exposure (SHAM) to hyperthermia (10 sessions in two weeks).

MAIN OUTCOME MEASURE

Changes in irisin and BDNF before and after short hyperthermia exposure.

RESULTS

Twenty participants were analyzed. Irisin increased significantly in group WBPH only: 6.3 μg/ml (mean with SD = 1.6) compared to 5.4 μg/ml (SD = 1.7) in SHAM group; This value was also higher than baseline (5.0 mean with SD = 1.1) in WBPH. After 10 sessions mean change in BDNF was higher in WBPH group vs SHAM: BDNF was 28,263 (SD = 4213) pg/ml in WBPH group and 24,064 (SD = 5600) pg/ml in SHAM group. BDNF concentrations were significantly higher than baseline values in WBPH group only, 28,263 (SD 4213) vs 25,888 (SD 4316) pg/ml.

CONCLUSION

In healthy young humans a 2-week, ten sessions programme consisting of repeated exposure to hyperthermia resulted in a significantly higher increase of circulating Irisin and BDNF.

[Monitoring of human physiological functions during the daily night sleep]

The basic somnological methodology, which is extensively used in the present time, focuses only on clinical practice. However, this approach is not appropriate for monitoring of physiological functions during natural sleep under home conditions. Our work was designed to develop a new information-and-equipment device for the reliable study of human physiological functions during sleep in the real everyday life. The information complex is a new portable microprocessor device and original software, which is constructed on the basis of PC and provides a control of vital physiological functions during sleep in the real everyday life. We developed a new methodology for the objective comprehensive study of sleep under real day-to-day conditions. This approach allows us to identify the phase structure of sleep and to control cardiovascular functions and breathing on the basis of a cross-correlation analysis of the heart rate and respiratory rate (that reflects the degree of emotional strain). The information system for control of sleep under living conditions is composed from interrelated units, which perform the following functions: registration, identification, and analysis of the phase structure of sleep; wake-up of a subject in a certain time during the pre-determined optimal phase of sleep (as regards the psychophysiological state of this subject); and interruption of a long-lasting hazardous phase of sleep. Due to a complex analysis of physiological functions, the information system provides monitoring of sleep under real living conditions and interruption of hazardous phases of sleep that can be accompanied by serious cardiovascular disorders (i.e., leading to cerebral stroke, myocardial infarction, and sudden death).

Stages of sleep after psychoemotional tension: the individual character of changes

This report describes complex psychophysiological studies of nocturnal sleep in healthy humans in normal concentrations and after emotional tension. A series of contemporary methods was used: questionnaires, psychological tests, motor tests, and polysomnography with heart rate recording. These experiments showed that psychoemotional tension induced changes mainly in the structure of the first sleep cycle, decreasing the proportion of the second stage of slow sleep in total nocturnal sleep, led to a redistribution of delta sleep, increasing delta sleep in the second half of nocturnal sleep, and suppressed the mechanisms underlying the organization of the phases of rapid sleep. Psychoemotional tension affected human cerebrovisceral functions, for example inducing increases in the frequency and variability of the heart rhythm during nocturnal sleep. The nature of these changes in sleep structure and autonomic responses depended on the personality characteristics of the individual person. Thus, the individual approach to the question of psychoemotional stress in sleep disturbances is, we believe, the most appropriate.

Microprocessor systems for self-control of vital bodily functions

This article presents a fundamentally novel approach to an urgent medico-social problem of providing the timely medical care. To maintain people's health and life in their everyday activities, a new concept of the medical instrument-making industry was put forward. This concept was developed in terms of the theory of functional systems, which revealed the universal rules of self-regulation of bodily functions. The practical realization of the above-mentioned concept involved the construction, patenting, and production of a number of original devices capable of warning the patient about disorders in basic bodily functions. These devices included a Heart Protection System, a Stress Doser, a Physiological Clock, a Ration Controller, and a Mother-Fetus Controller. They can all be regarded as informational household microprocessor-based instruments of the 21st century.

Delta sleep-inducing peptide as a factor increasing the content of substance P in the hypothalamus and the resistance of rats to emotional stress

The influence of delta sleep-inducing peptide (DSIP, 60 and 120 nmole/kg, intraperitoneally) on the content of substance P (SP) in the hypothalamus of rats was studied in male rats of the August line. It was demonstrated that the administration of DSIP significantly increases the average content of SP in the hypothalamus, as well as its content in animals resistant to and predisposed to emotional stress. A daily one-time administration of DSIP before placing the rats in conditions of stress increases the content of SP in the hypothalamus which was decreased during emotional stress. The preliminary one-time administration of DSIP to animals subjected to a stressor influence also increases the SP content in the hypothalamus. It was established that a one-time administration of DSIP in a dose of 60 nmole/kg sharply decreases the classical manifestations of stress such as the hypertrophy of the adrenals and involution of the thymus.

Hemodynamics in emotional responses and in emotional stress

In the article, we present experimental data indicating that negative emotional states evoked by electrical stimulation of the ventromedial hypothalamus or by behavioral conflicts are accompanied by a predominance of vascular responses of a pressor character possessing the property of summation. In contrast, positive emotional states during a self-stimulation reaction or when animals attain behavioral results satisfying their major biological demands are accompanied by a predominance of pressor-depressor vascular reactions. In individual animals under conditions of experimental emotional stress in conflicting situations of a prolonged character, pronounced disturbances of cardiac-vascular functions occur. Predominantly pressor vascular reactions arise in response to forced stimulation of the ventromedial hypothalamus in such cases. It is shown that changes in vascular tonus plays a leading role in disturbances of AP regulation during stress of immobilization. The most frequent cause of death in animals under such conditions is a progressive fall of AP due to an abrupt decrease in the total peripheral resistance. The resistance of the cardiac-vascular functions to emotional stress is determined to a significant degree by genetic mechanisms.