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Heat exposure's effect on glucose tolerance depends on the amount of body exposed, likely relating to autonomic nervous system balance. We assessed how partial-body heat exposure at two different levels of the lower extremities affects glucose tolerance and autonomic nervous system balance, measured via heart rate variability. We hypothesized feet-heating would improve glucose tolerance without affecting heart rate variability, while calf-heating would worsen glucose tolerance and decrease heart rate variability compared to a thermoneutral control condition. In a randomized, controlled, crossover trial, healthy participants' (N = 31, 23(3) years, 45% male) glucose tolerance was measured in (A) thermoneutral; (B) feet-heating; and (C) calf-heating conditions. Every 30 min for 2 h, blood glucose, heart rate, heart rate variability, tympanic temperature, thermal comfort scores, and blood pressure were measured. There were significant interactions between condition and time for blood glucose (F (4.6,72.6) = 2.6, p = 0.036), heart rate (F (3.4, 54.5) = 3.5, p = 0.017), heart rate variability (F (4.3,63.2) = 7.5, p <.0001), tympanic temperature (F (8, 268) = 2.4, p = 0.014), and thermal comfort scores (F (8, 248) = 22.1, p < 0.0001). Calf-heating increased 90 min glucose (+12 (95% confidence interval, CI: 3–21) mg/dL, p = 0.013) and decreased heart rate variability throughout (mean decrease: 13%–22%, p < 0.007), while feet-heating lowered 90 min glucose (−7 (95% CI: −16 to +1) mg/dL, p = 0.090) without affecting heart rate variability (p = 0.14–0.99). Blood pressure and body temperature were similar between conditions, but heart rate and thermal comfort scores increased with heating. Calf-heating worsens, while feet-heating may improve, glucose tolerance. Changes in heart rate variability coincided with changes in glucose tolerance despite unchanged body temperature. Whether heart rate variability can be used to monitor autonomic nervous system balance during heating to optimize its acute effect on glycemic indices should be further explored. [ABSTRACT FROM AUTHOR]

Objective: To discuss the method for establishing the rat models of irritable bowel syndrome (IBS) by chronic water avoidance stress (WAS) method, and to evaluate its feasibility. Methods: Thirty male Wistar rats were randomly divided into control group (n=10) and model group (n=20). The rats in model group were induced by WAS method for 1 h everyday, lasting for 10 consecutive days; the rats in control group underwent no interventions. After modeling, the general conditions and body weights of the rats in two groups were observed and recorded. The elevated plus maze (EPM) test was used to detect the percentages of the number of open arm entries (OE) and the time spent in open arms (OT) of the rats in two groups; the abdominal withdrawal reflex (AWR) test was used to assess the visceral sensitivity of the rats in two groups; electrocardiography was used to detect the heart rate variability (HRV) of the rats in two groups; electromyography (EMG) of the external oblique muscle was used to detect the colorectal pain sensitivity thresholds of the rats in two groups; multi-channel physiological signal recorder was used to monitor the slow wave frequency of the colon of the rats in two groups. Results: There were no death rats in both groups during the modeling period. After modeling, the rats in model group exhibited poor mental status, reduced spontaneous activity, hypoactivity, disordered and dull fur, irritability, and unclean anal areas; whereas, the rats in control group showed no significant changes in the mental state, spontaneous activity, fur, and perianal area. Compared with control group, the body weight of the rats in model group was significantly decreased (P<0. 05). The EPM test results showed that compared with control group, the OE percentage and OT percentage of the rats in model group were significantly decreased (P<0. 01). The AWR test results showed that 12 rats in model group scored ≥3 points, indicating that the successful rate in creating the visceral pain models was 60%. Compared with control group, the low frequency (LF) signals and the ratio of LF/high frequency (HF) of the rats in model group were significantly increased (P<0. 01), and the HF was significantly decreased (P<0. 05). The EMG results showed that compared with control group, the coloretal pain sensitivity threshold of the colon of the rats in model group was significantly decreased (P<0. 01), and the slow wave frequency of the colon was significantly increased (P<0. 01). Conclusion: The WAS method for establishing the rat model of IBS effectively demonstrates the changes in behavior and mental state, increased the visceral sensitivity, accelerated colonic slow wave frequency, and autonomic nervous system imbalance; the WAS method can serve as an effective modeling approach for observing and evaluating the related drugs and interventions on treatment of IBS. [ABSTRACT FROM AUTHOR]

Background: Functions of the autonomic nervous system have cardinal importance in day-to-day life. Heart rate variability (HRV) has been shown to estimate the functioning of the autonomic nervous system. Imbalance in the functioning of the autonomic nervous system is seen to be associated with chronic conditions such as chronic kidney disease, cardiovascular diseases, diabetes mellitus, and so on. Purpose: To evaluate the efficacy of a non-contact ballistocardiography (BCG) system to calculate HRV parameters by comparing them to the parameters derived from a standard commercial software that uses an electrocardiogram (ECG). Methods: Current study captured an ECG signal using a three-channel ECG Holter machine, whereas the BCG signal was captured using a BCG sensor sheet consisting of vibroacoustic sensors placed under the mattress of the participants of the study. Results: The study was conducted on 24 subjects for a total of 54 overnight recordings. The proposed method covered 97.92% epochs of the standard deviation of NN intervals (SDNN) and 99.27% epochs of root mean square of successive differences (RMSSD) within 20 ms and 30 ms tolerance, respectively, whereas 98.84% of two-min intervals for low-frequency (LF) to high-frequency (HF) ratio was covered within a tolerance of 1. Kendall's coefficient of concordance was also calculated, giving a P <.001 for all the three parameters and coefficients 0.66, 0.55, and 0.44 for SDNN, RMSSD, and LF/HF, respectively. Conclusion: The results show that HRV parameters captured using unobtrusive and non-invasive BCG sensors are comparable to HRV calculated using ECG. [ABSTRACT FROM AUTHOR]

Introduction. It was found that the body's response to various stressful effects is largely determined by the ratio of the tone of the sympathetic and parasympathetic parts of the autonomic nervous system. It was revealed that in those days when a predominance of the parasympathetic nervous system tone was noted stressful effects caused more significant and negative changes in the body. The autonomic nervous system is also influenced by climatic factors. Materials and methods. 5305 males of different age were examined with the help of functional vegetative diagnostics according to the method of V. Makats. The bioelectric activity of 12 symmetric pairs of functionally active zones of the skin (24 FAZ), 12 on the hands and 12 on the feet, which reflect the functional activity of the sympathetic and parasympathetic nervous systems were studied. Results. In the study of systemic age dependence in all male observation groups the change of seasons of the year has been found to lead to changes in functional activity and homeostasis of the organism. The seasonal indicators of the activity of functional systems (FS) are clearly observed to duplicate the norm line, differing in amplitude and having the same orientation. Moreover, the presence of significant changes in the studied parameters of activity indicators of FS with the norm line indicates that all seasons of the year were characterized by differences. Conclusions. It has been established that the season change on the body leads to significant changes in functional activity and homeostasis of men of different age groups. The dependence of these indicators indicates a species evolutionary adaptation of a human to seasonal changes in climatic conditions.

Introduction. The autonomic nervous system is the main regulatory mechanism of a living organism that provides homeostasis. Objective: to investigate the effect of the Moon phases on the autonomic balance of the human body, the ratio of sympathetic nervous system activity to the parasympathetic nervous system and the functional health of the population. Materials and methods. 1592 males of different age were examined with the help of functional vegetative diagnostics according to the method of V. Makats. The bioelectric activity of 12 symmetric pairs of functionally active zones of the skin (24 FAZ), 12 on the hands and 12 on the feet, which reflect the functional activity of the sympathetic and parasympathetic nervous systems were studied. Results. In the male group aged 3-6 years old, the chaotic pattern of functional dependencies is related to the physiological and functional immaturity of the adaptation processes and the speed of their formation and stabilization in the body of children. In the male group of 12-15 years old in different phases of the Moon the changes in activity indicators of functional systems with much smaller amplitude are observed, though the nature and direction of changes in activity remain similar, which indicates the stabilization of adaptation mechanisms in the body. In the male group aged 21-50 years old maximum amplitude fluctuations in the functional activity of the systems and vegetative homeostasis are observed in the new Moon and the full one, which indicates a decrease in adaptation processes associated with age-related decrease in physiological and biochemical processes in the body and the appearance of the organism in the body. Conclusions. It has been established that the change of the Moon phases leads to significant changes in the functional activity and homeostasis of the body of men of different age groups. On-phase Moon activity indicators of functional systems duplicating the norm line have the same orientation, differing in amplitude, forming age-specific features of the tone of the autonomic nervous system.

Background Bariatric surgery is considered an effective method for sustained weight loss, but may cause various nutritional complications. The aim of this study was to evaluate the nutritional status of minerals and vitamins, food consumption, and to monitor physiologic parameters in patients with obesity before and 6 months after Roux-en-Y gastric bypass surgery (RYGB). Methods Thirty-six patients who had undergone RYGB were prospectively evaluated before and 6 months after surgery. At each phase their weight, height, body mass index (BMI), Electro Sensor Complex (ES Complex) data, food consumption, and total protein serum levels, albumin, prealbumin, parathyroid hormone (PTH), zinc (Zn), B12 vitamin (VitB12), iron (Fe), ferritin, copper (Cu), ionic calcium (CaI), magnesium (Mg), and folic acid were assessed. Results The mean weight loss from baseline to 6 months after surgery was 35.34±4.82%. Markers of autonomic nervous system balance ( P <.01), stiffness index ( P <.01), standard deviation of normal-to-normal R-R intervals (SDNN) ( P <.01), and insulin resistance ( P <.001) were also improved. With regard to the micronutrients measured, 34 patients demonstrated some kind of deficiency. There was a high percentage of Zn deficiency in both pre- (55.55%) and postoperative (61.11%) patients, and 33.33% of the patients were deficient in prealbumin postoperatively. The protein intake after 6 months of surgery was below the recommended intake (<70 g/d) for 88.88% of the patients. Laboratory analyses demonstrated an average decrease in total protein ( P <.05), prealbumin ( P = .002), and PTH ( P = .008) between pre- and postsurgery, and a decrease in the percentage of deficiencies for Mg ( P <.05), CaI ( P <.05), and Fe ( P = .021). Conclusion Despite improvements in the autonomic nervous system balance, stiffness index markers and insulin resistance, we found a high prevalence of hypozincemia at 6 months post-RYGB. Furthermore, protein supplements were needed to maintain an adequate protein intake up to 6 months postsurgery. [ABSTRACT FROM AUTHOR]

In noncardiac chest pain (NCCP), altered visceral perception may result from abnormal cerebral processing of sensory input rather than abnormalities of afferent pathways. However, the interactions between symptoms, autonomic function and oesophageal stimuli are poorly studied. Oesophageal stimulation elicits reproducible cortical evoked potentials [CEP] and modulates heart rate variability via vagal pathways, as visible on power spectrum analysis of heart rate variability [PS-HRV]. These methods are increasingly used to study the function of visceral afferent neural pathways in human. The aim of this study was to compare EP and PS-HRV during oesophageal stimuli in NCCP and controls. Twelve healthy volunteers (one female, 11 male; aged 24–51 years; mean 32 ± 8 years), and eight NCCP patients (three female, five male; age range 26–58, mean 40.5 ± 10 years) were studied. Electrical oesophageal stimulation (EOS; 200 μs, 0.2 Hz, 25 stimuli) was applied to the oesophageal wall 5 cm above the lower oesophageal sphincter (LOS), and perception thresholds (measured in mA) determined. EP responses were recorded using 22 standard electroencephalogram scalp electrodes. Autonomic activity was assessed using PS-HRV, before, during, and after oesophageal stimulation. Measured PS-HRV indices included high frequency (HF; 0.15–0.5 Hz) and low frequency (LF; 0.06–0.15 Hz) power, respectively, assessing vagal and sympathetic activity, and the LF/HF ratio. EOS perception occurred at lower thresholds in NCCP than in controls (3.6 ± 1 vs. 7.8 ± 2 mA, P < 0.05). EP amplitude was greater (13 ± 2 vs. 6 ± 1 μV, P < 0.0001), and latency longer in controls vs. NCCP (191 ± 7 ms vs. 219 ± 6 ms, P < 0.001). In NCCP, EOS decreased sympathetic outflow (low frequency peak on PS-HRV) and increased cardiovagal activity (high frequency peak, P < 0.02) to a significantly higher degree in comparison with controls. During EOS, heart rate decreased in NCCP from 68 vs. 62 beats min–1 (P < 0.003) but not in controls. In NCCP patients, EOS was perceived at lower intensities and was associated with a greater cardiovagal reflex response. EP responses associated with EOS were smaller in NCCP than in controls, suggesting that an increased perception of oesophageal stimuli results from an enhanced cerebral processing of visceral sensory input in NCCP, rather than from hyperalgesic responses in visceral afferent pathways. [ABSTRACT FROM AUTHOR]