Parasympathetic Activity Research Articles

The relationship between cardiac activity, behaviour and endogenous oxytocin and vasopressin in Prader-Willi Syndrome: An exploratory study

This study aimed to increase our understanding of cardiac activity abnormalities in Prader-Willi Syndrome (PWS) and the relationship between cardiac activity, PWS behaviours thought to be associated with cardiac vagal tone and endogenous oxytocin and vasopressin levels. We compared cardiac activity (respiratory sinus arrhythmia (RSA), low-frequency heart rate variability (LF-HRV), heart period) in 30 adolescents and adults with PWS to 30 typically developing age-matched controls. RSA, LF-HRV, and heart period were lower in individuals with PWS than in the control group. In the control group, RSA was higher for females than males. However, for those with PWS, there was no difference between the sexes. Individuals with the mUPD genetic subtype had lower RSA and LF-HRV than participants with the PWS deletion subtype and compared to typically developing controls, no difference was found between the latter two groups. Heart period was also lower for those with mUPD compared to controls. Higher RSA reduced the odds of having temper outbursts and skin-picking. RSA was lower in those with PWS and psychosis compared to those with PWS without psychosis. Finally, we found RSA correlated with vasopressin for those with mUPD but not deletion. There was no relationship between RSA and oxytocin plasma or saliva levels. Our findings suggest autonomic dysfunction in PWS that is more marked in mUPD than deletion and potentially due to greater loss of parasympathetic activity in mUPD.

Sleep and cardiac autonomic modulation in older adults: Insights from an at-home study with auditory deep sleep stimulation.

The autonomic nervous system regulates cardiovascular activity during sleep, likely impacting cardiovascular health. Aging, a primary cardiovascular risk factor, is associated with cardiac autonomic disbalance and diminished sleep slow waves. Therefore, slow waves may be linked to aging, autonomic activity and cardiovascular health. However, it is unclear how sleep and slow waves are linked to cardiac autonomic profiles across multiple nights in older adults. We conducted a randomized, crossover trial involving healthy adults aged 62-78 years. Across 2 weeks, we applied auditory stimulation to enhance slow waves and compared it with a SHAM period. We measured sleep parameters using polysomnography and derived heart rate, heart rate variability approximating parasympathetic activity, and blood pulse wave approximating sympathetic activity from a wearable. Here, we report the results of 14 out of 33 enrolled participants, and show that heart rate, heart rate variability and blood pulse wave within sleep stages differ between the first and second half of sleep. Furthermore, baseline slow-wave activity was related to cardiac autonomic activity profiles during sleep. Moreover, we found auditory stimulation to reduce heart rate variability, while heart rate and blood pulse wave remained unchanged. Lastly, within subjects, higher heart rate coincided with increased slow-wave activity, indicating enhanced autonomic activation when slow waves are pronounced. Our study shows the potential of cardiac autonomic markers to offer insights into participants' baseline slow-wave activity when recorded over multiple nights. Furthermore, we highlight that averaging cardiac autonomic parameters across a night may potentially mask dynamic effects of auditory stimulation, potentially playing a role in maintaining a healthy cardiovascular system.

Abstract 47: Deletion of PRR in AgRP Neurons of the Arcuate Nucleus Contributes to the Development of DOCA-Salt Hypertension

Agouti-related protein (AgRP) neurons, a key neuronal population within the arcuate nucleus (ARC), are known for their pivotal roles in regulating energy- and glucose homeostasis. However, their involvement in cardiovascular regulation remains poorly understood. Using RNAscope in situ hybridization, we found that 95.4% of the ARC AgRP neurons express the (pro)renin receptor (PRR), a component of the brain renin-angiotensin system that is crucial for blood pressure (BP) regulation. We therefore hypothesized that PRR signaling in the ARC AgRP neurons plays a regulatory role in the development of hypertension. To test this hypothesis, we selectively deleted PRR in ARC AgRP neurons by crossing AgRP-IRES-Cre mice with PRR fl/fl mice. Using RNAscope, as expected, AgRP Cre+ PRR fl/y mice displayed a significantly lower PRR mRNA in the ARC AgRP neurons than WT mice (76.3 ± 6.1 vs. 127.7 ± 2.9 AFU, p < 0.05), indicating efficient ablation of PRR in ARC AgRP neurons. To examine the impact of PRR deletion in the ARC AgRP neurons on BP, the AgRP Cre+ PRR fl/y and control mice were implanted with telemetry probes to monitor BP continuously. After baseline recording, mice received DOCA-salt treatment (50 mg DOCA + saline as drinking water) for two weeks. BP variability and standard time domain heart rate variability (HRV) parameters, including overall HRV (SDNN) and short-term HRV (rMSSD), were analyzed from beat-to-beat intervals (n = 2-7 mice/group). At baseline, there was no difference between the two groups in BP, BP variability, and HRV. Two weeks of DOCA-salt induced a significantly higher BP in AgRP Cre+ PRR fl/y mice than the controls (156.2 ± 6 vs. 119.4 ± 3 mmHg, p < 0.05), while BP variability did not differ between the two groups. Noteworthy, AgRP Cre+ PRR fl/y mice exhibited lower SDNN than the controls (13.3 ± 4 vs. 19.4 ± 4 ms), indicating increased sympathetic and/or reduced parasympathetic nervous activity. This lower SDNN suggests impaired cardiac autonomic function and adaptability to physiological demands in AgRP Cre+ PRR fl/y mice. Concurrently, AgRP Cre+ PRR fl/y mice showed a lower rMSSD (4.7 ± 0.5 vs. 10.8 ± 3.5 ms), implying reduced parasympathetic activity. In conclusion, deletion of PRR in the ARC AgRP neurons results in compromised cardiac autonomic function associated with the development of hypertension. Our findings underscore a novel protective role of PRR signaling in the ARC AgRP neurons in BP regulation.

Abstract 66: Early-Life Sodium Restriction Programs Salt-Sensitivity of Autonomics and Blood Pressure in Adult C57BL/6J Mice

Extremely premature birth is a risk factor for sodium (Na) depletion due to renal immaturity and urine Na losses. We have proposed that Na depletion in preterm infants mechanistically contributes to their increased risk for cardiovascular and metabolic disease observed in adulthood, potentially due to changes during hypothalamic development. In humans, the hypothalamus matures between 20-25 weeks of gestation; in mice, this developmental window occurs between postnatal day (PD) 21 and PD42. Previously, we demonstrated in mice that dietary Na restriction from PD21 to PD42 induced long-lasting increases in energy expenditure via exaggerated autonomic activity. Therefore, we hypothesized that restricting dietary Na from PD21 to PD42 would similarly induce programmed changes in cardiovascular control via changes in autonomic and neurohypophyseal functions. Male C57BL/6J mice were provided a customized low (0.04%, n=7) or supplemented (0.30%, n=8) Na version of the soy protein-free Teklad 2920x diet from PD21 to PD42, after which they were returned to the standard (0.15% Na) 2920x diet. Radiotelemetric blood pressure (BP) transducers were implanted at 7-8 weeks of age. At 10 weeks of age, no differences in BP or heart rate (HR) were noted between groups. All animals were switched to a high (1%) Na diet at 12 weeks of age. At 16 weeks of age, systolic BP was not altered in the 0.30% Na group but significantly increased in the 0.04% Na group compared to the week 10 baseline (24h avg: +6±2 mmHg, p<0.05). Ganglionic block with chlorisondamine or β-adrenergic block with propranolol reduced heart rate (HR) to a greater extent (each p<0.05) in the 0.04% group. Conversely, muscarinic block with atropine resulted in a smaller increase in HR in this group (p<0.05). Urine elimination rates of aldosterone (0.30%: 1.96±0.44 vs 0.04%: 2.92±0.064 ng/d) and copeptin (0.30%: 0.16±0.03 vs. 0.04%: 0.14±0.02 ng/d) were similar between groups. Finally, at 18 weeks of age, all mice received the angiotensin AT 1 R antagonist losartan in drinking water. This caused a greater BP reduction in the 0.04% group at 20 weeks (24h avg: -12±2 vs -19±2 mmHg, p<0.05). Together, these data indicate that dietary Na restriction during hypothalamic development programs increased salt sensitivity of BP via a mechanism involving AT 1 R and characterized by increased sympathetic yet decreased parasympathetic activity.

Evaluation of high altitude training camps with heart rate recovery and heart rate variability analysis: beneficial effect in elite swimmers.

The available evidence on the impact of altitude training on sports performance is inconclusive. Heart rate variability (HRV) and heart rate recovery (HRR) are among the most frequently used parameters in athletic performance analysis and monitoring. Our study aims to investigate the effect of high altitude training on HRR and HRV, which are reliable predictors of athletic performance. Elite national swimmers were included in the study. Time domain and frequency domain analyzes were performed with the Polar Verity Sense device and Kubios HRV software. HRR were measured at one-minute intervals for the first 15 minutes after peak heart rate, and then recorded at the 20th, 25th and 30th minutes. A significant difference is observed from the beginning to the 11th minute. The P value at 1, 3, 5, 7 and 11 minutes is 0.001, 0.023, 0.032, 0.019 and 0.020, respectively. Similarly, a significant change was observed in delta HRR. Among the HRV parameters, RMSSD, SDNN, Poincaré SD1 and PNS are statistically significant. P values are 0.004, 0.018, 0.024 and 0.013 respectively. High altitude training program has a positive effect on HRV and CRV in elite swimmers. This condition is associated with increased cardiac parasympathetic activity. Time domain analyses have proven to be more beneficial for HRV. HRR and HRV are effective, reliable and inexpensive methods of performance monitoring of elite athletes.

O10 HEART RATE VARIABILITY AS EARLY MARKER OF CARDIAC INJURY IN HYPERTENSIVE YOUNG ADULTS

Background: Hypertension remains a life-threatening risk factor for cardiovascular diseases globally. It is not only common to middle age or aged group but also affect young individuals. Heart rate variability (HRV) gives an inference of the overall cardiac function and health of an individual. Thus, the aim of this study was to investigate whether HRV could be an early marker and a valid alternative to biochemical probes for the early detection of cardiac injury and systemic inflammation in hypertensive young adults. Materials and methods: A total number of 300 participants were recruited by fixed sampling of the case control study grouped into normotensive and hypertensive young groups. Informed consent was obtained from all participants before the procedure. Blood pressure with some anthropometric data were collected. Afterward, each participant’s HRV data was acquired by conducting a 5-minute resting ECG. Then, 5 ml of blood was taken through sterile venepuncture, centrifuged at 3000 rpm for 15 mins and biochemical analysis was performed for plasma troponin-I, troponin-T and inflammatory markers (TNF-alpha and NF-kappaB). Results: HRV assessment showed significant decrease in HRV parameters of parasympathetic activity (SDNN, RMSSD, HF) in the hypertensive young group. LF also showed significant decrease in the hypertensive group. But, LF/HF (sympatho-vagal balance) showed significant increase in the hypertensive group. LF correlates with plasma TNF-α (r = -0.6167) and NF-kB (r = -0.6673) at p = 0.0003 and p<0.0001, respectively. In addition, LF correlates with plasma Troponin-I (r = -0.6393) and Troponin-T (r = -0.5719) at p = 0.0001 and p = 0.0010, respectively. LF/HF had no correlation with these biomarkers. Thus, HRV correlates with plasma troponin-I, troponin-T, TNF-alpha and NF-kappaB in hypertensive young adults. Conclusion: HRV can be used as an early marker of cardiac injury and inflammation in young hypertensive individuals.

The effect of age on heart rate variability indices during and following high-intensity continuous exercise in masters and young cyclists.

This study compared heart rate variability (HRV) parameters of cardiovascular autonomic regulation between well-trained masters and young cyclists at rest, during and following a continuous cycle (CTS) protocol. Ten masters (age = 56 ± 5years) and eight young (age = 26 ± 3years) cyclists completed a 100min experimental protocol consisting of a 60min CTS cycling bout at 95% of Ventilatory Threshold 2 followed by 40min of supine recovery. Beat-to-beat heart rate was measured continuously, and HRV parameters analysed at standardised 5min intervals during rest, exercise and recovery. The root mean square of the successive differences (RMSSD), low-frequency power and high-frequency power parameters were corrected by division of the R-R interval (time domain), or R-R interval squared (frequency domain). Further, the RMSSD and RMSSD:RR for successive 60-s R-R intervals at the onset (0-10min) and offset (60-70min) of CTS exercise were analysed over 10-min periods. The natural logarithm (Ln) of skewed parameters was taken for analysis. Significant interaction effects (P < 0.05) for 5min segments were found for (LnRMSSD, LnRMSSD:RR, LnHF and LnHF:RR2. Masters cyclists demonstrated lower values of parasympathetic activity at rest and during recovery (15-20min and 35-40min) compared to younger cyclists. However, similar HRV responses were observed during exercise, including throughout the acute onset and offset periods (P > 0.05). This data shows that cardiac autonomic regulation during, or immediately following CTS exercise may not be influenced by age, but masters athletes may exhibit a lower baseline for parasympathetic activity.

Horses’ Cardiovascular and Glucocorticoid Responses to Equine-Assisted Therapy with Women with Intellectual Disability: An Exploratory Study

ABSTRACT Research on equine-assisted therapy (EAT) has primarily been centered on human health. Relatively few studies have addressed the impact of EAT on horses. This study sought to monitor four experienced therapy horses’ cardiovascular and glucocorticoid activity over the course of standardized EAT sessions designed to support women with intellectual disability. In the control condition, horses completed the EAT protocol solely with the therapist, thereby resembling a training session. Descriptive data analysis revealed higher levels of heart rate during an experimental EAT session and increased salivary cortisol when horses were navigated by the client through an obstacle course during the “challenge” phase of the protocol, pointing at a greater physical demand due to the recipient on horseback. Given the parasympathetic activity and overall heart rate variability across experimental EAT sessions and the cortisol recovery after the sessions, the findings do not give rise to any acute animal welfare concerns. For a more holistic interpretation of the present research results, further investigation into the horse perception of EAT, based on a bigger sample size and additional markers of welfare, is needed.

Effects of Biofeedback Training on Shooters' Performance, Stress Levels, and HRV

This study aimed to explore the impact of a 12-week biofeedback training on shooters' performance, stress levels, and heart rate variability (HRV). Thirty-six shooters aged 18-24 (18 subjects in each group) participated. The experimental group underwent 12 weeks of biofeedback and shooting training, while the control group only received shooting training. Results showed significant improvements in performance, stress levels, and HRV parameters in the experimental group, reflecting enhanced parasympathetic activity. It was further revealed that TP value was negatively correlated with stress level and positively correlated with performance, and stress level was negatively correlated with performance.

Multidimensional analysis of heart rate variability and burden of illness in bipolar disorder

IntroductionPatients with bipolar disorder (BD) face disproportionate rates of cardiovascular disease. While several mechanisms have been proposed for this association, both are multifactorial and heterogeneous illnesses, and it is unlikely that any individual factor can account for a significant portion of their association. Potential mediators have been mostly studied in isolation even though they are interrelated. Furthermore, few studies have accounted for baseline cardiovascular functioning or burden of illness. MethodsWe sought to analyze the association between burden of illness, phase of the illness (e.g., depressive) and heart rate variability (HRV) in 48 patients diagnosed with BD using canonical correlation analysis. We hypothesized that the association between burden of illness and HRV measures would be different depending on the clinical phase (i.e., euthymia, depression or (hypo)mania). ResultsA longer duration of (hypo)manic episodes was associated with higher rates of hypertension and increased sympathetic activation, along with lower rates of migraine and family history of suicide. In the second canonical variable, a later age at onset of (hypo)manic episodes was associated with higher parasympathetic activity. LimitationsSmall sample size; while the magnitudes of correlations for these top functions were large, none of the models were statistically significant. ConclusionsThere are different dimensions to the association between burden of illness and HRV in BD. The first dimension could comprise higher sympathetic activation in the context of longer (hypo)manic episodes, with lower rates for clinical variables that have been associated with a predominant depressive polarity (e.g., family history of suicide and migraine).

Cardiac autonomic regulation during submaximal exercise in women with fibromyalgia.

Fibromyalgia (FM) patients present impaired cardiac autonomic regulation during maximal exercise; however, it is unknown whether these alterations also manifest during submaximal exercise. The aim of this study was to compare the on-transient heart rate (HR) response and HR variability during a constant-load submaximal cycling exercise between FM and control (CON) women. Ten women with FM (age: 45.2±9.3 years) and 10 age-matched CON women (age: 48.4±6.1 years) performed a 15-min cycling exercise, with the work rate fixed at 50% of the individual peak power output attained in a maximal graded exercise test. The time intervals between consecutive heartbeats were recorded regularly during the exercise for subsequent analysis of on-transient HR response and HR variability indices. The on-transient HR time constant was similar (P=0.83) between the FM (41.0±14.1 sec) and CON (42.2±10.4 sec). During the 5-10 and 10-15 min of exercise, HR variability indices indicating sympathetic and parasympathetic activities were similar (P>0.05) between FM and CON groups. In conclusion, women with FM presented a normal cardiac autonomic response to submaximal cycling exercise. These findings have clinical relevance, as submaximal exercises are commonly prescribed for FM patients.

Childhood Family Stress and Women's Health: Parasympathetic Activity as a Risk and Resiliency Factor.

Childhood family stress (CFS) exacerbates risk for physical health problems across the lifespan. Health risks associated with CFS are particularly relevant for women who tend to endorse more CFS than men. Importantly, some evidence suggests that individuals may vary in their susceptibility to CFS. Parasympathetic activity, which helps to regulate automatic bodily activity (e.g., breathing, digestion), has been proposed to represent a marker of plasticity to environmental exposure. However, no research to date has tested whether parasympathetic activity may modulate the impact of early adversity on health. We examined whether parasympathetic activity would moderate the link between CFS and health complaints in a sample of 68 undergraduate women (Mean age = 19.44). Participants self-reported CFS and health complaints. Parasympathetic activity was indexed using high-frequency heart rate variability (HF-HRV) and was evaluated by measuring changes in HF-HRV in response to and following a laboratory-based stress induction. Multiple regression analyses indicated that CFS was significantly associated with more health complaints. Further, HF-HRV in response to stress and during recovery relative to baseline significantly moderated relationship between CFS and health complaints. Specifically, more CFS was significantly associated with more health complaints among women who showed mean or greater decreases in HF-HRV in response to stress. Additionally, lower levels of CFS were associated with fewer health complaints among women who showed mean or greater HF-HRV during recovery relative to baseline. Findings highlight the importance of parasympathetic activity in modulating stress-health links.

Resting vagally-mediated heart rate variability in the laboratory is associated with momentary negative affect and emotion regulation in daily life.

Vagally-mediated heart rate variability (vmHRV) is a physiological index reflecting parasympathetic activity that has been linked to emotion regulation (ER) capacity. However, very limited research has examined associations of physiological indices of regulation such as vmHRV with emotional functioning in daily life. The few studies that exist have small samples sizes and typically focus on only a narrow aspect of ER or emotional functioning. In this study, we examined associations between vmHRV assessed in the laboratory and emotional/mental health functioning in daily life using a 7-day ecological momentary assessment design in 303 adult community participants. We hypothesized that higher resting vmHRV would be associated with higher positive affect (PA), lower negative affect (NA), less affective variability, greater well-being, fewer dysphoria symptoms, greater use of engagement ER strategies, and less use of avoidance ER strategies, as assessed in daily life. Results revealed that higher resting vmHRV in the laboratory (as indexed by both high frequency heart rate variability, HF-HRV, and the root mean of successive square deviations between heart beats, RMSSD) was significantly associated with less frequent use of avoidance ER strategies in daily life. Theoretical and clinical implications are discussed, including the association of vmHRV with negatively valenced, rather than positively valenced, daily life experiences.

Monitoring the heart rate variability of servicewomen of the Armed Forces of Ukraine during the legal regime of martial law

The article features the results of the analysis of heart rate variability of 30 female military personnel (n=30). The purpose of this study was to assess the state of regulatory mechanisms of the autonomic nervous system. The analysis of heart rate variability indicators reflects the general level of autonomic regulation, which is important for assessing the physical and psychological state of military personnel. The RRNN parameter had a median of 814.5 ms, which corresponds to the norm for healthy individuals and indicates a normal level of cardiac activity of females being under the research. The SDNN indicator, which characterizes the total effect of autonomic regulation of blood circulation, was 37.4 ms on the median, which also corresponds to the norm and indicates an adequate level of adaptation capabilities of the body. However, RMSSD was at the median below normal, indicating reduced recovery and high levels of stress among female military personnel. pNN50, which reflects the proportion of consecutive RR intervals differing by more than 50 ms, was also below normal, further confirming reduced parasympathetic activity. The LF index was 301.0 ms² on the median of female military personnel, which is at the lower limit of the norm. The result we obtained may indicate a reduced sympathetic influence or a general depletion of adaptation reserves. The VLF indicator, which characterizes neurohumoral regulation, was also below the norm, which indicates a possible depletion of the body's adaptive reserves. Such studies make it possible to detect signs of fatigue or insufficient recovery in time and take the necessary measures to optimize the training process and the performance of official duties. Our research confirms that heart rate variability is an important indicator of the body's adaptive capabilities, especially in the conditions of martial law, where stress and physical exertion are constant factors of influence.

Analysis of perioperative autonomic nervous system activity to visualize stress in pediatric patients undergoing alveolar bone graft surgery.

Perioperative stress in pediatric patients is often difficult to assess via interviews; thus, an objective measure to assess perioperative stress is needed. To visualize perioperative stress, we observed autonomic nervous system (ANS) activity, circulatory dynamics, and psychological status in pediatric patients undergoing alveolar bone grafting under general anesthesia. This prospective observational study included 40 patients aged 8-12 years who were scheduled for alveolar bone grafting in our hospital. ANS activity was analyzed using heart rate variability the day before surgery, during general anesthesia, 2h postoperatively, 24h postoperatively, and the day before discharge. ANS assessment included LF/HF (sympathetic nervous system activity) and HF (parasympathetic nervous system activity). Additionally, heart rate (HR), systolic blood pressure (SBP), face scale (FS) score were recorded. Data from 31 patients, excluding dropouts, were analyzed. The ratio of change to the preoperative value was compared. After surgery, the LF/HF, HR, SBP, and FS score significantly increased (P < 0.01) and HF significantly decreased (2h postoperatively: P < 0.05, 24h postoperatively, before discharge: P < 0.01). SBP recovered to preoperative values 24h postoperatively, and HR and FS scores recovered to preoperative values before discharge. However, even before discharge, LF/HF remained significantly higher than preoperative values, and HF remained significantly lower than preoperative values (P < 0.01). Conclusion We observed perioperative stress from multiple perspectives. Circulatory dynamics and psychological status recovered by the day before discharge; however, ANS activity did not. Therefore, evaluating ANS activity may be useful in visualizing potential perioperative stress in pediatric patients.

Assessing the Role of the Autonomic Nervous System as a Driver of Sleep Quality in Patients With Multiple Sclerosis: Observation Study

Background Low sleep quality is a common symptom of multiple sclerosis (MS) and substantially decreases patients’ quality of life. The autonomic nervous system (ANS) is crucial to healthy sleep, and the transition from wake to sleep produces the largest shift in autonomic activity we experience every day. For patients with MS, the ANS is often impaired. The relationship between the ANS and perceived sleep quality in patients with MS remains elusive. Objective In this study, we aim to quantify the impact of the ANS and MS on perceived sleep quality. Methods We monitored 77 participants over 2 weeks using an arm-worn wearable sensor and a custom smartphone app. Besides recording daily perceived sleep quality, we continuously recorded participants’ heart rate (HR) and HR variability on a per-second basis, as well as stress, activity, and the weather (20,700 hours of sensor data). Results During sleep, we found that reduced HR variability and increased motion led to lower perceived sleep quality in patients with MS (n=53) as well as the age- and gender-matched control group (n=24). An activated stress response (high sympathetic activity and low parasympathetic activity) while asleep resulted in lower perceived sleep quality. For patients with MS, an activated stress response while asleep reduced perceived sleep quality more heavily than in the control group. Similarly, the effect of increased stress levels throughout the day is particularly severe for patients with MS. For patients with MS, we found that stress correlated negatively with minimal observed HR while asleep and might even affect their daily routine. We found that patients with MS with more severe impairments generally recorded lower perceived sleep quality than patients with MS with less severe disease progression. Conclusions For patients with MS, stress throughout the day and an activated stress response while asleep play a crucial role in determining sleep quality, whereas this is less important for healthy individuals. Besides ensuring an adequate sleep duration, patients with MS might thus work to reduce stressors, which seem to have a particularly negative effect on sleep quality. Generally, however, sleep quality decreases with MS disease progression.

Parasympathetic tone activity, heart rate, and grimace scale in conscious horses of 3 breeds before, during, and after nociceptive mechanical stimulation.

Parasympathetic tone activity (PTA) in response to nociceptive stimulus in conscious non-sedated horses is unknown. Study PTA, heart rate (HR), and horse grimace scale (HGS) at rest and during mechanical nociceptive stimulation. Ninety healthy young adult horses (females, males): 30 each of Friesians, Quarter Horses, and Warmbloods. Prospective control study. The study consisted of habituation to equipment (Day 1), baseline recordings (Days 2 and 3), and nociceptive testing applying mild pressure to the metacarpus (Day 4). Parasympathetic tone, HR, and HGS were recorded simultaneously on Days 2 to 4. Each study lasted 30 minutes and was done in triplicate at 3 different time points per day. Baseline PTA was not different among breeds. It decreased in Warmbloods and Quarter Horses during placement of the stimulus device without stimulation (P < .01). A significant decrease in PTA (P < .001) occurred during nociceptive stimulus (marked in Quarter Horses, intermediate in Warmbloods, and mild in Friesians). Heart rate and HGS increased significantly (P < .001) during the stimulus in all breeds but returned to baseline poststimulation. Friesians required higher pressure (P < .05) to elicit an aversive response to the stimulus. Horses' PTA, HR, and HGS change in response to a mild mechanical nociceptive stimulus with Friesians showing less variation. Stress induced a decrease in PTA in Quarter Horses and Warmbloods but not in Friesians. Friesians appeared to be more tolerant to pain based on PTA, HR, and HGS findings compared with other breeds.

Short-term exposure to indoor artificial light at night during sleep impairs cardiac autonomic function of young healthy adults in China

The artificial light at night (ALAN) exposure has emerged as a significant environmental and public health concern globally. However, there is far less evidence on the health effects of indoor ALAN than on outdoor ALAN. Moreover, evidence on cardiovascular effects of indoor ALAN is more limited. To evaluate the association between short-term exposure to ALAN during sleep with heart rate variability (HRV) in young healthy adults, as well as the mediating role of blood oxygen saturation (SpO2), and to further explore the intervention effects of shading habits, this prospective repeated measurement study was conducted among 81 adults with 150 nights (1324h) of HRV monitoring. HRV and SpO2 were monitored during sleep, concurrently with the measurement of indoor and outdoor ALAN. Shading habits were defined as whether to wear blindfolds or draw bed curtains during sleep, and were collected by questionnaires. Linear mixed-effect model was conducted to assess the association between ALAN exposure and HRV indices. The role of SpO2 in the association was analyzed using mediation analyses. We found that indoor ALAN exposure reduced parasympathetic activity and imbalanced cardiac autonomic function. We also found that the use of outdoor ALAN may underestimate or misestimate the potential health effects of ALAN. A significant mediation effects were observed on standard deviation of normal-to-normal intervals (SDNN; p-value for ACME = 0.014) and the ratio of low frequency power to high frequency power (LF/HF; p-value for ACME = 0.026) through minimum SpO2 after indoor ALAN exposure. The association between indoor ALAN and HRV was more pronounced among participants without shading habits during sleep. This study provides general population-based evidence that short-term exposure to indoor ALAN was significantly associated with impaired HRV, and SpO2 partially mediated the association. Improve shading habits during sleep may mitigate the adverse effects of indoor ALAN.

EFEKTIVITAS SLOW STROKE BACK MASSAGE TERHADAP TEKANAN DARAH DAN KUALITAS TIDUR PENDERITA HIPERTENSI

Known as hypertension, or high blood pressure, is a non-communicable disease (NCD). Preliminary study data from Dr. Kariadi Semarang Central Public Hospital indicated 561 patients with hypertension over the last three years (2021–2023). Hypertension symptoms often resemble those of other diseases and can vary among individuals, including fatigue, palpitations, increased blood pressure, nosebleeds, headaches, and nocturia, which can disrupt sleep quality. One of the non-pharmacological effort to prevent hypertension is slow-stroke back massage, This study aimed to determine the effect of slow-stroke back massage on blood pressure and sleep quality in hypertension sufferers. The research design employed a quasi-experimental method with a one-group pretest-posttest approach, involving 42 respondents selected through purposive sampling. The results demonstrated that slow-stroke back massage effectively reduced systolic blood pressure (p-value = 0.00) and improved sleep quality scores (p-value = 0.00). Slow-stroke back massage can enhance relaxation and increase parasympathetic nerve activity, thereby reducing the heart's workload. This study recommends that nurses apply slow-stroke back massage therapy in hospitals to help control blood pressure and improve the sleep quality of hypertension sufferers.

Ação Imunomoduladora da Estimulação Parassimpática promovida pelo Exercício Físico

Introduction: Physical exercise promotes the stimulation of the vagal nerve and different neural networks, contributing to a more effective anti-inflammatory response in order to contribute to cardiovascular, metabolic and immunological benefits. Objective: To associate the role of physical exercise with parasympathetic stimulation and its possible implications in immunomodulation Methods: This is a qualitative, explanatory and descriptive study on the immunomodulatory action of parasympathetic activation through physical exercise through a bibliographic review. The databases used were: PubMed, Scopus, Scielo and Web of Science involving all original articles from January 2015 and June 2024. Results: The main findings are related to differences in physical exercise intensity, which can contribute to the modulation of the innate immune system and the expression of neutrophil and lymphocyte cell populations, which can contribute to a more specific immune response. Aerobic training and strength training had similar responses in reducing BMI and glycated hemoglobin, reducing sympathetic tone, increasing parasympathetic tone, and improving the sympatho/vagal balance for controlling heart rate variability. There was a negative association between vagal neuroimmunomodulation (NIM) and mortality, since the lower the NIM index, the shorter the survival time in the population sample. Conclusion: Aerobic physical exercise and strength training can contribute to the activation of the parasympathetic system and immune system and provide better adjustments in the innate and adaptive immune response dependent on the intensity and volume of training.