Evaluation of Local Skeletal Muscle Blood Flow in Manipulative Therapy by Diffuse Correlation Spectroscopy

Manipulative therapy (MT) is applied to motor organs through a therapist’s hands. Although MT has been utilized in various medical treatments based on its potential role for increasing the blood flow to the local muscle, a quantitative validation of local muscle blood flow in MT remains challenging due to the lack of appropriate bedside evaluation techniques. Therefore, we investigated changes in the local blood flow to the muscle undergoing MT by employing diffuse correlation spectroscopy, a portable and emerging optical measurement technology that non-invasively measures blood flow in deep tissues. This study investigated the changes in blood flow, heart rate, blood pressure, and autonomic nervous activity in the trapezius muscle through MT application in 30 volunteers without neck and shoulder injury. Five minutes of MT significantly increased the median local blood flow relative to that of the pre-MT period (p < 0.05). The post-MT local blood flow increase was significantly higher in the MT condition than in the control condition, where participants remained still without receiving MT for the same time (p < 0.05). However, MT did not affect the heart rate, blood pressure, or cardiac autonomic nervous activity. The post-MT increase in muscle blood flow was significantly higher in the participants with muscle stiffness in the neck and shoulder regions than in those without (p < 0.05). These results suggest that MT could increase the local blood flow to the target skeletal muscle, with minimal effects on systemic circulatory function.

Analysis of Heart Rate Asymmetry During Sleep Stages

It is one of the hot spots in recent years to explore changes in the sleep stage by assessing autonomic nervous activity. In recent years, heart rate asymmetry (HRA) is often used to measure the activity of autonomic nerves. However, the relationship between HRA and sleep stage is not clear. We performed Porta’s index (PI), Guzik’s index (GI), slope index (SI) and area index (AI) analyses on RR intervals per 30-s for understanding the HRA during sleep. Two measurement protocols were set: 1) the HRA values were calculated; 2) the degrees of heart rate deviation from symmetry were estimated. Results showed that PI significantly decreased from N1 and N2 to N3 (p<0.01), and it is increased the highest in REM than other stages (p<0.05). The asymmetry of HRA were significantly lower in N3 (PI and AI p’s<0.05; GI and SI p’s<0.01), and it increased in REM (PI p<0.05; GI, SI and AI p’s<0.0001). The results suggested that HRA has the potential to be used in sleep stage monitoring.

Balance of Autonomic Nervous Activity, Exercise, and Sleep Status in Older Adults: A Review of the Literature

While older people are frequently known to experience sleep disturbances, there are also many older people who have a good quality of sleep. However, little is known about the balance of autonomic nervous activity, exercise habits, and sleep status in healthy older adults. This study reviews the literature regarding balance of the autonomic nervous activity, exercise, and sleep in healthy older adults. Relevant articles were searched from electronic databases using the combination of the following keywords: “Autonomic nervous activity”, “sleep status”, “sleep”, “healthy older adults”, “aging”, “heart rate variability (HRV)” and “exercise”. Articles were included if they met inclusion criteria: (1) Published in English, (2) Article types: research and review articles, (3) Main outcome was related to the autonomic nervous activity, lifestyle, sleep, and/or healthy aging, and (4) Fully accessed. From 877 articles that were identified, 16 articles were included for review. Results showed that the autonomic nervous activity changes with increasing age, particularly a constant decline in cardiac vagal modulation due to the significant decrease in the nocturnal parasympathetic activity. In addition, the autonomic nervous activity was also related to sleep status and lifestyle, particularly the capability to exercise. In preparing older people toward a healthy aging, maintaining good sleep quality and exercise is suggested.

Giving Social Support at Work May Reduce Inflammation on Employees Themselves: A Participatory Workplace Intervention Study Among Japanese Hospital Nurses

ObjectivePreviously, we reported that the participatory workplace intervention was effective in reducing stress-related inflammatory markers, i.e., interleukin-6, among 31 Japanese female nurses. During the analysis, we recognized that our intervention might have increased prosocial behaviors like giving social support to others in some participants. Based on this assumption, we ran a secondary analysis, which examined the effect of giving social support to others on inflammatory markers, autonomic nervous activity, and perceived job stress before and after a 5-month intervention. We divided participants into two groups; those who had increased scores on giving social support after the intervention (Group 1, n = 13), and those who had decreased/unchanged in the scores (Group 2, n = 17). Friedman test was used to examine the changes in outcome measures by the group. ResultsGroup 1 showed significant decreases in interferon-γ, interleukin-6, and interleukin-12/23p40 immediately after the intervention, while interleukin-12/23p40 remained stably decreased three months later; Group 2 did not show changes in these markers. No significant changes were observed regarding autonomic nervous activity and perceived job stress. This study presented a significant insight that giving social support at work may provide health benefits towards employees themselves, via decreasing inflammation in the body.

Effect on autonomic nervous activity of applying hot towels for 10 s to the back during bed baths

Background Bed baths are a daily nursing activity to maintain patients’ hygiene. Those may provide not only comfort but also relaxation. Notably, applying a hot towel to the skin for 10 s (AHT10s) during bed baths helped to reduce the risk of skin tears and provided comfort and warmth in previous studies. However, it is still unclear whether autonomic nervous system is affected by bed baths. Thus, this study investigated the effect on the autonomic nervous activity of applying hot towels for 10 s to the back during bed baths. Methods This crossover study had 50 participants (25 men and women each; average age 22.2 ± 1.6 years; average body mass index 21.4 ± 2.2 kg/m2) who took bed baths with and without (control condition: CON) AHT10s on their back. Skin temperature, heart rate variability (HRV), and blood pressure (BP) were measured. Subjective evaluations and the State-Trait Anxiety Inventory in Japanese were also performed. Results A significant interaction of time and bed bath type on skin surface temperature was observed (p < .001). Regarding the means of skin surface temperature at each measurement time point, those for AHT10s were significantly higher than those for CON. Although the total state-anxiety score significantly decreased in both the bed bath types after intervention, the mean values of comfort and warmth were higher for bed baths with AHT10s than for CON (p < .05) during bed baths; AHT10s was significantly higher in warmth than CON after 15 min (p = .032). The interaction and main effects of time on HRV and BP and that of bed bath type were not significant. Conclusion Bed baths that involved AHT10s caused participants to maintain a higher skin temperature and warmer feeling than under the wiping-only condition; they also provided comfort during the interventions. However, the bed baths with AHT10s did not allow participants to reach a relaxed state; moreover, there was no change in autonomic nerve activity. This may be due to participants’ increased anxiety from skin exposure and the intervention being limited to one part of the body.

Alterations in the autonomic nerve activities of prenatal autism model mice treated with valproic acid at different developmental stages

Autism spectrum disorder (ASD) is characterized by impairment of social communication, repetitive behavior and restrictive interest. The risk of ASD is strongly associated with the prenatal period; for instance, the administration of valproic acid (VPA) to pregnant mothers increases risk of ASD in the child. Patients with ASD often exhibit an alteration in the autonomic nervous system. In this study, we assessed the autonomic nervous activity at each prenatal developmental stage of model mice of ASD treated with VPA, to clarify the relationship between timing of exposure and ASD symptoms. The assessment of the autonomic nervous activity was performed based on the analysis of electrocardiography data collected from fetal and adult mice. Interestingly, VPA model mouse fetuses exhibited a significantly lower activity of the sympathetic nervous system. In contrast, sympathetic nervous activity at P0 was significantly higher. In adult VPA model mice, the parasympathetic activity of female VPA mice was suppressed. Moreover, female VPA mice showed reduced the parasympathetic activity after exposure to restraint stress. These results suggest that the autonomic nervous activity of VPA model mice was altered from the fetal stage, and that the assessment of autonomic nervous activities at an early developmental stage could be useful for the understanding of ASD.