The Association of Cigarette Smoking With High-Frequency Heart Rate Variability: An Ecological Momentary Assessment Study

Protocol for a randomized controlled trial comparing phone-based prenatal mindfulness training to usual care for pregnant people at risk for hypertensive disorders of pregnancy

Hypertensive disorders of pregnancy (HDP) are the most common medical conditions in pregnancy and a leading cause of maternal morbidity and mortality in the United States. There are few interventions available to prevent HDP, and those currently available do not target underlying mechanisms of disease. Mindfulness training (MT) is effective at reducing blood pressure in non-pregnant patients with pre-hypertension and hypertension and has proven more effective at blood pressure reduction than other stress management interventions. MT thus holds great promise as a mind-body intervention to prevent HDP. This randomized trial will harness subjective and objective ecological momentary assessment methodology combined with wearable biosensor technology to capture psychological, physiological, and interpersonal processes through which MT may lead to improved maternal cardiovascular parameters. Pregnant women at risk for HDP will be randomized to an 8-week phone-delivered MT intervention or usual care. Through these methods, we will evaluate psychological, physiological, and interpersonal responses to daily experiences linking MT to cardiovascular parameters among women at risk for HDP.

Phenotyping the autonomic nervous system in pregnancy using remote sensors: potential for complication prediction

Objectives: The autonomic nervous system (ANS) plays a central role in dynamic adaptation during pregnancy in accordance with the pregnancy demands which otherwise can lead to various pregnancy complications. Despite the importance of understanding the ANS function during pregnancy, the literature lacks sufficiency in the ANS assessment. In this study, we aimed to identify the heart rate variability (HRV) function during the second and third trimesters of pregnancy and 1 week after childbirth and its relevant predictors in healthy pregnant Latina individuals in Orange County, CA. Materials and methods: N = 16 participants were enrolled into the study from which N = 14 (N = 13 healthy and n = 1 complicated) participants proceeded to the analysis phase. For the analysis, we conducted supervised machine learning modeling including the hierarchical linear model to understand the association between time and HRV and random forest regression to investigate the factors that may affect HRV during pregnancy. A t-test was used for exploratory analysis to compare the complicated case with healthy pregnancies. Results: The results of hierarchical linear model analysis showed a significant positive relationship between time (day) and average HRV (estimated effect = 0.06; p < 0.0001), regardless of being healthy or complicated, indicating that HRV increases during pregnancy significantly. Random forest regression results identified some lifestyle and sociodemographic factors such as activity, sleep, diet, and mental stress as important predictors for HRV changes in addition to time. The findings of the t-test indicated that the average weekly HRV of healthy and non-healthy subjects differed significantly (p < 0.05) during the 17 weeks of the study. Conclusion: It is imperative to focus our attention on potential autonomic changes, particularly the possibility of increased parasympathetic activity as pregnancy advances. This observation may challenge the existing literature that often suggests a decline in parasympathetic activity toward the end of pregnancy. Moreover, our findings indicated the complexity of HRV prediction, involving various factors beyond the mere passage of time. To gain a more comprehensive understanding of this dynamic state, future investigations should delve into the intricate relationship between autonomic activity, considering diverse parasympathetic and sympathetic metrics, and the progression of pregnancy.

A study to characterize the lead isotopic fingerprint in PM2.5 emitted from incense stick and cigarette burning

The incense sticks and cigarettes burning are key sources of particulate matter with a diameter of ≤ 2.5 μm (PM_2.5) in indoor and outdoor air. While lead (Pb) isotope ratios provide valuable insights into the origin of particle pollution, their applicability for investigating these source remains unclear. The Pb isotope ratios in the PM_2.5 emitted from these two sources were analyzed, and effects of brands or nicotine contents on the ratios were assessed. In addition, As, Cr, and Pb were analyzed to investigate whether Pb isotope ratios can serve as an indicator for the source investigation of these metals. We found that average ratios of ²⁰⁶Pb/²⁰⁴Pb, ²⁰⁶Pb/²⁰⁷Pb, and ²⁰⁸Pb/²⁰⁷Pb in cigarettes were heavier than those in incense sticks. Scatter plots of Pb isotope ratios indicated an overlap of values for incense sticks or cigarettes linked to different brands, in that ratios for cigarettes with high nicotine content were heavier than for those with low nicotine content. Scatter plots of As, Cr, or Pb concentration against Pb isotope ratios clearly distinguished the effects of cigarette burning versus incense sticks with respect to PM_2.5 of these metals. Results indicate that brand differences did not affect the determination of PM_2.5 in these two sources. We suggest that Pb isotope ratios can be a useful tool in investigating the influence of incense sticks and of cigarettes (with high or low nicotine content) burning to PM_2.5 and associated metals.

An Examination of Cardiac Vagal Control Indices and Cognitive Stress Appraisal in Cigarette Smokers

Identifying factors that influence how individuals who smoke cigarettes respond to stress is important as stress is a risk factor for smoking and its maintenance. This study examined the modulatory role of cardiac vagal control (CVC), a physiological correlate of self-regulation, on cognitive stress appraisal processes of adults who smoke. Sixty daily cigarette smokers were randomized to receive positive or negative feedback during a modified Trier Social Stress Test. Pre- and post-task stress appraisals were assessed and resting and reactivity CVC measures were computed. Moderated regression models assessed if the relation between feedback condition and post-task stress appraisal varied as a function of CVC. We hypothesized that participants receiving negative feedback would report greater post-task stress appraisal compared to participants receiving positive feedback, and the strength of the effect of both feedback groups would be greater at higher levels of CVC. All models showed significant main effects of feedback condition (b =  - 0.42, p = 0.01; b =  - 0.45, p = 0.01) on post-task stress appraisal: participants receiving negative feedback reported greater post-task stress appraisal. No significant main or interactive effects of CVC and feedback condition on post-task stress appraisal were observed. This study demonstrates that stress appraisals of daily cigarette smokers are sensitive to social feedback, but are not moderated by individual differences in CVC. Future investigations are needed to clarify whether this finding is explained by smoking-specific impairments in CVC as well as the distinct and interactive effects of physiological and psychological processes implicated in stress and smoking risk.

Ultrasound evaluation of vagus nerve cross-sectional area in a community-dwelling elderly Japanese cohort

OBJECTIVES

Although the vagus nerve (VN) is easily observed by ultrasonography, few studies have evaluated the cross-sectional area (CSA) of the VN in healthy older individuals from East Asia. In this study, we aimed to report reference values for the CSA of the VN in community-dwelling elderly Japanese individuals and to identify any associated medical history and/or lifestyle factors.

METHODS

The present study included 336 participants aged ≥ 70 years from a prospective cohort study conducted in Yahaba, Japan from October 2021 to February 2022. The CSA of the VN was measured bilaterally at the level of the thyroid gland by ultrasonography. Simple linear regression analysis and generalized estimating equation were conducted to identify the associations between clinical and background factors and the CSA of the VN.

RESULTS

In our cohort, the median CSA of the VN was 1.3 mm2 (interquartile range [IQR] 1.1-1.6) on the right side and 1.2 mm2 (IQR 1.0-1.4) on the left side. Generalized estimating equation showed that history of head injury (β = 0.19, p < .01), current smoking habit (β = -0.09, p = .03), and BMI (β = 0.02, p < .01) were independently associated with the CSA of the VN.

CONCLUSION

We have reported reference VN CSA values for community-dwelling elderly Japanese individuals. In addition, we showed that the CSA of the VN was positively associated with a history of head injury and BMI and inversely associated with current smoking habit.

Associations between affective factors and high-frequency heart rate variability in primary care patients with depression

OBJECTIVE

Depression is a risk factor for cardiovascular disease (CVD), and subgroups of people with depression may be at particularly elevated CVD risk. Lower high-frequency heart rate variability (HF HRV), which reflects diminished parasympathetic activation, is a candidate mechanism underlying the depression-CVD relationship and predicts cardiovascular events. Few studies have examined whether certain depression subgroups - such as those with co-occurring affective factors - exhibit lower HF HRV. The present study sought to assess associations between co-occurring affective factors and HF HRV in people with depression.

METHODS

Utilizing baseline data from the 216 primary care patients with depression in the eIMPACT trial, we examined cross-sectional associations of depression's co-occurring affective factors (i.e., anxiety symptoms, hostility/anger, and trait positive affect) with HF HRV. HF HRV estimates were derived by spectral analysis from electrocardiographic data obtained during a supine rest period.

RESULTS

Individual regression models adjusted for demographics and depressive symptoms revealed that anxiety symptoms (standardized regression coefficient β = -0.24, p = .002) were negatively associated with HF HRV; however, hostility/anger (β = 0.02, p = .78) and trait positive affect (β = -0.05, p = .49) were not. In a model further adjusted for hypercholesterolemia, hypertension, diabetes, body mass index, current smoking, CVD prevention medication use, and antidepressant medication use, anxiety symptoms remained negatively associated with HF HRV (β = -0.19, p = .02).

CONCLUSION

Our findings suggest that, in adults with depression, those with comorbid anxiety symptoms have lower HF HRV than those without. Co-occurring anxiety may indicate a depression subgroup at elevated CVD risk on account of diminished parasympathetic activation.

Stable C and N isotopes of PM2.5 and size-segregated particles emitted from incense stick and cigarette burning

This work measured the δ¹³C and δ¹⁵N signatures in PM_2.5 and size-segregated particles emitted from incense stick and cigarette burning in different brands or nicotine contents for pollution source identification indoors. Three popular brands of incense stick and cigarette were selected for experiments. A personal environmental monitoring sampler and a Sioutas cascade impactor were used to collect PM_2.5 and size-segregated particles, respectively, for isotopic signatures analyses. Our data showed that both δ¹³C and δ¹⁵N values were heavier from incense stick burning (δ¹³C: 27.3 ± 0.5; δ¹⁵N: 8.63 ± 1.35) than cigarette (δ¹³C: 28.5 ± 0.2; δ¹⁵N: 4.15 ± 0.69). The scatter plots of δ¹³C and TC/PM_2.5 and of δ¹⁵N and TN/PM_2.5 can be applied to distinguish particle pollution sources and assess the influence of cigarette burning to PM_2.5 according to different nicotine contents. The δ¹³C values in size-segregated particles were similar to incense stick or cigarette burning; the δ¹³C values in PM_2.5 were significantly higher than those in size-segregated particles. However, the nitrogen amount was too low in most of the size-segregated particles to analyze δ¹⁵N from incense stick and cigarette burning. These results suggest that the δ¹³C signatures on PM_2.5 cannot represent the isotopic characteristics of size-segregated particles and δ¹⁵N has limitation for pollution source identification of different particle sizes.

Evidence for the association between physiological and emotional states in adolescents and young adults without psychopathology under ecologically valid conditions

Well-powered studies on the physiological concomitants underlying affect and its regulation during emerging adulthood are warranted to provide novel insight into mental health. The association between autonomic nervous system activity and emotional states occurring under natural conditions in daily life was investigated in individuals (N = 549, age 14-21, females 45.6%) without any lifetime mental disorder from an epidemiological cohort study in Germany. Using ecological momentary assessment, mood and optimism/pessimism were assessed over 4 days simultaneously with continuous heart rate monitoring. Lower vagal activity was found in mood states accompanied by high arousal (wakefulness, mania) and greater vagal activity in mood states with low arousal (calmness, pessimism). Findings illustrate important associations between autonomic nervous system activity and mood in youth under ecologically valid conditions. Vagal activity presents a prominent pathway by which mood may influence physiological function or vice versa. In contrast to commonly performed laboratory assessments, the ambulatory assessment in participants' daily life allows an application of the results to the field.

Phasic heart rate variability and the association with cognitive performance: A cross-sectional study in a healthy population setting

Introduction

Sympathovagal balance measured by heart rate variability is a core component of psychophysiological research. Through the close link of physiological and psychological aspects, often a reduced heart rate variability is associated with impaired cognitive function. A better understanding of the associations between cognitive and cardiovascular dysfunctions is necessary to prevent the manifestation of diseases. Therefore, this study investigated phasic heart rate variability using rest, anticipatory, stress, and recovery periods and the association with high and low cognitive performance in a generally healthy population setting.

Methods

114 healthy individuals (40 males, 74 females) aged 20 to 70 participated in the cross-sectional study. The heart rate variability based on standard deviation of NN intervals (SDNN), and the root means square of successive differences (RMSSD), low frequency (LF), high frequency (HF) and LF/HF ratio and its association with high and low cognitive performance measured by the California Verbal Learning Task II were examined.

Results

The results of this study indicate that the paradigm was successful in producing stress and showed a significant association between phasic heart rate variability (SDNN) and verbal episodic memory performance, irrespective of age and sex.

Discussion

The results of this study suggest that a reduced heart rate variability is associated with reduced cognitive function regardless of age and sex and seem to be an early indicator of sympathovagal disbalance.

Conclusion

This leads to the conclusion that differences between high and low cognitive performance might show differences in heart rate variability at an early stage, where no diseases are yet manifest.

Sleep Quality Associated with Habitual Physical Activity Level and Autonomic Nervous System of Smokers

BACKGROUND

Few studies have examined the relationship of one's habitual physical activity level and autonomic nervous system (ANS) modulation on sleep quality in smokers.

OBJECTIVE

The aim of this study was to identify changes in the sleep quality of smokers and its relation with their habitual physical activity level and ANS modulation.

METHODS

Forty-two smokers were divided into two groups according to the 50th percentile of the moderate-to-vigorous physical activity (MVPA). Sleep quality was assessed using the Mini-sleep Questionnaire, and ANS modulation was assessed by indices of heart rate variability (HRV). To examine the possible mean differences, the analysis of covariance (ANCOVA) was used, adjusted for age, sex, body composition, pack-years, beta-blockers, anxiety, and depression in log base 10, not including qualitative data, such as sex and beta-blockers. Correlations were made by using the Spearman rank correlation. The statistical significance was set at 5.

RESULTS

The smokers who were less active showed poor sleep quality (p=0.048) and insomnia (p=0.045). Furthermore, the less active group presented decreased parasympathetic modulation [HF (un; p=0.049); RMSSD (ms; p=0.047) and SD1 (ms; p=0.047)] and an increased LF (un) index (p=0.033) and LF/HF ratio (p=0.040). A positive correlation between the total Mini-sleep score with LF (un) index (r=0.317, p=0.041) and LF/HF ratio (r=0.318, p=0.040) and negative correlation with HF (un) index (r= -0.322, p=0.038).

CONCLUSIONS

Smokers with lower levels of habitual physical activity showed poor sleep quality and alterations in autonomic nervous system modulation; (Arq Bras Cardiol. 2020; [online].ahead print, PP.0-0).

Gender-Based Vegetarian and Nonvegetarian Dietary Impact on Cardiac Autonomic Function of Heart Rate Variability

Objective: Cardiovascular disease is one among the major mortality threats throughout the world. Autonomic activity of the nervous system can be examined by heart rate variability (HRV) analysis. Association of sympathetic and parasympathetic activities is directly related to HRV modulation. The aim of the study is to determine variations in HRV parameters among adult/adolescent male and female subjects due to vegetarian and nonvegetarian diet.Method: Ninety undergraduate students in each male and female group (N = 180) volunteered for the study. Based upon food habits, male and female subjects were categorized into four groups. Short-term (5-minute) heart rate recordings were measured from the subjects in a seated position before breakfast with minimum of 12 hours' fasting. Two-way analysis of variance was performed among the time and frequency domain variables.Results: Time domain variables are observed as significant (p < 0.05) between vegetarian males and females and also (p < 0.05) between male vegetarian and female nonvegetarians for standard deviation of NN intervals. Frequency domain HRV indices such as low frequency (LF; p = 0.01), high frequency (HF; p = 0.0001), and LF/HF (p < 0.001) resulted between male and female vegetarians. Significance of LF (p = 0.02), HF (p < 0.0001), and LF/HF (p < 0.01) was measured between male vegetarians and female nonvegetarians. LF (p = 0.02), HF (p = 0.04), and LF/HF (p = 0.002) resulted between nonvegetarian males and females. HF (p = 0.05) was enumerated between male vegetarians and nonvegetarians.Conclusions: Significant predominance of sympathetic cardiac activity was observed among male nonvegetarian consumers more than female vegetarians. Analysis demonstrates that the gender-based influence of vegetarian and nonvegetarian diet has significant correlation under HRV measurements.

The Association of Autonomic Nervous System Function With Ischemic Stroke, and Treatment Strategies

Acute ischemic stroke, especially minor stroke, and transient ischemic attack have high risks of recurrence and exacerbation into severe ischemic strokes. It remains challenging to perform risk stratification and screen high-risk groups for initiation of early treatment in these patients. Moreover, with the growing population of patients with chronic small vessel disease, the mechanisms and clinical implications require further investigation. Traditional tools such as the ABCD2 score (age, blood pressure, clinical features, duration of symptoms, diabetes) have only moderate predictive value in patients with transient ischemic attack or minor stroke. By contrast, measurement of changes in heart rate variability (HRV) is an important and novel tool for risk stratification and outcome prediction in patients with cardiovascular diseases, as it reflects the overall level of autonomic nervous system dysfunction. Thus, abnormal HRV may be useful for prognosis and improve stratification of stroke patients with diverse risks. HRV may also partially explain autonomic nervous dysfunction and other manifestations during the process of chronic cerebral small vessel disease. In summary, measurement of HRV may contribute to early initiation of interventions in acute or chronic stroke patients using novel treatments involving rebalancing of autonomic nervous system function.

Potential benefits of integrating ecological momentary assessment data into mHealth care systems

The advancement of wearable/ambulatory technologies has brought a huge change to data collection frameworks in recent decades. Mobile health (mHealth) care platforms, which utilize ambulatory devices to collect naturalistic and often intensively sampled data, produce innovative information of potential clinical relevance. For example, such data can inform clinical study design, recruitment approach, data analysis, and delivery of both "traditional" and novel (e.g., mHealth) interventions. We provide a conceptual overview of how data measured continuously or repeatedly via mobile devices (e.g., smartphone and body sensors) in daily life could be fruitfully used within a mHealth care system. We highlight the potential benefits of integrating ecological momentary assessment (EMA) into mHealth platforms for collecting, processing, and modeling data, and delivering and evaluating novel interventions in everyday life. Although the data obtained from EMA and related approaches may hold great potential benefits for mHealth care system, there are also implementation challenges; we briefly discuss the challenges to integrating EMA into mHealth care system.

Heart Rate Variability in Individual Psychotherapy: Associations With Alliance and Outcome

Heart rate variability (HRV) can be conceptualized as a marker of an individual's capability to adaptively respond to its environment and has been linked with mental health. Although conceptually and empirically linked to social behavior and thus relevant in the therapeutic setting, HRV is seldom investigated directly within therapy sessions. In the present examination, we aimed at addressing this research gap by assessing patients' and therapists' HRVs both ambulatory within therapy sessions and under resting conditions. Drawing on polyvagal theory, we hypothesized that higher in-session HRV is accompanied with higher therapeutic alliance ratings. Further, we expected baseline HRV to predict symptomatic outcome and to increase over the course of therapy. In a sample of 53 outpatients receiving 25 sessions of cognitive behavioral therapy, we measured HRV, therapeutic alliance and depressive symptoms on four occasions. Multilevel modeling analyses demonstrated that patients with higher in-session high-frequency HRV rated the therapeutic alliance higher. Baseline HRV predicted symptomatic outcome and increased over the course of therapy. Possible explanations involve a link between in-session HRV and in-session behavior and should be investigated in future studies. The results highlight the usefulness of in-session HRV as a promising process variable in psychotherapy research.

Theoretical implications and clinical support for heart rate variability biofeedback for substance use disorders

Heart rate variability (HRV) biofeedback is an accessible, cost-effective intervention that has demonstrated clinical value for numerous physical and mental health conditions; however, research on HRV biofeedback in substance use disorders (SUD) is in its nascence. We argue that HRV biofeedback may be particularly beneficial as an adjunct treatment for SUD by targeting bodily systems that are known to be disrupted by chronic substance use and are not historically the focus of psychosocial or pharmacological SUD treatment approaches. In addition to advocating for HRV biofeedback applications in SUD, we identify several gaps within the existing experimental literature, and propose new studies that could accelerate understanding of how and for whom HRV biofeedback is most likely to promote positive behavior change.

The Vagus Nerve Can Predict and Possibly Modulate Non-Communicable Chronic Diseases: Introducing a Neuroimmunological Paradigm to Public Health

Global burden of diseases (GBD) includes non-communicable conditions such as cardiovascular diseases, cancer and chronic obstructive pulmonary disease. These share important behavioral risk factors (e.g., smoking, diet) and pathophysiological contributing factors (oxidative stress, inflammation and excessive sympathetic activity). This article wishes to introduce to medicine and public health a new paradigm to predict, understand, prevent and possibly treat such diseases based on the science of neuro-immunology and specifically by focusing on vagal neuro-modulation. Vagal nerve activity is related to frontal brain activity which regulates unhealthy lifestyle behaviors. Epidemiologically, high vagal activity, indexed by greater heart rate variability (HRV), independently predicts reduced risk of GBD and better prognosis in GBD. Biologically, the vagus nerve inhibits oxidative stress, inflammation and sympathetic activity (and associated hypoxia). Finally, current non-invasive methods exist to activate this nerve for neuro-modulation, and have promising clinical effects. Indeed, preliminary evidence exists for the beneficial effects of vagal nerve activation in diabetes, stroke, myocardial infarction and possibly cancer. Thus, we propose to routinely implement measurement of HRV to predict such GBD in populations, and to test in randomized controlled trials effects of non-invasive vagal nerve activation on prevention and treatment of GBD, reflecting possible neuro-modulation of health.

Combining ecological momentary assessment with objective, ambulatory measures of behavior and physiology in substance-use research

Whereas substance-use researchers have long combined self-report with objective measures of behavior and physiology inside the laboratory, developments in mobile/wearable electronic technology are increasingly allowing for the collection of both subjective and objective information in participants' daily lives. For self-report, ecological momentary assessment (EMA), as implemented on contemporary smartphones or personal digital assistants, can provide researchers with near-real-time information on participants' behavior and mood in their natural environments. Data from portable/wearable electronic sensors measuring participants' internal and external environments can be combined with EMA (e.g., by timestamps recorded on questionnaires) to provide objective information useful in determining the momentary context of behavior and mood and/or validating participants' self-reports. Here, we review three objective ambulatory monitoring techniques that have been combined with EMA, with a focus on detecting drug use and/or measuring the behavioral or physiological correlates of mental events (i.e., emotions, cognitions): (1) collection and processing of biological samples in the field to measure drug use or participants' physiological activity (e.g., hypothalamic-pituitary-adrenal axis activity); (2) global positioning system (GPS) location information to link environmental characteristics (disorder/disadvantage, retail drug outlets) to drug use and affect; (3) ambulatory electronic physiological monitoring (e.g., electrocardiography) to detect drug use and mental events, as advances in machine learning algorithms make it possible to distinguish target changes from confounds (e.g., physical activity). Finally, we consider several other mobile/wearable technologies that hold promise to be combined with EMA, as well as potential challenges faced by researchers working with multiple mobile/wearable technologies simultaneously in the field.

Using the experience-sampling method to examine the psychological mechanisms by which participatory art improves wellbeing

AIMS

To measure the immediate impact of art-making in everyday life on diverse indices of wellbeing ('in the moment' and longer term) in order to improve understanding of the psychological mechanisms by which art may improve mental health.

METHODS

Using the experience-sampling method, 41 artists were prompted (with a 'beep' on a handheld computer) at random intervals (10 times a day, for one week) to answer a short questionnaire. The questionnaire tracked art-making and enquired about mood, cognition and state of consciousness. This resulted in 2,495 sampled experiences, with a high response rate in which 89% of questionnaires were completed.

RESULTS

Multi-level modelling was used to evaluate the impact of art-making on experience, with 2,495 'experiences' (experiential-level) nested within 41 participants (person-level). Recent art-making was significantly associated with experiential shifts: improvement in hedonic tone, vivid internal imagery and the flow state. Furthermore, the frequency of art-making across the week was associated with person-level measures of wellbeing: eudemonic happiness and self-regulation. Cross-level interactions, between experiential and person-level variables, suggested that hedonic tone improved more for those scoring low on eudemonic happiness, and further that, those high in eudemonic happiness were more likely to experience phenomenological features of the flow state and to experience inner dialogue while art-making.

CONCLUSION

Art-making has both immediate and long-term associations with wellbeing. At the experiential level, art-making affects multiple dimensions of conscious experience: affective, cognitive and state factors. This suggests that there are multiple routes to wellbeing (improving hedonic tone, making meaning through inner dialogue and experiencing the flow state). Recommendations are made to consider these factors when both developing and evaluating public health interventions that involve participatory art.