Autonomic Nervous System Indices Research Articles

Psychophysiological markers of athlete burnout: a call to arms.

Burnout is a growing problem in high-performance sport and has negative consequences for athletes (e.g., mental ill-health). It is therefore important to effectively monitor athlete burnout to aid intervention efforts. While self-report measures are available (e.g., athlete burnout questionnaire), the limitations associated with these measures (e.g., social desirability bias) means that objective physiological markers may also be useful. Thus, this article critically discusses potential biomarkers of athlete burnout, drawing on research inside and outside of sport to offer an overview of the current state-of-the-art in this research area. First, it outlines what athlete burnout is, its deleterious consequences, and discusses existing psychological assessments. The article then critically discusses literature on hypothalamic-pituitary-adrenal axis (e.g., salivary cortisol) and autonomic nervous system (e.g., heart rate variability) indices of burnout, highlighting some promising biomarkers for future research (e.g., salivary cortisol at bedtime, vagally-mediated heart rate variability at rest). Finally, the article concludes by highlighting key considerations and offering recommendations for future research (e.g., use of more homogenous methods in assessing burnout and physiological parameters). As a result, the intention of this article is to spark more higher quality research on the psychophysiology of athlete burnout, thereby helping tackle this prominent issue in high-performance sport.

Progressive Impairment of Cardiac Autonomic Regulation as the Number of Metabolic Syndrome Components Increases.

Metabolic syndrome (MetS) is associated with an increased risk of cardiovascular diseases. Compelling evidence supports the key role of dysfunction in the autonomic nervous system (ANS) in that association, as well as mutual correlation among the components of MetS. The autonomic nervous system index (ANSI) is a percentile-ranked unitary proxy of cardiac autonomic regulation (CAR) that is designed to be free of age and sex bias, with higher values indicating better autonomic control. This study investigates CAR using the ANSI in patients with MetS. A total of 133 patients referred to the Exercise Medicine Clinic of Istituto Auxologico Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) underwent CAR assessment using the ANSI and answered lifestyle questions in ad hoc questionnaires. The participants were retrospectively subdivided into two groups according to the presence or absence of MetS criteria. Of the subjects, 58 were diagnosed with MetS, and 75 were not (no MetS). The ANSI was significantly impaired (32.9 vs. 44.8, P<0.01) in the MetS group, and ANSI scores showed a decreasing trend (P=0.004) as the number of MetS components increased. No significant lifestyle differences were found between the groups. The ANSI was significantly reduced in subjects with MetS, and CAR impairment became progressively more apparent as the number of MetS components increased.

Crosstalk between neurovegetative control, bone status and physical exercise: clinical use of a unitary autonomic nervous system index in postmenopausal women with osteoporosis

Crosstalk between neurovegetative control, bone status and physical exercise: clinical use of a unitary autonomic nervous system index in postmenopausal women with osteoporosis

Assessment of symptom severity in psychotic disorder patients based on heart rate variability and accelerometer mobility data

Background:Advancement in mental health care requires easily accessible, efficient diagnostic and treatment assessment tools. Viable biomarkers could enable objectification and automation of the diagnostic and treatment process, currently dependent on a psychiatric interview. Available wearable technology and computational methods make it possible to incorporate heart rate variability (HRV), an indicator of autonomic nervous system (ANS) activity, into potential diagnostic and treatment assessment frameworks as a biomarker of disease severity in mental disorders, including schizophrenia and bipolar disorder (BD). Method:We used a commercially available electrocardiography (ECG) chest strap with a built-in accelerometer, i.e. Polar H10, to record R-R intervals and physical activity of 30 hospitalized schizophrenia or BD patients and 30 control participants through ca. 1.5-2 h time periods. We validated a novel approach to data acquisition based on a flexible, patient-friendly and cost-effective setting. We analyzed the relationship between HRV and the Positive and Negative Syndrome Scale (PANSS) test scores, as well as the HRV and mobility coefficient. We also proposed a method of rest period selection based on R-R intervals and mobility data. The source code for reproducing all experiments is available on GitHub, while the dataset is published on Zenodo. Results:Mean HRV values were lower in the patient compared to the control group and negatively correlated with the results of the PANSS general subcategory. For the control group, we also discovered the inversely proportional dependency between the mobility coefficient, based on accelerometer data, and HRV. This relationship was less pronounced for the treatment group. Conclusions:HRV value itself, as well as the relationship between HRV and mobility, may be promising biomarkers in disease diagnostics. These findings can be used to develop a flexible monitoring system for symptom severity assessment.

Camera-Based Seismocardiogram for Heart Rate Variability Monitoring.

Heart rate variability (HRV) is a crucial metric that quantifies the variation between consecutive heartbeats, serving as a significant indicator of autonomic nervous system (ANS) activity. It has found widespread applications in clinical diagnosis, treatment, and prevention of cardiovascular diseases. In this study, we proposed an optical model for defocused speckle imaging, to simultaneously incorporate out-of-plane translation and rotation-induced motion for highly-sensitive non-contact seismocardiogram (SCG) measurement. Using electrocardiogram (ECG) signals as the gold standard, we evaluated the performance of photoplethysmogram (PPG) signals and speckle-based SCG signals in assessing HRV. The results indicated that the HRV parameters measured from SCG signals extracted from laser speckle videos showed higher consistency with the results obtained from the ECG signals compared to PPG signals. Additionally, we confirmed that even when clothing obstructed the measurement site, the efficacy of SCG signals extracted from the motion of laser speckle patterns persisted in assessing the HRV levels. This demonstrates the robustness of camera-based non-contact SCG in monitoring HRV, highlighting its potential as a reliable, non-contact alternative to traditional contact-PPG sensors.

Prevalence and predictors of preoperative cardiac autonomic dysfunction among elective neurosurgical patients: A prospective observational study.

The autonomic nervous system (ANS) is cardinal for systemic homeostasis. Autonomic dysfunction is prevalent in as high as 65% of patients presenting for cardiac surgery in the Indian scenario. Pre-existing cardiac autonomic dysfunction (CAD) in surgical patients can accentuate perioperative haemodynamic fluctuations during stressful intraoperative events, predispose to adverse cardiac events, and contribute to morbidity and mortality. The prevalence and predictors of CAD in the elective neurosurgical population are unknown in the Indian scenario. The current study was conducted to bridge this knowledge gap. In this single-centre prospective observational study conducted at a tertiary care neurosciences centre, among 400 consenting adult patients of either gender, between 18 and 80 years of age, undergoing elective neurosurgery, the preoperative ANS function at the bedside was assessed as the primary outcome measure. The ANS status was evaluated using ANSiscope™-derived indices of heart rate variability. The diagnosis of CAD was made when the ANS index exceeded a threshold of 13.5. Data regarding predictors of CAD were collected from patient records as the secondary outcome measure. Statistical analysis was done using the R software. A P-value of <0.05 was considered statistically significant. The prevalence of preoperative CAD in our study population was 79.7% (319/400 patients). None of the demographic and baseline clinical characteristics we studied predicted CAD in our study. We observed a significant prevalence of preoperative CAD among elective neurosurgical patients. None of the parameters we evaluated predicted CAD in our study.

Household food insecurity is associated with greater autonomic dysfunction testing score in Latinos with type 2 diabetes.

We examined household food insecurity (HFI) and autonomic nervous system (ANS) function in a subset of low-income Latinos with type 2 diabetes with data from a stress management trial. InclusionLatino or Hispanic, Spanish speaking, age less than 18 years, ambulatory status, type 2 diabetes more than 6 months, A1c less than 7.0%. ExclusionPain or dysfunction in hands (e.g., arthritis) precluding handgrip testing; medical or psychiatric instability. HFI was assessed with the 6-item U.S. household food security survey module; with responses to > = 1 question considered HFI. An ANS dysfunction index was calculated from xix autonomic function tests which were scored 0 = normal or 1 = abnormal based on normative cutoffs and then summed. Autonomic function tests were: 1) 24-hour heart rate variability as reflected in standard deviation of the normal-to-normal (SDNN) heart rate acquired with 3-channel, 7-lead ambulatory electrocardiogram (Holter) monitors; 2) difference between the highest diastolic blood pressure (DBP) during sustained handgrip and the average DBP at rest; 3) difference between baseline supine and the minimal BP after standing up; and, from 24-hour urine specimens 4) cortisol, 5) normetanephrine, and, 6) metanephrine. Thirty-five individuals participated, 23 (65.7%) of them were women, age mean = 61.6 (standard deviation = 11.2) years, HbA1c mean = 8.5% (standard deviation = 1.6) and 20 participants (57.1%) used insulin. Twenty-two participants (62.9%) reported HFI and 25 (71.4%) had one or more abnormal ANS measure. Independent t-tests showed that participants with HFI had a higher ANS dysfunction index (mean = 1.5, standard deviation = 0.9) than patients who were food secure (mean = 0.7, standard deviation = 0.8), p = 0.02. Controlling for financial strain did not change significance. Total ANS index was not related to glycemia, insulin use or other socioeconomic indicators. In this sample, HFI was associated with ANS dysfunction. Policies to improve food access and affordability may benefit health outcomes for Latinos with diabetes.

Impact of different cooling solutions on autonomic modulation in horses in a novice endurance ride

Cooling down is essential for horse recovery before veterinary inspection during an endurance ride. As salt potentially decreases water temperature, we tested whether adding salt to the water used to cool horses could aid their recovery. Twelve healthy Arabian horses participating in a novice endurance ride were divided evenly into two groups. Heart rate variability (HRV) variables, including time and frequency domains, non-linear results, and autonomic nervous system indices, were determined before recovery and at 1-min intervals for 9 min during recovery using either cold or cold-saline water. An interaction between water type and time was observed in the modulation of the SD of beat-to-beat (RR) intervals, square root of the mean squared differences between successive RR intervals (RMSSD), HRV triangular index, very low-frequency band (VLF), low-frequency band/high-frequency band ratio, and SD of the Poincaré plot perpendicular to the line of identity (SD1) non-linear results. A decrease in heart rate and the sympathetic nervous system index corresponding to an increase in RR intervals and the parasympathetic nervous system (PNS) index was observed over time. A rise in the triangular interpolation of the normal-to-normal intervals, number of successive RR interval pairs that differ more than 50 ms, low-frequency band, and total power, coinciding with decreased stress index, was detected at 9 min of recovery. A difference between RMSSD and SD1 was observed between groups, in which they were higher in horses cooling with cold-saline water when compared to cold water at 5 min after cooling began. An increase in VLF was seen at 9 min only in horses cooled with cold-saline water. In conclusion, different water types distinctly impacted HRV in horses. The predominant PNS activity in horses recovering with cold-saline water reflects its positive impact on cooling during an endurance ride.

Impact of comorbidities on heart rate variability in patients with high cardiovascular risk

Abstract Introduction Heart rate variability (HRV) measures the variation in time intervals between successive heartbeats (RR intervals) and is considered a measure of a healthy regulatory system. It is influenced by a variety of factors, including age and comorbidities. We estimate temporal HRV metrics, such as the standard deviation of RR intervals (SDNN), and frequency metrics, such as the normalized high frequency component of the RR intervals (HFNU), to identify which were best for characterizing inter-individual differences by age, gender, and health status. Purpose Understand inter-individual differences in HRV and the influence of age, gender, and available comorbidities. Methods Data from at least one 2-week single-lead ECG were obtained from the 1,742 participants of the trial. Inclusion criteria for the study are defined as follows: age of 75 years or older, or a male older than age 55 years or female older than 65 years with 1 or more comorbidities that are risk factors for cardiovascular diseases. We adopted a linear regression method, where each HRV measure constitutes the outcome of a separate model, while the demographic characteristics (age and gender), the heart rate (HR), and the presence of comorbidities (yes/no for each comorbidity) are used as predictor variables. Age has been evaluated as a quadratic term to assess non-linearity of the association, and an age-gender interaction term has also been evaluated. Coefficients are expressed in terms of standard deviations, allowing for a direct comparison between metrics with different scales and variability. The HRV metrics are evaluated every 5 minutes, then the average value over a 1-day period is considered as input for the model. Results Temporal HRV metrics were lower among women compared with men and increased with age. They were higher in the presence of many disease states, including chronic heart failure (CHF), obesity (OBE), chronic obstructive pulmonary disease (COP), and sleep apnea (SA), but were lower among those with history of myocardial infarction (MI), chronic renal failure (CRF), and use of beta blocker medications (BB). There was no significant association of these metrics with hypertension or diabetes. For frequency metrics, analysis was limited to HFNU due to the high correlations among these measures. HFNU had strong positive associations with all co-morbidities except stroke, with particularly large coefficients for CHF, COP, and MI. HFNU values were also higher among subjects taking beta blockers. (Figure) Conclusion HRV can be an indicator of autonomic nervous system (ANS) dysfunction, which is often present in many diseases. By measuring HRV, clinicians can gain insights into the state of the ANS and potentially identify early warning signs of disease progression or complications.HRV and comorbidities

Assessing the cardiac autonomic response to bicycle exercise in Olympic athletes with different loads of endurance training: new insights from statistical indicators based on multilevel exploratory factor analysis.

Aim: The mechanisms governing the organism's response to exercise are complex and difficult to study. Spectral analysis of heart rate variability (HRV) could represent a convenient methodology for studying humans' autonomic nervous system (ANS). However, difficulties in interpreting the multitude of correlated HRV-derived indices, mainly when computed over different time segments, may represent a barrier to its usage. This preliminary investigation addressed to elite athletes proposes a novel method describing the cardiac autonomic response to exercise based on multilevel exploratory factor analysis (MEFA), which reduces the multitude of HRV-derived indices to fewer uncorrelated ANS indicators capable of accounting for their interrelationships and overcoming the above difficulties. Methods: The study involved 30 Italian Olympic athletes, divided into 15 cyclists (prevalent high-intensity endurance training) and 15 shooters (prevalent technical training with low-intensity endurance component). All athletes underwent a complete test of a dynamic protocol, constituted by a rest-stand test followed by a stepwise bicycle stress test subdivided into a single bout of progressive endurance (from aerobic to anaerobic) exercise and recovery. Then, by spectral analysis, values of 12 ANS proxies were computed at each time segment (9 epochs in all) of the complete test. Results: We obtained two global ANS indicators (amplitude and frequency), expressing the athletes' overall autonomic response to the complete test, and three dynamic ANS indicators (amplitude, signal self-similarity, and oscillatory), describing the principal dynamics over time of the variability of RR interval (RRV). Globally, cyclists have significantly higher amplitude levels (median ± MAD: cyclists 69.9 ± 20.5; shooters 37.2 ± 19.4) and lower frequency levels (median ± MAD: cyclists 37.4 ± 14.8; shooters 78.2 ± 10.2) than shooters, i.e., a parasympathetic predominance compared to shooters. Regarding the RRV dynamics, the signal self-similarity and oscillatory indicators have the strongest sensitivity in detecting the rest-stand change; the amplitude indicator is highly effective in detecting the athletes' autonomic changes in the exercise fraction; the amplitude and oscillatory indicators present significant differences between cyclists and shooters in specific test epochs. Conclusion: This MEFA application permits a more straightforward representation of the complexity characterizing ANS modulation during exercise, simplifying the interpretation of the HRV-derived indices and facilitating the possible real-life use of this non-invasive methodology.

Relaxing Effect of Mozart's Classical Music on the Autonomic Nervous System and Stress Index in an Elderly Man

Relaxing Effect of Mozart's Classical Music on the Autonomic Nervous System and Stress Index in an Elderly Man

Association of intra-shift nap duration with heart rate variability in medical night shift workers.

Napping during night shifts effectively reduces disease risk and improves work performance, but few studies have investigated the association between napping and physiological changes, particularly in off-duty daily lives. Changes in the autonomic nervous system precede diseases like cardiovascular disease, diabetes, and obesity. Heart rate variability is a good indicator of autonomic nervous system. This study aimed to investigate the link between night shift nap durations and heart rate variability indices in the daily lives of medical workers. As indicators of chronic and long-term alterations, the circadian patterns of heart rate variability indices were evaluated. We recruited 146 medical workers with regular night shifts and divided them into four groups based on their self-reported nap durations. Heart rate variability circadian parameters (midline-estimating statistic of rhythm, amplitude, and acrophase) were obtained by obtaining 24-h electrocardiogram on a day without night shifts, plotting the data of the heart rate variability indices as a function of time, and fitting them into periodic cosine curves. Using clinical scales, depression, anxiety, stress, fatigue, and sleepiness were assessed. Linear regression analysis revealed a positive relationship between 61-120-min naps and 24-h, daytime, and night-time heart rate variability indices, and the parasympathetic activity oscillation amplitude (indexed by high-frequency power, the square root of the mean of the sum of squares of differences between adjacent normal intervals, standard deviation of short-term R-R-interval variability) within one circadian cycle. This study indicated that napping for 61-120 min during night shifts could benefit medical workers' health, providing physiological evidence to promote nap management.

Myocardial reporalization duration reflects autonomic nervous system activity in Takotsubo syndrome

Abstract Funding Acknowledgements Type of funding sources: None. Background Sympathetic overdrive has been proposed as a major precursor in Takotsubo syndrome (TTS) development. ECG changes in TTS often persist in time beyond the recovery of the cardiac systolic function and their prognostic significance remains unclear. Autonomic nervous system (ANS) fluctuations affect myocardial repolarization as well as the presence of myocardial oedema and active ischemia. Purpose In this study we aimed to investigate the correlation between indices of ANS activity and the degree of QT interval prolongation during the course of TTS. Methods We studied 30 patients (29 women, mean age: 66 ± 11 years, 17.2% history of diabetes mellitus) with a TTS diagnosis established after multimodality imaging evaluation, which included cardiac magnetic resonance imaging. Daily ECG recordings during the acute phase of the TTS were available for all patients. Both sympathetic and parasympathetic activity were evaluated with time and frequency domain indices of heart rate variability (HRV). Moreover, sympathetic tone was assessed by means of muscle sympathetic nerve activity (MSNA). All investigations were completed within 30 days of the index event. ANS indices were correlated with the maximum measured QTc interval of each patient during the acute phase of TTS. Results Maximal QTc interval during the acute TTS phase exhibited a linear correlation with indices of sympathetic withdrawal. Specifically, QTc duration was positively correlated with rMSSD (r=430, p=0.036) and high frequency FFT (=0,497, p=0,016) whereas it was inversely associated with MSNA results measured in oscillations/100 heart beats (r=-573, p=0,007). In a multivariate analysis model standardized for patients’ age, left ventricular ejection fraction (synchronous with ECG measurements) and the usage of beta blocker medications the aforementioned results remained statistically significant (Table 2). Conclusion In our population of TTS patients, increased parasympathetic activity and sympathetic withdrawal within the first month of the index event reflect increased repolarization duration during the acute phase of the syndrome.

Cardiac Autonomic Regulation and Metabolic Syndrome: Clinical Use of A Unitary Autonomic Nervous System Index

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Systematic Review and Meta-Analysis: Altered Autonomic Functioning in Youths With Emotional Dysregulation

To systematically investigate if there is a significant association between markers of autonomic functioning and emotional dysregulation (ED) in children and adolescents. Based on a preregistered protocol (PROSPERO: CRD42021239635), PubMed, Web of Knowledge/Science, Ovid MEDLINE, Embase, and APA PsycInfo databases were searched until April 21, 2021, to identify empirical studies reporting indices of autonomic nervous system (ANS) functioning in youths meeting DSM (version III, IV, IV-TR, 5 or 5-TR) or International Classification of Diseases (ICD) (version 9 or 10) criteria for any psychopathological/neurodevelopmental condition and assessed for ED with a validated scale. Eligible outcomes included correlation coefficients between ED and ANS measures or differences in ANS measures between youths with and without ED. Study quality was assessed with the Appraisal tool for Cross-Sectional Studies (AXIS) and the Newcastle-Ottawa Scale (NOS) for cohort studies. Random-effects meta-analyses were used for data synthesis. There were 12 studies (1,016 participants) included in the descriptive review and 9 studies (567 participants) included in the meta-analyses. No evidence of a significant association between ED and altered cardiac or electrodermal functioning was found. However, exploratory meta-regressions suggested a possible association between reduced resting-state cardiac vagal control and increased ED. This study did not find evidence of an association between ED and autonomic dysfunction. However, preliminary evidence that reduced vagal control at rest might be a transdiagnostic marker of ED in young people was found. Additional studies comparing autonomic measures in youths with and without ED are needed and should also assess the effects of interventions for ED on ANS functioning. Systematic Review and Meta-Analysis: Is Autonomic Nervous System Functioning Atypical in Children and Adolescents With Emotional Dysregulation? https://www.crd.york.ac.uk/prospero/; CRD42021239635.

Changes in Physiological Indices Before and After Nursing Care of Postoperative Patients With Esophageal Cancer in the ICU.

Various stressors have been identified in patients in the intensive care unit (ICU), including postoperative pain, ventilatory management, and nursing care. However, sedated patients are less responsive, and nurses have difficulty capturing their stressors. To investigate patient stress caused by nursing care performed in the ICU on sedated patients based on changes in physiological indices. We observed nursing care performed on patients with postoperative esophageal cancer under sedation in the ICU. This included endotracheal suctioning and turning, the time required for the care, and the patients' behavioral responses. Information on arousal levels, autonomic nervous system indices, and vital signs were also obtained. The changes in indicators before and after care were then compared and analyzed. There were 14 patients in the study. The mean age of the patients was 68 years. Ninety-nine scenes of nursing care were observed, and in six of these, additional bolus sedation was administered because of the patient's significant body movements. In endotracheal suctioning, no significant changes were observed in all indicators. In turning, vital signs changed significantly, and when both were continued, all indicators changed significantly. Our study found that different types and combinations of nursing care may cause different stresses to the patients. Moreover, the autonomic nervous system indices may be more likely to react to stresses in a variety of nursing care, while arousal levels may be more likely to react to burdensome stresses. If the characteristics of these physiological indicators can be understood and effectively utilized during care, it may be possible to better identify and reduce patient stress during sedation management.

Feature analysis for drowsiness detection based on facial skin temperature using variational autoencoder : a preliminary study

ABSTRACT Technology to detect signs of drowsiness in drivers is essential even in the age of automated driving to prevent traffic accidents. In this study, facial skin temperature, which can be measured remotely using infrared thermography, as a measure for determining drowsiness was in focus. Facial skin temperature is an autonomic nervous system index that depends on skin blood flow. It is known that facial skin temperature changes depending on the physiological and psychological state, and that it is affected by drowsiness. We focused on an anomaly detection algorithm called the variational autoencoder (VAE). In this study, a model to detect drowsiness was constructed using VAE with only the facial skin temperature during arousal from sleep and search was made for facial areas where skin temperature fluctuates with drowsiness using the model. As a result, it was found that the side of the nasal dorsum may fluctuate with drowsiness and that facial skin temperature may fluctuate asymmetrically with drowsiness. Skin temperature around the orbit was shown to be an area of possible physiological and psychological significance related to autonomic nervous system activity. Based on the above, the degree of anomaly was confirmed to vary depending on the degree of drowsiness, indicating the usefulness of using VAE for drowsiness detection based on facial skin temperature.

Autonomic tone in children and adults: Pupillary, electrodermal and cardiac activity at rest

Considering the suspected involvement of the autonomic nervous system (ANS) in several neurodevelopmental disorders, a description of its tonus in typical populations and of its maturation between childhood and adulthood is necessary. We aimed to arrive at a better understanding of the maturation of the sympathetic (SNS) and parasympathetic (PNS) tonus by comparing children and adults at rest, via recordings of multiple ANS indices. We recorded simultaneously pupil diameter, electrodermal activity (EDA) and cardiac activity (RR interval and HRV: heart rate variability) in 29 children (6–12 years old) and 30 adults (20–42 years old) during a 5-min rest period. Children exhibited lower RR intervals, higher LF peak frequencies, and lower LF/HF (low frequency/high frequency) ratios compared to adults. Children also produced more spontaneous EDA peaks, reflected in a larger EDA AUC (area under the curve), in comparison with adults. Finally, children displayed a larger median pupil diameter and a higher pupillary hippus frequency than adults. Our results converged towards higher SNS and PNS tones in children compared to adults. Childhood would thus be characterized by a high autonomic tone, possibly reflecting a physiological state compatible with developmental acquisitions.

Association of depression and parasympathetic activation with glycemic control in type 2 diabetes mellitus

AimPatients with type 2 diabetes mellitus exhibited autonomic nervous system (ANS) dysfunction and comorbidities with depressive or anxiety symptoms were related to poor glycemic control. Heart rate variability (HRV) converted from electrocardiogram (ECG) has been used as the ANS index. The study aimed to explore the associations between depression, anxiety, HRV, and glycemic control in patients with type 2 diabetes mellitus. MethodsThe Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) questionnaires were used to assess depressive and anxiety symptoms in 647 patients with type 2 diabetes mellitus (mean age was 63 ± 10 years, 56 % males). The ECG raw signals were collected from a 5-min sitting and resting baseline and then transformed to HRV indices referring ANS activation. Blood glucose and lipid profiles including glycated hemoglobin (HbA1c), high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglyceride were obtained from the electronic medical records. ResultsNinety-nine (15 %) participants had depressive symptoms and 59 (9 %) had anxiety symptoms. Depression and HbA1c were negatively correlated with parasympathetic activation. Depression and anxiety were positively correlated with sympathetic activation. After controlling for demographic data and lipid profiles, depression was a significant positive predictor for HbA1c levels; and HRV indices (lnLF and lnHF) were the significant negative predictors for HbA1c levels. Mediation effect analysis showed that depression was a mediator between parasympathetic activation and glycemic control. ConclusionsLower parasympathetic activation and higher depressive symptoms may affect glycemic control in patients with type 2 diabetes mellitus. Intervention programs targeting to increase parasympathetic activities and reducing depression could be further tested for their effects on glycemic outcomes for potential clinical use.

Autonomic Nervous System Indices of Player Readiness During Elite-Level Rugby Union Game-Week Microcycles.

Grainger, A, Heffernan, S, Waldron, M, and Sawczuk, T. Autonomic nervous system indices of player readiness during elite-level rugby union game-week microcycles. J Strength Cond Res 36(11): 3173-3178, 2022-Elite-level rugby union (RU) is a high-intensity contact sport that involves large training and match volumes across a season, which can lead to postmatch fatigue. Autonomic nervous system (ANS) regulation and perceived fatigue have been suggested to relate to measures of training and match load in RU. However, there have been no studies to assess specific ANS variables in elite RU during in-season microcycles. Player readiness during game-week microcycles was measured via heart rate variability (HRV) indices, direct current potential and self-reported well-being among 13, elite, male RU players. To enable comparison, data collection days were categorized in relation to their proximity to match day, ranging from match day minus 3 (MD - 3), to match day plus 3 (MD + 3). Differences between match days were evaluated using general linear models and Cohen's d effect sizes. There were significant differences between MD and MD + 1 for ANS indices (RMSSD p = 0.04, d = -0.66, 95% CI 0.11-1.20; the standard deviation of NN intervals p = 0.04, d = -0.66, 95% CI 0.12-1.20; total power p = 0.05, d = -0.65, 95% CI 0.11-1.20) and wellness measures (readiness p = 0.18; d = -2.33, 95% CI, 1.54-3.13; energy p = 0.02; d = -2.24, 95% CI 1.44-3.03; soreness p = 0.00; d = -2.42, 95% CI 1.63-3.23). Match day plus 3 effects were significantly greater than MD + 1 in several ANS responses, with wellness recovering at a slower time-course than ANS responses. Measures of HRV are dysregulated postmatch, but based on their rapid recovery thereafter, using HRV to assess readiness of elite-level players in RU across a weekly microcycle could be limited and requires further investigation.