Role of biological sex in normal cardiac function and in its disease outcome - a review

An investigation of the acute effects of dance on heart rate variability in people with Parkinson's

BACKGROUND

There is limited research investigating heart rate variability (HRV) in Parkinson's during dance. The aim of this study was to investigate the effects of dance on HRV in people with Parkinson's (PwP).

METHODS

Ten PwP were recruited from a Parkinson's dance class and completed six sessions; the first half was danced sitting down, while the latter half was standing up. Breathing rate, skin temperature and HRV data were collected and analysed by repeated measures analysis of variance.

RESULTS

Analysing all six sections together showed skin temperature (p < 0.001), heart rate (HR; p = 0 .029), short-term HRV (SD1; p = 0.025), normalised standard deviation of all the R-R intervals (nSDRR; p = 0.028), and breathing rate (BR; p = 0.001) were significantly different.

CONCLUSIONS

Significant changes in HR, SD1, nSDRR, BR and skin temperature of PwP occurred during all sections, showing dance improved autonomic function. Further work examining the long-term effects of HRV in a community setting is needed to understand the potential benefits of dance for PwP.

Using Free-Living Heart Rate Data as an Objective Method to Assess Physical Activity: A Scoping Review and Recommendations by the INTERLIVE-Network Targeting Consumer Wearables

Wearable technologies open up new avenues for the assessment of individual physical activity behaviour. Particularly, free-living heart rate (HR) data assessed by optical sensors are becoming widely available. However, while an abundancy of scientific information and guidance exists for the processing of raw acceleration data, no universal recommendations for the utilization of continuous HR recordings during free-living conditions are available. Towards Intelligent Health and Well-Being: Network of Physical Activity Assessment (INTERLIVE®) is a joint European initiative of six universities and one industrial partner. The consortium was founded in 2019 and strives towards developing best-practice recommendations in the context of consumer wearables and smartphones. The aim of this scoping review (following PRISMA-ScR procedures) and recommendations was to provide best-practice protocols for deriving individual physical activity profiles from continuous HR recordings by wearables. The recommendations were developed through an initial scoping review, grey literature searches of promotional material and user manuals of leading wearable manufacturers as well as evidence-informed discussions among the members of the INTERLIVE®-network. The scoping review was performed on the generic domains required for physical activity assessment, namely: (1) 'assessment of maximal heart rate', (2) 'determination of basal and/or resting heart rate' and (3) 'heart rate-derived intensity zones', for which we finally included a total of 72, 2 and 11 eligible papers, respectively. Gathering recent knowledge, we provide a decision tree and detailed recommendations for the analysis of free-living HR data to derive individual physical activity profiles. Moreover, we also provide examples of HR-metric calculations that help to illustrate data processing and reporting.

Sex differences in cardiorespiratory control under hypoxia: the roles of oxygen desaturation and hypoxic exposure time

Introduction

Males and females differ anatomically and functionally in cardiorespiratory regulation, with males tending to experience greater oxygen desaturation under hypoxia. Therefore, sex might moderate cardiorespiratory responses to acute hypoxia exposure. Accordingly, we hypothesized that sex differences in cardiovascular and ventilatory responses would be more pronounced with equal hypoxia duration (iso-time) but less pronounced at similar oxygen desaturation levels (iso-saturation).

Methods

Twenty-two (12 females) healthy individuals were exposed to normoxia (10 min at FiO2 = 0.21) and hypoxia (10 min at FiO2 = 0.115), respectively. Pulse oxygen saturation (SpO2), R-R intervals, cardiac output, blood pressure (BP), and ventilatory data were continuously recorded during spontaneous breathing. Spectral analysis of R-R intervals and systolic BP revealed cardiovascular autonomic modulation in the low- (LF; 0.04-0.15 Hz) and high-frequency (HF; 0.15-0.40 Hz) bands and alpha-index (α-LF) assessed spontaneous baroreflex sensitivity (BRS). Sex differences were compared in iso-saturation and iso-time analyses.

Results

At 10 min of hypoxia (iso-time), males desaturated more than females (interaction: p = 0.004), and hypoxia-induced tachycardia in both groups (p < 0.001), but no "sex-time" interaction was found for cardiovascular data. In contrast, only males responded with ventilatory responses during iso-time hypoxia, decreasing breathing frequency (interaction: p = 0.022) and increasing tidal volume (Vt) (interaction: p = 0.036). Otherwise, during iso-saturation (SpO2-matched ∼91%), heart rate and LF of R-R intervals increased more in females than in males (interaction: p = 0.049). However, only males increased Vt (interaction; p = 0.037).

Conclusion

Our data indicate that females counterbalance hypoxia mainly by systemic circulatory adjustments, while males use both, circulatory and ventilatory adjustments.

X-Chromosome-Linked miRNAs Regulate Sex Differences in Cardiac Physiology

BACKGROUND

Males and females exhibit distinct anatomic and functional characteristics of the heart, predisposing them to specific disease states.

METHODS

We identified microRNAs (miRNAs/miR) with sex-differential expression in mouse hearts.

RESULTS

Four conserved miRNAs are present in a single locus on the X-chromosome and are expressed at higher levels in females than males. We show miRNA, miR-871, is responsible for decreased expression of the protein SRL (sarcalumenin) in females. SRL is involved in calcium signaling, and we show it contributes to differences in electrophysiology between males and females. miR-871 overexpression mimics the effects of the cardiac physiology of conditional cardiomyocyte-specific Srl-null mice. Inhibiting miR-871 with an antagomir in females shortened ventricular repolarization. The human orthologue of miR-871, miR-888, coevolved with the SRL 3' untranslated region and regulates human SRL.

CONCLUSIONS

These data highlight the importance of sex-differential miRNA mechanisms in mediating sex-specific functions and their potential relevance to human cardiac diseases.

Analysis of Physical Activity Using Wearable Health Technology in US Adults Enrolled in the All of Us Research Program: Multiyear Observational Study

BACKGROUND

To date, no studies have examined adherence to the 2018 Physical Activity Guidelines for Americans (PAGA) in real-world longitudinal settings using objectively measured activity monitoring data. This study addresses this gap by using commercial activity monitoring (Fitbit) data from the All of Us dataset.

OBJECTIVE

The primary objectives were to describe the prevalence of adherence to the 2018 PAGA and identify associated sociodemographic determinants. Additionally, we compared 3 distinct methods of processing physical activity (PA) data to estimate adherence to the 2008 PAGA.

METHODS

We used the National Institutes of Health's All of Us dataset, which contains minute-level Fitbit data for 13,947 US adults over a 7-year time span (2015-2022), to estimate adherence to PAGA. A published step-based method was used to estimate metabolic equivalents and assess adherence to the 2018 PAGA (ie, ≥150 minutes of moderate- to vigorous-intensity PA per week). We compared the step-based method, the heart rate-based method, and the proprietary Fitbit-developed algorithm to estimate adherence to the 2008 PAGA.

RESULTS

The average overall adherence to the 2018 PAGA was 21.6% (3006/13,947; SE 0.4%). Factors associated with lower adherence in multivariate logistic regression analysis included female sex (relative to male sex; adjusted odds ratio [AOR] 0.66, 95% CI 0.60-0.72; P<.001); BMI of 25.0-29.9 kg/m2 (AOR 0.53, 95% CI 0.46-0.60; P<.001), 30-34.9 kg/m2 (AOR 0.30, 95% CI 0.25-0.36; P<.001), or ≥35 kg/m2 (AOR 0.13, 95% CI 0.10-0.16; P<.001; relative to a BMI of 18.5-24.9 kg/m2); being aged 30-39 years (AOR 0.66, 95% CI 0.56-0.77; P<.001), 40-49 years (AOR 0.79, 95% CI 0.68-0.93; P=.005), or ≥70 years (AOR 0.74, 95% CI 0.62-0.87; P<.001; relative to being 18-29 years); and non-Hispanic Black race or ethnicity (AOR 0.63, 95% CI 0.50-0.79; P<.001; relative to non-Hispanic White race or ethnicity). The Fitbit algorithm estimated that a larger percentage of the sample (10,307/13,947, 73.9%; 95% CI 71.2-76.6) adhered to the 2008 PAGA compared to the heart rate method estimate (4740/13,947, 34%; 95% CI 32.8-35.2) and the step-based method (1401/13,947, 10%; 95% CI 9.4-10.6).

CONCLUSIONS

Our results show significant sociodemographic differences in PAGA adherence and notably different estimates of adherence depending on the algorithm used. These findings warrant the need to account for these disparities when implementing PA interventions and the need to establish an accurate and reliable method of using commercial accelerometers to examine PA, particularly as health care systems begin integrating wearable device data into patient health records.

Identifying sex similarities and differences in structure and function of the sinoatrial node in the mouse heart

Background

The sinoatrial node (SN) generates the heart rate (HR). Its spontaneous activity is regulated by a complex interplay between the modulation by the autonomic nervous system (ANS) and intrinsic factors including ion channels in SN cells. However, the systemic and intrinsic regulatory mechanisms are still poorly understood. This study aimed to elucidate the sex-specific differences in heart morphology and SN function, particularly focusing on basal HR, expression and function of hyperpolarization-activated HCN4 and HCN1 channels and mRNA abundance of ion channels and mRNA abundance of ion channels contributing to diastolic depolarization (DD) and spontaneous action potentials (APs).

Methods

Body weight, heart weight and tibia length of 2- to 3-month-old male and female mice were measured. Conscious in-vivo HR of male and female mice was recorded via electrocardiography (ECG). Unconscious ex-vivo HR, stroke volume (SV) and ejection fraction (EF) were recorded via echocardiography. Ex-vivo HR was measured via Langendorff apparatus. Volume of atria, ventricles and whole hearts were measured from the ex-vivo hearts by microcomputed tomography (micro-CT). Immunohistochemistry targeting HCN4 and HCN1 was conducted in the SN and RA tissues from both male and female hearts. The funny current (I f) of SN cells in 1 nM and following wash-on of 1 μM isoproterenol (ISO) were recorded via whole cell patch clamp. The APs of SN tissue were recorded via sharp microelectrode and optical mapping of membrane voltage. The relative abundance of mRNAs was measured in male and female mice by qPCR.

Results

Heart weight to tibia length ratio and heart volume of females were significantly smaller than males. Unconscious in-vivo HR in male mice was higher than that in females. Conscious in-vivo HR, ex-vivo HR, SV, and EF showed no notable difference between male and female mice. Immunohistochemistry revealed HCN4, HCN1, and the sum of HCN4 and HCN1, expression in the SN was notably elevated compared with the RA in both male and females, but there was no sex difference in these channels expression. There were also no significant sex differences in the V 0.5 of I f in SN cells in the presence of 1 nM ISO, however wash-on 1 μM ISO in the same cells induced a significantly increased shift of V 0.5 to more positive voltages in males than in females. The expression of mRNA coding for adrenergic receptor beta-1 (Adrb1) and cholinergic receptors muscarinic 2 (chrm2) in male mice was higher compared with that in female mice. Early diastolic depolarization (EDD) rate in APs from peripheral SN (pSN) from male mice were higher than these in female mice. Mice of both sexes showed equivalent frequency of SN APs and spatial localization of the leading site in control, and similar significant response to ISO 100 nM superfusion.

Conclusion

Males display faster in-vivo HR, but not ex-vivo HR, than females associated with increased expression of Adrb1 in male versus female. This suggests a possible difference in the β-adrenergic modulation in males and females, possibly related to the greater ISO response of I f observed in cells from males. The role of hormonal influences or differential expression of other ion channels may explain these sex-specific variations in HR dynamics. Further investigations are necessary to pinpoint the precise molecular substrates responsible for these differences.

Elevated heart rate and decreased muscle endothelial nitric oxide synthase in early development of insulin resistance

Insulin resistance (IR) is a risk factor for the development of several major metabolic diseases. Muscle fiber composition is established early in life and is associated with insulin sensitivity. Hence, muscle fiber composition was used to identify early defects in the development of IR in healthy young individuals in the absence of clinical manifestations. Biopsies were obtained from the thigh muscle, followed by an intravenous glucose tolerance test. Indices of insulin action were calculated and cardiovascular measurements, analyses of blood and muscle were performed. Whole body insulin sensitivity (SIgalvin) was positively related to expression of type I muscle fibers (r = 0.49; P < 0.001) and negatively related to resting heart rate (HR, r = -0.39; P < 0.001), which was also negatively related to expression of type I muscle fibers (r = -0.41; P < 0.001). Muscle protein expression of endothelial nitric oxide synthase (eNOS), whose activation results in vasodilation, was measured in two subsets of subjects expressing a high percentage of type I fibers (59 ± 6%; HR = 57 ± 9 beats/min; SIgalvin = 1.8 ± 0.7 units) or low percentage of type I fibers (30 ± 6%; HR = 71 ± 11; SIgalvin = 0.8 ± 0.3 units; P < 0.001 for all variables vs. first group). eNOS expression was 1) higher in subjects with high type I expression; 2) almost twofold higher in pools of type I versus II fibers; 3) only detected in capillaries surrounding muscle fibers; and 4) linearly associated with SIgalvin. These data demonstrate that an altered function of the autonomic nervous system and a compromised capacity for vasodilation in the microvasculature occur early in the development of IR.NEW & NOTEWORTHY Insulin resistance (IR) is a risk factor for the development of several metabolic diseases. In healthy young individuals, an elevated heart rate (HR) correlates with low insulin sensitivity and high expression of type II skeletal muscle fibers, which express low levels of endothelial nitric oxide synthase (eNOS) and, hence, a limited capacity to induce vasodilation in response to insulin. Early targeting of the autonomic nervous system and microvasculature may attenuate development of diseases stemming from insulin resistance.

The feigned annoyance and frustration test to activate the sympathoadrenal medullary system

When perceived as threatening, social interactions have been shown to trigger the sympathoadrenal medullary system as well as the hypothalamic-pituitary-adrenal axis resulting in a physiologic stress response. The allostatic load placed on human health and physiology in the context of acute and chronic stress can have profound health consequences. The purpose of this study was to develop a protocol for a lab-based stress stimulus using social-evaluative threat. While several valid, stress-stimulating protocols exist, we sought to develop one that triggered a physiologic response, did not require significant lab resources, and could be completed in around 10 min. We included 53 participants (29 men and 24 women) and exposed them to a modified version of the Stroop Color-Word Interference Task during which the participants were made to feel they were performing the task poorly while the lead researcher feigned annoyance and frustration. After exposure to this Feigned Annoyance and Frustration (FAF) Test, both the men and women in this study demonstrated a statistically significant and clinically meaningful increase in subjective stress on the visual analog scale. Additionally, the men in this study demonstrated a statistically significant increase in heart rate and salivary α-amylase concentrations after exposure to the test. The women in this study did not demonstrate a statistically significant increase in the physiologic stress biomarkers. This protocol for the FAF Test shows promise to researchers with limited time and resources who are interested in experimentally activating the sympathoadrenal medullary system.

ARTEMIS: An alarm threshold and policy mining system for the intensive care unit

BACKGROUND

Alarm fatigue is a major technology-induced hazard for patients and staff in intensive care units. Too many - mostly unnecessary - alarms cause desensitisation and lack of response in medical staff. Unsuitable alarm policies are one reason for alarm fatigue. But changing alarm policies is a delicate issue since it concerns patient safety.

OBJECTIVE

We present ARTEMIS, a novel, computer-aided clinical decision support system for policy makers that can help to considerably improve alarm policies using data from hospital information systems.

METHODS

Policy makers can use different policy components from ARTEMIS' internal library to assemble tailor-made alarm policies for their intensive care units. Alternatively, policy makers can provide even more highly customised policy components as Python functions using data the hospital information systems. This can even include machine learning models - for example for setting alarm thresholds. Finally, policy makers can evaluate their system of policies and compare the resulting alarm loads.

RESULTS

ARTEMIS reports and compares numbers of alarms caused by different alarm policies for an easily adaptable target population. ARTEMIS can compare policies side-by-side and provides grid comparisons and heat maps for parameter optimisation. For example, we found that the utility of alarm delays varies based on target population. Furthermore, policy makers can introduce virtual parameters that are not in the original data by providing a formula to compute them. Virtual parameters help measuring and alarming on the right metric, even if the patient monitors do not directly measure this metric.

CONCLUSION

ARTEMIS does not release the policy maker from assessing the policy from a medical standpoint. But as a knowledge discovery and clinical decision support system, it provides a strong quantitative foundation for medical decisions. At comparatively low cost of implementation, ARTEMIS can have a substantial impact on patients and staff alike - with organisational, economic, and clinical benefits for the implementing hospital.

Inhibition of striatal dopamine release by the L-type calcium channel inhibitor isradipine co-varies with risk factors for Parkinson's

Ca2+ entry into nigrostriatal dopamine (DA) neurons and axons via L-type voltage-gated Ca2+ channels (LTCCs) contributes, respectively, to pacemaker activity and DA release and has long been thought to contribute to vulnerability to degeneration in Parkinson's disease. LTCC function is greater in DA axons and neurons from substantia nigra pars compacta than from ventral tegmental area, but this is not explained by channel expression level. We tested the hypothesis that LTCC control of DA release is governed rather by local mechanisms, focussing on candidate biological factors known to operate differently between types of DA neurons and/or be associated with their differing vulnerability to parkinsonism, including biological sex, α-synuclein, DA transporters (DATs) and calbindin-D28k (Calb1). We detected evoked DA release ex vivo in mouse striatal slices using fast-scan cyclic voltammetry and assessed LTCC support of DA release by detecting the inhibition of DA release by the LTCC inhibitors isradipine or CP8. Using genetic knockouts or pharmacological manipulations, we identified that striatal LTCC support of DA release depended on multiple intersecting factors, in a regionally and sexually divergent manner. LTCC function was promoted by factors associated with Parkinsonian risk, including male sex, α-synuclein, DAT and a dorsolateral co-ordinate, but limited by factors associated with protection, that is, female sex, glucocerebrosidase activity, Calb1 and ventromedial co-ordinate. Together, these data show that LTCC function in DA axons and isradipine effect are locally governed and suggest they vary in a manner that in turn might impact on, or reflect, the cellular stress that leads to parkinsonian degeneration.

Sex differences in Black Veterans with PTSD: women versus men have higher sympathetic activity, inflammation, and blunted cardiovagal baroreflex sensitivity

PURPOSE

Post-traumatic stress disorder (PTSD) is associated with greater risk of incident hypertension and cardiovascular disease (CVD). Inflammation and autonomic derangements are suggested as contributing mechanisms. Women and Black adults have higher CVD risk associated with stress; however, whether there is a sex difference in autonomic and inflammatory mechanisms among Black individuals with PTSD is not known. We hypothesized that Black women with PTSD have higher inflammation, sympathetic nervous system (SNS) activity and impaired baroreflex sensitivity (BRS).

METHODS

In 42 Black Veterans with PTSD (Women, N = 18 and Men, N = 24), we measured inflammatory biomarkers, continuous blood pressure (BP), heart rate (HR) and muscle sympathetic nerve activity (MSNA) at rest and during arterial BRS testing via the modified Oxford technique.

RESULTS

Groups were matched for age and body mass index (BMI). Resting BP was similar between groups, but HR was higher (76 ± 12 vs. 68 ± 9 beats/min, p = 0.021) in women compared to men. Although women had lower PTSD symptoms severity (57 ± 17 vs. 68 ± 12 a.u.), resting MSNA (27 ± 13 vs. 16 ± 5 bursts/min, p = 0.003) was higher in women compared to men, respectively. Likewise, cardiovagal BRS was blunted (p = 0.002) in women (7.6 ± 4.3 ms/mmHg) compared to men (15.5 ± 8.4 ms/mmHg) while sympathetic BRS was not different between groups (p = 0.381). Black women also had higher (p = 0.020) plasma levels of interleukin-2 (IL-2).

CONCLUSION

Black women with PTSD have higher resting HR and MSNA, greater impairment of cardiovagal BRS and possibly higher inflammation. These findings suggest a higher burden of autonomic and inflammatory derangements in Black women compared to Black men with PTSD.

Computational screen for sex-specific drug effects in a cardiac fibroblast signaling network model

Heart disease is the leading cause of death in both men and women. Cardiac fibrosis is the uncontrolled accumulation of extracellular matrix proteins, which can exacerbate the progression of heart failure, and there are currently no drugs approved specifically to target matrix accumulation in the heart. Computational signaling network models (SNMs) can be used to facilitate discovery of novel drug targets. However, the vast majority of SNMs are not sex-specific and/or are developed and validated using data skewed towards male in vitro and in vivo samples. Biological sex is an important consideration in cardiovascular health and drug development. In this study, we integrate a cardiac fibroblast SNM with estrogen signaling pathways to create sex-specific SNMs. The sex-specific SNMs demonstrated high validation accuracy compared to in vitro experimental studies in the literature while also elucidating how estrogen signaling can modulate the effect of fibrotic cytokines via multi-pathway interactions. Further, perturbation analysis and drug screening uncovered several drug compounds predicted to generate divergent fibrotic responses in male vs. female conditions, which warrant further study in the pursuit of sex-specific treatment recommendations for cardiac fibrosis. Future model development and validation will require more generation of sex-specific data to further enhance modeling capabilities for clinically relevant sex-specific predictions of cardiac fibrosis and treatment.

Cardiovascular sex-differences: insights via physiology-based modeling and potential for noninvasive sensing via ballistocardiography

In this study, anatomical and functional differences between men and women in their cardiovascular systems and how these differences manifest in blood circulation are theoretically and experimentally investigated. A validated mathematical model of the cardiovascular system is used as a virtual laboratory to simulate and compare multiple scenarios where parameters associated with sex differences are varied. Cardiovascular model parameters related with women's faster heart rate, stronger ventricular contractility, and smaller blood vessels are used as inputs to quantify the impact (i) on the distribution of blood volume through the cardiovascular system, (ii) on the cardiovascular indexes describing the coupling between ventricles and arteries, and (iii) on the ballistocardiogram (BCG) signal. The model-predicted outputs are found to be consistent with published clinical data. Model simulations suggest that the balance between the contractile function of the left ventricle and the load opposed by the arterial circulation attains similar levels in females and males, but is achieved through different combinations of factors. Additionally, we examine the potential of using the BCG waveform, which is directly related to cardiovascular volumes, as a noninvasive method for monitoring cardiovascular function. Our findings provide valuable insights into the underlying mechanisms of cardiovascular sex differences and may help facilitate the development of effective noninvasive cardiovascular monitoring methods for early diagnosis and prevention of cardiovascular disease in both women and men.

The role of fetal heart rate in first trimester sonograms in prediction of fetal sex: a systematic review and meta-analysis

BACKGROUND

Early fetal sex determination is worthy of providing alertness about possible x-linked disorders, as well as predicting sex-related pregnancy complications and outcomes. Satisfying the curiosity of parents is another advantage. In this way, several studies have been performed which have shown conflicting results.

AIM

We planned a systematic review for identifying any plausible role of Fetal Heart Rate (FHR) for early predicting fetal sex during the first trimester of non-complicated pregnancies.

METHODS

This is a meta-analysis in which PubMed and Scopus databases were searched using different related keywords to find similar articles up to December 2022. Then the articles were screened to find eligible articles and finally, the articles entered in the meta-analysis were analyzed using Stata software (Stata Corp, College Station, TX). Standardized mean difference (SMD) and their 95% confidence interval (CI) were estimated.

RESULTS

A total of 223 articles were evaluated and five articles were included in the meta-analysis. The results showed that there is a significant heterogeneity between the articles (p = 0.012, I-squared = 69.0%). The results of meta-analysis with a random model showed that there is no significant difference between male and female genders in terms of mean FHR (SMD = 0.04, 95%CI = -0.09-0.16, Z = 0.59, p = 0.553).

CONCLUSION

This systematic review and meta-analysis showed that even though male fetuses show faster FHR but such sex-related difference is minimal. Therefore, first-trimester FHR is not a reliable predictive test for fetal sex determination. Further studies are recommended to achieve a more precise conclusion.

TRIAL REGISTRATION

PROSPERO: CRD42023418291.

Gender differences in two-dimensional and three-dimensional speckle tracking echocardiography left ventricular measurements among healthy preschool pediatric population

BACKGROUND

Speckle-tracking echocardiography (STE) is an upcoming echocardiographic modality to measure global as well as segmental left ventricular systolic function expressed numerically as strain values independent of angle and ventricular geometry. We conducted this prospective study on 200 healthy preschool children with structurally normal hearts, to determine gender-based differences in two-dimensional (2D) global longitudinal strain (GLS) and three-dimensional (3D) GLS.

RESULTS

Age-matched 104 males and 96 females were included, 2D GLS results for the males showed longitudinal strain ranging from - 18.1 to - 29.8 with a mean of - 21.7202 ± 5.094322, while for females 2D GLS ranged from - 18.1 to - 30.7 with a mean of - 22.0646 ± 2.167802, also 3D GLS values were measured and compared based on gender, where 3D GLS in males ranged from - 18 to - 24 with a mean value of 20.49 ± 1.28, while for females ranged from - 17 to - 30 with a mean value of 20.47 ± 1.755. The gender-based difference for both 2D GLS and 3D GLS showed non-significant P values.

CONCLUSION

In healthy subjects below 6 years, 2D STE and 3D STE values showed no difference between males and females, unlike the adult population, to the best of our knowledge, this is one of the few studies in the literature that aims at comparing these measurements in the healthy pediatric group. In routine clinical practice, these values may be used to assess myocardial function or the early signs of malfunction.

Effect of air blowing inside isolated hospital clothing on perceptual and physiological heat strain in laboratory conditions

Heat stress is one of the most common complaints of health care employees who wear isolation gowns to protect themselves from biological agents, particularly during the warmer seasons. This study was conducted in a climatic chamber to determine the influence of airflow within isolated hospital gowns on physiological-perceptual heat strain indices. The experiment was conducted in three trials: regular clothes (CON), an impenetrable gown without air blowing (GO), and a gown with air blowing (GO + FAN) at temperature conditions of 27 °C and 25% relative humidity (RH). During the trial, physiological-perceptual response data were recorded for a half-hour on a treadmill at a speed of km/hr and a slope of 0% activity at 5-min intervals. The ASHRAE Likert scale was used to assess thermal comfort (TC), thermal sensation (TS), and skin wetness sensation (WS). As the results show, there was a significant difference in mean scores for TC and WS in both sexes when working in the CON, GO, and GO + FAN groups (P < 0.001). In women, the mean scores for TS, TC, and WS reduced considerably (P < 0.001) in the GO and GO + FAN in the amount of 10 and 12 CFM (20 [Formula: see text]/h), but in males, there was a statistically significant difference between mean scores (P < 0.001) in the GO + FAN at 12 CFM (20 [Formula: see text]/h) and 14 CFM (24 [Formula: see text]/h). Also, the greatest difference between the average heart rate, chest temperature, and temperature inside the clothes in women and men in the trials GO and GO + FAN was observed in the air flow 12 CFM and 14 CFM, respectively (P < 0.001). The usage of an air blower in isolated hospital clothes has been shown to influence physiological-perceptual parameters in men and women substantially. The existence of airflow in these gowns can improve safety, performance, and thermal comfort while also decreasing the risk of heat-related disorders.

Coupling analysis of heart rate variability and cortical arousal using a deep learning algorithm

Frequent cortical arousal is associated with cardiovascular dysfunction among people with sleep-disordered breathing. Changes in heart rate variability (HRV) can represent pathological conditions associated with autonomic nervous system dysfunction. Previous studies showed changes in cardiac activity due to cortical arousals. However, few studies have examined the instantaneous association between cortical arousal and HRV in an ethnically diverse population. In this study, we included 1,069 subjects' full night ECG signals from unattended polysomnography in the Multi-Ethnic Study of Atherosclerosis dataset. An automated deep learning tool was employed to annotate arousal events from ECG signals. The etiology (e.g., respiratory, or spontaneous) of each arousal event was classified through a temporal analysis. Time domain HRVs and mean heart rate were calculated on pre-, intra-, and post-arousal segments of a 25-s period for each arousal event. We observed that heart rate and HRVs increased during the arousal onsets in the intra-arousal segments, regardless of arousal etiology. Furthermore, HRVs response to cortical arousal occurrence differed according to gender and the sleep stages in which arousal occurred. The more intense HRVs variation due to arousal in females can contribute to a potentially stronger association between arousal burden and long-term mortality. The excessive abrupt sympathetic tone elevation in REM caused by arousal may provide insights on the association between sleep and sudden cardiac death.

Effects of gender-affirming hormone therapy on cardiovascular risk factors focusing on glucose metabolism in an Austrian transgender cohort

Objective

We aimed to investigate the effect of gender-affirming hormone therapy (GAHT) on cardiovascular disease risk factors focusing on glucose tolerance.

Patients and Methods

This primarily translational study enrolled 16 transgender persons assigned female at birth (AFAB), 22 assigned male at birth (AMAB), and 33 age- and BMI-matched cisgender controls at the Medical University of Vienna from 2013 to 2020. A 3-Tesla MRI scan to measure intramyocardial, pancreatic, hepatic fat content and subcutaneous-to-visceral adipose tissue ratio (SAT/VAT-ratio), an oral glucose tolerance test (oGTT), bloodwork including brain natriuretic peptide (pro-BNP), sex hormones and two glucose-metabolism related biomarkers (adiponectin, betatrophin) were performed.

Results

Estrogen intake was associated with higher fasting insulin (p = 0.034) and Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) (p = 0.037), however, lower HbA1c levels (p = 0.031) in AMAB than cisgender males. Adiponectin (p = 0.001) and betatrophin (p = 0.034) levels were higher in AMAB than cisgender males, but similar to cisgender females. Compared to cisgender females, AFAB displayed no differences in glucose metabolism or SAT/VAT-ratio. AFAB had lower pro-BNP levels (p = 0.014), higher liver enzymes (AST: p = 0.011; ALT: p = 0.012) and lower HDL levels (p = 0.017) than cisgender females, but comparable levels to cisgender males. AMAB showed an increased heart rate (p < 0.001) and pro-BNP (p = 0.002) levels, but a more favorable SAT/VAT-ratio (p = 0.013) and lower creatine kinase (CK) (p = 0.001) than cisgender males. There were no relevant differences in organ fat content between transgender persons and their respective cisgender controls.

Conclusion

In AMAB, most investigated parameters adapted to levels seen in cisgender females except for parameters related to fasted insulin resistance. AMAB should be monitored with respect to the development of insulin resistance.

Deaths in Open Water Swimming Races in Brazil from 2009 to 2019

Since the inclusion in the Olympic Games (2008), open swimming races have attracted greater media attention and, therefore, have a greater number of practitioners, especially in Brazil, an extremely favorable country for this sport. However, increasing reports of fatal incidents in open water races brought the medical and scientific community to attention. The aim of this study was to review the characteristics of deaths in open waters events in Brazil from 2009 to 2019. The survey was divided into 3 steps: 1) contacting sports-related federations and companies, including swimming and triathlon federations, master associations and event organizing companies; 2) internet search; and 3) personal communication with athletes, coaches, organizers, and health personnel. A total of 12 deaths were observed in open water swimming races, including triathlon swimming segment races in Brazil from 2009 to 2019. The average was 1.1 deaths per year, whereas in the last 3 years (2017-2019) the average was 3 deaths per year. The male participants accounted for 11 deaths (91.7%), the average age was 47 years old, experienced athletes were more affected (80%), and incidents occurred mainly in ocean waters (75%). The increase of deaths in the last 3 years draws attention, and the best way to reduce the deaths by drowning in open waters in Brazil, is to understand the profile and causes, to propose solutions.

Heart rate control and its predictors in patients with heart failure and sinus rhythm. Data from the European Society of Cardiology Long-Term Registry

BACKGROUND

Higher resting heart rate (HR) in patients with heart failure (HF) and sinus rhythm (SR) is associated with increased mortality. In patients hospitalized for HF, the aim herein, was to assess the use and dosage of guideline-recommended HR lowering medications, HR control at discharge and predictors of HR control.

METHODS

In the present study, were Polish participants of the European Society of Cardiology HF Long-Term (ESC-HF-LT) Registry. Those selected were hospitalized for HF, with reduced ejection fraction (HFrEF) and SR at discharge (n = 236). The patients were divided in two groups ( < 70 and ≥ 70 bpm). Logistic regression was used to identify the predictors of HR ≥ 70 bpm.

RESULTS

Of patients with HFrEF and SR, 59% had HR ≥ 70 bpm at hospital discharge. At discharge, 96% and only 0.5% of the patients with HFrEF and SR received beta-blocker and ivabradine, respectively. In the HF groups < 70 and ≥ 70 bpm, only 11% and 4% of patients received beta-blocker target doses, respectively. There was no difference in the use of other guideline-recommended medications. Age, New York Heart Association class, HR on admission and lack of HR lowering medications were predictors of discharge HR ≥ 70 bpm.

CONCLUSIONS

Heart rate control after hospitalization for HFrEF is unsatisfactory, which may be attributed to suboptimal doses of beta-blockers, and negligence in use other HR lowering drugs (including ivabradine).

Gender differences in professional drivers’ fatigue level measured with BAlert mobile app: A psychophysiological, time efficient, accessible, and innovative approach to fatigue management

Addressing fatigue is useful in a variety of scenarios and activities. Fatigue has recently been studied from a psychophysiological standpoint. As a result, the expression and impact of peripheral and central fatigue has been evaluated. Driving is one occupation where tiredness has disastrous consequences. BAlert is a smartphone app that approaches exhaustion with psychophysiological measures. More specifically, it evaluates the level of fatigue via heart rate variability (HRV) data and the cognitive compromise via Stroop effect. The goal of this study is to determine if there are gender differences in fatigue levels among professional drivers using the BAlert app. Statistically significant differences were found in the number of hours awake, in different parameters of HRV (AVNN, PNN50, RMSSD, and SDNN), in the level of stress, as well as in the cognitive response evaluated through the app. The results are discussed and their implications for the management of work fatigue are presented.

Re-evaluating methods reporting practices to improve reproducibility: an analysis of methodological rigor for the Langendorff whole-heart technique

In recent decades, the scientific community has seen an increased interest in rigor and reproducibility. In 2017, concerns of methodological thoroughness and reporting practices were implicated as significant barriers to reproducibility within the preclinical cardiovascular literature, particularly in studies employing animal research. The Langendorff, whole-heart technique has proven to be an invaluable research tool, being modified in a myriad of ways to probe questions across the spectrum of physio- and pathophysiologic function of the heart. As a result, significant variability in the application of the Langendorff technique exists. This literature review quantifies the different methods employed in the implementation of the Langendorff technique and provides brief examples of how individual parametric differences can impact the outcomes and interpretation of studies. From 2017-2020, significant variability of animal models, anesthesia, cannulation time, and perfusate composition, pH, and temperature demonstrate that the technique has diversified to meet new challenges and answer different scientific questions. The review also reveals which individual methods are most frequently reported, even if there is no explicit agreement upon which parameters should be reported. The analysis of methods related to the Langendorff technique suggests a framework for considering methodological approach when interpreting seemingly contradictory results, rather than concluding that results are irreproducible.

Patient-specific finite element analysis of heart failure and the impact of surgical intervention in pulmonary hypertension secondary to mitral valve disease

Pulmonary hypertension (PH), a chronic and complex medical condition affecting 1% of the global population, requires clinical evaluation of right ventricular maladaptation patterns under various conditions. A particular challenge for clinicians is a proper quantitative assessment of the right ventricle (RV) owing to its intimate coupling to the left ventricle (LV). We, thus, proposed a patient-specific computational approach to simulate PH caused by left heart disease and its main adverse functional and structural effects on the whole heart. Information obtained from both prospective and retrospective studies of two patients with severe PH, a 72-year-old female and a 61-year-old male, is used to present patient-specific versions of the Living Heart Human Model (LHHM) for the pre-operative and post-operative cardiac surgery. Our findings suggest that before mitral and tricuspid valve repair, the patients were at risk of right ventricular dilatation which may progress to right ventricular failure secondary to their mitral valve disease and left ventricular dysfunction. Our analysis provides detailed evidence that mitral valve replacement and subsequent chamber pressure unloading are associated with a significant decrease in failure risk post-operatively in the context of pulmonary hypertension. In particular, right-sided strain markers, such as tricuspid annular plane systolic excursion (TAPSE) and circumferential and longitudinal strains, indicate a transition from a range representative of disease to within typical values after surgery. Furthermore, the wall stresses across the RV and the interventricular septum showed a notable decrease during the systolic phase after surgery, lessening the drive for further RV maladaptation and significantly reducing the risk of RV failure.

Heart Rate Variability Reveals Altered Autonomic Regulation in Response to Myocardial Infarction in Experimental Animals

The analysis of beating rate provides information on the modulatory action of the autonomic nervous system on the heart, which mediates adjustments of cardiac function to meet hemodynamic requirements. In patients with myocardial infarction, alterations of heart rate variability (HRV) have been correlated to the occurrence of arrhythmic events and all-cause mortality. In the current study, we tested whether experimental rodent models of myocardial infarction recapitulate dynamics of heart rate variability observed in humans, and constitute valid platforms for understanding mechanisms linking autonomic function to the development and manifestation of cardiovascular conditions. For this purpose, HRV was evaluated in two engineered mouse lines using electrocardiograms collected in the conscious, restrained state, using a tunnel device. Measurements were obtained in naïve mice and animals at 3-∼28 days following myocardial infarction, induced by permanent coronary artery ligation. Two mouse lines with inbred and hybrid genetic background and, respectively, homozygous (Homo) and heterozygous (Het) for the MerCreMer transgene, were employed. In the naïve state, Het female and male mice presented prolonged RR interval duration (∼9%) and a ∼4-fold increased short- and long-term RR interval variability, with respect to sex-matched Homo mice. These differences were abrogated by pharmacological interventions inhibiting the sympathetic and parasympathetic axes. At 3-∼14 days after myocardial infarction, RR interval duration increased in Homo mice, but was not affected in Het animals. In contrast, Homo mice had minor modifications in HRV parameters, whereas substantial (> 50%) reduction of short- and long-term RR interval variation occurred in Het mice. Interestingly, ex vivo studies in isolated organs documented that intrinsic RR interval duration increased in infarcted vs. non-infarcted Homo and Het hearts, whereas RR interval variation was not affected. In conclusion, our study documents that, as observed in humans, myocardial infarction in rodents is associated with alterations in heart rhythm dynamics consistent with sympathoexcitation and parasympathetic withdrawal. Moreover, we report that mouse strain is an important variable when evaluating autonomic function via the analysis of HRV.

Sexual dimorphism in testosterone programming of cardiomyocyte development in sheep

Perturbed in utero hormone milieu leads to intrauterine growth retardation (IUGR), a known risk factor for left ventricular (LV) dysfunction later in life. Gestational testosterone (T) excess predisposes offspring to IUGR and leads to LV myocardial disarray and hypertension in adult females. However, the early impact of T excess on LV programming and if it is female specific is unknown. LV tissues were obtained at day 90 gestation from days 30-90 T-treated or control fetuses (n = 6/group/sex) and morphometric and molecular analyses were conducted. Gestational T treatment increased cardiomyocyte number only in female fetuses. T excess upregulated receptor expression of insulin and insulin-like growth factor. Furthermore, in a sex-specific manner, T increased expression of phosphatidylinositol 3-kinase (PI3K) while downregulating phosphorylated mammalian target of rapamycin (pmTOR)-to-mTOR ratio suggestive of compensatory response. T excess 1) upregulated atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), markers of stress and cardiac hypertrophy and 2) upregulated estrogen receptors1 (ESR1) and 2 (ESR2), but not in androgen receptor (AR). Thus, gestational T excess upregulated markers of cardiac stress and hypertrophy in both sexes while inducing cardiomyocyte hyperplasia only in females, likely mediated via insulin and estrogenic programming.NEW & NOTEWORTHY The present study demonstrates sex-specific effects of gestational T excess between days 30 and 90 of gestation on the cardiac phenotype. Furthermore, the sex-specific programming is likely secondary to perturbation in both estrogen and insulin signaling pathways collectively. These findings are supportive of the role of androgen excess to serve as early biomarkers of CVD and could be critical in identifying therapeutic targets for LV hypertrophy and predict long-term CVD.

Relation Between Coronary Tortuosity and Vasomotor Dysfunction in Patients Without Obstructed Coronaries?

Background: A large proportion of patients with angina and no obstructive coronary artery disease (ANOCA) has underlying coronary vasomotor dysfunction (CVDys), which can be diagnosed by a coronary function test (CFT). Coronary tortuosity is a common angiographic finding during the CFT. Yet, no data exist on the association between vasomotor dysfunction and coronary tortuosity.

Aim: To investigate the association between CVDys and coronary tortuosity in patients with ANOCA

Methods: All consecutive ANOCA patients who underwent clinically indicated CFT between February 2019 and November 2020 were included. CFT included acetylcholine spasm testing to diagnose epicardial or microvascular spasm, and adenosine testing to diagnose microvascular dysfunction (MVD). MVD was defined as an index of microvascular resistance (IMR) ≥ 25 and/or coronary flow reserve (CFR) <2.0. Coronary tortuosity, was scored (no, mild, moderate or severe) based on the angles of the curvatures in the left anterior descending (LAD) artery on angiography.

Results: In total, 228 patients were included (86% female, mean age 56 ± 9 years). We found coronary artery spasm in 81% of patients and MVD in 45% of patients (15%: abnormal CFR, 30%: abnormal IMR). There were 73 patients with no tortuosity, 114 with mild tortuosity, 41 with moderate tortuosity, and no patients with severe tortuosity. No differences were found in cardiovascular risk factors or medical history, and the prevalence of CVDys did not differ between the no tortuosity, mild tortuosity and moderate tortuosity group (82, 82, and 85%, respectively).

Conclusion: In this study, CVDys was not associated with coronary tortuosity. Future experimental and clinical studies on the complex interplay between coronary tortuosity, wall shear stress, endothelial dysfunction and coronary flow are warranted.

A cohort study investigating the occurrence of differences in care provided to men and women in an intensive care unit

It has been reported that there are differences in the care given within the intensive care unit (ICU) between men and women. The aim of this study is to investigate if any differences still exist between men and women regarding the level of intensive care provided, using prespecified intensive care items. This is a retrospective cohort study of 9017 ICU patients admitted to a university hospital between 2006 and 2016. Differences in use of mechanical ventilation, invasive monitoring, vasoactive treatment, inotropic treatment, echocardiography, renal replacement therapy and central venous catheters based on the sex of the patient were analysed using univariate and multivariable logistic regressions. Subgroup analyses were performed on patients diagnosed with sepsis, cardiac arrest and respiratory disease. Approximately one third of the patients were women. Overall, men received more mechanical ventilation, more dialysis and more vasoactive treatment. Among patients admitted with a respiratory disease, men were more likely to receive mechanical ventilation. Furthermore, men were more likely to receive levosimendan if admitted with cardiac arrest. We conclude that differences in the level of intensive care provided to men and women still exist.

Preparing for the long-haul: Autonomic complications of COVID-19

As global numbers of COVID-19 grow, chronic neurological symptoms, including those of autonomic dysfunction, are being reported with increasing frequency. Mounting evidence suggests that many patients experience chronic and sometimes debilitating symptoms long after their acute infectious period, leading to the new diagnostic category of post-acute COVID syndrome. Many symptoms of post-acute COVID syndrome appear autonomic in nature, suggesting that autonomic impairment may play a central role in the underlying pathophysiology. In this review, we discuss the autonomic symptoms and manifestations of post-acute COVID syndrome, potential mechanisms involved, and future directions for a better understanding of this novel condition.

Measurement of respiratory rate using wearable devices and applications to COVID-19 detection

We show that heart rate enabled wearable devices can be used to measure respiratory rate. Respiration modulates the heart rate creating excess power in the heart rate variability at a frequency equal to the respiratory rate, a phenomenon known as respiratory sinus arrhythmia. We isolate this component from the power spectral density of the heart beat interval time series, and show that the respiratory rate thus estimated is in good agreement with a validation dataset acquired from sleep studies (root mean squared error = 0.648 min^-1, mean absolute error = 0.46 min^-1, mean absolute percentage error = 3%). We use this respiratory rate algorithm to illuminate two potential applications (a) understanding the distribution of nocturnal respiratory rate as a function of age and sex, and (b) examining changes in longitudinal nocturnal respiratory rate due to a respiratory infection such as COVID-19. 90% of respiratory rate values for healthy adults fall within the range 11.8-19.2 min^-1 with a mean value of 15.4 min^-1. Respiratory rate is shown to increase with nocturnal heart rate. It also varies with BMI, reaching a minimum at 25 kg/m², and increasing for lower and higher BMI. The respiratory rate decreases slightly with age and is higher in females compared to males for age <50 years, with no difference between females and males thereafter. The 90% range for the coefficient of variation in a 14 day period for females (males) varies from 2.3-9.2% (2.3-9.5%) for ages 20-24 yr, to 2.5-16.8% (2.7-21.7%) for ages 65-69 yr. We show that respiratory rate is often elevated in subjects diagnosed with COVID-19. In a 7 day window from D_-1 to D₊₅ (where D₀ is the date when symptoms first present, for symptomatic individuals, and the test date for asymptomatic cases), we find that 36.4% (23.7%) of symptomatic (asymptomatic) individuals had at least one measurement of respiratory rate 3 min^-1 higher than the regular rate.

Sex-Specific Impacts of Exercise on Cardiovascular Remodeling

Cardiovascular diseases (CVD) remain the leading cause of death in men and women. Biological sex plays a major role in cardiovascular physiology and pathological cardiovascular remodeling. Traditionally, pathological remodeling of cardiovascular system refers to the molecular, cellular, and morphological changes that result from insults, such as myocardial infarction or hypertension. Regular exercise training is known to induce physiological cardiovascular remodeling and beneficial functional adaptation of the cardiovascular apparatus. However, impact of exercise-induced cardiovascular remodeling and functional adaptation varies between males and females. This review aims to compare and contrast sex-specific manifestations of exercise-induced cardiovascular remodeling and functional adaptation. Specifically, we review (1) sex disparities in cardiovascular function, (2) influence of biological sex on exercise-induced cardiovascular remodeling and functional adaptation, and (3) sex-specific impacts of various types, intensities, and durations of exercise training on cardiovascular apparatus. The review highlights both animal and human studies in order to give an all-encompassing view of the exercise-induced sex differences in cardiovascular system and addresses the gaps in knowledge in the field.

Monitoring Symptoms of Infectious Diseases: Perspectives for Printed Wearable Sensors

Infectious diseases possess a serious threat to the world's population, economies, and healthcare systems. In this review, we cover the infectious diseases that are most likely to cause a pandemic according to the WHO (World Health Organization). The list includes COVID-19, Crimean-Congo Hemorrhagic Fever (CCHF), Ebola Virus Disease (EBOV), Marburg Virus Disease (MARV), Lassa Hemorrhagic Fever (LHF), Middle East Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS), Nipah Virus diseases (NiV), and Rift Valley fever (RVF). This review also investigates research trends in infectious diseases by analyzing published research history on each disease from 2000-2020 in PubMed. A comprehensive review of sensor printing methods including flexographic printing, gravure printing, inkjet printing, and screen printing is conducted to provide guidelines for the best method depending on the printing scale, resolution, design modification ability, and other requirements. Printed sensors for respiratory rate, heart rate, oxygen saturation, body temperature, and blood pressure are reviewed for the possibility of being used for disease symptom monitoring. Printed wearable sensors are of great potential for continuous monitoring of vital signs in patients and the quarantined as tools for epidemiological screening.

Gender-specific characteristics of hypertrophic response in cardiomyocytes derived from human embryonic stem cells

Introduction: Gender-specific phenotypes of the heart were reported with respect to both physiology and pathology. While most differences were associated with the sex hormones, differential expression of genes received special attention, particularly X-Y chromosomes’ genes.

Methods: Here, we compared cardiogenesis by gene expression analysis of lineage specific markers and X-Y chromosomes’ genes, during in vitro differentiation of XY and XX human embryonic stem cells (hESC), in a hormone-free setup.

Results: Downregulation of pluripotency marker (NANOG) and upregulation of cardiac mesoderm and progenitor markers (GATA4, TBX5, NKX2.5, ISL1) was remained temporally similar in differentiating XY and XX hESCs. Isoproterenol treatment of XY and XX hESC-derived cardiomyocytes (hESCCM) induced hypertrophy in a sex-specific manner, with female cardiomyocytes showing response at higher isoproterenol concentration and a later time point of differentiation. Interestingly, KDM5C as an X-linked gene, was markedly upregulated in both hypertrophied male and female cardiomyocytes.

Conclusion: Collectively, our results indicated a temporally identical cardiogenesis, but more susceptibility of XY hESC-CM to hypertrophic stimulus in a hormone-free condition.

Sources of Inaccuracy in Photoplethysmography for Continuous Cardiovascular Monitoring

Photoplethysmography (PPG) is a low-cost, noninvasive optical technique that uses change in light transmission with changes in blood volume within tissue to provide information for cardiovascular health and fitness. As remote health and wearable medical devices become more prevalent, PPG devices are being developed as part of wearable systems to monitor parameters such as heart rate (HR) that do not require complex analysis of the PPG waveform. However, complex analyses of the PPG waveform yield valuable clinical information, such as: blood pressure, respiratory information, sympathetic nervous system activity, and heart rate variability. Systems aiming to derive such complex parameters do not always account for realistic sources of noise, as testing is performed within controlled parameter spaces. A wearable monitoring tool to be used beyond fitness and heart rate must account for noise sources originating from individual patient variations (e.g., skin tone, obesity, age, and gender), physiology (e.g., respiration, venous pulsation, body site of measurement, and body temperature), and external perturbations of the device itself (e.g., motion artifact, ambient light, and applied pressure to the skin). Here, we present a comprehensive review of the literature that aims to summarize these noise sources for future PPG device development for use in health monitoring.

Outdoor Walking Speeds of Apparently Healthy Adults: A Systematic Review and Meta-analysis

BACKGROUND

Walking outdoors can be used by many individuals to meet public health guidelines for moderate-to-vigorous-intensity physical activity. The speed at which adults walk may be a proxy for intensity. Traditional estimates of indoor walking speed are unlikely to reflect self-selected usual or other instructed paces of outdoor walking speed.

OBJECTIVE

To inform estimates of pace-based walking speed of apparently healthy adults in outdoor settings.

METHODS

We searched four electronic databases for articles published in English between January 1970 and March 2019. Studies that reported walking speed (m/s), cadence (steps/min), or intensity (mL/kg/min) of ambulatory, apparently healthy, and community-dwelling adults (> 18 years) were included. Walking speed categories were defined according to the description provided in each study. Meta-analysis was used to synthesise speed, cadence, and intensity data by slow, usual, medium, fast, and maximal pace (where reported).

RESULTS

Thirty-five studies, representing 14,015 participants (6808 women, 5135 men, and 2072 sex not specified), were identified. The mean (95% CI) walking speed for slow, usual, medium, fast, and maximal pace was 0.82 (0.77-0.86), 1.31 (1.27-1.35), 1.47 (1.44-1.49), 1.72 (1.64-1.81), and 1.62 (1.45-1.79) m/s, respectively. Mean cadence (95% CI) for usual and fast paces were 116.65 (114.95-118.35) and 126.75 (121.87-131.63) steps/min, respectively. The mean oxygen consumption (95% CI) for the usual and medium paces was 11.97 (11.69-12.25) and 13.34 (12.94-13.73) mL/kg/min, respectively.

CONCLUSION

These findings provide greater clarity with regard to how various indicators of enacted walking pace, speed, and intensity overlap and how each can be best communicated in the real-world setting to optimise health-related outcomes. Pace-based instructions can be used to support walking in outdoor settings within public health guidelines.

Dyslipidemia and Its Components Across Body Mass Index Levels Among Type II Diabetic Patients in the West of Iran

Background:

The combination of dyslipidemia, obesity, and hyperglycemia can accelerate the progression to cardiovascular disease. Therefore, this study aimed to investigate dyslipidemia and its components across body mass index (BMI) levels among type II diabetic patients.

Methods:

The data for this cross-sectional study were extracted from the records of diabetic patients during 2014 to 2015. About 2,300 diabetic patients had been registered, and finally, the records of 2,110 patients which were fully completed were investigated. Dyslipidemia was defined based on the NCEP/ATP III classification of lipid profile. In order to investigate about nonlinear relationship between BMI and dyslipidemia, and its components, restricted cubic spline method was used.

Results:

The median age of patients was 55 (IQR = 14) years. 61.11% was females. The median of BMI, triglyceride, cholesterol, HDL-Chol, and LDL-Chol were 28.3 kg/m², 167, 193, 41, and 110 mg/dL in patients, respectively. The prevalence of dyslipidemia was 91.29% (95% CI: 90.05–92.54). Being overweight, diabetic patients were associated with an increased risk of dyslipidemia (OR = 1.87–2.78), hypertriglyceridemia (OR = 1.64; 95% CI: 1.29–2.09), and hypo-HDL (OR = 1.55; 95% CI: 1.20–2.01). Similarly, obesity also increased the risk of dyslipidemia (OR = 1.94; 95% CI: 1.28–2.95), hypertriglyceridemia (OR = 1.66; 95% CI: 1.29–2.12), and hypo-HDL (OR = 1.86; 95% CI: 1.41–2.43). The nonlinear dose–response relationship was associated with a significant increase then decrease in the risk of dyslipidemia, hypertriglyceridemia, and hypo-HDL in men and women as per 1 kg/m² increase in BMI.

Conclusions:

With regards to the result, we know that there is no linear relationship between lipid profiles and BMI, the bell-shape association between dyslipidemia, hypertriglyceridemia, and hypo-HDL needs to be further investigated in both diabetic and general population in men and women separately. In addition, for public health section, an appropriate intervention is of most important priorities.

Lower Cardiac Output Relates to Longitudinal Cognitive Decline in Aging Adults

BACKGROUND

Subclinical reductions in cardiac output correspond to lower cerebral blood flow (CBF), placing the brain at risk for functional changes.

OBJECTIVES

This study aims to establish the consequences of reduced cardiac output on longitudinal cognitive outcomes in aging adults.

METHODS

Vanderbilt Memory and Aging Project participants free of clinical dementia and heart failure (n = 306, 73 ± 7, 58% male) underwent baseline echocardiography to assess cardiac output (L/min) and longitudinal neuropsychological assessment at baseline, 18 months, 3 and 5 years. Linear mixed-effects regressions related cardiac output to trajectory for each longitudinal neuropsychological outcome, adjusting for age, sex, race/ethnicity, education, body surface area, Framingham Stroke Risk Profile score, apolipoprotein E (APOE) ε4 status and follow-up time. Models were repeated, testing interactions with cognitive diagnosis and APOE-ε4 status.

RESULTS

Lower baseline cardiac output related to faster declines in language (β = 0.11, p = 0.01), information processing speed (β = 0.31, p = 0.006), visuospatial skills (β = 0.09, p = 0.03), and episodic memory (β = 0.02, p = 0.001). No cardiac output x cognitive diagnosis interactions were observed (p > 0.26). APOE-ε4 status modified the association between cardiac output and longitudinal episodic memory (β = 0.03, p = 0.047) and information processing speed outcomes (β = 0.55, p = 0.02) with associations stronger in APOE-ε4 carriers.

CONCLUSION

The present study provides evidence that even subtle reductions in cardiac output may be associated with more adverse longitudinal cognitive health, including worse language, information processing speed, visuospatial skills, and episodic memory performances. Preservation of healthy cardiac functioning is important for maintaining optimal brain aging among older adults.

Post-Translational S-Nitrosylation of Proteins in Regulating Cardiac Oxidative Stress

Like other post-translational modifications (PTMs) of proteins, S-nitrosylation has been considered a key regulatory mechanism of multiple cellular functions in many physiological and disease conditions. Emerging evidence has demonstrated that S-nitrosylation plays a crucial role in regulating redox homeostasis in the stressed heart, leading to discoveries in the mechanisms underlying the pathogenesis of heart diseases and cardiac protection. In this review, we summarize recent studies in understanding the molecular and biological basis of S-nitrosylation, including the formation, spatiotemporal specificity, homeostatic regulation, and association with cellular redox status. We also outline the currently available methods that have been applied to detect S-nitrosylation. Additionally, we synopsize the up-to-date studies of S-nitrosylation in various cardiac diseases in humans and animal models, and we discuss its therapeutic potential in cardiac protection. These pieces of information would bring new insights into understanding the role of S-nitrosylation in cardiac pathogenesis and provide novel avenues for developing novel therapeutic strategies for heart diseases.

Lymphatic Function and Dysfunction in the Context of Sex Differences

Endothelial cells are the building blocks of the blood vascular system and exhibit well-characterized sexually dimorphic phenotypes with regard to chromosomal and hormonal sex, imparting innate genetic and physiological differences between male and female vascular systems and cardiovascular disease. However, even though females are predominantly affected by disorders of lymphatic vascular function, we lack a comprehensive understanding of the effects of sex and sex hormones on lymphatic growth, function, and dysfunction. Here, we attempt to comprehensively evaluate the current understanding of sex as a biological variable influencing lymphatic biology. We first focus on elucidating innate and fundamental differences between the sexes in lymphatic function and development. Next, we delve into lymphatic disease and explore the potential underpinnings toward bias prevalence in the female population. Lastly, we incorporate more broadly the role of the lymphatic system in sex-biased diseases such as cancer, cardiovascular disease, reproductive disorders, and autoimmune diseases to explore whether and how sex differences may influence lymphatic function in the context of these pathologies.

Transcriptome and Functional Profile of Cardiac Myocytes Is Influenced by Biological Sex

BACKGROUND

Although cardiovascular disease is the primary killer of women in the United States, women and female animals have traditionally been omitted from research studies. In reports that do include both sexes, significant sexual dimorphisms have been demonstrated in development, presentation, and outcome of cardiovascular disease. However, there is little understanding of the mechanisms underlying these observations. A more thorough understanding of sex-specific cardiovascular differences both at baseline and in disease is required to effectively consider and treat all patients with cardiovascular disease.

METHODS AND RESULTS

We analyzed contractility in the whole rat heart, adult rat ventricular myocytes (ARVMs), and myofibrils from both sexes of rats and observed functional sex differences at all levels. Hearts and ARVMs from female rats displayed greater fractional shortening than males, and female ARVMs and myofibrils took longer to relax. To define factors underlying these functional differences, we performed an RNA sequencing experiment on ARVMs from male and female rats and identified ≈600 genes were expressed in a sexually dimorphic manner. Further analysis revealed sex-specific enrichment of signaling pathways and key regulators. At the protein level, female ARVMs exhibited higher protein kinase A activity, consistent with pathway enrichment identified through RNA sequencing. In addition, activating the protein kinase A pathway diminished the contractile sexual dimorphisms previously observed.

CONCLUSIONS

These data support the notion that sex-specific gene expression differences at baseline influence cardiac function, particularly through the protein kinase A pathway, and could potentially be responsible for differences in cardiovascular disease presentation and outcomes.

The inflammatory state provokes sexual dimorphism in left ventricular and electrocardiographic effects of chronic cyclosporine in rats

Although cardiotoxicity has been recognized as an adverse effect of cyclosporine A (CSA), no information exists regarding sex specificity of CSA cardiotoxicity. We tested the hypothesis that left ventricular (LV) and electrocardiographic (ECG) effects of CSA and related inflammatory/histopathological derangements are sex related. CSA reduced the LV slope of end-systolic pressure volume relationship and increased isovolumic relaxation constant. These effects were more pronounced in male compared to female rats, suggesting LV systolic and diastolic dysfunction. ECG recordings showed elevated ST segments and increased QTc and T peak trend intervals in CSA-treated male rats, markers of LV ischemia and arrhythmogenesis. In female rats, CSA delayed AV conduction, as reflected by prolonged PR interval. Other sex-related effects for CSA included (i) increased blood cholesterol, and reduced rates of rise and fall in LV pressure and nuclear factor kappa B and angiotensin receptors type 1 expressions in male rats, and (ii) increased LV adiponectin in females. Histopatholgically, CSA caused vascular congestion, blood extravasation, and pyknotic or even absent nuclei in both sexes. In conclusion, rats exhibit sex-independent susceptibility to negative LV and histopathological influences of CSA. These effects become more intensified in male rats, perhaps on account of aggravated ischemic and inflammatory milieus.

Is female gender associated with worse outcome after ST elevation myocardial infarction?

Objectives

To investigate the impact of gender in outcomes of patients with ST segment myocardial infarction in a setting with limited access to primary percutaneous coronary intervention

Methods

In 1017 consecutive patients hospitalized with ST segment myocardial infarction during years 2008–2013, distribution of risk factors, therapeutic methods, heart failure and in-hospital mortality were compared between males and females. Association of gender and primary outcomes was determined after adjustment for confounding factors.

Results

Females were significantly older (66 ± 12.1 years vs. 59.5 ± 12.7 years, p < 0.001). Prevalence of hypertension, hyperlipidemia and diabetes was significantly higher in females (72.2% vs. 39%, p < 0.001, 36.1% vs. 20.3%, p < 0.001, 46.5% vs. 32.1%, p < 0.001, respectively). Presentation delay was similar in males and females. Females received reperfusion therapy more than males (63.2%vs. 55.8%, p = 0.032). Development of heart failure and in-hospital mortality were significantly higher in females (36.5% vs. 27.2%, p = 0.003 and 19.4% vs. 12.1%, p = 0.002, respectively).

However in multivariate analysis, female gender was not independently associated with increased rate of heart failure and in-hospital mortality

Conclusion

In a center with low rate of primary percutaneous coronary intervention, crude rates of heart failure and in-hospital mortality are higher in females; however, the association is lost after adjustment for baseline characteristics

Generation of Small Single Domain Nanobody Binders for Sensitive Detection of Testosterone by Electrochemical Impedance Spectroscopy

A phage display library of variable domain of the heavy chain only antibody or nanobody (Nb) was constructed after immunizing a bactrian camel with testosterone. With the smaller molecular size (15 kDa), improved solubility, good stability, high affinity, specificity, and lower immunogenicity, Nbs are a promising tool in the next generation of diagnosis and medical applications. Testosterone is a reproductive hormone, playing an important role in normal cardiac function and being the highly predictive marker for many diseases. Herein, a simple and sensitive immunosensor based on electrochemical impedance spectroscopy (EIS) and Nbs was successfully developed for the determination of testosterone. We successfully isolated the antitestosterone Nbs from an immune phage display library. Moreover, one of the Nbs was biotinylated according to in vivo BirA system, which showed the highest production yield and the most stable case. Further, the EIS immunosensor was set up for testosterone detection by applying the biotinylated antitestosterone Nb. As a result, the biosensor exhibited a linear working range from 0.05 to 5 ng mL(-1) with a detection limit of 0.045 ng mL(-1). In addition, the proposed immunosensor was successfully applied in determining testosterone in serum samples. In conclusion, the proposed immunosensor revealed high specificity of testosterone detection and showed as a potential approach for sensitive and accurate diagnosis of testosterone.

A priming dose of protons alters the early cardiac cellular and molecular response to (56)Fe irradiation

PURPOSE

Recent evidence suggests that the heart may be injured by ionizing radiation at lower doses than was previously thought. This raises concerns about the cardiovascular risks from exposure to radiation during space travel. Since space travel is associated with exposure to both protons from solar particle events and heavy ions from galactic cosmic rays, we here examined the effects of a "priming" dose of protons on the cardiac cellular and molecular response to a "challenge" dose of (56)Fe in a mouse model.

METHODS

Male C57BL/6 mice at 10 weeks of age were exposed to sham-irradiation, 0.1 Gy of protons (150 MeV), 0.5 Gy of (56)Fe (600 MeV/n), or 0.1 Gy of protons 24 hours prior to 0.5 Gy of (56)Fe. Hearts were obtained at 7 days post-irradiation and western-blots were used to determine protein markers of cardiac remodeling, inflammatory infiltration, and cell death.

RESULTS

Exposure to (56)Fe caused an increase in expression of α-smooth muscle cell actin, collagen type III, the inflammatory cell markers mast cell tryptase, CD2 and CD68, the endothelial glycoprotein thrombomodulin, and cleaved caspase 3. Of all proteins investigated, protons at a dose of 0.1 Gy induced a small increase only in cleaved caspase 3 levels. On the other hand, exposure to protons 24 hours before (56)Fe prevented all of the responses to (56)Fe.

CONCLUSIONS

This study shows that a low dose of protons may prime the heart to respond differently to a subsequent challenge dose of heavy ions. Further investigation is required to identify responses at additional time points, consequences for cardiac function, threshold dose levels, and mechanisms by which a proton priming dose may alter the response to heavy ions.

GPR30 decreases cardiac chymase/angiotensin II by inhibiting local mast cell number

Chronic activation of the novel estrogen receptor GPR30 by its agonist G1 mitigates the adverse effects of estrogen (E2) loss on cardiac structure and function. Using the ovariectomized (OVX) mRen2.Lewis rat, an E2-sensitive model of diastolic dysfunction, we found that E2 status is inversely correlated with local cardiac angiotensin II (Ang II) levels, likely via Ang I/chymase-mediated production. Since chymase is released from cardiac mast cells during stress (e.g., volume/pressure overload, inflammation), we hypothesized that GPR30-related cardioprotection after E2 loss might occur through its opposing actions on cardiac mast cell proliferation and chymase production. Using real-time quantitative PCR, immunohistochemistry, and immunoblot analysis, we found mast cell number, chymase expression, and cardiac Ang II levels were significantly increased in the hearts of OVX-compared to ovary-intact mRen2.Lewis rats and the GPR30 agonist G1 (50 mg/kg/day, s.c.) administered for 2 weeks limited the adverse effects of estrogen loss. In vitro studies revealed that GPR30 receptors are expressed in the RBL-2H3 mast cell line and G1 inhibits serum-induced cell proliferation in a dose-dependent manner, as determined by cell counting, BrdU incorporation assay, and Ki-67 staining. Using specific antagonists to estrogen receptors, blockage of GPR30, but not ERα or ERβ, attenuated the inhibitory effects of estrogen on BrdU incorporation in RBL-2H3 cells. Further study of the mechanism underlying the effect on cell proliferation showed that G1 inhibits cyclin-dependent kinase 1 (CDK1) mRNA and protein expression in RBL-2H3 cells in a dose-dependent manner.