Mediating function of heart failure in the causal relationship between diastolic blood pressure and hypertensive renal disease with renal failure:a mediated Mendelian randomization study

Objective:To study the causality relationship between diastolic blood pressure(DBP)and hypertensive renal disease with renal failure(HRDRF)and the mediating role of hear t failure(HF)in the causality relationship by network Mendelian randomization(MR).Methods:Genome-wide analysis of DBP,HRDRF,and HF was downloaded from the public database(Genome-Wide Analysis Study[GWAS])and was used to analyze the results and to conduct mediated MR analysis.Results:Analysis showed that DBP was positively correlated with HRDRF(OR=1.0002,95%CI:1.0001–1.0003,P=1.8076e-05)and DBP was positively correlated with HF(OR=1.0295,95%CI:1.0221–1.0370,P=2.5292e-15).HF and HRDRF had a positive causal effect(OR=1.0001,95%CI:1.0000–1.0001,P=0.0152).Mediation analysis showed that the contribution ratio of HF to the combined effect of DBP and HRDRF was 24.69%.Conclusions:DBP can increase the risk of renal disease with renal failure,and HF may play an impor tant role in mediating this causal relationship.

THE CENTRAL DISTRIBUTION OF ADRENOMEDULLIN AND ITS EFFECTS ON BLOOD PRESSURE AND HEART RATE IN RATS

The present study was designed to make certain whether there exists adrenomedullin (ADM) in the rat central nervous system and evaluated the hemodynamic actions of intracerebroventricular administration (ICVA) of human ADM[13-52]. By immunohistochemistry (ABC method),We found that there was a discrete localization of ADM-positive immunoreactivity in the rat central system including cerebral cortex,paraventricular tissues, hypothalamus, cerebella cortex, mesencephalon and medulla oblongata. By reverse transcription-polymerase chain reaction(RT-PCR) analysis, rat ADM mRNA was found to be expressed in rat brain. These above results of immunohistochemistry and RT-PCR suggest that ADM exists in the rat brain. We also found that centrally administered ADM[13-52]in a dose of 0.4 to 3. 2 nmol/kg provoked marked, prolonged and dosedependent increases in mean arterial blood pressure (MABP) and heart rate (HR). To clarify the mechanisms of the hemodynamic changes induced by centrally administered ADM [13-52]. the effect of centrally administered ADM [13-52] on renal sympathetic nerve activity (RSNA) was studied. The result showed that centrally administered ADM [13-52] ( 1. 6 nmol/kg) provoked a marked increase in RSNA .therefore .the increases in MABP and HR induced by centrally administered ADM [13-52]might be due to the stimulation of central sympathetic mechanism. In addtion,we also compared the relationship of activity and structure among the different fragments of ADM. In conclusion, ADMexists in the rat brain, and it may play an important role in the central control of cardiovascular system.

Blood Pressure and Heart Rate Measurements Using Photoplethysmography with Modified LRCN

In this study,single-channel photoplethysmography(PPG)signals were used to estimate the heart rate(HR),diastolic blood pressure(DBP),and systolic blood pressure(SBP).A deep learning model was proposed using a long-term recurrent convolutional network(LRCN)modified from a deep learning algorithm,the convolutional neural network model of the modified inception deep learning module,and a long short-term memory network(LSTM)to improve the model’s accuracy of BP and HR measurements.The PPG data of 1,551 patients were obtained from the University of California Irvine Machine Learning Repository.How to design a filter of PPG signals and how to choose the loss functions for deep learning model were also discussed in the study.Finally,the stability of the proposed model was tested using a 10-fold cross-validation,with an MAE±SD of 2.942±5.076 mmHg for SBP,1.747±3.042 mmHg for DBP,and 1.137±2.463 bpm for the HR.Compared with its existing counterparts,the model entailed less computational load and was more accurate in estimating SBP,DBP,and HR.These results established the validity of the model.

Assessing the Association between Heart Attack, High Blood Pressure, and Heart Disease Mortality Rates and Particulate Matter and Socioeconomic Status Using Multivariate Geostatistical Model

This study addresses the public concerns of potential adverse health effects from ambient fine particulate matter as well as socioeconomic factors. Heart attack, high blood pressure, and heart disease mortality rates were investigated against fine particulate matter and socioeconomic status, for all counties in the United States in 2013. Multivariate multiple regressions as well as multivariate geostatistical predictions show that these are significant factors towards assessing the causal inferences between exposure to air pollution and socioeconomic status and the three mortality rates.

Predictive Value of Blood Pressure,Heart Rate,and Blood Pressure/Heart Rate Ratio in a Chinese Subpopulation with Vasovagal Syncope

Objective:The head-up tilt test(HUTT)is widely used but is time-consuming and not cost-effective to evaluate patients with vasovagal syncope(VVS).The present study aims to verify the hypothesis that ambulatory blood pressure(BP)monitoring(ABPM)and the simplistic tilt test may be potential alternatives to the HUTT.Methods:The study consecutively enrolled 360 patients who underwent the HUTT to evaluate VVS.BP),heart rate(HR),and BP/HR ratios derived from ABPM and the simplistic tilt test were evaluated to predict the presence,pattern,and stage of syncope during the HUTT.Results:Mixed response was the commonest pattern,and syncope occurred frequently with infusion of isoproterenol at a rate of 3μg/min.During the simplistic tilt test,the cardioinhibitory group had higher tilted BP/HR ratios than the vasodepressor group,while the vasodepressor group had a faster tilted HR and a larger HR difference than the cardioinhibitory group.The higher the BP/HR ratio in the tilted position,the higher the isoproterenol dosage needed to induce a positive response.During ABPM,BP/HR ratios were signifi cantly higher in the cardioinhibitory group than in the vasodepressor group.The higher the ABPM-derived BP,the higher the dosage of isoproterenol needed to induce syncope.There were signifi cant correlations in BP/HR ratios between ABPM and the supine position in the vasodepressor group,while signifi cant correlation was found only for the diastolic BP/HR ratio between ABPM and the tilted position in the cardioinhibitory group.The mixed pattern shared correlative features of the other two patterns.Conclusion:ABPM and the simplistic tilt test might be used as promising alternatives to the HUTT in VVS evaluation in clinical settings.

Cardiovascular age of aviation personnel: based on the principal component analysis of heart rate and blood pressure variability

Objective: To introduce a method to calculate cardiovascular age, a new, accurate and much simpler index for assessing cardiovascular autonomic regulatory function, based on statistical analysis of heart rate and blood pressure variability (HRV and BPV) and baroreflex sensitivity (BRS) data. Methods: Firstly, HRV and BPV of 89 healthy aviation personnel were analyzed by the conventional autoregressive (AR) spectral analysis and their spontaneous BRS was obtained by the sequence method. Secondly, principal component analysis was conducted over original and derived indices of HRV, BPV and BRS data and the relevant principal components, PCi orig and PCi deri (i=1, 2, 3,...) were obtained. Finally, the equation for calculating cardiovascular age was obtained by multiple regression with the chronological age being assigned as the dependent variable and the principal components significantly related to age as the regressors. Results: The first four principal components of original indices accounted for over 90% of total variance of the indices, so did the first three principal components of derived indices. So, these seven principal components could reflect the information of cardiovascular autonomic regulation which was embodied in the 17 indices of HRV, BPV and BRS exactly with a minimal loss of information. Of the seven principal components, PC2 orig , PC4 orig and PC2 deri were negatively correlated with the chronological age ( P <0 05), whereas the PC3 orig was positively correlated with the chronological age ( P <0 01). The cardiovascular age thus calculated from the regression equation was significantly correlated with the chronological age among the 89 aviation personnel ( r =0.73, P <0 01). Conclusion: The cardiovascular age calculated based on a multi variate analysis of HRV, BPV and BRS could be regarded as a comprehensive indicator reflecting the age dependency of autonomic regulation of cardiovascular system in healthy aviation personnel.

Different prognostic association of systolic blood pressure at different time points with postdischarge events in patients hospitalized for decompensated heart failure

Background The association of systolic blood pressure(SBP) with mortality in heart failure(HF) patients is paradoxical, and the time points of baseline SBP are also different across prior studies. We hypothesized that the levels of SBP at admission and at discharge had different associations with postdischarge events. Methods The study population included patients hospitalized for decompensated HF in the Heart Failure Center of Fuwai Hospital from January 1, 2009 to December 31, 2014. The primary outcome was a composite of cardiovascular(CV) death and heart transplantation. Multivariate Cox proportional-hazards and restricted cubic spline analyses were used to assess the relationships between SBP at different time points and outcomes. Results In total, 2005 patients were included with a median follow-up of 48.4 months. The median age was 59 years, and 69.9% were male. Multivariate Cox analyses showed that compared with SBP < 105 mm Hg, higher SBP at admission was associated with better long-term primary outcome(105–119 mm Hg, HR = 0.764, P = 0.005;120-134 mm Hg, HR = 0.658, P < 0.001;≥ 135 mm Hg, HR = 0.657, P = 0.001). Patients whose discharge SBP was higher than 135 mm Hg had a similar primary outcome as those with SBP < 105 mm Hg(HR = 0.969, P = 0.867), and the results remained unchanged even after adjusting for admission SBP(HR = 1.235, P = 0.291). The results of restricted cubic spline analysis indicated similar associations. Conclusions Lower but not higher SBP at admission is associated with more CV deaths/heart transplantations(a reverse J-shaped curve). In contrast, there is a U-shaped association between discharge SBP and CV mortality/heart transplantation.

Effects of Impaired Glucose Metabolism on Heart Rate Variability and Blood Pessure Variability in Essential Hpertensive Patients

To investigate the effects of impaired glucose metabolism （IGM） on cardiovascular autonomic nervous systems in essential hypertensive （EH） patients by comparing heart rate variability （HRV） and blood pressure variability （BPV） in EH patients with or without type 2 diabetes mellitus （T2DM）. Simultaneous 24-h recordings of ambulatory ECG and blood pressure monitoring were performed in 36 male old patients with simple EH and 33 male old patients with EH combined with T2DM. HRV analysis included time domain parameters such as SDNN, SDANN, SDNNi, rMSSD and pNN50, and total spectral power （TP） of HRV, which mainly consists of VLF, LF and HF component along with LF/HF ratio, was also obtained. The value of ambulatory blood pressure was represented as the mean blood pressure （mean systolic/mSBP, diastolic/mDBP and pulse pressure/mPP） during different periods （24 h/24 h, day time/d and night time/n）. Standard deviation （SD） as well as coefficient of variance （CV） of blood pressure during each above-mentioned period were obtained to reflect the long-term BPV. Our result showed that SDNN, SDNNi, SDANN, rMSSD, PNN50, TP and HF of HRV in cases of EH with T2DM were all significantly lower than those in simple EH subjects （P〈0.05）. No significant differences in VLF or LF was found between the two groups （P〉0.05）, while LF/HF ratio was significantly higher in EH with T2DM patients than in simple EH subjects （P〈0.01）. Moreover, dmSBP, 24 h-mPP and dmPP were all significantly higher in EH with T2DM patients than in simple EH subjects （P〈0.05）, while nmSBP, 24 h-mSBP, 24 h-mDBP, dmDBP, nmDBP or nmPP showed no significant difference between this two groups of patients （P〉0.05）. And dSBPSD, dSBPCV and 24 h-SBPSD were all significantly higher in EH with T2DM patients than in simple EH subjects （P〈0.05）, while the other BPV indexes showed no significant difference between this two groups （P〉0.05）. It is concluded that the cardiovascular autonomic nervous systems in EH patients was further impaired by T2DM, displaying lowering of HRV and enlargement of BPV, which in turn induced abnormal structural and functional changes of cardiovascular systems. Therefore, improving cardiovascular autonomic nervous systems might reduce the occurrence of cardiovascular complications in the EH patients with IGM.

Acu-TENS lowers blood lactate levels and enhances heart rate recovery after exercise

Objective:The primary aim of this study is to investigate the effect of application of transcutaneous electrical nerve stimulation over acupuncture points(Acu-TENS)on postexercise blood lactate level.The secondary aim is to explore the effect of Acu-TENS on heart rate recovery and its association with autonomic nervous system.Methods:Twenty healthy subjects(mean age 26.9
1.3)acting as their own controls,were randomized to receive either Acu-TENS or Placebo-TENS as the first of two intervention protocols,implemented one week apart.During Acu-TENS,subjects received 45 min TENS bilaterally over the acupoints Neiguan(PC6).Subjects receiving Placebo-TENS had identical electrode placement but with no electrical output from the TENS unit despite an active output light.Interventions were followed by a 10-min ergometer exercise at 70%age-predicted maximal heart rate.Oxygen consumption and heart rate(HR)were recorded continuously throughout exercise.Blood lactate and blood pressure were taken at 4 time points:prior to,immediately after,at 15-min after exercise,and when HR had returned to baseline values.Results:The post-exercise blood lactate level in the Acu-TENS group was lower than that of the placebo group by 1.12
0.39 mmol/L(p Z 0.01).The Acu-TENS group also had a faster return of HR to pre-exercise level compared to placebo(9.98
4.54 min,p Z 0.047).Heart rate variability analysis inferred reduced sympathetic modulation during exercise after Acu-TENS.There was no between-group difference in post-exercise oxygen consumption.Conclusion:Acu-TENS lowered post-exercise blood lactate level and enhanced heart rate recovery after moderate exercise.The role of Acu-TENS in exercise performance and energy metabolism warrants further investigation.(ClinicalTrails.gov Identifier:NCT01102634)a 2014 Beijing University of Chinese Medicine.Production and hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/3.0/).

Empirical Studies of Effects of High Blood Pressure on Medical Costs and Heart Disease: Is the 2017 ACC/AHA Guideline Supported by Enough Evidence?

Background: The American College of Cardiology (ACC), American Heart Association (AHA) and other organizations announced a new hypertension guideline in November 2017. However, previous studies have pointed out that this new guideline might lack sufficient evidence to justify its use. Data and Methods: The effects of blood pressure (BP) on medical costs and on the probability of having heart disease as anamnesis are analyzed. We used a dataset containing 175,123 medical checkups and 6,312,125 receipts from 88,211 individuals obtained from three health insurance societies from April 2013 to March 2016. The dataset was divided into subgroups based on whether the patients had diabetes and took hypertension medications. The power transformation and probit models were used in the study. Results: We observed negative effects of systolic BP (SBP) on medical costs in most subgroups. We could not find evidence that higher SBP made the medical costs and probability of having heart diseases higher. The results raise uncertainty about the reliability of the new guideline, at least for SBP. Conclusion: The results of this study did not support the new 2017 ACC/AHA guideline, at least for SBP. The new guideline must be more carefully reevaluated by additional studies. Limitations: The dataset was observatory, the sample period was only 3 years, and we could not complete a time-series analysis of individuals.

An Analysis of the Effects of Blood Pressure and Antihypertensive Drugs on Heart Disease

Background: The American College of Cardiology (ACC), American Heart Association (AHA) and other organizations announced a new hypertension guideline (2017 ACA/AHA Guideline) in November 2017. However, other organizations such as the European Society of Cardiology and European Society of Hypertension maintained their diagnostic thresholds. It is necessary to evaluate the effects of blood pressure (BP) and antihypertensive drugs on the probability of having heart disease (HD). Data and Methods: The effects of BP, antihypertensive drugs and other factors on the probability of undergoing HD treatment were analyzed. We used a dataset containing 83,287 medical check-up and treatment records obtained from 35,504 individuals in 5 fiscal years. The probit models were used in the study. Considering the possibility of endogeneity problems, different types of models were used. Results: We could not find evidence that a higher systolic BP increased the probability of undergoing HD treatment. However, diastolic BP increased the probability in most of the models. Taking antihypertensive drugs also increased the probability of undergoing HD treatment. Diabetes was another important risk factor. Conclusion: The results of this study did not support the new 2017 ACC/AHA Guideline. It is necessary to choose proper drugs and methods to reduce the risks of side effects. Limitations: The dataset was observatory, the data were obtained from just one medical society, and sample selection bias might exist.

Screening, Treatment and Control of High Blood Pressure on Five Sites in Mali

Introduction: High blood pressure is defined as blood pressure greater than or equal to 140 mm Hg for systolic and or 90 mm Hg for diastolic. It constitutes a major public health problem, the leading chronic disease in the world. The objective was to determine the prevalence, treatment rate and control of hypertension. Methods: This was a cross-sectional and descriptive study which took place over a period of 6 months in a hospital environment and in the general population. Results: Of the 1000 participants, 637 had hypertension, giving a prevalence of 63.70% with a female predominance. Thirty-three percent (33%) were unaware of their high blood pressure. The age group 60 and more was the most represented (44%). A proportion of 33 and 23.20 were overweight and obese participants, respectively. Male subjects were more overweight than female, unlike obesity which was more common among female subjects. Sixty-two percent (62%) of hypertensives were treated, of whom 44% were non-compliant. The excessively high cost and consumption of medications as needed were the main factors in therapeutic non-compliance. Twenty-two percent (22%) of all hypertensive patients and 35% of treated hypertensive patients were controlled. Women were more treated but less observant and less controlled than men. Therapeutic coverage and combination therapy rates were lower in rural areas. Hypertensives who had a high level of education were better treated and controlled than those who had no level. Conclusion: High blood pressure remains a real public health problem in Mali. It is more common in people aged 60 and over and in females. One in three hypertensives were unaware of their hypertension. The majority received antihypertensive treatments, but only a minority of them had their hypertension controlled.

Effect of music on blood pressure, pulse rate and respiratory rate of asymptomatic individuals: A randomized controlled trial

A slight reduction of blood pressure and heart rate can reduce the risk of developing cardiovascular disease. Maintenance of the respiratory rate within the normal range has also being identified as crucial for a healthy heart. Use of Indian and western music have been considered among many preventive programmes for long time in order to risk reduction associated with cardio vascular diseases. Therefore the aim of this study is to describe the effect of Indian classical music on systolic and diastolic blood pressure, pulse rate and respiratory rate in asymptomatic individuals aged 45 to 65 years. Methodology: A community based randomized intervention study was conducted in 252 asymptomatic individuals. The study group (n = 127) listened to a music based on Indian classical system (entire track of 22 minutes). The control group (n = 125) was kept silent for a similar time period. Systolic and diastolic blood pressure, pulse rate and respiratory rate of each study participant were monitored before and after the intervention. Results: Statistically significant reduction in systolic blood pressure (8.53 mmHg), diastolic blood pressure (5.8 mmHg), pulse rate (5.16 breaths per minute) and respiratory rate (2.55 per minute) were observed in the study group after listening to the music (p < 0.01). In the control group, changes observed during the period of intervention were not significant (p > 0.05). The reduction was independent of gender, age, education level, practicing a mind relaxation technique and preferred type of music of the participant. Conclusions: Listening to Indian classical music for about 22 minutes significantly reduced systolic and diastolic blood pressure, pulse rate and respiratory rate of asymptomatic individuals. Hence, music may have a potential benefit in cardio vascular disease preventive programmes.

A Study into Blood Flow, Heart Rate Variability, and Body Surface Temperature While Listening to Music

In this study we examined the relaxing effects of listening to music on a total of 12 women aged from their 20s to their 40s by measuring their blood flow, heart rate variability, and their body surface temperature. As a result, We found that there was a tendency for the volume of blood flow to the fingertips to significantly increase when listening to classical music, but there was a variety of changes in blood flow between each age group for healing music and J-Pop music. When measuring heart rate it was found that the LF/HF value, which is an index for the autonomic nervous system which shows tension and stress, fell significantly when listening to each type of music. Lastly, there was a trend for body surface temperature to rise when listening to classical or healing music, a rise which was particularly significant when listening to healing music. This study shows that a relaxing effect can be expected for all indices when listening to classical music. However, for healing music and J-Pop, personal musical preferences seemed to have an effect and the results were varied.

Relationship between Obesity, Serum Uric Acid, Serum Potassium and Glomerular Filtration Rate with Electric Left Ventricular Hypertrophy in Blacks Central Africans with High Blood Pressure

The authors conducted a retrospective study over a period of 6 months in a hypertensive population in order to determine the correlation between serum uric acid on glomerular filtration rate (GFR) and estimated serum potassium with left ventricular hypertrophy (LVH) and obesity. This study enrolled 122 patients including 63 women (51.6%). The mean age was 55.9 ± 10.6 years (range 30 to 74 years). Obesity weight was found in 38 cases (31.1%) of which 20?were men (33.9%) and 18 women (28.6%). Abdominal obesity was found in 104 cases (85.2%). The average serum uric acid in patients with obesity weight was 63.3 ± 18.9 mg/L vs 62.4 ± 14.2 mg/L for no-obese patients (p?= 0.63). The average serum potassium in obese patients was 4.06 ± 0.42 mEq/L vs 4.02 ± 0.46 mEq/L for no-obese (p?= 0.65). The average GFR was 73.4 ± 21.4 ml/L in obese patients vs 66.6 ± 22.6 ml/min in no-obese (p?= 0.03). The LVH was found in 81 cases (66.4%). The LVH was found in 65 (62.5%) obese patients vs?16 (88%) non-obese patients (OR = 4.8, 95% 1.04?-?22?p?= 0.02). Only abdominal?obesity has been correlated with left ventricular hypertrophy after multivariate analysis. Emphasis must be focused on public health actions for effective and appropriate measures against obesity and hypertension, whose prevalence is increasing in our region.

The Relationship between Abnormal Circadian Blood Pressure Rhythm and Risk of Readmission in Patients with Heart Failure with Preserved Ejection Fraction

Objective:Abnormal circadian blood pressure rhythm has been revealed to be associated with hypertensive target organ damage and cardiovascular events,but its association with readmission risk in patients with heart failure with preserved ejection fraction(HFpEF)remains unknown.We conducted a retrospective study to explore the relationship between circadian blood pressure rhythm and readmission risk in HFpEF patients.Methods:We retrospectively collected baseline and follow-up data on HFpEF patients who underwent ambulatory blood pressure monitoring(ABPM)from May 2015 to October 2019.Patient circadian blood pressure rhythms defi ned by ABPM were grouped as dipper,nondipper,or riser patterns.Univariate and multivariate linear regression analyses were performed to assess the association between circadian blood pressure rhythm and readmission risk.Results:A total of 122 patients were enrolled in this study.The mean age and ejection fraction were 69.87 years and 61.44%,respectively,with mean the N-terminal pro-B-type natriuretic peptide(NT-proBNP)level being 1048.15 pg/mL.There were signifi cant differences in the 24-hour systolic blood pressure(SBP),sleep SBP,and sleep diastolic blood pressure(DBP)among the three groups,where the 24-hour SBP,sleep SBP,and sleep DBP in the riser pattern group were markedly higher than in the dipper pattern group.Notably,serum NT-proBNP levels,the proportion of patients readmitted for heart failure and the mean number of admissions differed markedly among three groups.Instructively,multivariate linear regression analysis showed that the riser pattern was a signifi cant and independent risk factor for increased serum NT-proBNP level(β=929.16,95%confi dence interval 178.79–1679.53,P=0.016).In multivariate logistic regression analysis,the riser pattern was demonstrated to be a signifi cant risk factor for readmission(odds ratio 11.23,95%confi dence interval 2.01–62.67,P=0.006)in HFpEF patients.Conclusion:The riser blood pressure pattern is a potential risk factor for elevated serum NT-proBNP level and readmission in HFpEF patients.

Blood pressure and stature in Helicobacter pylori positive and negative persons

To evaluate vital signs and body indices in Helicobacter pylori (H. pylori) positive and negative persons. A total of 22 centres entered the study. They were spread over the whole country, corresponding well to the geographical distribution of the Czech population. A total of 1818 subjects (aged 5-98 years) took part in the study, randomly selected out of 38147 subjects. H. pylori infection was investigated by means of a 13C-urea breath test. Data on height, weight, systolic and diastolic blood pressure and heart rate were collected at the clinics of general practitioners. The overall prevalence of H. pylori infection was 30.4% (402/1321) in adults (≥ 18 year-old) and 5.2% (26/497) in children and adolescents (≤ 17 year-old). Once adjusted for age and gender, only a difference in body mass index remained statistically significant with H. pylori positive adults showing an increase of 0.6 kg/m2 in body mass index. Once adjusted for age and gender, we found a difference in height between H. pylori positive and H. pylori negative children and adolescents. On further adjustment for place of residence, this difference became statistically significant, with H. pylori positive children and adolescents being on average 3.5 cm shorter. H. pylori positive adults were significantly older compared to H. pylori negative subjects. Once adjusted for age and gender, H. pylori infection had no impact on body weight, body mass index and vital signs either in adults or children and adolescents. Chronic H. pylori infection appeared to be associated with short stature in children. H. pylori infection did not influence blood pressure, body weight and body mass index either in adults or children and adolescents.

Power Spectral Analysis of Heart Rate Variability of Driver Fatigue

This investigation was to evaluate the driving fatigue based on power spectral analysis of heart rate variability (HRV) under vertical vibration. Forty healthy male subjects (29.7±3.5 years) were randomly divided into two groups, Group A (28.8±4.3 years) and Group B (30.6±2.7 years). Group A (experiment group) was required to perform the simulated driving and Group B (control group) kept calm for 90 min. The frequency domain indices of HRV such as low frequency (0.04 0.15 Hz, LF), high frequency (0.150.4 Hz, HF), LF/HF together with the indices of hemodynamics such as blood pressure (BP) and heart rate (HR) of the subjects between both groups were calculated and analyzed after the simulated driving. There were significances of the former indices between both groups (P<0.05). All the data collected after experiment of Group A was observed the remarkable linear correlation (P<0.05) and parameters and errors of their linear regression equation were stated (α=0.05, P<0.001) in this paper, respectively. The present study investigated that sympathetic activity of the subjects enhanced after the simulated driving while parasympathetic activities decreased. The sympathovagal balance was also improved. As autonomic function indictors of HRV reflected fatigue level, quantitative evaluation of driving mental fatigue from physiological reaction could be possible.

The Effect of Baroreflex Function on Blood Pressure Variability

Objective: The aim of this study was to assess the relationship of blood pressure variability (BPV) and heart rate variability (HRV) to investigate the effect of baroreflex function on blood pressure variability. Methods: This study consisted of 111 subjects, including 32 normotensives and 79 hypertensives. All the subjects were given two concurrent tests: 24-hour Holter ECG and ambulatory blood pressure monitoring. According to standard deviation of normal-to-normal sinus RR intervals (SDNN) derived from the Holter ECG, the hypertensives were divided into two groups: an HRV normal group with SDNN > 100 ms and an HRV abnormal group with

Psychological stress and long-term blood pressure variability of military young males:The cardiorespiratory fitness and hospitalization events in armed forces study

BACKGROUND Acute stress might increase short-term heart rate variability and blood pressure variability(BPV);however,chronic stress would not alter short-term BPV in animal models.AIM To examine the association of psychological stress with long-term BPV in young male humans.METHODS We prospectively examined the association of chronic psychological stress with long-term BPV in 1112 healthy military males,averaged 32.2 years from the cardiorespiratory fitness and hospitalization events in armed forces study in Taiwan.Psychological stress was quantitatively evaluated with the Brief Symptom Rating Scale(BSRS-5),from the least symptom of 0 to the most severe of 20,and the five components of anxiety,insomnia,depression,interpersonal sensitivity,and hostility(the severity score in each component from 0 to 4).Longterm BPV was assessed by standard deviation(SD)for systolic and diastolic blood pressure(SBP and DBP),and average real variability(ARV),defined as the average absolute difference between successive measurements of SBP or DBP,across four visits in the study period from 2012 to 2018(2012-14,2014-15,2015-16,and 2016-18).RESULTS The results of multivariable linear regressions showed that there were no correlations of the BSRS-5 score with SDSBP,SDDBP,ARVSBP,and ARVDBP after adjusting for all the covariates[β(SE):-0.022(0.024),-0.023(0.026),-0.001(0.018),and 0.001(0.020),respectively;P>0.05 for all].In addition,there were also no correlations between each component of the BSRS score and the long-term BPV indexes.CONCLUSION Our findings suggest that chronic psychological stress might not be associated with long-term BPV in military young male humans.