Effects of fine particulate on heart rate variability in Beijing: a panel study of healthy elderly subjects

Purpose  

This study aims to investigate the effects of ambient fine particulate (particulate matter with an aerodynamic diameter of 2.5 μm or less, PM_2.5) exposure within several minutes on Heart Rate Variability (HRV) of the healthy elderly subjects in the general environments (indoor and outdoor).     

Association between sense of coherence and heart rate variability in healthy subjects

Objectives This report investigates whether there is any association between sense of coherence (SOC), as a coping measure in confronting stressful conditions, and heart rate variability (HRV), as a measure of the cardiac autonomic nervous system during the daily life pattern. Methods Sixteen healthy university students (14 males and 2 females) filled in the validated Japanese version of the SOC-13 questionnaire before being informed about the study protocol. For each participant, we calculated 5-minute HRV indices using logarithmically transformed data on frequency domains for HRV derived by 24-hour Holter monitoring. Frequency domains for HRV recordings were investigated for the 24-hour time periods. Results The correlation coefficient between the SOC scores and the high frequency power of HRV (0.15–0.40) was positively significant during the resting sitting position (r≥0.60, P<0.05). After grouping SOC scores by the median, the high frequency domain of HRV was higher in high SOC subjects for most of the 24-hour time period. Conclusion A higher SOC could modulate the parasympathetic tone of cardiac autonomic activity, especially during the resting sitting position.     

老年高血压合并OSAHS患者心率变异性临床影响

目的临床上,阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea hypopnea synd,OSAHS)患者常常合并高血压现象,并诱发各种心血管事件,严重影响患者生命健康。本研究分析OSAHS对老年高血压患者心率变异性(heart rate variability,HRV)临床价值。方法在2016-07-01-2018-07-01天河区冼村街社区卫生服务中心接诊的老年高血压患者选择合并OSAHS患者为OSAHS组,否则为非OSAHS组。对比两组一般资料,睡眠监测指标和心率变异性指标。结果 OSAHS组呼吸暂停低通气指数、平均呼吸暂停时间和平均低通气时间分别为(20.15±4.58)次/h、(24.82±4.25)s和(19.06±5.22)s,均高于非OSAHS组的(2.13±0.33)次/h、(4.29±1.01)s和(2.91±0.60)s,t值分别为31.148、37.303和24.396,均P0.001;OSAHS组RR间期标准差、RR间期平均值标准差和相邻RR间期差值的均方根分别为(89.21±13.94)、(86.63±17.35)和(21.44±7.28)ms,均低于非OSAHS组的(118.16±15.63)、(121.55±16.54)和(27.98±10.28)ms,t值分别为10.972、11.563和10.422,均P0.001;OSAHS组高频段功率为(9.13±3.74)Hz,低于非OSAHS组的(11.32±4.26)Hz,t=3.006,P=0.003;低频段功率/高频段功率为(2.23±0.31),高于非OSAHS组的(1.96±0.34),t=4.658,P0.001。结论 OSAHS合并高血压患者出现HRV的可能性较大,是导致患者心血管事件的重要原因。     

大气可吸入颗粒物对大鼠心率变异性的影响

目的研究可吸入颗粒物对大鼠心率变异性的影响。方法24只SD大鼠,均为雄性,体重150~200 g。随机分为两组(实验组、对照组),每组12只。实验组大鼠按25 mg(1 ml)/kg体重经气管内缓慢注入颗粒物生理盐水悬液染毒,每周染毒2次,连续染毒4周;对照组以生理盐水代替颗粒物悬液。大鼠麻醉后经皮下引导电极连续采集心电信号,计算SDNN和r-MSSD。统计学处理采用SPSS统计学软件,组间比较用t检验或方差分析,P0.05为差异有统计学意义。结果2组大鼠首次和末次染毒之后30 min的心率均较染毒之前明显下降;两组大鼠首次染毒之前和末次染毒之前的心率差异无统计学意义;两组大鼠首次染毒之后和末次染毒之后30 min的心率差异无统计学意义。两组大鼠首次染毒之前和首次染毒之后30 min的心率变异性差异无统计学意义;末次染毒之前和末次染毒之后30 min的心率变异性差异无统计学意义;实验组末次染毒之前和末次染毒之后30min的心率变异性分别较首次染毒之前和首次染毒之后30 min时明显下降(P0.05);与对照组比较,实验组末次染毒之前和染毒之后30 min的心率变异性明显下降(P0.05)。结论本研究表明可吸入颗粒物能够导致心率变异性的降低。     

Effects of concentrated ambient particles on heart rate variability in spontaneously hypertensive rats

In the present study, the cardiovascular toxicity of PM(2.5) was determined in spontaneously hypertensive (SH) rats using the standard deviation of normal-to-normal intervals (SDNN) and root mean square of successive differences of adjacent normal-to-normal intervals (RMSSD) as outcome measurements. Four SH rats implanted with radiotelemetry transmitters were repeatedly exposed to concentrated PM(2.5) in nose-only exposure chambers. Gravimetric analysis revealed the mean post-concentrating mass concentration of particles during the 5 h of exposure was 202 mug/m(3). Using each animal as its own control and linear mixed-effects model, to adjust for circadian nature and individual differences, we found that SDNN decreased by 15% initially then gradually decreased to 60% of the initial value at the end of exposure. Our results indicate that concentrated PM(2.5) may decrease SDNN on SH rats during PM exposure. The study also showed that SDNN is more sensitive to PM induced effects than RMSSD.     

前列地尔控制性降压对老年患者心率变异性的影响

目的 研究前列地尔用于老年患者控制性降压时对心率变异性(HRV)的影响.方法 86例择期全身麻醉下行鼻内窥镜手术的老年患者按随机数字表法分为前列地尔组(43例)和硝酸甘油组(43例).两组术中分别以前列地尔和硝酸甘油持续输注,使平均动脉压(MAP)下降25％～30％.以降压前(T0)、降至目标血压时(T1)、降至目标血压后5min(T2)、降至目标血压后30min(T3)、停降压时(T4)及停降压后30 min(T5)为时间点,记录两组MAP、心率(HR)、血浆乳酸(LAC)水平及HRV各指标[总功率(TP)、低频功率(LF)、高频功率(HF)及LF/HF],并进行比较.结果 硝酸甘油组T1～T4时HR较T0时增快(P＜0.05),且较前列地尔组同时间点显著增快(P＜0.05),T5时硝酸甘油组HR较T0时仍增快(P＜0.05);而前列地尔组T1～T5时HR与T0时比较差异无统计学意义(P＞0.05).两组各时间点LAC水平组内及组间比较差异均无统计学意义(P＞0.05).T1～T4时两组TP、LF、HF较T0时明显下降(P＜0.05),前列地尔组T1～T4时HF明显高于硝酸甘油组(P＜0.05);T1～T4时前列地尔组LF/HF与T0时比较差异无统计学意义(P＞0.05),而硝酸甘油组T1～T4时LF/HF显著升高(P＜0.05),同时也高于前列地尔组(P＜0.05);T5时两组TP、LF、HF均回升,T5时前列地尔组HF高于硝酸甘油组(P＜0.05);T5时前列地尔组LF/HF仍维持在T0时水平,而硝酸甘油组LF/HF水平虽下降但仍高于T0时水平且高于前列地尔组(P＜0.05).结论 前列地尔用于控制性降压时更易维持心脏自主神经的均衡性,有利于老年患者围手术期安全.     

Ambient fine particles modify heart rate variability in young healthy adults

Particulate air pollution has been related with cardiopulmonary morbidity and mortality. Recent studies have shown that an increase in particulate matter (PM)(2.5) ambient concentrations was associated with a decrease in heart rate variability (HRV) in the elderly with cardiovascular conditions, which could increase the risk of death. In order to assess if this association could also be observed in young adults, we studied 40 young healthy residents of the Mexico City Metropolitan Area (MCMA) who underwent 13 h Holter electrocardiographic and PM(2.5) personal monitoring. HRV was evaluated in time domain: the standard deviation of normal RR intervals (SDNN) and the percentage of differences between adjacent normal RR intervals larger than 50 ms (pNN50). In multivariate analysis with mixed effects models, a significant negative association of pNN50 with PM(2.5) accumulative exposure was found. An increase in 30 microg/m(3) of the average PM(2.5) personal exposure in the previous 2 h decreased the pNN50 in 0.08% (P=0.01). This observation revealed an acute effect related to environmental exposure to PM(2.5) with regard to HRV in normal youngsters. The long-term health consequences of this association in young healthy adults remain to be clarified.     

Investigation of noise exposure effect on heart rate variability parameters

This paper deals with the study of the effect of 135 min exposure to noise with intensity Leq 95 dB(A) in experimental conditions. Three experimental sessions: before, at the onset, and at the end of the noise exposure were conducted. The comparison of heart rate variability (HRV) parameters before and on the onset of the experiment showed tendency for significant decrease of the cardiointervals variability parameters: standard deviation (SD), sum of positive differences between successive cardiointervals (S), total wave energy in the cardiotachogram (S*Ns), mean difference between successive cardiointervals (V). Statistically significant increase of the mean value was found at HRV parameters related to the distribution of the cardiointervals: control adequacy parameter (IARP), equilibrium autonomic parameter (IVE), autonomous balance (IVB), homeostasis parameter (HI). At the end of the third experimental session HRV parameters were almost restored, but they did not achieve the initial values. An elevation of the sympathetic activity under noise exposure effect was found. In this aspect, the heart rate variability parameters were interpreted as a sensitive indicator for the quality of cardiac rhythm and they can be used for assessment of the functional status and the level of preserving of the adaptive reserves of the investigated persons.     

Personal exposure to submicrometer particles and heart rate variability in human subjects

We conducted a study on two panels of human subjects--9 young adults and 10 elderly patients with lung function impairments--to evaluate whether submicrometer particulate air pollution was associated with heart rate variability (HRV). We measured these subjects' electrocardiography and personal exposure to number concentrations of submicrometer particles with a size range of 0.02-1 microm (NC0.02-1) continuously during daytime periods. We used linear mixed-effects models to estimate the relationship between NC0.02-1 and log10-transformed HRV, including standard deviation of all normal-to-normal intervals (SDNN), square root of the mean of the sum of the squares of differences between adjacent NN intervals (r-MSSD), low frequency (LF, 0.04-0.15 Hz), and high frequency (HF, 0.15-0.40 Hz), adjusted for age, sex, body mass index, tobacco exposure, and temperature. For the young panel, a 10,000-particle/cm3) increase in NC0.02-1 with 1-4 hr moving average exposure was associated with 0.68-1.35% decreases in SDNN, 1.85-2.58% decreases in r-MSSD, 1.32-1.61% decreases in LF, and 1.57-2.60% decreases in HF. For the elderly panel, a 10,000-particle/cm3 increase in NC0.02-1 with 1-3 hr moving average exposure was associated with 1.72-3.00% decreases in SDNN, 2.72-4.65% decreases in r-MSSD, 3.34-5.04% decreases in LF, and 3.61-5.61% decreases in HF. In conclusion, exposure to NC0.02-1 was associated with decreases in both time-domain and frequency-domain HRV indices in human subjects.     

Ambient particulate air pollution, heart rate variability, and blood markers of inflammation in a panel of elderly subjects

Epidemiologic studies report associations between particulate air pollution and cardiopulmonary morbidity and mortality. Although the underlying pathophysiologic mechanisms remain unclear, it has been hypothesized that altered autonomic function and pulmonary/systemic inflammation may play a role. In this study we explored the effects of air pollution on autonomic function measured by changes in heart rate variability (HRV) and blood markers of inflammation in a panel of 88 elderly subjects from three communities along the Wasatch Front in Utah. Subjects participated in multiple sessions of 24-hr ambulatory electrocardiographic monitoring and blood tests. Regression analysis was used to evaluate associations between fine particulate matter [aerodynamic diameter less than or equal to 2.5 microm (PM2.5)] and HRV, C-reactive protein (CRP), blood cell counts, and whole blood viscosity. A 100- microg/m3 increase in PM2.5 was associated with approximately a 35 (SE = 8)-msec decline in standard deviation of all normal R-R intervals (SDNN, a measure of overall HRV); a 42 (SE = 11)-msec decline in square root of the mean of the squared differences between adjacent normal R-R intervals (r-MSSD, an estimate of short-term components of HRV); and a 0.81 (SE = 0.17)-mg/dL increase in CRP. The PM2.5-HRV associations were reasonably consistent and statistically robust, but the CRP association dropped to 0.19 (SE = 0.10) after excluding the most influential subject. PM2.5 was not significantly associated with white or red blood cell counts, platelets, or whole-blood viscosity. Most short-term variability in temporal deviations of HRV and CRP was not explained by PM2.5; however, the small statistically significant associations that were observed suggest that exposure to PM2.5 may be one of multiple factors that influence HRV and CRP.     

Acute exposure to environmental tobacco smoke and heart rate variability

Environmental tobacco smoke (ETS) has been associated with cardiovascular mortality. Pathophysiologic pathways leading from ETS exposure to cardiopulmonary disease are still being explored. Reduced cardiac autonomic function, as measured by heart rate variability (HRV), has been associated with cardiac vulnerability and may represent an important pathophysiologic mechanism linking ETS and risk of cardiac mortality. In this study we evaluated acute ETS exposure in a commercial airport with changes in HRV in 16 adult nonsmokers. We conducted ambulatory electrocardiographic (ECG) monitoring for 8-hr periods while participants alternated 2 hr in nonsmoking and smoking areas. Nicotine and respirable suspended particle concentrations and participants' blood oxygen saturation were also monitored. We calculated time and frequency domain measures of HRV for periods in and out of the smoking area, and we evaluated associations with ETS using comparative statistics and regression modeling. ETS exposure was negatively associated with all measures of HRV. During exposure periods, we observed an average decrement of approximately 12% in the standard deviation of all normal-to-normal heart beat intervals (an estimate of overall HRV). ETS exposures were not associated with mean heart rate or blood oxygen saturation. Altered cardiac autonomic function, assessed by decrements in HRV, is associated with acute exposure to ETS and may be part of the pathophysiologic mechanisms linking ETS exposure and increased cardiac vulnerability.     

Acute effects of ozone on EEG activity, sleep-wakefulness and heart rate in rats.

Effects of exposure to O3 on EEG activity, sleep-wakefulness and heart rate were examined using conscious rats which had been chronically implanted with electrodes for EEG, EMG and ECG recordings. Exposure to 0.5 ppm O3 for 6 hrs and 1.0 ppm O3 for 3 hrs suppressed amounts of wakefulness (W) and paradoxical sleep (PS) at the expense of an increase in slow-wave sleep (SWS), and lowered the amplitude of fast EEG waves and heart rate (HR). The lowered EEG amplitude and the suppressed PS recovered more rapidly during the post-exposure period than did the lowered HR. The ip administration of atropine sulfate blocked the suppressed W, the increased SWS and the lowered HR, while the lowered EEG amplitude and the suppressed PS were not blocked. These observations suggest that the O3-induced bradycardia results from enhanced activity of cardiac parasympathetic nerves and that the O3-induced changes in W and SWS result secondarily from some circulatory factor including the bradycardia.     

Acute effects of low levels of ambient ozone on peak expiratory flow rate in a cohort of Australian children

BACKGROUND: We enrolled a cohort of primary schoolchildren with a history of wheeze (n = 148) in an 11-month longitudinal study to examine the relationship between ambient ozone concentrations and peak expiratory flow rate. METHODS: Enrolled children recorded peak expiratory flow rates (PEFR) twice daily. We obtained air pollution, meteorological and pollen data. In all, 125 children remained in the final analysis. RESULTS: We found a significant negative association between daily mean deviation in PEFR and same-day mean daytime ozone concentration (beta-coefficient = 0.88; P = 0.04) after adjusting for co-pollutants, time trend, meteorological variables, pollen count and ALTERNARIA: count. The association was stronger in a subgroup of children with bronchial hyperreactivity and a doctor diagnosis of asthma (beta-coefficient = -2.61; P = 0.001). There was no significant association between PEFR and same-day daily daytime maximum ozone concentration. We also demonstrated a dose-response relationship with mean daytime ozone concentration. CONCLUSIONS: Moderate levels of ambient ozone have an adverse health effect on children with a history of wheezing, and this effect is larger in children with bronchial hyperreactivity and a doctor diagnosis of asthma.     

60例老年2型糖尿病患者心率变异性及血压变异性分析

目的 本研究旨在探索老年男性2型糖尿病患者心率变异性及血压变异性的变化.方法 入选人群均为老年男性,共100例,其中对照组（A组）40例,2型糖尿病组（B组）60例.进行24小时动态心电图及24小时动态血压监测.收集其HRV时域指标、BP及BPV长时变异性指标,之后进行对比分析,了解老年男性2型糖尿病患者心率变异性及血压变异性的变化.结果 与对照组相比,2型糖尿病组HRV时域指标减少（P＜0.05）;与对照组相比,2型糖尿病组BPV增大（dSBPSD、dSBPCV等,P〈0.05）.结论 老年2型糖尿病患者组HRV时域指标减少及BPV增大,提示其心脏自主神经功能受损.这对患者病情的严重程度、治疗、预后进行判断、指导和评估是具有重要价值的.     

Air pollution and heart rate variability among the elderly in Mexico City

BACKGROUND: Suspended particles and ozone have been associated with varying degrees of cardiac autonomic dysfunction. METHODS: In Mexico City, residents from a nursing home underwent heart rate variability analysis every other day for 3 months. Indoor and outdoor PM2.5 (particulate matter less than 2.5 mm in diameter) were measured daily at the nursing home. Levels of ozone and other atmospheric pollutants were obtained from a nearby automated monitoring station. RESULTS: Of the initial 42 screened participants, 34 (81%) were followed during the study period. The 24-hour average levels of indoor PM2.5 ranged from 15 to 67 micro g/m3, and outdoor PM2.5 ranged from 9 to 87 micro g/m3. Daily 1-hour maximum ozone levels ranged from 47 to 228 ppb. After adjusting for age and heart rate, we observed a strong decrease in the high frequency component of heart rate variability and the average 24-hour concentrations of PM2.5. Participants with hypertension had considerably larger reductions in their HF-HRV (high frequency-heart rate variability) component in relation to both ozone and PM2.5 exposure. CONCLUSIONS: Our results suggest that ambient levels of PM2.5 and ozone can reduce the high-frequency component of heart rate variability in elderly subjects living in Mexico City and that subjects with underlying hypertension are particularly susceptible to this effect.     

Haematologic pattern in healthy elderly subjects

BACKGROUND: A more prolonged life expectancy is associated with an increased morbidity rate with marked alterations of physiologic and metabolic functions in the body. The haematologic pattern can be modified during ageing because of reduced cellular replication and enhanced fibrosis in the bone marrow. Nevertheless it is not clear whether ageing represents the cause or the result of these phenomena. METHODS: In order to evaluate wide variation of data on the haematologic pattern in elderly subjects, we studied one hundred eight healthy subjects (27 males, 81 females; ranging from 50 to 99 years), living in their home. RESULTS: We observed a reduction in serum iron and transferrin and an increase in serum ferritin levels during ageing, with a consequential iron tissue stores increase. CONCLUSIONS: Our data suggested that senescence was associated with an increased incidence of anemia, which cannot be considered a normal feature of aging, the physicians must investigate each cause of anemia in elderly subjects. Haematological pattern is in the normal range in healthy elderly subjects, even if we found significant age-linked changes. We conclude that a progressive impairment of bone marrow functions is the most important factor in determining significant changes of hematopoiesis in healthy elderly subjects.     

Effect of different vibration frequencies on heart rate variability and driving fatigue in healthy drivers

Objective This investigation was to assess the effect of different vibration frequencies on heart rate variability (HRV) and driving fatigue in healthy subjects during simulated driving, by the use of power spectrum analysis and subjective evaluation.Materials and methods Sixty healthy subjects (29.6±3.3 years) were randomly divided into three groups, A, B and C, and the subjects of each group participated in the simulated driving for 90 min with vertical sinusoidal vibration (acceleration 0.05 g) of 1.8 Hz (group A), 6 Hz (group B) and no vibration (group C), respectively. Low-frequency (LF) and high-frequency (HF) components of HRV, reflecting sympathetic and parasympathetic activities, and the LF:HF ratio, indicating sympathovagal balance, were measured throughout all periods. All indices of HRV were calculated in the pre-experiment period, mid-experiment period and end-experiment period, and were analyzed by repeated measures analysis of variance. Subjective responses to a questionnaire were obtained after the simulated task for the three groups.Results Significant differences in all indices of HRV were observed between different experiment periods and between any two groups. The ratings of subjective fatigue exhibited significant differences between any two groups.Conclusion The drivers fatigue ratings were associated with vibration frequencies in simulated driving. The study quantitatively demonstrated that different effects on autonomic nerve activities were induced by different vibration frequencies.     

心率变异性分析在老年临床麻醉中的应用进展

心率变异性分析主要是研究逐次心跳周期间的差异变化,包括神经液体因素对心血管系统调节的信息,能够有效判断心血管疾病病情.心率变异性是反映自主神经系统活性和定量评估交感神经与迷走神经张力以及平衡性,从而判断心血管疾病的病情和预后.心率变异性可能是预测心脏性猝死和心律失常事件有价值的指标.心率变异性分析能够运用到其他多种系统...     

老年糖尿病合并高血压患者心率变异性变化的研究

目的：探讨老年糖尿病合并高血压患者心率变异性的变化及临床意义。方法：对63例老年糖尿病合并高血压患者（分为不伴有LVH组和伴有LVH组），分别与对照组进行频域指标分析对比。结果：糖尿病合并高血压不伴LVH和LF，LF／HF比值明显升高，HF降低，差异显著；同时糖尿病合并高血压伴有LVH组各项指标变化更为明显（P〈0．01）。结论：老年糖尿病合并高血压患者心率变异性变化比健康老年人变化更为明显，HRV有助于心脏自主神经病变的早期发现和早期诊断。