Relationship between chronic stress, nutritional status, neutrophil-lymphocyte ratio, and heart rate variability among active military police officers in a metropolitan region

Heart rate variability, but not heart rate, is associated with handgrip strength and mortality in older Africans at very low cardiovascular risk: A population-based study

As reports show cardiovascular (CV) risks in first-degree relatives (FDR) of type2 diabetics, and autonomic imbalance predisposing to CV risks, in the present study we have assessed the contribution of sympathovagal imbalance (SVI) to CV risks in these subjects. Body mass index (BMI), waist-to-hip ratio (WHR), basal heart rate (BHR), blood pressure (BP), rate pressure product (RPP), and spectral indices of heart rate variability (HRV) were reordered and analyzed in FDR of type2 diabetics (study group, n=293) and in subjects with no family history of diabetes (control group, n=405). The ratio of low-frequency (LF) to high-frequency (HF) power of HRV (LF-HF), a sensitive marker of SVI, was significantly increased (P<0.001) in the study group compared with the control group. The SVI in the study group was due to concomitant sympathetic activation (increased LF) and vagal inhibition (decreased HF). In the study group, the LF-HF ratio was significantly correlated with BMI, WHR, BHR, BP and RPP. Multiple regression analysis showed an independent contribution of LF-HF to hypertension status (P=0.000), and bivariate logistic regression showed significant prediction (odds ratio 2.16, confidence interval 1.130-5.115) of LF-HF to increased RPP, the marker of CV risk, in the study group. Sympathovagal imbalance in the form of increased sympathetic and decreased parasympathetic activity is present in FDR of type2 diabetics. Increased resting heart rate, elevated hypertension status, decreased HRV and increased RPP in these subjects make them vulnerable to CV risks. SVI in these subjects contributes to CV risks independent of the degree of adiposity.

OPINION article Front. Physiol., 12 September 2014Sec. Clinical and Translational Physiology https://doi.org/10.3389/fphys.2014.00347

INTRODUCTION: It is well known that type 2 diabetes mellitus (T2DM) produces cardiovascular autonomic neuropathy (CAN), which may affect the cardiac autonomic modulation. However, it is unclear whether the lack of glycemic control in T2DM without CAN could impact negatively on cardiac autonomic modulation. Objective: To evaluate the relationship between glycemic control and cardiac autonomic modulation in individuals with T2DM without CAN. Descriptive, prospective and cross sectional study.METHODS: Forty-nine patients with T2DM (51±7 years) were divided into two groups according to glycosylated hemoglobin (HbA1c): G1≤7% and G2&gt;7.0%. Resting heart rate (HR) and RR interval (RRi) were obtained and calculated by linear (Mean iRR; Mean HR; rMSSD; STD RR; LF; HF; LF/HF, TINN and RR Tri,) and non-linear (SD1; SD2; DFα1; DFα2, Shannon entropy; ApEn; SampEn and CD) methods of heart rate variability (HRV). Insulin, HOMA-IR, fasting glucose and HbA1c were obtained by blood tests.RESULTS: G2 (HbA1c≤7%) showed lower values for the mean of iRR; STD RR; RR Tri, TINN, SD2, CD and higher mean HR when compared with G1 (HbA1c &gt; 7%). Additionally, HbA1c correlated negatively with mean RRi (r=0.28, p=0.044); STD RR (r=0.33, p=0.017); RR Tri (r=-0.35, p=0.013), SD2 (r=-0.39, p=0.004) and positively with mean HR (r=0.28, p=0.045). Finally, fasting glucose correlated negatively with STD RR (r=-0.36, p=0.010); RR Tri (r=-0.36, p=0.010); TINN (r=-0.33, p=0.019) and SD2 (r=-0.42, p=0.002).CONCLUSION: We concluded that poor glycemic control is related to cardiac autonomic modulation indices in individuals with T2DM even if they do not present cardiovascular autonomic neuropathy.

BackgroundThe use of autonomic modulation as a predictor of cardiovascular risk inwomen with breast cancer is important.ObjectiveTo evaluate the cardiac autonomic modulation of postmenopausal women usingaromatase inhibitors for breast cancer treatment, as well as its relationwith the following biochemical variables.MethodsPostmenopausal women who did not have breast cancer (n = 33) andpostmenopausal women with breast cancer (n = 15). For evaluation of theautonomic modulation the heart rate was recorded beat-to-beat for 30 minutesand the series of RR intervals obtained were used to calculate the followingheart rate variability indices: Mean RR ms, SDNN (standard deviation of allnormal RR intervals, expressed in milliseconds) ms, Mean HR, RMSSD (squareroot of the mean of the squared differences between adjacent normal RRinterval) ms, NN50 (number of pairs of successive NNs that differ by morethan 50 ms) count, pNN50% (proportion of NN50 divided by total number ofNNs), RRtri (RR triangular), TINN (triangular interpolation of NN interval)ms, SD1 ms, SD2 ms, LF ms2, HF ms2, LH/HFms2. The values of biochemical variables (fasting glycemia,triglycerides, HDL-cholesterol, and C-reactive protein) were analyzed byblood sample.ResultsLower values of heart rate variability indices were observed inpostmenopausal women with breast cancer in relation to postmenopausal womenwho did not have breast cancer: Mean RR (p = 0.03); SDNN (p = 0.03); RMSSD(p = 0.03); NN50 count (p = 0.03); pNN50 % (p = 0.03); RRtri (p = 0.02); SD1(p = 0.01); SD2 (p = 0.02); LF ms2 (p = 0.01); HF ms2(p = 0.03).There was an inversely proportional correlation between theindices SDNN, SD2, and HFms2 with triglycerides (SDNN p = 0.04;SD2 p = 0.04; HF ms2 p = 0.04). No statistically significantcorrelations were found between heart rate variability indices and othersvariables. Statistical significance was set at 5% for all analyses.ConclusionWomen with breast cancer present reduced autonomic modulation and in thesewomen of heart rate variability indices are inversely correlated withtriglyceride values.

Objectives: To investigate the relationship between sleep disordered breathing (SDB) and cardiac autonomic modulation (CAM) in a population-based sample of adolescents. Methods: We used available data from 400 adolescents who completed the follow up examinations in the population-based PSCC study. 1-night polysomnography was used to assess apnea hypopnea index (AHI). AHI was used to define no-SDB (AHI&lt;1), mild SDB (1≤AHI&lt;5), and moderate SDB (AHI≥5). CAM was assessed by heart rate variability (HRV) analysis of beat-to-beat normal R-R intervals from a 39-hour high resolution Holter ECG. The HRV indices in frequency domain [high frequency power (HF), low frequency power (LF), and LF/HF ratio] and time domain [standard deviation of normal RR intervals (SDNN), and the square root of the mean squared difference of successive normal RR intervals (RMSSD), and heart rate (HR)] were calculated on a 30-minute basis (78 repeated measures). Mixed-effects models were used to assess the SDB and HRV relationship. Results: The mean age was 16.9 yrs (SD=2.19), with 54% male and 77% white. The mean (SD) AHI were 0.52 (0.26), 2.38 (1.03), and 12.27 (14.54) for no-, mild-, and moderate-SDB participants. The age, race, sex, and BMI percentile adjusted mean (SE) HRV indices across three SDB groups are presented in Table 1. In summary, sleep disordered breathing was associated with lower HRV and higher HR in this population-based adolescent sample, with a significant dose-response relationship. Conclusion: moderate SDB in adolescents is already associated with lower HRV, indicative of sympathetic activation and lower parasympathetic modulation, which has been associated with cardiac events in adults.

Influence of Parasympathetic Modulation in Doppler Mitral Inflow Velocity in Individuals without Heart Disease

Introduction: Autonomic nervous system (ANS) dysfunction may contribute to the elevated incidence of hypertension, diabetes and coronary heart disease (CHD) among persons with shortened sleep duration. However, prior studies were conducted in adults who had obstructive sleep apnea (OSA), a correlate of short sleep, or using experimental designs that restricted sleep. To explore whether sleep duration is associated with ANS function in adults free from OSA, we tested whether sleep duration was associated with heart rate variability (HRV) indices that represent autonomic modulation of heart rate. Methods: The Chicago Area Sleep Study (CASS) identified men and women ages 35-64 via commercially available telephone listings. Data from 406 participants who had an apnea/hypopnea index&lt;15 based on 1 night of in-home apnea detection (ApneaLink TM ) were studied. Participants wore wrist actigraphs for 7 days (Actiwatch TM ) to determine average sleep duration, sleep percentage (% of time during overnight sleep interval spent sleeping) and minutes of wake after sleep onset (WASO). A validated questionnaire, the Epworth Sleepiness Scale (ESS), was used to determine daytime sleepiness. Electrocardiograms were continuously recorded from participants for 10 minutes s from supine participants; time and frequency domain HRV indices were calculated from the RR interval to estimate overall autonomic modulation of heart rate (standard deviation of normal RR intervals [SDNN]) and parasympathetic modulation heart rate (high frequency power [HF], square root of the mean squared difference of successive R-R intervals [rMSSD]). Height and weight were measured and hypertension and diabetes were determined according to JNC-VII and American Diabetes Association 2010 criteria, respectively. Results: Participants’ mean age was 47.5 years, and 56% were female. Average sleep duration was 7.03 hours (SD=1.15), sleep percentage was 83% (SD=20.1), WASO was 41.4 min (SD=21) and the ESS score was 6.75 (SD=4.1). Following adjustment for age, race, sex, BMI, hypertension, diabetes, physical activity and smoking, sleep duration (per 1 hr) was significantly (p&lt;0.01) inversely associated with SDNN (β=−2.5, SE=1.12), rMSSD (β=−2.6, SE=1.1) and log-transformed HF (β=−0.11, SE=0.05). Findings were similar in the subset of 285 participants with AHI&lt;5. Conclusions: In contrast to prior studies, shorter sleep duration was associated with more favorable parasympathetic modulation of HR. These unexpected findings may suggest that ANS dysfunction associated with OSA may be attributed to hypoxemia rather than the direct effects of shortened sleep duration.

BackgroundIvabradine is a novel specific heart rate (HR)-lowering agent that improvesevent-free survival in patients with heart failure (HF).ObjectivesWe aimed to evaluate the effect of ivabradine on time domain indices of heart ratevariability (HRV) in patients with HF.MethodsForty-eight patients with compensated HF of nonischemic origin were included.Ivabradine treatment was initiated according to the latest HF guidelines. For HRVanalysis, 24-h Holter recording was obtained from each patient before and after 8weeks of treatment with ivabradine.ResultsThe mean RR interval, standard deviation of all normal to normal RR intervals(SDNN), the standard deviation of 5-min mean RR intervals (SDANN), the mean of thestandard deviation of all normal-to-normal RR intervals for all 5-min segments(SDNN index), the percentage of successive normal RR intervals exceeding 50 ms(pNN50), and the square root of the mean of the squares of the differences betweensuccessive normal to normal RR intervals (RMSSD) were low at baseline beforetreatment with ivabradine. After 8 weeks of treatment with ivabradine, the mean HR(83.6 ± 8.0 and 64.6 ± 5.8, p < 0.0001), mean RR interval (713± 74 and 943 ± 101 ms, p < 0.0001), SDNN (56.2 ± 15.7 and87.9 ± 19.4 ms, p < 0.0001), SDANN (49.5 ± 14.7 and 76.4 ±19.5 ms, p < 0.0001), SDNN index (24.7 ± 8.8 and 38.3 ± 13.1 ms,p < 0.0001), pNN50 (2.4 ± 1.6 and 3.2 ± 2.2 %, p < 0.0001),and RMSSD (13.5 ± 4.6 and 17.8 ± 5.4 ms, p < 0.0001)substantially improved, which sustained during both when awake and whileasleep.ConclusionOur findings suggest that treatment with ivabradine improves HRV in nonischemicpatients with HF.

Objectives: Sleep disorders cause changes of autonomic nervous system (ANS) which affect cardiovascular system. Primary insomnia (PI) makes acceleration of sympathetic nervous system (SNS) tone by sleep deficiency and arousal. Obstructive sleep apnea syndrome (OSAS) sets off SNS by frequent arousals and hypoxemias during sleep. We aimed to compare the changes of heart rate variability (HRV) indices induced by insomnia or sleep apnea to analyze for ANS how much to be affected by PI or OSAS. Methods: Total 315 subjects carried out nocturnal polysomnography (NPSG) were categorized into 4 groups - PI, mild, moderate and severe OSAS. Severity of OSAS was determined by apnea-hypopnea index (AHI). Then we selected 110 subjects considering age, sex and valance of each group's size [Group 1 : PI (mean age= yrs, AHI yrs, AHI 5-15, n=30), Group 3 : moderate OSAS (mean age yrs, AHI 16-30, n=30), Group 4 : severe OSAS (mean age= yrs, AHI >30, n=30)]. Comparison of HRV indices among the four groups was performed with ANCOVA (adjusted for age and body mass index) and Sidak post-hoc test. Results: We found statistically significant differences in HRV indices between severe OSAS group and the other groups (PI, mild OSAS and moderate OSAS). And there were no significant differences in HRV indices among PI, mild and moderate OSAS group. In HRV indices of PI and severe OSAS group showing the most prominent difference in the group comparisons, average RR interval were and ms (p=0.016), standard deviation of NN interval (SDNN) was and ms (p=0.022), SDNN index was and (p and (p=0.008), very low frequency (VLF) was and (p=0.035), low frequency (LF) was and (p=0.003). Conclusions: VLF and LF which were correlated with SNS tone showed more increased differences between severe OSAS group and PI group than other group comparisons. We could suggest that severe OSAS group was more influential to increased SNS activity than PI group.

The stress of operational missions may challenge the maintenance of body homeostasis, affecting soldiers' cardiac autonomic control, promoting dehydration, and compromising performance. Therefore, we aimed to determine the effects of peacekeeper patrol operation in Haiti on soldiers' hydration status and cardiac autonomic modulation, and to determine whether fluctuations in autonomic modulation were associated with changes in hydration status, energy expenditure (EE), and aerobic fitness (V[Combining Dot Above]O2max). A group of 20 soldiers (23.5 ± 4.7 years; V[Combining Dot Above]O2max 52.9 ± 4.5 ml·kg⁻¹·min⁻¹) completed an operational patrol mission with a mean duration of 160.6 ± 28.6 minutes. Before (Pre) and after (Post) the operation, the soldiers' body masses (BMs) were measured and 5-minute heart rate interbeat (R-R) intervals were recorded at rest to estimate heart rate variability (low-frequency [LF] and high-frequency [HF] power, and sympathovagal balance [LF/HF]). During the mission, EE was estimated using heart rate (HR) monitors. Changes from Pre to Post in BM (%BM loss) and LF/HF (ΔLF/HF) were used to evaluate the soldiers' dehydration levels and autonomic modulation, respectively. The mean EE was 711.0 ± 208.7 kcal. From pre to post, increases (p < 0.01) were noted in LF normalized units (n.u.) and LF/HF and decreases (p < 0.01) were noted in BM, R-R interval, and HF n.u. The variation in ΔLF/HF correlated with EE (r = 0.49; p = 0.02), V[Combining Dot Above]O2max (r = -0.42; p = 0.05), and %BM loss (r = 0.53; p = 0.02). The results demonstrated that an operational peacekeeper patrol with an approximate duration of 160 minutes promoted both dehydration and an imbalance in the autonomic modulation of soldiers' HR. The reduction in sympathovagal balance correlated with EE, dehydration, and aerobic conditioning.

The aim of this study was to examine whether autonomic modulation of heart rate as measured by heart rate variability and heart rate complexity at rest and during static handgrip exercise differs between individuals with and without paraplegia. This study also examined the relationships between heart rate complexity and heart rate variability parameters. Heart rate variability and complexity were evaluated in 20 individuals with paraplegia and in 20 individuals without paraplegia during 3 mins of rest and 2 mins of static handgrip exercise at 30% of maximum isometric strength. Spectral decomposition of heart rate variability was used to obtain total power, power in low-frequency and high-frequency ranges, and the ratio of low- to high-frequency power. Heart rate complexity was quantified with sample entropy, a measure of irregularity of the beat-to-beat time series. Sample entropy was lower (P < 0.05) at rest and during exercise in participants with paraplegia. Total, high-, and low-frequency powers as well as the ratio of low- to high-frequency power did not differ between groups. Sample entropy did not significantly correlate with low- and high-frequency powers or their ratio. Individuals with paraplegia show lower heart rate complexity at rest and during static exercise. This finding may have implications for cardiovascular morbidity in persons with paraplegia. Heart rate complexity may provide unique information regarding cardiac autonomic modulation, different from that provided by traditional heart rate variability measures.

SUMMARYBACKGROUND:Patients with coronavirus disease 2019 on automatic mechanical ventilation have greater heart rate modulation with greater parasympathetic modulation.OBJECTIVE:To analyze the autonomic modulation of heart rate in critically ill patients with coronavirus disease 2019 on invasive mechanical ventilation.METHODS:A cross-section study was carried out with 36 individuals divided into two groups. The control group included patients of both genders, in orotracheal intubation with invasive mechanical ventilation under controlled assisted mode, hospitalized in the intensive care unit for another 24 h. In the non-COVID group, patients diagnosed with coronavirus disease 2019 in the same condition mentioned in the control group.RESULTS:There was a significant increase in heart rate variability (standard deviation of all normal RR intervals recorded at an interval of time; p=0.001; triangular interpolation histogram of RR intervals; p=0.048; and SD2; p=0.014) in the coronavirus disease group compared to the non-COVID group. Successively, the parameters that demonstrate parasympathetic modulation are shown to be higher in the group of patients with coronavirus disease 2019 (root mean square of the square of differences between adjacent normal RR intervals in an interval of time; p<0.001; pNN50; p<0.001; SD1; p=0.002; and high frequency; p=0.022).CONCLUSIONS:There was a greater autonomic modulation of heart rate with a greater parasympathetic modulation in patients with coronavirus disease 2019 on mechanical ventilation.

Altered autonomic regulation after cardiac operations precipitates cardiac arrhythmias, affects repolarization, and increases the risk of sudden cardiac death. We sought to clarify how the 2 different techniques of coronary artery bypass grafting (CABG), namely conventional CABG using cardiopulmonary bypass (on-pump) and beating-heart CABG without cardiopulmonary bypass (off-pump), affect cardiac autonomic regulation and arrhythmic disturbances postoperatively. We included 57 consecutive patients, 28 in the on-pump group and 29 in the off-pump group. The electro-cardiographic recordings were performed on the preoperative day and the fourth, seventh, and twenty-eighth day after operation. Fifteen-minute digital recordings were taken; one channel was used to record electrocardiogram and the other breathing. Detailed analyses of arrhythmia, heart rate, and heart rate variability indices were performed on respective days to assess sympathetic and parasympathetic modulation of the heart and relate it to detected arrhythmic disturbances. Total power, low-frequency power, which indicates baroreceptor-mediated sympathetic modulation, and high-frequency power, indicating parasympathetic vagal modulation, declined significantly in both groups after CABG (P < .001); however, 7 days after CABG, total and high-frequency power were better preserved in the off-pump group. Mean RR interval was longer in the off-pump group at 7 (P= .006) and 28 days (P= .008) after surgery. The total incidence of arrhythmic events was higher in the on-pump group on the seventh day (P = .017, adjusted odds ratio = 8.6, 95% confidence interval 1.4-80.3). The results show profound impairment of cardiac autonomic regulation after CABG, showing better preserved cardiac autonomic modulation 7 days after beating-heart revascularization. Evidence suggests that slower restoration of heart rate and increased incidence of arrhythmic events after CABG using cardiopulmonary bypass are the result not only of impaired cardiac autonomic regulation but also of the involvement of additional factors of nonautonomic origin.

The aim of this study was to compare heart rate variability (HRV) indices before and after a table tennis match, depending in match result. HRV indices were measured before (PRE) and after (POST) match periods to 21 table tennis players (21.86 ± 8.34 yr) in 30 matches. No significant differences were found neither in PRE nor in POST measures comparing winners and losers. A significantly lower value (p &lt; 0.05) was found in mean of RR intervals (mean RR), standard deviation of RR intervals (SDNN), the natural logarithm transform of the root mean square of successive differences between normal heartbeats (LnRMSSD), relative number of successive RR interval pairs that differ more than 50 ms (pNN50), cross (SD1) and longitudinal (SD2) axis of Poincaré plot comparing POST values with PRE values. Nevertheless, low frequency index expressed in absolute power (LF Power) and high frequency indices expressed in absolute power (HF power) and normalised power (HF Power) showed different trends depending on the results (p &lt; 0.05). The obtained results show a HRV decrease after table tennis match regardless the match result, in both time domain and non-linear indices. However, frequency domain indices show a different trend depending on the match outcome.