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1.
Cardiovascular dysautonomia in Achalasia Patients: Blood pressure and heart rate variability alterations.
Rivera, AL, Estañol, B, Macias-Gallardo, JJ, Delgado-Garcia, G, Fossion, R, Frank, A, Torres-Villalobos, GM
PloS one. 2021;(3):e0248106
Abstract
Achalasia is a disease characterized by the inability to relax the esophageal sphincter due to a degeneration of the parasympathetic ganglion cells located in the wall of the thoracic esophagus. Achalasia has been associated with extraesophageal dysmotility, suggesting alterations of the autonomic nervous system (ANS) that extend beyond the esophagus. The purpose of the present contribution is to investigate whether achalasia may be interpreted as the esophageal manifestation of a more generalized disturbance of the ANS which includes alterations of heart rate and/or blood pressure. Therefore simultaneous non-invasive records of the heart inter-beat intervals (IBI) and beat-to-beat systolic blood pressure (SBP) of 14 patients (9 female, 5 male) with achalasia were compared with the records of 34 rigorously screened healthy control subjects (17 female, 17 male) in three different conditions: supine, standing up, and controlled breathing at 0.1 Hz, using a variety of measures in the time and spectral domains. Significant differences in heart rate variability (HRV) and blood pressure variability (BPV) were observed which seem to be due to cardiovagal damage to the heart, i.e., a failure of the ANS, as expected according to our hypothesis. This non-invasive methodology can be employed as an auxiliary clinical protocol to study etiology and evolution of achalasia, and other pathologies that damage ANS.
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2.
Regional microglial populations in central autonomic brain regions in SUDEP.
Somani, A, El-Hachami, H, Patodia, S, Sisodiya, S, Thom, M
Epilepsia. 2021;(6):1318-1328
Abstract
OBJECTIVE Sudden unexpected death in epilepsy (SUDEP) may arise as a result of autonomic dysfunction during a seizure. The central autonomic networks (CANs) modulate brainstem cardiorespiratory regulation. Recent magnetic resonance imaging (MRI) studies in SUDEP have shown cortical and subcortical volume changes and altered connectivity between CAN regions, but the pathological correlate is unknown. Because neuroinflammation is both a cause and a consequence of seizures and may relate to regional brain pathology, our aim was to evaluate microglial populations in CANs in SUDEP. METHODS In 55 postmortem cases, including SUDEP, epilepsy controls without SUDEP and nonepilepsy controls, we quantified Iba1-expressing microglia in 14 cortical and thalamic areas that included known CAN regions. RESULTS Mean Iba1 labeling across all brain regions was significantly higher in SUDEP cases compared to epilepsy and nonepilepsy controls. There was significant regional variation in Iba1 labeling in SUDEP cases only, with highest labeling in the medial thalamus. Significantly higher labeling in SUDEP cases than epilepsy and nonepilepsy controls was consistently noted in the superior temporal gyrus. In cases with documented seizures up to 10 days prior to death, significantly higher mean Iba1 labeling was observed in SUDEP compared to epilepsy controls. SIGNIFICANCE Our findings support microglial activation in SUDEP, including cortical and subcortical regions with known autonomic functions such as the thalamus and superior temporal gyrus. This may be relevant to cellular pathomechanisms underlying cardioregulatory failure during a seizure.
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3.
High Fasting Glycemia Predicts Impairment of Cardiac Autonomic Control in Adults With Type 2 Diabetes: A Case-Control Study.
Silva, LRB, Gentil, P, Seguro, CS, de Oliveira, GT, Silva, MS, Zamunér, AR, Beltrame, T, Rebelo, ACS
Frontiers in endocrinology. 2021;:760292
Abstract
INTRODUCTION Type 2 diabetes (T2D) is characterized by a metabolic disorder that elevates blood glucose concentration. Chronic hyperglycemia has been associated with several complications in patients with T2D, one of which is cardiac autonomic dysfunction that can be assessed from heart rate variability (HRV) and heart rate recovery (HRR) response, both associated with many aspects of health and fitness, including severe cardiovascular outcomes. OBJECTIVE To evaluate the effects of T2D on cardiac autonomic modulation by means of HRV and HRR measurements. MATERIALS AND METHODS This study has an observational with case-control characteristic and involved ninety-three middle-aged adults stratified into two groups (control group - CG, n = 34; diabetes group - DG, n = 59). After signing the free and informed consent form, the patients were submitted to the evaluation protocols, performed biochemical tests to confirm the diagnosis of T2D, collection of R-R intervals for HRV analysis and cardiopulmonary effort test to quantify HRR. RESULTS At rest, the DG showed a reduction in global HRV (SDNN= 19.31 ± 11.72 vs CG 43.09 ± 12.74, p < 0.0001), lower parasympathetic modulation (RMSSD= 20.49 ± 14.68 vs 52.41 ± 19.50, PNN50 = 4.76 ± 10.53 vs 31.24 ± 19.24, 2VD%= 19.97 ± 10.30 vs 28.81 ± 9.77, p < 0.0001 for both indices) and higher HRrest when compared to CG. After interruption of physical exercise, a slowed heart rate response was observed in the DG when compared to the CG. Finally, a simple linear regression showed that fasting glycemia was able to predict cardiac autonomic involvement in volunteers with T2D. CONCLUSION Patients with T2D presented lower parasympathetic modulation at rest and slowed HRR after physical exercise, which may be associated with higher cardiovascular risks. The findings show the glycemic profile as an important predictor of impaired cardiac autonomic modulation.
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4.
No modulation of postprandial metabolism by transcutaneous auricular vagus nerve stimulation: a cross-over study in 15 healthy men.
Vosseler, A, Zhao, D, Fritsche, L, Lehmann, R, Kantartzis, K, Small, DM, Peter, A, Häring, HU, Birkenfeld, AL, Fritsche, A, et al
Scientific reports. 2020;(1):20466
Abstract
Experimental evidence suggests a crucial role of the autonomic nervous system in whole body metabolism with major regulatory effects of the parasympathetic branch in postprandial adaptation. However, the relative contribution of this mechanism is still not fully clear in humans. We therefore compared the effects of transcutaneous auricular vagus nerve stimulation (taVNS, Cerbomed Nemos) with sham stimulation during an oral glucose tolerance test in a randomized, single-blind, cross-over design in 15 healthy lean men. Stimulation was performed for 150 min, 30 min before and during the entire oral glucose tolerance test with stimulation cycles of 30 s of on-phase and 30 s of off-phase and a 25 Hz impulse. Heart rate variability and plasma catecholamine levels were assessed as proxies of autonomic tone in the periphery. Neither analyzed heart rate variability parameters nor plasma catecholamine levels were significantly different between the two conditions. Plasma glucose, insulin sensitivity and insulin secretion were also comparable between conditions. Thus, the applied taVNS device or protocol was unable to achieve significant effects on autonomic innervation in peripheral organs. Accordingly, glucose metabolism remained unaltered. Therefore, alternative approaches are necessary to investigate the importance of the autonomic nervous system in postprandial human metabolism.
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5.
Risk Factors Associated with Cardiac Autonomic Modulation in Obese Individuals.
Oliveira, C, Silveira, EA, Rosa, L, Santos, A, Rodrigues, AP, Mendonça, C, Silva, L, Gentil, P, Rebelo, AC
Journal of obesity. 2020;:7185249
Abstract
Obesity leads to an imbalance in the autonomic nervous system, especially in increased sympathetic modulation and decreased vagal tone, and some anthropometric, metabolic, and lifestyle variables may increase the risk of developing cardiovascular disease. Objective. To analyze the association between cardiovascular autonomic modulation and biochemical and anthropometric markers, food intake, and physical activity level in severely obese individuals. Methodology. The present study is a cutout of a randomized clinical trial "Effect of nutritional intervention and olive oil in severe obesity" (DieTBra Trial), where the baseline data were analyzed. Anthropometric data, biochemical exams, heart rate variability (HRV), accelerometry, and 24 h recall (R24H) of obese patients (body mass index BMI ≥35 kg/m2) were collected. Results. 64 obese patients were analyzed, with a mean age of 39.10 ± 7.74 years (27 to 58 years). By HRV analysis, in the frequency domain, the obese had a higher predominance of sympathetic autonomic modulation (low frequency (LF) 56.44 ± 20.31 nu) and lower parasympathetic modulation (high frequency (HF) 42.52 ± 19.18 nu). A negative association was observed between the variables Homeostasis Evaluation Model (HOMA-IR) and HF (p = 0.049). In the physical activity analysis, there was a negative association between moderate to vigorous physical activity and the sympathetic component (p = 0.043), and for sedentary time (ST), there was a negative association with HF (p = 0.049) and LF/HF (p = 0.036) and a positive association with LF (p = 0.014). For multiple linear regression, waist circumference (WC) and HOMA-IR values were negatively associated with HF (β = -0.685, p = 0.010; β = -14.989, p = 0.010; respectively). HOMA-IR (β = 0.141, p = 0.003) and the percentage of lipids ingested (β = -0.030, p = 0.043) were negatively associated with LF/HF. Conclusion. Among the cardiovascular risk variables studied, insulin resistance and central adiposity showed the greatest influence on cardiac autonomic modulation of obese, increasing the risk for cardiovascular disease.
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6.
Avocado (Persea americana) pulp improves cardiovascular and autonomic recovery following submaximal running: a crossover, randomized, double-blind and placebo-controlled trial.
Sousa, FH, Valenti, VE, Pereira, LC, Bueno, RR, Prates, S, Akimoto, AN, Kaviani, M, Garner, DM, Amaral, JAT, de Abreu, LC
Scientific reports. 2020;(1):10703
Abstract
Previous studies have demonstrated that regular avocado consumption presents advantageous effects on cardiovascular system. However, little attention has been paid to the use of avocado as a dietary supplement, in particular, for individuals involved in physical exercise training. Therefore, this study aims to evaluate the effect of acute avocado pulp intake on cardiovascular and autonomic recovery subsequent to moderate exercise. Using a crossover, randomized, double-blind and placebo-controlled trial design, 16 healthy female adults underwent two protocols: Avocado pulp (600 mg in capsule) and placebo (600 mg starch in capsule). After the ingestion of Avocado pulp or placebo, the subjects were seated for 60 min at rest, followed by running on a treadmill at a submaximal level and then remained seated for 60 min during recovery from the exercise. Heart rate (HR), heart rate variability (HRV) [rMSSD, SD1, HF (ms2)] and skin conductance were evaluated before and during exercise, as well as during recovery. HR, systolic blood pressure, HRV and skin conductance recovered faster when subjects were given avocado pulp prior to exercise. In conclusion, avocado pulp improved cardiovascular and autonomic recovery after exercise, suggesting a reduced risk of cardiovascular events after exertion. The current results support the beneficial effects of ingestion of avocado prior to submaximal treadmill running.
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7.
Autonomic function, postprandial hypotension and falls in older adults at one year after critical illness.
Ali Abdelhamid, Y, Weinel, LM, Hatzinikolas, S, Summers, M, Nguyen, TAN, Kar, P, Phillips, LK, Horowitz, M, Deane, AM, Jones, KL
Critical care and resuscitation : journal of the Australasian Academy of Critical Care Medicine. 2020;(1):53-62
Abstract
OBJECTIVE Postprandial hypotension occurs frequently in older survivors of critical illness at 3 months after discharge. We aimed to determine whether postprandial hypotension and its predictors - gastric dysmotility and cardiovascular autonomic dysfunction - persist or resolve as older survivors of critical illness recover, and whether postprandial hypotension after intensive care unit (ICU) discharge is associated with adverse outcomes at 12 months. DESIGN Prospective observational study. SETTING Tertiary medical-surgical ICU. PARTICIPANTS Older adults (aged ≥ 65 years) who had been studied 3 months after ICU discharge and who returned for a follow-up study at 12 months after discharge. MAIN OUTCOME MEASURES On both occasions after fasting overnight, participants consumed a 300 mL drink containing 75 g glucose, radiolabelled with 20 MBq 99mTcphytate. Blood pressure, heart rate, blood glucose concentration and gastric emptying rate were measured concurrently before and after ingestion of the drink. Falls, quality of life, hospitalisation and mortality rates were also quantified. RESULTS Out of 35 older adults studied at 3 months, 22 returned for the follow-up study at 12 months. Postprandial hypotension was evident in 29% of participants (95% CI, 14-44%) at 3 months and 10% of participants (95% CI, 1-30%) at 12 months. Postprandial hypotension at 3 months was associated with a more than threefold increase in the risk of falls in the year after ICU discharge (relative risk, 3.7 [95% CI, 1.6-8.8]; P = 0.003). At 12 months, gastric emptying was normal (mean time taken for 50% of gastric contents to empty, 101.6 [SD, 33.3] min) and cardiovascular autonomic dysfunction prevalence was low (9% [95% CI, 1-29%]). CONCLUSIONS In older adults who were evaluated 3 and 12 months after ICU discharge, postprandial hypotension at 3 months was associated with an increased risk of subsequent falls, but the prevalence of postprandial hypotension decreased with time.
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8.
Cardiac-Autonomic Responses to In-Season Training Among Division-1 College Football Players.
Flatt, AA, Esco, MR, Allen, JR, Robinson, JB, Bragg, A, Keith, CM, Fedewa, MV, Earley, RL
Journal of strength and conditioning research. 2020;(6):1649-1656
Abstract
Flatt, AA, Esco, MR, Allen, JR, Robinson, JB, Bragg, A, Keith, CM, Fedewa, MV, and Earley, RL. Cardiac-autonomic responses to in-season training among Division-1 college football players. J Strength Cond Res 34(6): 1649-1656, 2020-Despite having to endure a rigorous in-season training schedule, research evaluating daily physiological recovery status markers among American football players is limited. The purpose of this study was to determine whether recovery of cardiac-autonomic activity to resting values occurs between consecutive-day, in-season training sessions among college football players. Subjects (n = 29) were divided into groups based on position: receivers and defensive backs (SKILL, n = 10); running backs, linebackers, and tight-ends (MID-SKILL, n = 11) and linemen (LINEMEN, n = 8). Resting heart rate (RHR) and the natural logarithm of the root mean square of successive differences multiplied by 20 (LnRMSSD) were acquired at rest in the seated position before Tuesday and Wednesday training sessions and repeated over 3 weeks during the first month of the competitive season. A position × time interaction was observed for LnRMSSD (p = 0.04), but not for the RHR (p = 0.33). No differences in LnRMSSD between days was observed for SKILL (Tuesday = 82.8 ± 9.3, Wednesday = 81.9 ± 8.7, p > 0.05). Small reductions in LnRMSSD were observed for MID-SKILL (Tuesday = 79.2 ± 9.4, Wednesday = 76.2 ± 9.5, p ≤ 0.05) and LINEMEN (Tuesday = 79.4 ± 10.5, Wednesday = 74.5 ± 11.5, p ≤ 0.05). The individually averaged changes in LnRMSSD from Tuesday to Wednesday were related to PlayerLoad (r = 0.46, p = 0.02) and body mass (r = -0.39, p = 0.04). Cardiac-parasympathetic activity did not return to resting values for LINEMEN or MID-SKILL before the next training session. Larger reductions in LnRMSSD tended to occur in players with greater body mass despite having performed lower workloads, although some individual variability was observed. These findings may have implications for how coaches and support staff address training and recovery interventions for players demonstrating inadequate cardiovascular recovery between sessions.
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9.
Dietary supplementation with L-carnosine improves patient-reported outcomes, autonomic nervous system performance, and brain metabolism in 3 adult patients with multiple sclerosis.
Zanini, D, Jezdimirovic, T, Stajer, V, Ostojic, J, Maksimovic, N, Ostojic, SM
Nutrition research (New York, N.Y.). 2020;:63-69
Abstract
This pilot trial reports the effects of L-carnosine administration on autonomic nervous system performance, brain metabolism, and various patient- and clinician-reported outcomes in a case series of patients with multiple sclerosis (MS). We hypothesized that medium-term L-carnosine supplementation would improve selected patient- and clinician-reported outcomes in MS patients, with no negative effects on self-reported side effects. L-carnosine (2 g/day) was administered orally for 8 weeks in 2 women and one man suffering from MS. The intensity of symptoms and signs of MS after L-carnosine administration diminished in 5 out of 7 domains in CASE 1, in 3 out of 7 domains in CASE 2, and one domain in CASE 3; general fatigue was reduced in all 3 cases at the follow-up. This was accompanied by an improved walking distance to exhaustion in all patients, with values improved for 51.1% in CASE 1, 19.5% in CASE 2, and 2.1% in CASE 3 at 8-week follow-up. Tests of autonomic cardiovascular reflexes demonstrate normalized parasympathetic modulation and balanced sympathetic function after L-carnosine intervention in all MS cases. An increase in serum total antioxidant capacity (TAC) was found at 8-week follow-up in all patients (from 4.6 to 49.6%); this was accompanied by lower blood lactate at post-administration in all cases (23.5% on average). Single-voxel 1.5 T MR spectroscopy revealed increased brain choline-contained compounds (18.9% on average), total creatine (21.2%), and myo-inositol levels (12.3%) in girus cinguli at 8-week follow-up in all MS cases. This case study demonstrates that an 8-week intervention with L-carnosine appears to be a safe and beneficial therapeutic strategy with regard to the reduction of presence and severity of symptoms of MS.
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10.
Ameliorating Effects and Autonomic Mechanisms of Transcutaneous Electrical Acustimulation in Patients With Gastroesophageal Reflux Disease.
Hu, Y, Zhang, B, Shi, X, Ning, B, Shi, J, Zeng, X, Liu, F, Chen, JD, Xie, WF
Neuromodulation : journal of the International Neuromodulation Society. 2020;(8):1207-1214
Abstract
BACKGROUND/AIM: Gastric dysmotility is one of pathophysiologies of gastroesophageal reflux disease (GERD). The aim of this study was to investigate the effects of transcutaneous electrical acustimulation (TEA) on gastric accommodation and gastric slow waves, and evaluate possible mechanisms in patients with GERD. METHODS Thirty patients were studied in two randomized sessions of sham-TEA and TEA with the measurements of esophageal high-resolution manometry (HRM), gastric accommodation assessed by a nutrient-drinking test, electrogastrogram (EGG), electrocardiogram (ECG), and postprandial dyspeptic symptoms. RESULTS Compared with sham-TEA, TEA improved nutrient drinking-induced fullness (42.0 ± 3.3 vs. 31.0 ± 3.5, P = 0.003) at 10 min after the drink, and belching right after the drink (22.0 ± 4.6 vs. 11.7 ± 3.1, P = 0.012) and at 10 min (16.0 ± 3.8 vs. 3.0 ± 1.5, P = 0.002) after the drink. TEA also improved gastric accommodation (954 ± 37 mL vs. 857 ± 47 mL, P = 0.001) and normalized maximal drink-induced impairment in gastric slow waves. Concurrently, TEA enhanced vagal activity assessed from spectral analysis of heart rate variability in the postprandial state (0.42 ± 0.03 vs. 0.49 ± 0.04, P = 0.039). The vagal activity was positively correlated with the percentage of normal slow waves (r = 0.528; P = 0.003) and negatively correlated with the regurgitation score (r = -0.408, P = 0.025). CONCLUSIONS Acute TEA increases gastric accommodation, improves gastric slow waves, and reduces postprandial fullness and belching, possibly mediated via the vagal mechanisms.