Is the Association Between Education and Sympathovagal Balance Mediated by Chronic Stressors?

Background This study investigated whether raised chronic stress in low education groups contributes to education differences in cardiovascular disease by altering sympathovagal balance. Methods This study included cross-sectional data of 10,202 participants from the multi-ethnic, population-based HELIUS-study. Sympathovagal balance was measured by baroreflex sensitivity (BRS), the standard deviation of the inter-beat interval (SDNN) and the root mean square of successive differences between normal heartbeats (RMSSD). The associations between chronic stressors (work, home, psychiatric, financial, negative life events, lack of job control and perceived discrimination) in a variety of domains and BRS, SDNN and RMSSD were assessed using linear regression, adjusted for age, ethnicity, waist-to-hip ratio and pack-years smoked. Mediation analysis was used to assess the contribution of chronic stress to the association between education and sympathovagal balance. Results Modest but significant associations were observed between financial stress and BRS and SDNN in women, but not in RMSSD nor for any outcome measure in men. Women with the highest category of financial stress had 0.55% lower BRS (ms/mmHg; β = -0.055; CI = -0.098, -0.011) and 0.61% lower SDNN (ms; β = -0.061; CI = -0.099, -0.024) than those in the lowest category. Financial stress in women contributed 7.1% to the association between education and BRS, and 13.8% to the association between education and SDNN. Conclusion No evidence was found for the hypothesized pathway in which sympathovagal balance is altered by chronic stress, except for a small contribution of financial stress in women.

Heart rate and cardiac autonomic responses to concomitant deep breathing, hand grip exercise, and circulatory occlusion in healthy young adult men and women

Background Deep breathing (DB) and handgrip (HG) exercise -with and without circulatory occlusion (OC) in muscle-, have been shown to have beneficial effects on cardiovascular function; however, the combination of these maneuvers on heart rate (HR) and cardiac sympathovagal balance have not been previously investigated. Therefore, the aim of the present study was to evaluate the effect of simultaneous DB, HG, and OC maneuvers on the sympathovagal balance in healthy women and men subjects. Methods and results Electrocardiogram and ventilation were measured in 20 healthy subjects (Women: n = 10; age = 27 ± 4 years; weight = 67.1 ± 8.4 kg; and height = 1.6 ± 0.1 m. Men: n = 10; age = 27 ± 3 years; weight = 77.5 ± 10.1 kg; and height = 1.7 ± 0.1 m) at baseline and during DB, DB + HG, or DB + HG + OC protocols. Heart rate (HR) and respiratory rate were continuously recorded, and spectral analysis of heart rate variability (HRV) were calculated to indirectly estimate cardiac autonomic function. Men and women showed similar HR responses to DB, DB + HG and DB + HG + OC. Men exhibited a significant HR decrease following DB + HG + OC protocol which was accompanied by an improvement in cardiac autonomic control evidenced by spectral changes in HRV towards parasympathetic predominance (HRV High frequency: 83.95 ± 1.45 vs. 81.87 ± 1.50 n.u., DB + HG + OC vs. baseline; p < 0.05). In women, there was a marked decrease in HR after completion of both DB + HG and DB + HG + OC tests which was accompanied by a significant increase in cardiac vagal tone (HRV High frequency: 85.29 ± 1.19 vs. 77.93 ± 0.92 n.u., DB + HG vs. baseline; p < 0.05). No adverse effects or discomfort were reported by men or women during experimental procedures. Independent of sex, combination of DB, HG, and OC was tolerable and resulted in decreases in resting HR and elevations in cardiac parasympathetic tone. Conclusions These data indicate that combined DB, HG and OC are effective in altering cardiac sympathovagal balance and reducing resting HR in healthy men and women.

Assessment of heart rate variability (HRV) in subjects with type 2 diabetes mellitus with and without diabetic foot: correlations with endothelial dysfunction indices and markers of adipo-inflammatory dysfunction

Background Some studies have suggested that patients with diabetes and foot complications have worse cardiovascular and cerebrovascular risk profiles, higher degrees of endothelial dysfunction and arterial stiffness and a higher inflammatory background than patients with diabetes without diabetic foot complications. Patients with diabetes mellitus have an alteration in the sympathovagal balance as assessed by means of heart rate variability (HRV) analysis, which is also related to the presence of endothelial dysfunction. Other studies suggest a possible role of inflammation coexisting with the alteration in the sympathovagal balance in favor of the atherosclerotic process in a mixed population of healthy subjects of middle and advanced age. Aims The aim of this study was to evaluate the degree of alteration of sympathovagal balance, assessed by HRV analysis, in a cohort of patients with diabetes mellitus with diabetic foot and in control subjects without diabetic foot compared with a population of healthy subjects and the possible correlation of HRV parameters with inflammatory markers and endothelial dysfunction indices. Methods We enrolled all patients with diabetic ulcerative lesions of the lower limb in the Internal Medicine with Stroke Care ward and of the diabetic foot outpatient clinic of P. Giaccone University Hospital of Palermo between September 2019 and July 2020. 4-h ECG Holter was performed. The following time domain HRV measures were analyzed: average heart rate, square root of the mean of successive differences of NN (RMSSD), standard deviation or square root of the variance (SD), and standard deviation of the means of the NN intervals calculated over a five-minute period (SDANN/5 min). The LF/HF ratio was calculated, reactive hyperemia was evaluated by endo-PAT, and serum levels of vaspine and omentin-1 were assessed by blood sample collection. Results 63 patients with diabetic foot, 30 patients with diabetes and without ulcerative complications and 30 patients without diabetes were enrolled. Patients with diabetic ulcers showed lower mean diastolic blood pressure values than healthy controls, lower MMSE scores corrected for age, lower serum levels of omentin-1, lower RHI values, higher body weight values and comparable body height values, HF% and LF/HF ratio values. We also reported a negative correlation between the RHI value and HRV indices and the expression of increased parasympathetic activity (RMSDD and HF%) in subjects with diabetic foot and a statistically significant positive correlation with the LF/HF ratio and the expression of the sympathovagal balance. Discussion Patients with diabetic foot show a higher degree of activation of the parasympathetic system, expressed by the increase in HF values, and a lower LF/HF ratio. Our findings may corroborate the issue that a parasympathetic dysfunction may have a possible additive role in the pathogenesis of other vascular complications in subjects with diabetic foot.

Sympathetic Predominance Before Tourniquet Deflation is Associated With a Reduction in Arterial Blood Pressure After Tourniquet Deflation During Total Knee Arthroplasty

High dependency of arterial blood pressure (ABP) on enhanced sympathetic activity, which maintains vascular tone, leads to hypotension after hemodynamic insults that blunt the sympathetic activity. Therefore, we hypothesized that sympathovagal balance before tourniquet deflation (TD) determines the extent of a reduction in ABP after TD during total knee arthroplasty (TKA). Fifty-four hypertensive female patients undergoing TKA under spinal anesthesia were analyzed. The sympathovagal balance [low-to-high frequency ratio of heart rate variability (LF/HF)] before TD was defined as (LF/HF during 5 min before TD-preanesthetic LF/HF)/preanesthetic LF/HF (%). An increase in its value represents a shift in sympathovagal balance toward sympathetic predominance. The percent change in the mean ABP (MAP) after TD was defined as (minimum MAP during 10 min after TD-averaged MAP during 5 min before TD)/averaged MAP during 5 min before TD (%). Simple linear regression was performed to assess the correlation between the sympathovagal balance before TD and change in MAP after TD. The correlation was also assessed by multiple linear regression controlling for age, duration of tourniquet inflation, and spinal anesthesia-induced hypotension. Thirty-two minutes (on average) after tourniquet inflation, the MAP was decreased by 12.1 (-3.0 to 47.9) % [mean (range)] upon TD (P<0.001). The sympathovagal balance before TD was negatively proportional to the change in MAP after TD in both simple and multiple linear regression models (R2=0.323 and 0.340, P<0.001). A shift in sympathovagal balance toward sympathetic predominance before TD is associated with a decrease in ABP after TD.

Increased Sympathetic Tone in Congestive Heart Failure and Comorbid PainAcute Friend Turns Chronic Foe and a Novel Pharmacologic Corrective Approach

Acute pain and congestive heart failure (CHF) both increase sympathetic (S) tone, decreasing pain and improving cardiac output. However, chronically high S increases pain and worsens CHF. Mechanisms will be discussed, and off-label ranolazine is a novel potential pharmacologic remedy in chronic CHF: (1) Fifty-four CHF patients were randomized to adjunctive RAN (RANCHF, 1000mg bid) vs. NORANCHF. Autonomic measurements (ANX 3.0 Autonomic Monitor) were taken at baseline and 1 yr. Fifty-nine % of patients in both groups were initially abnormal, including high sympathovagal balance (SB) that normalized in 10/12 (83%) RANCHF patients vs. 2/11 (18%) NORANCHF patients. High SB developed in 5/11 (45%) NORANCHF vs. 1/11(9%) RANCHF patients; (2) Matched CHF patients were given adjunctive RAN (1000 mg po-bid) (RANCHF, 41 systolic, 13 diastolic) vs. NORANCHF (43 systolic, 12 diastolic). Echocardiographic LVEF and autonomic measures were obtained at baseline and follow-up (mean 23.7 months). LVEF increased in 70% of RANCHF patients, an average of 11.3 units. Mean LVEF remained unchanged in NORANCHF patients. At baseline, 28% of patients had high SB. RAN normalized SB in >50%; the NORANCHF group had a 20% increase in patients with high SB. RAN reduced (composite endpoint) CHF admissions, cardiac death, ventricular tachycardia/fibrillation[vt/vf] by 40 % In conclusion, RAN substantially corrects the maladaptive SNS CHF response. Since 1 mechanism of action of RAN is a strongly use-dependent inhibition of the Nav1.7 in S ganglia, RAN should provide pain relief in chronically S-mediated pain syndromes.

PHYSIOLOGICAL AND HYGIENIC CORRELATES OF TEACHERS’ OCCUPATIONAL BURNOUT SYNDROME DEVELOPMENT

The aim: To determine physiological and hygienic correlates of teachers’ occupational burnout syndrome development in general secondary education institutions. Materials and methods: The study involved 427 teachers of general secondary education institutions of Sumy region aged 21 to 71 years old, representing four pedagogical categories. During the study physiological, hygienic, psychological, mathematical and statistical research methods were used. Results: A high level of occupational burnout was found in teachers of general secondary education institutions of the regional center (12,43 %), which was mainly accompanied by the formed resistance symptom-complex (39,45 %, р<0,01). According to the correlation analysis, significant physiological-hygienic and psychological factors of occupational burnout formation were determined. They include: workload (r=-0,32, р<0,05), lessons duration (r=-0,32, р<0,05), using computer at work (r=0,36, р<0,05), workbook checking (r=0,41, р<0,05), extracurricular work (r=0,35, р<0,05), time spent on household chores on Sunday (r=0,36, р<0,05), time spent on conversations with parents (r=0,36, р<0,05), emotional state (r=-0,35, р<0,05). Physiological markers are: sympathovagal balance (r=0,34, р<0,05), relative sympathetic activity (r=0,27, р<0,05), relative parasympathetic activity (r=-0,32, р<0,05). Conclusions: It has been found out that investigated physiological and socio-hygienic factors have “threshold” levels, the excess of which significantly affects teachers’ occupational burnout. Predictably adverse effects have: workload for persons under 42 years, non-contact (more than 4 points) and hyper-reflective communication model (more than 5 points), time spent on household chores on Sunday (more than 3 hours), emotional state (less than 5 points), relative parasympathetic activity above 50 %, sympathovagal balance above 1,3 relative units, autonomic regulation index below 6 %.

Effects of nasal high flow on nocturnal hypercapnia, sleep, and sympathovagal balance in patients with neuromuscular disorders

Purpose In neuromuscular disorders (NMD), inspiratory muscle weakness may cause sleep-related hypoventilation requiring non-invasive ventilation (NIV). Alternatively, nasal high flow therapy (NHF) may ameliorate mild nocturnal hypercapnia (NH) through washout of anatomical dead space and generation of positive airway pressure. Ventilatory support by NIV or NHF might have favourable short-term effects on sympathovagal balance (SVB). This study comparatively investigated the effects of NHF and NIV on sleep-related breathing and SVB in NMD patients with evolving NH. Methods Transcutaneous CO2 (ptcCO2), peripheral oxygen saturation (SpO2), sleep outcomes and SVB (spectral analysis of heart rate, diastolic blood pressure variability) along with haemodynamic measures (cardiac index, total peripheral resistance index) were evaluated overnight in 17 patients. Polysomnographies (PSG) were randomly split into equal parts with no treatment, NIV and NHF at different flow rates (20 l/min vs. 50 l/min). In-depth analysis of SVB and haemodynamics was performed on 10-min segments of stable N2 sleep taken from each intervention. Results Compared with no treatment, NHF20 and NHF50 did not significantly change ptcCO2, SpO2 or the apnea hypopnea index (AHI). NHF50 was poorly tolerated. In contrast, NIV significantly improved both gas exchange and AHI without adversely affecting sleep. During daytime, NHF20 and NHF50 had neutral effects on ventilation and oxygenation whereas NIV improved ptcCO2 and SpO2. Effects of NIV and NHF on SVB and haemodynamics were neutral during both night and daytime. Conclusions NHF does not correct sleep-disordered breathing in NMD patients with NH. Both NHF and NIV exert no immediate effects on SVB.