Forfatterarkiv: Marius

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The relationship between heart rate variability and inflammatory markers in cardiovascular diseases.

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Om hvrodan lav HRV bidrar til hjerte/kar problematikk og betennelser.

http://www.ncbi.nlm.nih.gov/pubmed/18819754

INTRODUCTION:

Recent evidence implicates a cholinergic anti-inflammatory pathway. Because vagus nerve activity mediates some heart rate variability (HRV), this qualitative review examines the literature concerning circulating cytokines and HRV in cardiovascular function in humans. This qualitative review examines the literature concerning circulating cytokines and HRV in cardiovascular function in humans.

METHODS:

Thirteen studies on HRV, inflammation, and cardiovascular function were located by electronic library search and descriptively reviewed.

RESULTS:

The relationship between HRV and inflammation was studied in healthy controls, patients with acute or stable coronary heart disease (CHD), patients with metabolic syndrome or impaired glucose tolerance and patients with kidney failure. Investigations focused mainly on Interleukin-6 (IL-6) and C-reactive peptide (CRP). The majority of reviewed studies reported that parasympathetic nervous system tone as inferred from heart rate variability is inversely related to inflammatory markers (r values between -0.2 and -0.4). The relationships with inflammatory markers were similar whether derived from ECG signals as short as 5-30min or from 24-h ECG readings for HRV analyses. While inflammatory markers appear to be related to HRV, it is a mistake to assume that the traditional «vagal measures» of HRV (such as high frequency heart rate variability) are the driving factors. Indeed, low frequency heart rate variability, a complex measure reflecting both parasympathetic and sympathetic activity, is the more commonly associated measure linked to inflammatory markers.

DISCUSSION:

Heart rate variability is inversely correlated with inflammatory markers in healthy individuals as well as in those with cardiovascular diseases.

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Relationship between Heart Rate Variability, Interleukin-6, and Soluble Tissue Factor in Healthy Subjects

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Om hvrodan HRV relateres til betennelsesfaktorer.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2373608/

Decreased heart rate variability (HRV) has been associated with an increased risk of atherosclerosis. We hypothesized that a decrease in frequency domains of resting HRV would be associated with elevated plasma levels of interleukin (IL)-6 and soluble tissue factor (sTF) both previously shown to prospectively predict atherothrombotic events in healthy subjects. Subjects were 102 healthy and unmedicated black and white middle-aged men and women. We determined IL-6 and sTF antigen in plasma and HRV measures from surface electrocardiogram data using spectral analysis. All statistical analyses controlled for age, gender, ethnicity, smoking status, blood pressure, and body mass index. Low amounts of low frequency (LF) power (β=-0.31, p=0.007) and high frequency (HF) power (β=-0.36, p=0.002) were associated with increased amounts of IL-6, explaining 7% and 9% of the variance, respectively. Interactions between LF power and IL-6 (p=0.002) and between HF power and IL-6 (p=0.012) explained 8% and 5%, respectively, of the variance in sTF. Post hoc analyses showed associations between IL-6 and sTF when LF power (β=0.51, p<0.001) and HF power (β=0.48, p<0.001) were low but not when LF power and high HF power were high. The findings suggest that systemic low-grade inflammatory activity is associated with a decrease in HRV. Furthermore, there was a positive relationship between plasma levels of IL-6 and sTF antigen when HRV was low. Inflammation and related hypercoagulability might particularly contribute to atherothrombotic events in a setting of decreased HRV.

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Neural regulators of innate immune responses and inflammation.

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Om hvordan nervesystemet, spesielt vagus, regulerer betennelser.

http://www.ncbi.nlm.nih.gov/pubmed/15378203

The nervous system regulates immune function and inflammation. Experimental evidence shows an important role of the autonomic nervous system in the bidirectional communication between the brain and the immune system, underlying the ability of the brain to monitor immune status and control inflammation. Here we review the involvement of the autonomic nervous system in regulating inflammation, with a focus on the vagus nerve. The clinical implications of the recently discovered anti-inflammatory role of the efferent vagus nerve are also discussed.

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Flere studier om elektrisk stimulering av vagusnerven

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Nevner at elektrisk stimuli av vagusnerven gir bedre overlevelsesrate for personer med hjerte/kar problematikk.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3082733/

Nevner at vagus-stimulering ga mindre opplevelse av smerte

http://www.ncbi.nlm.nih.gov/pubmed/22621941

Moreover, active t-VNS significantly reduced pain ratings during sustained application of painful heat for 5 min compared to sham condition.

Beskriver hvordan vagus nerven kan benyttes i behandling av smertetilstander.

http://www.ncbi.nlm.nih.gov/pubmed/11810366

First reports of attenuation of chronic pain by VNS indicate that the method might be an option for pain treatment in the future.

Beskriver hvordan vagusnerven gir endringer i hjernestammen, som virker smertedempende.

http://www.ncbi.nlm.nih.gov/pubmed/16076058

Our results show a clear antinociceptive effect of VNS in models of acute or inflammatory pain with different stimulation protocols including the one used in epileptic patients. Using immunocytochemical methods, we find that activity changes in spinal trigeminal nucleus neurons could underlie at least part of the VNS-induced analgesia.

Elektrisk vagus-stimulering mot migrene.

http://www.ncbi.nlm.nih.gov/pubmed/14636821

All patients with migraine reported reductions in headache frequency and numeric rating scale score for average and least headache intensity.

Elektrisk stimulering av vagus mot migrene.

http://www.ncbi.nlm.nih.gov/pubmed/15658944

In conclusion, VNS may be an effective therapy for intractable chronic migraine and cluster headaches and deserves further trials.

Elektrisk stimulering av vagus gir mindre smertereaksjon.

http://www.ncbi.nlm.nih.gov/pubmed/10779664

During VNS at settings 100% of those used clinically to control their seizures, subjects showed a statistically significant decrease in their thermal pain threshold of 1.1+/-0.4 degrees C.

 

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Breathing at a rate of 5.5 breaths per minute with equal inhalation-to-exhalation ratio increases heart rate variability.

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Denne nevner at 5.5 pust i minuttet gir best HRV, og at innpust og utpust skal være lik lengde.

http://www.ncbi.nlm.nih.gov/pubmed/24380741

Abstract

OBJECTIVES:

Prior studies have found that a breathing pattern of 6 or 5.5 breaths per minute (bpm) was associated with greater heart rate variability (HRV) than that of spontaneous breathing rate. However, the effects of combining the breathing rate with the inhalation-to-exhalation ratio (I:E ratio) on HRV indices are inconsistent. This study aimed to examine the differences in HRV indices and subjective feelings of anxiety and relaxation among four different breathing patterns.

METHODS:

Forty-seven healthy college students were recruited for the study, and a Latin square experimental design with a counterbalance in random sequences was applied. Participants were instructed to breathe at two different breathing rates (6 and 5.5 breaths) and two different I:E ratios (5:5 and 4:6). The HRV indices as well as anxiety and relaxation levels were measured at baseline (spontaneous breathing) and for the four different breathing patterns.

RESULTS:

The results revealed that a pattern of 5.5 bpm with an I:E ratio of 5:5 produced a higher NN interval standard deviation and higher low frequency power than the other breathing patterns. Moreover, the four different breathing patterns were associated with significantly increased feeling of relaxation compared with baseline.

CONCLUSION:

The study confirmed that a breathing pattern of 5.5 bpm with an I:E ratio of 5:5 achieved greater HRV than the other breathing patterns. This finding can be applied to HRV biofeedback or breathing training in the future.

 

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Physical activity, by enhancing parasympathetic tone and activating the cholinergic anti-inflammatory pathway, is a therapeutic strategy to restrain chronic inflammation and prevent many chronic diseases.

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Beskriver hvordan trening aktiverer vagus og demper betennelser.

http://www.ncbi.nlm.nih.gov/pubmed/23395411 

Chronic diseases are the leading cause of death in the world and chronic inflammation is a key contributor to many chronic diseases. Accordingly, interventions that reduce inflammation may be effective in treating multiple adverse chronic conditions. In this context, physical activity is documented to reduce systemic low-grade inflammation and is acknowledged as an anti-inflammatory intervention. Furthermore, physically active individuals are at a lower risk of developing chronic diseases. However the mechanisms mediating this anti-inflammatory phenotype and range of health benefits are unknown. We hypothesize that the «cholinergic anti-inflammatory pathway» (CAP) mediates the anti-inflammatory phenotype and range of health benefits associated with physical activity. The CAP is an endogenous, physiological mechanism by which acetylcholine from the vagus nerve, interacts with the innate immune system to modulate and restrain the inflammatory cascade. Importantly, higher levels of physical activity are associated with enhanced parasympathetic (vagal) tone and lower levels of C-reactive protein, a marker of low-grade inflammation. Accordingly, physical activity, by enhancing parasympathetic tone and activating the CAP, may be a therapeutic strategy to restrain chronic inflammation and prevent many chronic diseases.

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Omega-3 Polyunsaturated Fatty Acids and Heart Rate Variability

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Nevner hvordan omega-3 kan gi bedre HRV.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3217222

Omega-3 polyunsaturated fatty acids (PUFA) may modulate autonomic control of the heart because omega-3 PUFA is abundant in the brain and other nervous tissue as well as in cardiac tissue. This might partly explain why omega-3 PUFA offer some protection against sudden cardiac death (SCD). The autonomic nervous system is involved in the pathogenesis of SCD. Heart rate variability (HRV) can be used as a non-invasive marker of cardiac autonomic control and a low HRV is a predictor for SCD and arrhythmic events. Studies on HRV and omega-3 PUFA have been performed in several populations such as patients with ischemic heart disease, patients with diabetes mellitus, patients with chronic renal failure, and in healthy subjects as well as in children. The studies have demonstrated a positive association between cellular content of omega-3 PUFA and HRV and supplementation with omega-3 PUFA seems to increase HRV which could be a possible explanation for decreased risk of arrhythmic events and SCD sometimes observed after omega-3 PUFA supplementation. However, the results are not consistent and further research is needed.

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Caloric restriction may reverse age-related autonomic decline in humans

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Nevner hvordan kalorifattig diett (som f.eks. faste) påvirke vagusnerven.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3598611/

Caloric restriction (CR) retards aging in laboratory rodents. No information is available on the effects of long-term CR on physiologic markers of aging and longevity in humans. Heart rate variability (HRV) is a marker for cardiac autonomic functioning. The progressive decline in HRV with aging and the association of higher HRV with better health outcomes are well established. Heart rate variability assessment is a reliable tool by which the effects of CR on autonomic function can be assessed. Time- and frequency-domain analyses compared 24-h HRV in 22 CR individuals aged 35–82 years and 20 age-matched controls eating Western diets (WD). The CR group was significantly leaner than the WD group. Heart rate was significantly lower, and virtually, all HRV values were significantly higher in the CR group than in the WD group (P < 0.002). Heart rate variability in the CR individuals was comparable with published norms for healthy individuals 20 years younger. In addition, when differences in HRAUTHOR: Please define HR. and HRV between CR and WD were compared with previously published changes in HRV induced in healthy adults given atenolol, percent differences in each measure were generally similar in direction and magnitude and suggested declines in sympathetic and increases in parasympathetic modulation of HR and increased circadian variability associated with CR. These findings provide evidence that CR has direct systemic effects that counter the expected age-associated changes in autonomic function so that HRV indexes in CR individuals are similar to those of individuals 20 years younger eating WDs.

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You may need the vagus nerve to understand pathophysiology and to treat diseases

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Denne studien gir en omfattende gjennomgang av hvordan stimulering av vagusnerven kan være viktig å fokusere på i behandling av forskjellige sykdommer.
These diseases include cardiovascular disease, cancer, Alzheimer’s disease and the metabolic syndrome. Three basic mechanisms contribute to such illnesses: local oxidative stress and DNA damage, inflammatory reactions and excessive sympathetic responses, all of which are inhibited by vagal nerve activity.
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Voluntarily produced increases in heart rate variability modulate autonomic effects of endotoxin induced systemic inflammation: an exploratory study.

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Denne viser hvordan HRV biofeedback øker vagus funksjon og demper symptomer på endotoxin-indusert betennelse, noe som ofte brukes i studier på systemisk inflammasjon. De så ingen endring på betennelsesmarkørene i denne, kanskje fordi den bare var på noen timer, men de så stor bedring av symptomer hos de som gjorde HRV biofeedback pust.

http://www.ncbi.nlm.nih.gov/pubmed/20635134

Exposure of healthy people to lipopolysaccharide (LPS; endotoxin) produces a pro-inflammatory response, subjective symptoms, and decreased heart rate variability (HRV). Given the efficacy of HRV biofeedback (BF) for treating asthma, the large autonomic effects of HRV BF, and the link between vagus nerve activity and inflammation, we hypothesized that HRV BF would dampen the acute manifestations of systemic inflammation induced by LPS challenge. Healthy participants age 18-40 were randomly assigned to four-one-hour training sessions of either HRV BF (n = 6) or a control 15/min paced breathing condition (n = 5) prior to acute experimentally induced LPS exposure. Participants were coached to do the procedures for 10 min each at five hourly time points after LPS injection, and then 2 h later. Subjective symptoms, HRV parameters, and plasma cytokine levels were measured at each time point, 2 h afterward, and the following morning. Participants were able to perform the procedures both during four pre-exposure training sessions and while experiencing LPS-induced symptoms. The HRV BF group showed significant attenuation of the LPS-induced decline in HRV for the 6 h following LPS exposure, suggesting that HRV BF decreased autonomic dysfunction produced by LPS-induced inflammation. HRV BF also reduced symptoms of headache and eye sensitivity to light, but did not affect LPS-induced levels of pro-inflammatory cytokines or symptoms of nausea, muscle aches, or feverishness. Further evaluation of HRV BF appears to be warranted among patients with inflammatory conditions.