The potential anti-inflammatory benefits of improving physical fitness in hypertension

The relationship between blood pressure and functional fitness of older adults in Korea

Hypertension, also known as high blood pressure (BP), is a critical health issue that can cause cardiovascular disease. It is observed more frequently in older adults. Thus, this study aimed to identify the functional fitness and body composition factors that significantly influence both systolic and diastolic BPs in older adults. Data from 155,266 older adults (51,751 men [33.3%] and 103,505 women [66.7%]) who underwent functional fitness tests between 2013 and 2018 were analyzed. The following seven functional fitness tests were conducted: (a) aerobic endurance (2-min step), (b) upper body muscle strength (hand grip strength), (c) lower body muscle endurance (chair sit-and-stand), (d) flexibility (sit-and-reach), (e) agility (Timed Up and Go), and (f) body composition (body mass index [BMI] and body fat percentage). Systolic and diastolic BPs were used as outcome variables. In examining the proposed relationships, the regression analysis revealed that BMI, body fat percentage, sit-and-reach, 2-min step, hand grip, chair sit-and-stand, and Timed Up and Go were significantly associated with reduced systolic and diastolic body pressures.

Unveiling the role of exercise training in targeting the inflammatory paradigm of heart failure with preserved ejection fraction: a narrative review

Heart failure with preserved ejection fraction (HFpEF) is currently lacking an effective pharmacological treatment with impact on major outcomes such as hospitalization and mortality. Exercise training (EXT) is recognized as an important nonpharmacological tool, capable of improving exercise capacity and quality of life, and has even been associated with a reduction in hospitalization and cardiovascular mortality risk. However, this positive impact largely lacks a physiological explanation. The aim of this narrative review was to provide an overview of the available data supporting the hypothesis that the beneficial role of EXT in HFpEF might be due to its effects on targeting the inflammatory paradigm described for this disease. A comprehensive literature search was conducted using the PubMed-NCBI database. We reviewed the effects of EXT throughout each step of the pathophysiological pathway leading to HFpEF and found clinical and/or preclinical evidence supporting the reduction of systemic inflammation, endothelial dysfunction, microvascular rarefaction, and myocardial stiffness. We also highlighted some gaps in the knowledge or topics that deserve further clarification in future studies. In conclusion, despite the scarcity of clinical studies in this population, there is compelling evidence suggesting that EXT modulates crucial aspects of the inflammatory pathway described for HFpEF and future investigation on cellular and molecular mechanisms are encouraged.

Physiological persona differences based on stress and inflammation between meditators and healthy controls

Background Nowadays, yoga is endorsed and advised routinely to stay fit and healthy, as well as control many chronic diseases including diabetes type 2, hypertension, coronary artery diseases, etc. Now, our assumption is that those who do regular yoga have different persona than who do not do yoga regularly. We planned to test our hypothesis scientifically, and therefore baseline physiological characteristics with stress and inflammation levels in long-term and short-term meditators and healthy novice controls were analyzed. Methods In this retrospective analysis, 97 male participants were included for their Baseline analysis. Fifteen apparently healthy subjects practicing preksha meditation (since >5 years, at least 5 days a week) were included as long-term meditators (LTMs); 58 subjects who attended one of our short-term yoga-based lifestyle intervention programs for 2 weeks were included as short-term meditators (STMs); 24 male novice subjects, who did not participate in any yogic intervention, were included as healthy controls. Here, we analyzed the Baseline plasma levels of stress and inflammatory markers, cortisol, β-endorphin, interleukin (IL)-6 and tumor necrosis factor (TNF)-α in long-term meditators vs. short-term meditators vs. healthy controls. Outcome measures The study parameters body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), plasma levels of stress and immune markers, cortisol, β-endorphin (β-Ed), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), were assessed in all the three groups at baseline. Results Significant (p<0.05) differences were observed at baseline for plasma levels of stress and inflammatory markers as well as body mass index and systolic blood pressure among LTM vs. STM vs. healthy controls. Conclusions Our observations suggest that the subjects who do regular yoga-meditation practice have better stress & inflammation status than comparable age matched healthy controls.

Effects of Acute and Chronic Exercise on Immunological Parameters in the Elderly Aged: Can Physical Activity Counteract the Effects of Aging?

Immunosenescence is characterized by deterioration of the immune system caused by aging which induces changes to innate and adaptive immunity. Immunosenescence affects function and phenotype of immune cells, such as expression and function of receptors for immune cells which contributes to loss of immune function (chemotaxis, intracellular killing). Moreover, these alterations decrease the response to pathogens, which leads to several age-related diseases including cardiovascular disease, Alzheimer's disease, and diabetes in older individuals. Furthermore, increased risk of autoimmune disease and chronic infection is increased with an aging immune system, which is characterized by a pro-inflammatory environment, ultimately leading to accelerated biological aging. During the last century, sedentarism rose dramatically, with a concomitant increase in certain type of cancers (such as breast cancer, colon, or prostate cancer), and autoimmune disease. Numerous studies on physical activity and immunity, with focus on special populations (i.e., people with diabetes, HIV patients) demonstrate that chronic exercise enhances immunity. However, the majority of previous work has focused on either a pathological population or healthy young adults whilst research in elderly populations is scarce. Research conducted to date has primarily focused on aerobic and resistance exercise training and its effect on immunity. This review focuses on the potential for exercise training to affect the aging immune system. The concept is that some lifestyle strategies such as high-intensity exercise training may prevent disease through the attenuation of immunosenescence. In this context, we take a top-down approach and review the effect of exercise and training on immunological parameters in elderly at rest and during exercise in humans, and how they respond to different modes of training. We highlight the impact of these different exercise modes on immunological parameters, such as cytokine and lymphocyte concentration in elderly individuals.

Isometric Exercise Training for Managing Vascular Risk Factors in Mild Cognitive Impairment and Alzheimer's Disease

Alzheimer’s disease (AD) is the most common form of dementia diagnosed amongst the elderly. Mild cognitive impairment (MCI) is a condition often indicative of the earliest symptomatology of AD with 10%–15% of MCI patients reportedly progressing to a diagnosis of AD. Individuals with a history of vascular risk factors (VRF’s) are considered high risk candidates for developing cognitive impairment in later life. Evidence suggests that vascular injury resulting from untreated VRF’s promotes progression from MCI to AD and exacerbates the severity of dementia in AD, and neuroimaging studies have found that the neurodegenerative processes associated with AD are heavily driven by VRF’s that promote cerebral hypoperfusion. Subsequently, common links between vascular disorders such as hypertension and neurodegenerative disorders such as AD include compromised vasculature, cerebral hypoperfusion and chronic low grade inflammation (a hallmark of both hypertension and AD). Exercise has been demonstrated to be an effective intervention for blood pressure management, chronic low grade inflammation and improvements in cognition. Data from recent analyses suggests that isometric exercise training (IET) may improve vascular integrity and elicit blood pressure reductions in hypertensives greater than those seen with dynamic aerobic and resistance exercise. IET may also play an effective role in the management of VRF’s at the MCI stage of AD and may prove to be a significant strategy in the prevention, attenuation or delay of progression to AD. A plausible hypothesis is that the reactive hyperemia stimulated by IET initiates a cascade of vascular, neurotrophic and neuro-endocrine events that lead to improvements in cognitive function.

Cardiac phenylethanolamine N-methyltransferase: localization and regulation of gene expression in the spontaneously hypertensive rat

Phenylethanolamine N-methyltransferase (PNMT) is the terminal enzyme in the catecholamine biosynthetic pathway responsible for adrenaline biosynthesis. Adrenaline is involved in the sympathetic control of blood pressure; it augments cardiac function by increasing stroke volume and cardiac output. Genetic mapping studies have linked the PNMT gene to hypertension. This study examined the expression of cardiac PNMT and changes in its transcriptional regulators in the spontaneously hypertensive (SHR) and wild type Wistar-Kyoto (WKY) rats. SHR exhibit elevated levels of corticosterone, and lower levels of the cytokine IL-1β, revealing systemic differences between SHR and WKY. PNMT mRNA was significantly increased in all chambers of the heart in the SHR, with the greatest increase in the right atrium. Transcriptional regulators of the PNMT promoter show elevated expression of Egr-1, Sp1, AP-2, and GR mRNA in all chambers of the SHR heart, while protein levels of Sp1, Egr-1, and GR were elevated only in the right atrium. Interestingly, only AP-2 protein-DNA binding was increased, suggesting it may be a key regulator of cardiac PNMT in SHR. This study provides the first insights into the molecular mechanisms involved in the dysregulation of cardiac PNMT in a genetic model of hypertension.

Fostering autonomous motivation, physical activity and cardiorespiratory fitness in rheumatoid arthritis: protocol and rationale for a randomised control trial

Background

People with rheumatoid arthritis are at greater risk of morbidity and mortality from cardiovascular disease than the general population. Sustained physical activity increases cardio-respiratory fitness and reduces cardiovascular disease risk factors. However, little is known about how we can effectively promote long-term participation in physical activity in patients with rheumatoid arthritis. The literature consistently calls for physical activity interventions, and their implementation, to be theoretically-grounded.

Methods/Design

This paper documents the protocol of a randomised control trial that investigates whether a Self-determination Theory-based intervention fosters the adoption and maintenance of physical activity (3, 6 and 12 months) sufficient to provide sustained cardiovascular and personal well-being benefits in patients with rheumatoid arthritis. The cost effectiveness of the intervention will also be determined. The trial is registered as Current Controlled Trials ISRCTN04121489.

Discussion

Results from this trial will provide guidance regarding key social environmental factors that can be manipulated to support motivational processes conducive to positive health behaviour change and optimal functioning in patients with Rheumatoid Arthritis.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-445) contains supplementary material, which is available to authorized users.

Pharmacological treatment and therapeutic perspectives of metabolic syndrome

Metabolic syndrome is a disorder based on insulin resistance. Metabolic syndrome is diagnosed by a co-occurrence of three out of five of the following medical conditions: abdominal obesity, elevated blood pressures, elevated glucose, high triglycerides, and low high-density lipoprotein-cholesterol (HDL-C) levels. Clinical implication of metabolic syndrome is that it increases the risk of developing type 2 diabetes and cardiovascular diseases. Prevalence of the metabolic syndrome has increased globally, particularly in the last decade, to the point of being regarded as an epidemic. The prevalence of metabolic syndrome in the USA is estimated to be 34% of adult population. Moreover, increasing rate of metabolic syndrome in developing countries is dramatic. One can speculate that metabolic syndrome is going to induce huge impact on our lives. The metabolic syndrome cannot be treated with a single agent, since it is a multifaceted health problem. A healthy lifestyle including weight reduction is likely most effective in controlling metabolic syndrome. However, it is difficult to initiate and maintain healthy lifestyles, and in particular, with the recidivism of obesity in most patients who lose weight. Next, pharmacological agents that deal with obesity, diabetes, hypertension, and dyslipidemia can be used singly or in combination: anti-obesity drugs, thiazolidinediones, metformin, statins, fibrates, renin-angiotensin system blockers, glucagon like peptide-1 agonists, sodium glucose transporter-2 inhibitors, and some antiplatelet agents such as cilostazol. These drugs have not only their own pharmacologic targets on individual components of metabolic syndrome but some other properties may prove beneficial, i.e. anti-inflammatory and anti-oxidative. This review will describe pathophysiologic features of metabolic syndrome and pharmacologic agents for the treatment of metabolic syndrome, which are currently available.

PPARα gene polymorphisms modulate the association between physical activity and cardiometabolic risk

BACKGROUND AND AIMS

Habitual physical activity is understood to help prevent type 2 diabetes and atherosclerotic cardiovascular disease via beneficial effects on both metabolism and the vascular system. However, individuals do not have uniform cardiometabolic responses to physical activity. Here we explore the extent to which variation in the proliferator-activated receptor-alpha (PPARα) gene, which modulates carbohydrate and lipid metabolism, vascular function, and inflammation, predicts the overall cardiometabolic risk (CMR) profile of individuals engaging in various levels of physical activity.

METHODS AND RESULTS

917 unrelated, community volunteers (52% female, of Non-Hispanic European ancestry) aged 30-54 years, participated in the cross-sectional study. Subjects were genotyped for 5 single nucleotide polymorphisms in the PPARα gene, from which common haplotypes were defined. A continuous measure of CMR was calculated as an aggregate of 5 traditional risk factors: waist circumference, resting blood pressure, fasting serum triglycerides, HDL-cholesterol and glucose. Regression models were used to examine the main and interactive effects of physical activity and genetic variation on CMR. One common PPARα haplotype (H-23) was associated with a higher CMR. This association was moderated by daily physical activity (B = -0.11, SE = 0.053, t = -2.05, P = 0.04). Increased physical activity was associated with a steeper reduction of CMR in persons carrying the otherwise detrimental H-23 haplotype.

CONCLUSIONS

Variations in the PPARα gene appear to magnify the cardiometabolic benefits of habitual physical activity.

Exercise affects symptom severity but not biological measures in depression and somatization - results on IL-6, neopterin, tryptophan, kynurenine and 5-HIAA

Exercise leads to symptom reduction in affective disorders and functional somatic syndromes. Biological hypotheses of underlying mechanisms include serotonergic and immunological pathways. We aimed to investigate biological features in persons with major depression and somatoform syndromes, and to analyze effects of short-term graded exercise on these parameters. Baseline values for depressive and somatoform symptoms, tryptophan, kynurenine, 5-hydroxyindoleacetic acid, neopterin and interleukin-6 were compared with those after one week of increased and one week of reduced physical activity. Thirty-eight persons with major depression, 27 persons with a minimum of 6-8 somatoform symptoms, and 48 healthy controls participated in the study. Depressive and somatoform symptoms were reduced after the active week, and an interaction pointed towards group-specific reduction of psychopathology. Participants with major depression had lower levels of kynurenine compared to controls, with intermediate concentrations in somatoform patients. There were no systematic associations of symptom improvement with biological changes. A possible limitation of the design is that a control condition with low physical activity, but no placebo condition was included. People with multiple somatoform symptoms and major depression benefit from a short and low-graded exercise intervention. These effects do not seem to be mediated by changes in serotonergic and inflammatory parameters.

Metabolic and anti-inflammatory effects of a home-based programme of aerobic physical exercise

AIMS

Regular exercise demonstrated the ability to provide enormous benefits to many diseases, atherosclerotic-based, degenerative and neoplastic, but also to grant anti-inflammatory actions, assessed by various authors in different populations. Despite of these clear benefits, many patients are unable to attain long-term results through chronic physical activity for different causes. On this basis, the aim of our study was to assess the metabolic and anti-inflammatory effects of a home-based programme of fast walking in patients affected by metabolic syndrome (MS).

MATERIALS AND METHODS

We enrolled 176 subjects with MS as stated by ATP III criteria. Patients were invited to walk for 1 h every day 5 days a week for 24 weeks. The walking velocity was required higher than the one retained 'comfortable' by the patient, previously assessed in the run-in visit. Monitoring of physical activity was carried out through an OMRON step counter type Walking Style II. All the subjects enrolled completed the training period.

RESULTS

After the 24 weeks of intervention body mass index changed from 31.59 to 29.23 (p < 0.001); mean waist circumference passed from 105.19 to 100.06 cm (p < 0.001); mean fasting glucose changed from 119.76 to 114.32 mg/dl (p < 0.001); for diabetic population (n = 70) mean glicated haemoglobin levels changed from 7.38% to 6.86% (p < 0.001); total cholesterol levels from 192.15 to 185.78 mg/dl (p < 0.001); HDL cholesterol levels raised from 44.03 to 47.63 mg/dl (p < 0.001); triglycerides levels lowered from 148.29 to 135.20 mg/dl (p < 0.001); WBC changed from 7361.08 to 7022.56/mm(3) (p < 0.001); hs-CRP from 0.55 to 0.28 mg/dl (p < 0.001); fibrinogen serum levels lowered from 339.68 to 314.86 mg/dl (p < 0.001).

CONCLUSIONS

A long-term home-based programme of aerobic physical activity improves metabolic asset and reduces systemic inflammation in sedentary people.

Concurrent physical activity modifies the association between n3 long-chain fatty acids and cardiometabolic risk in midlife adults

Greater consumption of n3 (ω3) polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can reduce risk for cardiovascular disease events, yet their effects on metabolic risk factors and diabetes remain unclear. This cross-sectional study used a community volunteer sample to test whether the associations between n3 fatty acids and cardiometabolic risk vary as a function of physical activity. Participants were 344 generally healthy adults, 30-54 y of age, not taking fish oil supplements or confounding medications. Serum phospholipid EPA and DHA were used together (EPA+DHA) as a biomarker of n3 fatty acid exposure. Cardiometabolic risk was calculated as a continuous measure based on standardized distributions of blood pressure, waist circumference, HDL cholesterol, triglycerides, glucose, and a simple count of risk factors. Insulin resistance was estimated from the homeostatic model assessment. Physical activity was found to predict cardiometabolic risk (P ≤ 0.02) and insulin resistance (P ≤ 0.02) and to moderate the association between EPA+DHA and both cardiometabolic risk (P-interaction ≤ 0.02) and insulin resistance (P-interaction ≤ 0.02). Specifically, higher EPA+DHA was associated with lower cardiometabolic risk and insulin resistance in persons engaged in regular physical activity but not in relatively inactive individuals. These findings were noted in several components of cardiometabolic risk, in men and women separately, and in models adjusted for overall diet quality. In midlife adults, habitual physical activity may be necessary to unmask the salutary effects of n3 fatty acids on cardiometabolic risk and insulin resistance.

A meta-analysis of mental health treatments and cardiac rehabilitation for improving clinical outcomes and depression among patients with coronary heart disease

OBJECTIVE

To quantify the efficacy of mental health (antidepressants & psychotherapies) and cardiac rehabilitation treatments for improving secondary event risk and depression among patients with coronary heart disease (CHD).

METHODS

Using meta-analytic methods, we evaluated mental health and cardiac rehabilitation therapies for a) reducing secondary events and 2) improving depression severity in patients with CHD. Key word searches of PubMed and Psychlit databases and previous reviews identified relevant trials.

RESULTS

Eighteen mental health trials evaluated secondary events and 22 trials evaluated depression reduction. Cardiac rehabilitation trials for the same categories numbered 17 and 13, respectively. Mental health treatments did not reduce total mortality (absolute risk reduction [ARR] = -0.001, confidence interval [95% CI] = -0.016 to 0.015; number needed to treat [NNT] = ∞), showed moderate efficacy for reducing CHD events (ARR = 0.029, 95% CI = 0.007 to 0.051; NNT = 34), and a medium effect size for improving depression (Cohen d = 0.297). Cardiac rehabilitation showed similar efficacy for treating depression (d = 0.23) and reducing CHD events (ARR = 0.017, 95% CI = 0.007 to 0.026; NNT = 59) and reduced total mortality (ARR = 0.016, 95% CI = 0.005 to 0.027; NNT = 63).

CONCLUSIONS

Among patients with CHD, mental health treatments and cardiac rehabilitation may each reduce depression and CHD events, whereas cardiac rehabilitation is superior for reducing total mortality risk. The results support a continued role for mental health treatments and a larger role for mental health professionals in cardiac rehabilitation.

Effects on blood pressure and autonomic nervous system function of a 12-week exercise or exercise plus DASH-diet intervention in individuals with elevated blood pressure

AIM

Hypertension is related to abnormalities in autonomic nervous system (ANS) function, with increased sympathetic output and decreased parasympathetic tone. Lifestyle interventions are the first line of treatment in hypertension, and decreased blood pressure (BP) effects may be related to changes in ANS function. Using heart rate recovery (HRR) from exercise as an index of parasympathetic tone and plasma noradrenaline as an index of sympathetic tone, we investigated the effects of lifestyle interventions on ANS function in patients with elevated BP.

METHODS

Sedentary participants with elevated BP were randomly assigned to either an exercise only (N = 25), exercise plus dietary approaches to stop hypertension (DASH) diet (N = 12), or waitlist control (N = 15) 12-week intervention. Plasma noradrenaline was measured at rest and participants performed a peak exercise test before and after the intervention. HRR was calculated as peak heart rate (HR) minus HR at 1 min post-exercise.

RESULTS

Heart rate recovery showed a significant group by time interaction; both intervention groups showed increases in HRR from pre- to post-intervention, while waitlist showed no change. Similarly, both exercise plus diet and exercise groups, but not waitlist, showed significant reductions in BP from pre- to post-intervention. Linear regression revealed that BP post-intervention was significantly predicted by change in HRR when controlling for pre-BP, age, gender and BMI.

CONCLUSIONS

Lifestyle interventions induced training-reduced BP and altered autonomic tone, indexed by HRR. This study indicates the importance of behavioural modification in hypertension and that increased parasympathetic function is associated with success in reduction of BP.

Leukocyte membrane bleb and pseudopod formation in hypertension

Leukocyte activation, including adhesion molecule expression, oxygen radical generation and, in animal studies, pseudopod formation, is a hallmark of hypertension. This study examined pseudopod and bleb formation and demonstrates that leukocytes from hypertensive individuals are more susceptible to produce membrane blebs than leukocytes from normotensive individuals. Bleb formation is likely indicative of apoptosis, thus this observation adds to previous observations of increased apoptosis in various tissues in hypertension.

Role of proinflammatory cytokines and redox homeostasis in exercise-induced delayed progression of hypertension in spontaneously hypertensive rats

Hypertension is a well-known risk factor for various cardiovascular diseases. Recently, exercise has been recommended as a part of lifestyle modification for all hypertensive patients. However, the precise mechanisms of exercise training (ExT)-induced effects on the development of hypertension are poorly understood. Therefore, we hypothesized that chronic ExT would delay the progression of hypertension in young spontaneously hypertensive rats (SHRs). In addition, we explored whether the beneficial effects of chronic ExT were mediated by reduced proinflammatory cytokines and improved redox status. We also investigated the involvement of nuclear factor-kappaB in exercise-induced effects. To test our hypotheses, young normotensive (Wistar-Kyoto) and SHRs were given moderate-intensity ExT for 16 weeks. Blood pressure was determined by the tail-cuff method, and cardiac function was assessed by echocardiography. Myocardial total reactive oxygen species and superoxide production were measured by electron paramagnetic resonance spectroscopy; tumor necrosis factor-alpha, interleukin-1beta, gp91(phox), and inducible NO synthase by real-time PCR; and nuclear factor kappaB activity by electrophoretic mobility shift assay. Chronic ExT in hypertensive rats resulted in significantly reduced blood pressure, reduced concentric hypertrophy, and improved diastolic function. ExT significantly reduced proinflammatory cytokines and inducible NO synthase, attenuated total reactive oxygen species and superoxide production, and increased antioxidants in SHRs. ExT also resulted in increased NO production and decreased nuclear factor kappaB activity in SHRs. In summary, chronic ExT delays the progression of hypertension and improves cardiac function in young SHRs; these ExT-induced beneficial effects are mediated by reduced proinflammatory cytokines and improved redox homeostasis via downregulation of nuclear factor-kappaB.

Baseline self reported functional health and vulnerability to post-traumatic stress disorder after combat deployment: prospective US military cohort study

OBJECTIVE

To determine if baseline functional health status, as measured by SF-36 (veterans), predicts new onset symptoms or diagnosis of post-traumatic stress disorder among deployed US military personnel with combat exposure.

DESIGN

Prospective cohort analysis.

SETTING

Millennium Cohort.

PARTICIPANTS

Combat deployed members who completed baseline (2001-3) and follow-up (2004-6) questionnaires. Self reported and electronic data used to examine the relation between functional health and post-traumatic stress disorder.

MAIN OUTCOME MEASURES

New onset post-traumatic stress disorder as measured by either meeting the DSM-IV criteria with the 17 item post-traumatic stress disorder checklist-civilian version or self report of a physician diagnosis at follow-up with the absence of both at baseline.

RESULTS

Of the 5410 eligible participants, 395 (7.3%) had new onset symptoms or diagnosis of post-traumatic stress disorder at the time of follow-up. Individuals whose baseline mental or physical component summary scores were below the 15th centile had two to three times the risk of symptoms or a diagnosis of post-traumatic stress disorder by follow-up compared with those in the 15th to 85th centile. Of those with new onset symptoms or diagnosis of post-traumatic stress disorder, over half (58%) of cases occurred among participants with scores below the 15th centile at baseline.

CONCLUSIONS

Low mental or physical health status before combat exposure significantly increases the risk of symptoms or diagnosis of post-traumatic stress disorder after deployment. More vulnerable members of a population could be identified and benefit from interventions targeted to prevent new onset post-traumatic stress disorder.

Inflammation at the molecular interface of atherogenesis: an anthropological journey

Despite the multifactorial nature of atherosclerosis, substantial evidence has established inflammation as an often surreptitious, yet critical and unifying driving force which promotes disease progression. To this end, research has defined molecular networks initiated by cytokines, growth factors and other pro-inflammatory molecules which promote hallmarks of atherosclerosis such as endothelial dysfunction, macrophage infiltration, LDL oxidation, cell proliferation and thrombosis. Although commonly associated with risk factors such as dyslipidemia, diabetes and hypertension, the global etiology of atherosclerosis may be alternatively attributed to underlying anthropological pressures. The agricultural, industrial and technological revolutions produced alterations in dietary, social and economic factors which have collectively exaggerated the exposure of the human genome to environmental stimuli. Furthermore, advances in sanitation, nutrition, and medicine have increased the lifespan of humans, effectively prolonging blood vessel exposure to these factors. As a result, the vasculature has become conditioned to respond to injury with what is arguably an overzealous immunological response; thus setting the stage for the prevalence of cardiovascular disease, including atherosclerotic plaque development in Western populations. Evidence suggests that each of these alterations can be linked to specific mediators in the inflammatory process. Integration of these factors with an inflammation-based hypothesis of atherosclerosis has yet to be extrapolated to observations in the realms of basic and clinical sciences and is the focus of this review.

Relationship between heart rate variability, interleukin-6, and soluble tissue factor in healthy subjects

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 (beta=-0.31, p=0.007) and high frequency (HF) power (beta=-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 (beta=0.51, p<0.001) and HF power (beta=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.

Chronic exercise reduces platelet activation in hypertension: upregulation of the L-arginine-nitric oxide pathway

Nitric oxide (NO) inhibits platelet function and plays a key role in the regulation of cardiovascular homeostasis. Essential hypertension is characterized by an increased risk of thrombus formation, and by an inhibition of intraplatelet NO bioactivity. We have previously shown that membrane transport of L-arginine is a rate-limiting step for platelet-derived NO synthesis. This study examined the effects of exercise on the platelet L-arginine-NO pathway and aggregation and systemic inflammation markers in 13 sedentary hypertensive patients subjected to 60 min of training activity (exercise group), predominantly aerobic, three times a week for a period of 12 weeks. Six sedentary hypertensive patients participated in the control group. After 12 weeks, L-arginine transport was significantly increased and associated with increased platelet NO synthase activity and cGMP levels and reduced platelet aggregation. Moreover, exercise training reduced plasma concentrations of fibrinogen and C-reactive protein and blood pressure. The control group did not change their previous intraplatelet L-arginine-NO results and systemic inflammatory markers levels. Thus, exercise training reduces inflammatory responses, restores NO synthesis in platelets and thereby contributes to the beneficial effects of exercise in hypertension. The present study adds exercise as a new tool to reduce morbidity and mortality associated with platelet activation in hypertension.