Influence of power and aerobic exercise training on haemostatic factors after coronary artery surgery

Impacts of Exercise Interventions on Inflammatory Markers and Vascular Adhesion Molecules in Patients With Heart Failure: A Meta-analysis of RCTs

Background

The aim of this meta-analysis was to investigate the effects of concurrent, aerobic, and resistance exercise on markers of inflammation and vascular adhesion molecules (high-sensitivity C-reactive protein [hs-CRP], interleukin [IL]-6, tumour necrosis factor-alpha [TNF-α], soluble intercellular adhesion molecule-1 [sICAM-1], soluble vascular cell adhesion molecule-1 [sVCAM-1], fibrinogen, IL-1-β, IL-10, IL-18, and E-selectin) in patients with heart failure (HF).

Methods

The PubMed, Scopus, Web of Science, and Google Scholar databases were searched for dates up to August 31, 2022. Randomized controlled trial studies for exercise interventions on circulating inflammatory and vascular adhesion markers in patients with HF were included. Standardized mean difference (SMD) and 95% confidence interval (CI) were calculated.

Results

A total of 45 articles were included. Exercise training significantly reduced hs-CRP (SMD -0.441 [95% CI: -0.642 to -0.240], P = 0.001), IL-6 (SMD -0.158 (95% CI: -0.303 to -0.013], P = 0.032), and sICAM-1 (SMD -0.282 [95% CI: -0.477 to -0.086], P = 0.005) markers. Analysis of subgroups revealed that a significant reduction occurred in hs-CRP level for the following subgroups: middle-aged, elderly, overweight status, aerobic exercise, concurrent training, both high and moderate intensity, and short-term, long-term, and very long-term follow-up, compared to a control group (P < 0.05). A significant reduction occurred in IL-6 and sICAM-1 levels for those in the following subgroups, compared to a control group (P < 0.05): middle-aged, aerobic exercise, moderate-intensity exercise, and short-term follow-up. A reduction in TNF-α level occurred for middle-aged patients, compared to a control-group (P < 0.05).

Conclusions

These exercise-related changes (improved inflammation and vascular adhesion markers) as clinical benefits in general, and for exercise-based cardiac rehabilitation in a more-specific format, improve clinical evolution and survival in patients with HF of different etiologies (registration number = CRD42021271423).

Haemostasis and fibrinolysis after regular high-intensity interval training in patients with coronary artery disease: a randomised controlled trial

IntroductionPatients with coronary artery disease (CAD) have prothrombotic changes compared with healthy individuals. Regular exercise reduces cardiovascular mortality in patients with stable CAD. However, the underlying mechanism for the beneficial effect is unknown. We investigated whether regular exercise would inhibit platelet aggregation and thrombin generation and increase fibrinolysis in patients with CAD.

MATERIALS AND METHODS

Patients with CAD were randomised 1:1 to a supervised high-intensity exercise training programme or standard care for 12 weeks. Blood samples were obtained at baseline and after 6 and 12 weeks. Platelet aggregation was evaluated with the Multiplate Analyser, thrombin generation using the calibrated automated thrombogram and fibrinolysis employing a clot lysis assay.

RESULTS

A total of 169 stable patients with CAD were randomised, and 142 patients (67±9 years, 83% males) completed the study; 64 in the exercise group and 78 in the standard care group. All but one patients received single antiplatelet therapy. From baseline to 12 weeks postintervention (Δ), no significant between-group differences were found in adenosine diphosphate-induced platelet aggregation (Δ-15 aggregation units (AU), AU×min, 95% CI -70 to 40 in the exercise group and Δ-26 AU×min, 95% CI -77 to 26 in the standard care group, p=0.44); endogenous thrombin potential (medians: Δ-5%, 95% CI -12 to 3 in the exercise group and Δ-6%, 95% CI -13 to 1 in the standard care group, p=0.26); nor in 50% clot lysis time (medians: Δ-9%, 95% CI -23 to 7 in the exercise group and Δ-17%, 95% CI -29 to -3 in the standard care group, p=0.60).

CONCLUSIONS

Twelve weeks of high-intensity whole-body endurance exercise did not affect platelet aggregation, thrombin generation or fibrinolysis in patients with stable CAD.

TRIAL REGISTRATION NUMBER

NCT04268992.

Effect of Vibrotherapy on Body Fatness, Blood Parameters and Fibrinogen Concentration in Elderly Men

Elderly people need activities that will positively contribute to a satisfactory process of getting older. Vibration training uses mechanical stimulus of a vibrational character that, similarly to other forms of physical activity, affects metabolic processes and conditions of health. The aim of this work was to assess the influence of thirty vibration treatments on body fatness, hematologic and rheologic indexes of blood, and proteinogram and fibrinogen concentration in elderly men’s blood. The study included twenty-one males, aged 60–70 years (mean age 65.3 ± 2.7), who were randomly assigned into a vibrotherapy group (VG) and took part in interventions on mattresses generating oscillatory-cycloid vibrations, and a control group (CG), without interventions. In all patients the following assessments were performed twice: an assessment of body fatness using the bioimpedance method, a complete blood count with a hematology analyzer, and erythrocyte aggregation by a laser-optical rotational cell analyzer; whereas, total plasma protein and fibrinogen values were established, respectively, by biuret and spectrophotometric methods. In order to compare the impact of vibrotherapy on changes in the analyzed variables, analysis of variance (ANOVA) or the Wilcoxon test were used. After applying thirty vibration treatments in the VG, a significant decrease in body fatness parameters was confirmed: BM (∆BM: −2.7 ± 2.0; p = 0.002), BMI (∆BMI: −0.9 ± 0.7; p = 0.002), BF (∆BF: −2.5 ± 2.5; p = 0.013), and %BF (∆%BF: −2.0 ± 2.7; p = 0.041), as well as in RBC (∆RBC: −0.1 ± 0.1; p = 0.035). However, changes in erythrocyte aggregation and proteinogram were not confirmed. It was found that after thirty treatments with VG, a significant decrease of fibrinogen level took place (∆ = −0.3 ± 0.3, p = 0.005). Application of thirty vibrotherapy treatments positively affected body fatness parameters and fibrinogen concentrations in the examined. However, further research should include a greater number of participants.

Effects of a 1-Year Physical Activity Intervention on Markers of Hemostasis among Breast Cancer Survivors: A Randomized Controlled Trial

Introduction  Physical activity may reduce the development of breast cancer. Whereas hypercoagulability has been linked to adverse outcomes in breast cancer patients, the effects of physical activity on their hemostatic factors are unknown. The study aimed to assess whether long-term (1 year) physical activity can affect hemostatic factors in breast cancer patients. Methods  Fifty-five women (35-75 years) with invasive breast cancer stage I/II were randomized to a physical activity intervention ( n  = 29) lasting 1 year or to a control group ( n  = 26), and analyzed as intention to treat. Fibrinogen, factor VII antigen, tissue factor pathway inhibitor, and von Willebrand factor (VWF) antigen as well as prothrombin fragment 1 + 2, the endogenous thrombin potential and D-dimer, were measured in plasma before intervention (baseline), and then after 6 and 12 months. Results  Maximal oxygen uptake (measure of cardiorespiratory fitness) decreased the first 6 months among the controls, but remained stable in the intervention group. We found no significant differences between the two study groups regarding any of the hemostatic factors, except a significantly higher increase in factor VII antigen in the intervention group. The effect of the intervention on VWF was, however, significantly affected by menopausal stage, and a significant effect of the intervention was found on VWF among postmenopausal women, even after adjustment for dietary intake. Conclusion  Long-term physical activity had no effect on the majority of the hemostatic factors measured, but led to increased plasma concentrations of factor VII antigen and prevented an increase in VWF concentration after breast cancer treatment in postmenopausal women. The clinical impact of these findings for risk of vascular thrombosis warrants further studies.

Hemostatic Adaptations to High Intensity Interval Training in Healthy Adult Men

Regular exercise is theorized to reduce cardiovascular risk by attenuating coagulation and augmenting fibrinolysis. However, these adaptations have not been consistently observed during traditional exercise programs. The purpose of this study was to examine hemostatic adaptations in healthy men following four (4W) and eight (8W) weeks of high intensity interval training. Twenty-one men (age=25±1 y; body mass index=26.5±6.4 kg/m²) completed eight weeks, three days/week of high intensity interval training on a cycle ergometer. Activated partial thromboplastin time, prothrombin time, and plasma concentrations of thrombin-antithrombin III, fibrinogen, tissue plasminogen activator, and plasminogen activator inhibitor-1 were assessed at baseline (BL), 4W, and 8W. Repeated measures ANOVA were used to determine potential effects of training. There were no significant changes observed for activated partial thromboplastin time (BL=43.3±5.5, 4W=43.2±5.1, 8W=44.2±6.4 s); prothrombin time (BL=13.2±0.9, 4W=13.0±0.6, 8W=13.1±0.8 s); thrombin-antithrombin III (BL=6.0±2.3, 4W=5.8±2.3, 8W=5.6±3.1 ng/mL); tissue plasminogen activator (BL=9.7±3.3, 4W=9.4±3.2, 8W=8.7±2.8 ng/mL); and plasminogen activator inhibitor-1 (BL=19.0±17.5, 4W=19.3±17.0, 8W=18.9±18.9 ng/mL) (all p>0.05). Fibrinogen was significantly lower at 4W (238.6±70.3 mg/dL) compared to BL (285.0±82.1 mg/dL; p<0.05) and 8W (285.3±83.2 mg/dL; p<0.05). These findings indicate that eight weeks of high intensity interval training does not influence coagulation potential and/or stimulate fibrinolysis.

Effect of cardiac rehabilitation on inflammation: A systematic review and meta-analysis of controlled clinical trials

BACKGROUND

This systematic review and meta-analysis aimed to assess the effect of cardiac rehabilitation (CR) on serum C-reactive protein (CRP) as an indicator of the inflammatory state and predictor of recurrent cardiovascular events.

METHODS

PubMed, SCOPUS, Cochrane library, and Google Scholar databases were searched up to January 2014 for original articles which investigated the effect of CR on CRP among adult patients with previous cardiovascular events. The random effects model was used to assess the overall effect of CR on the variation in serum CRP levels.

RESULTS

In the present systematic review and meta-analysis, 15 studies were included. The analysis showed that CR might significantly reduce high-sensitivity CRP (hs-CRP) levels [Difference in means (DM) = -1.81 mg/l, 95% confidence interval (CI): -2.65, -0.98; P = 0.004). However, the heterogeneity between studies was significant (Cochran's Q test, P < 0.001, I-squared = 84.9%). To find the source of variation, the studies were categorized based on study design (quality) and duration. The negative effect was higher among studies which followed their participants for 3 weeks or less (DM = -2.75 mg/l, 95% CI: -3.86, -1.64; P < 0.001) compared to studies which investigated the effect of CR for 3-8 weeks (DM = -0.89 mg/l, 95% CI: -1.35, -0.44; P < 0.001) and those which lasted more than 8 weeks (DM = -1.71 mg/l, 95% CI: -2.53, -0.89; P < 0.001). There was no evidence of heterogeneity when the categorization was based on the follow-up period.

CONCLUSION

Both short- and long-term CR have resulted in improvement in serum hs-CRP levels. CR can be perceived as a beneficial tool to reduce inflammatory markers among patients with previous cardiac events.

Physical activity in primary and secondary prevention of cardiovascular disease: Overview updated

Although the observed progress in the cardiovascular disease treatment, the incidence of new and recurrent coronary artery disease remains elevated and constitutes the leading cause of death in the developed countries. Three-quarters of deaths due to cardiovascular diseases could be prevented with adequate changes in lifestyle, including increased daily physical activity. New evidence confirms that there is an inverse dose-response relationship between physical activity and cardiovascular disease and mortality risk. However, participation in moderate to vigorous physical activity may not fully attenuate the independent effect of sedentary activities on increased risk for cardiovascular diseases. Physical activity also plays an important role in secondary prevention of cardiovascular diseases by reducing the impact of the disease, slowing its progress and preventing recurrence. Nonetheless, most of eligible cardiovascular patients still do not benefit from secondary prevention/cardiac rehabilitation programs. The present review draws attention to the importance of physical activity in the primary and secondary prevention of cardiovascular diseases. It also addresses the mechanisms by which physical activity and regular exercise can improve cardiovascular health and reduce the burden of the disease.

Inflammatory markers, D-dimer, pro-thrombotic factors, and physical activity levels in patients with peripheral arterial disease

Men and women with lower extremity peripheral arterial disease (PAD) have reduced physical activity levels compared with persons without PAD. We describe associations between physical activity levels with D-dimer, pro-coagulant factors, and inflammatory markers in patients with PAD. Participants were188 patients with PAD identified from non-invasive vascular laboratories. Physical activity was measured over 7 days with a vertical accelerometer. We measured the ankle brachial index (ABI) and levels of D-dimer, C-reactive protein (CRP), fibrinogen, serum amyloid A (SAA), prothrombin 1.2, t-PA antigen, PAI-1, and the t-PA antigen=PAI-1 ratio. Adjusting for age, sex, race, body mass index, ABI, comorbidities, smoking, total cholesterol=HDL ratio and statin use (for CRP only), we found significant inverse linear associations between physical activity levels and log D-dimer (p 1/4 0.002), log CRP (p < 0.001), fibrinogen (p 1/4 0.014), and log SAA (p 1/4 0.012). There were no significant associations between physical activity levels and other blood factors. In an analysis adjusting for all blood factors simultaneously along with known and potential confounders, log D-dimer was the only blood factor associated significantly with physical activity levels (p 1/4 0.036). Based on these findings, future studies should assess whether interventions to increase physical activity in patients with PAD reduce levels of D-dimer and inflammatory markers.

The influence of regular walking at different times of day on blood lipids and inflammatory markers in sedentary patients with coronary artery disease

OBJECTIVE

To examine the influence of walking at different times of day on lipids and inflammatory markers in sedentary patients with coronary artery disease (CAD).

METHODS

A total of 330 patients recruited from Nanjing between September 2011 and November 2012 were randomly assigned to a control group (n=110), morning (n=110) or evening walking group (n=110). Both the walking groups were asked to walk 30 min/day or more on at least 5 days/week either in the morning or evening for 12 weeks. Lipids and inflammatory markers were measured before and after exercise intervention.

RESULTS

Compared with baseline, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were improved in all groups. Significances were shown in the changes of fibrinogen, high sensitivity C-reactive protein (hsCRP), white blood cell (WBC) count, TC, triglycerides, LDL-C, lipoprotein(a) between groups. The evening walking group had a larger decrease in fibrinogen (0.16 ± 0.19 g/L, P<0.001), hsCRP (1.16 ± 1.07 mg/L, P<0.001), WBC count (0.76 ± 1.53·10(9)/L, P=0.004) and LDL-C (0.34 ± 0.31 mmol/L, P<0.001) than the other two groups.

CONCLUSIONS

Our walking program successfully resulted in a favorable change in lipids and inflammatory markers. Patients in the evening walking group gained more benefits than those walking in the morning walking group. NCT01887093.

Exercise intervention and inflammatory markers in coronary artery disease: a meta-analysis

BACKGROUND

Inflammatory activity plays a role in the development and progression of coronary artery disease (CAD), and exercise confers survival benefit. We performed a meta-analysis of changes in inflammatory biomarkers over the course of exercise interventions in patients with CAD.

METHODS

We searched MEDLINE, Embase, the Cochrane Collaboration, AMED, and CINAHL for studies reporting peripheral inflammatory biomarker concentrations before and after exercise interventions of ≥ 2 weeks in patients with CAD. Data were summarized using standard mean differences (SMD) and 95% CIs.

RESULTS

Twenty-three studies were included. Concentrations of C-reactive protein (CRP; SMD -0.345, 95% CI -0.444 to -0.246, n = 1,466, P < .001), interleukin 6 (SMD -0.546, 95% CI -0.739 to -0.353, n = 280, P < .001), fibrinogen (SMD -0.638, 95% CI -0.953 to -0.323, n = 247, P < .001), and vascular cell adhesion molecule 1 (SMD -0.413, 95% CI -0.778 to -0.048, n = 187, P = .027) were lower postintervention. Higher total cholesterol (B = -0.328, 95% CI -0.612 to -0.043, P = .026) and higher total/high-density lipoprotein cholesterol ratios (B = -0.250, 95% CI -0.425 to -0.076, P = .008) at baseline were associated with greater reductions in CRP. In controlled studies, follow-up concentrations of CRP (SMD -0.500, 95% CI -0.844 to -0.157, n(exercise/control) = 485/284, P = .004), and fibrinogen (SMD -0.544, 95% CI -1.058 to -0.030, n(exercise/control) = 148/100, P = .038) were lower in subjects who exercised compared with controls.

CONCLUSION

Exercise training is associated with reduced inflammatory activity in patients with CAD. C-reactive protein and fibrinogen have provided the strongest evidence. Higher baseline CRP and adverse baseline lipid profiles predicted greater reductions in CRP.

Thrombosis, physical activity, and acute coronary syndromes

Acute coronary syndromes (ACS) are common, life-threatening cardiac disorders that typically are triggered by rupture or erosion of an atherosclerotic plaque. Platelet deposition and activation of the blood coagulation cascade in response to plaque disruption lead to the formation of a platelet-fibrin thrombus, which can grow rapidly, obstruct coronary blood flow, and cause myocardial ischemia and/or infarction. Several clinical studies have examined the relationship between physical activity and ACS, and numerous preclinical and clinical studies have examined specific effects of sustained physical training and acute physical activity on atherosclerotic plaque rupture, platelet function, and formation and clearance of intravascular fibrin. This article reviews the available literature regarding the role of physical activity in determining the incidence of atherosclerotic plaque rupture and the pace and extent of thrombus formation after plaque rupture.

Exercise training-induced changes in coagulation factors in older adults

The coagulation cascade plays a critical role in the development of cardiovascular disease (CVD). Elevated plasma prothrombin fragment 1 + 2 (F1 + 2) and factor VIII antigen (FVIII:Ag) levels have been associated with a hypercoagulable state, enhancing the risk for vascular thrombotic events. Aerobic training is known to reduce CVD risk, and an improved coagulation profile may contribute to this reduction.

PURPOSE

To analyze the effect of 6 months of standardized aerobic exercise training on resting F1 + 2 and FVIII:Ag levels in men and postmenopausal women aged 50-75 while accounting for several possibly confounding factors.

MATERIALS AND METHODS

Sedentary men (N=16) and women (N=31) underwent supervised aerobic training 3 d x wk(-1) for 6 months while maintaining the American Heart Association step 1 diet. Baseline and final testing included measurement of F1 + 2, FVIII:Ag, plasma lipoprotein-lipid levels, body composition, and VO2max.

RESULTS

When adjusted for baseline values and changes in diastolic blood pressure with training, F1 + 2 was found to decrease significantly with exercise training from 1.493 +/- 0.058 to 1.422 +/- 0.059 nM (P=0.014). FVIII:Ag levels were found to increase significantly with training when adjusted for baseline values, from 152.5 +/- 6.7% of standard at baseline to 156.0 +/- 6.1% of standard at final testing (P=0.005). Training-induced changes in coagulation markers were independent of changes in blood lipids, aerobic capacity, and body composition.

CONCLUSIONS

: These results indicate that endurance training has a significant impact on the coagulation cascade, reducing coagulation activity in the common pathway and thrombin formation at rest while increasing the activation potential of the intrinsic pathway.

Plasma haemostatic markers, endothelial function and ambulatory blood pressure changes with home versus hospital cardiac rehabilitation: the Birmingham Rehabilitation Uptake Maximisation Study

BACKGROUND

Cardiac rehabilitation is an accepted therapeutic intervention in patients after myocardial infarction or coronary revascularisation. The effects of cardiac rehabilitation programmes, whether home based or hospital based, on haemostatic indices (as reflected by fibrinogen, plasma viscosity, fibrin D-dimer (an index of thrombogenesis), von Willebrand factor (vWf, an index of endothelial damage/dysfunction), soluble P-selectin (an index of platelet activation)), vasomotor function (using flow-mediated dilatation (FMD)) and ambulatory blood pressure (ABP) in patients with coronary heart disease are unknown.

METHODS

81 patients (66 men, mean (SD) 59 (11) years) after myocardial infarction or coronary revascularisation were randomised to comprehensive hospital-based (n = 40) or home-based (n = 41) cardiac rehabilitation. Plasma levels of vWf, D-dimer, fibrinogen, soluble P-selectin and plasma viscosity, as well as FMD and 24-h ABP, were measured at baseline and after 3 months of cardiac rehabilitation.

RESULTS

In patients who completed cardiac rehabilitation, levels of vWf, fibrinogen and D-dimer were significantly lower and FMD improved (all p<or=0.001), whereas levels were unchanged in controls. Significant reductions were also observed in 24-h mean systolic blood pressure, diastolic blood pressure and mean aortic pressure after completion of cardiac rehabilitation (all p<0.05). No significant differences were observed between the hospital-based and home-based cardiac rehabilitation programmes on these indices.

CONCLUSIONS

Cardiac rehabilitation improves haemostasis, endothelial function and ABP in patients with coronary heart disease, with no significant differences between home-based and hospital-based cardiac rehabilitation programmes. These effects may contribute to the beneficial effects of cardiac rehabilitation programmes on CV outcomes.

Effects of exercise training on 5 inflammatory markers associated with cardiovascular risk

BACKGROUND

Cross-sectional studies suggest that regular exercise has anti-inflammatory effects, leading to lower levels of several proatherogenic inflammatory markers. However, this has yet to be confirmed by randomized prospective trials. We performed a randomized controlled trial to assess whether exercise training decreases levels of 5 inflammatory markers linked to future cardiovascular risk: white blood cell count, fibrinogen, C-reactive protein, soluble intercellular adhesion molecule 1, and soluble CD40 ligand.

METHODS

One hundred fifty-two healthy female smokers were randomized to either 12 weeks of exercise training or health education as part of a smoking cessation program. Smoking was held steady for the first 6 weeks, and thereafter, smoking cessation was actively attempted. One hundred four participants completed 6 weeks, and 88 completed 12 weeks. Fitness and circulating inflammatory marker levels were measured at baseline, 6 weeks, and 12 weeks. To avoid potential confounding from changes in smoking exposure during the second 6 weeks of the trial, the primary end point was change in inflammatory marker levels from baseline to 6 weeks. Change in inflammatory markers from baseline to 12 weeks was a secondary end point.

RESULTS

At baseline, greater physical fitness was associated with lower white blood cell, fibrinogen, and C-reactive protein levels, but these associations were not statistically significant after adjusting for body mass index (P > .1 for all). Fitness improved significantly in the exercise group at both 6 and 12 weeks. However, there were no differences in levels of any inflammatory marker between the exercise and control groups at either 6 weeks (primary end point) or 12 weeks (secondary end point) (P > .05 for all comparisons).

CONCLUSION

In female smokers, baseline associations between fitness and inflammatory markers were largely attributable to differences in body fat; regular exercise did not reduce levels of any of the inflammatory markers studied despite a significant improvement in fitness at both 6 and 12 weeks.

Selected genetic polymorphisms and plasma coagulation factor VII changes with exercise training

We assessed the effects of coagulation factor VII (FVII) gene polymorphisms, lipid-related polymorphisms, and exercise training-induced plasma lipoprotein lipid changes on FVII level changes with exercise training in middle- to older-aged men and women. Forty-six healthy sedentary men and women were stabilized on a low-fat diet and then underwent baseline testing, 6 mo of endurance exercise training, and final testing. Plasma FVII-Ag levels decreased with exercise training (106.7 ± 1.4 vs. 104.2 ± 1.6%, P = 0.005). There were no significant differences in FVII-Ag changes with exercise training between -323 (0/10 bp)/-401 (G/T) haplotype or -402 (G/A) genotype groups. FVII-Ag changes with training were not correlated with changes in plasma lipoprotein lipids. In linear regression analyses, FVII-Ag changes with training remained significant after adjusting for training-induced plasma lipoprotein lipid changes ( P = 0.01). FVII changes with training were associated with apolipoprotein E genotype ( P = 0.012); this relationship was still evident after adjusting for training-induced plasma lipoprotein lipid changes ( P = 0.047). FVII changes with training also were significantly associated with human ATPase binding cassette-1 genotype ( P = 0.018); this relationship persisted after accounting for the effect of the training-induced plasma lipoprotein lipid changes ( P = 0.045). We conclude that plasma FVII-Ag changes with exercise training are more closely related to selected lipid-related genotypes than FVII gene promoter variants.

Exercise-induced changes in coagulation and fibrinolysis in healthy populations and patients with cardiovascular disease

This review highlights the clinical significance of coagulation and fibrinolytic responses, and adaptations in healthy individuals and patients with cardiovascular disease (CVD). Much of the review focuses on indicators of the potential for coagulation and fibrinolysis. The terms 'coagulation potential' and 'fibrinolytic potential' are used frequently, as much of the literature in the area of exercise haemostasis evaluates factors that reflect an increased potential for coagulation, while coagulation per se, may or may not be occurring. Similarly, fibrinolysis is definitively the lysis of inappropriate or excessive blood clot, which may or may not be occurring when the enzymes that stimulate fibrinolysis are activated. Nevertheless, markers of coagulation and fibrinolytic potential are associated with CVD, ischaemic events, and cardiovascular mortality. Additionally, fibrinolytic potential is associated with other established CVD risk factors. Ischaemic events triggered by physical exertion are more likely to occur due to an occlusive thrombus, suggesting the exercise-induced responses related to haemostasis are of clinical significance. The magnitude of increase in coagulation potential, platelet aggregation and fibrinolysis appears to be primarily determined by exercise intensity. Patients with CVD may also have a larger increase in coagulation potential during acute exercise than healthy individuals. Additionally, the magnitude of the fibrinolytic response is largely related to the resting fibrinolytic profile of the individual. In particular, high resting plasminogen activator inhibitor-1 may diminish the magnitude of tissue plasminogen activator response during acute exercise. Therefore, acute responses to exercise may increase the risk of ischaemic event. However, chronic aerobic exercise training may decrease coagulation potential and increase fibrinolytic potential in both healthy individuals and CVD patients. Due to the aforementioned importance of resting fibrinolysis on the fibrinolytic response to exercise, chronic aerobic exercise training may cause favourable adaptations that could contribute to decreased risk for ischaemic event, both at rest and during physical exertion.

Exercise and Training Effects on Blood Haemostasis in Health and Disease

In recent years, the dysfunction of the haemostatic system in relation to the clinical complications from arterioscleroses and cardiovascular diseases has become more recognised. Blood coagulation and fibrinolysis comprise two important physiological systems, which are regulated by a balance between activators and inhibitors. Activation of blood coagulation is associated with accelerated clot formation, whereas activation of blood fibrinolysis enhances the breakdown of the blood clot. Available evidence suggests that strenuous exercise induces activation of blood coagulation with simultaneous enhancement of blood fibrinolysis. Although the responses of blood coagulation and fibrinolysis appear to be related to the exercise intensity and its duration, recent reports suggest that moderate exercise intensity is followed by activation of blood fibrinolysis without concomitant hyper-coagulability, while very intense exercise is associated with concurrent activation of blood coagulation and fibrinolysis. Similar to blood coagulation and fibrinolysis, systemic platelet-related thrombogenic factors have been shown to be involved in the initiation and progression of atherogenesis and plaque growth. Although exercise effects on platelet aggregation and function in healthy individuals have been examined, the results reported have been conflicting. However, for patients with coronary heart disease, the balance of evidence available would strongly suggest that platelet aggregation and functions are increased with exercise. Few studies are available concerning the influence of training on blood coagulation and fibrinolysis and the exact effects of exercise training on the equilibrium between blood coagulation and fibrinolysis is not as yet known. Although the effects of physical training on platelets have been briefly investigated, available meagre evidence suggests that exercise training is associated with favourable effects on platelet aggregation and activation in both men and women.

Exercise and thrombosis

Long-term moderate or strenuous physical activity is associated with a considerable reduction in cardiovascular morbidity and mortality in primary and secondary prevention. Various mechanisms, including changes in lipids, lifestyle habits, and other positive physiologic effects, have been suggested to mediate these beneficial effects. In addition, the hemostatic and fibrinolytic systems appear to play an important role. Fibrinogen has been convincingly shown to be an independent cardiovascular risk factor. Other hemostatic and fibrinolytic parameters that are predictive of coronary events include factor VII, platelet hyperreactivity, plasminogen-activator inhibitor 1 (PAI-1), and tissue-plasminogen activator. The effects of exercise on fibrinogen have been intensively studied. Several randomized controlled trials, various other intervention studies and a large number of population-based cross-sectional studies all found an inverse relationship between measures of sport activity or leisure activity and plasma fibrinogen. The magnitude of the effect reported might be associated with a sizeable reduction in major coronary events. Relatively few data are available on the effects of endurance exercise on markers of the fibrinolytic system, with inconsistent results. Acute exercise leads to a transient activation of the coagulation system, which is accompanied by an increase in the fibrinolytic capacity in healthy subjects. Patients with ischemic heart disease, who cannot increase their fibrinolytic potential, however, may be at considerable risk for acute ischemic events if they are exposed to unaccustomed strenuous physical exertion.

Dose-response and coagulation and hemostatic factors

PURPOSE

The purpose of this study was to evaluate the dose-response relations of regular physical activity on platelet function, blood coagulation factors, and fibrinolytic factors, on the basis of studies with appropriate experimental design.

METHODS

MEDLINE-based literature search supplemented with relevant review articles and other individual articles was used. The review concentrates on controlled randomized clinical trials on the impact of regular physical exercise on platelet function, and on blood coagulation and fibrinolytic factors.

RESULTS

Physical exercise acutely activates platelets and the fibrinolytic system, and some factors of the blood coagulation cascade. These findings, the earliest of which were published already in the 1960s, are mainly derived from uncontrolled observations. These studies have led to the conclusion that unbalanced activation of the hemostatic system during acute exercise may be part of the mechanisms for sudden cardiac events during or shortly after heavy physical exercise. The effects of regular physical exercise on various aspects of platelet function, blood coagulation, and fibrinolysis have been the object in only a few controlled randomized trials. With the exception of data on platelet function, the results remain contradictory.

CONCLUSION

Controlled randomized clinical trials with adequate statistical power and experimental study designs with subjects of different ages and health status are warranted for the evaluation of the dose-response issues to clearly delineate the preventive and therapeutic potential of regular physical exercise.

Exercise and thrombosis

Long-term moderate or strenuous physical activity is associated with a considerable reduction in cardiovascular morbidity and mortality. This article reviews the evidence to suggest that part of the effect is mediated through the effects on thrombogenic factors. Fibrinogen has been convincingly shown to be an independent cardiovascular risk factor. Other hemostatic and fibrinolytic parameters that are predictive of coronary events include factor VII, platelet hyperreactivity, plasminogen activator inhibitor-1, and tissue-plasminogen activator. The effects of exercise on fibrinogen have been studied intensively. One randomized, controlled trial, two other intervention studies and a large number of population-based cross-sectional studies have consistently found an inverse relationship between various measures of sport activity or leisure activity and plasma levels of fibrinogen. The magnitude of the effect might be associated with a sizeable reduction in major coronary events. Relatively few data are available on endurance exercise and markers of the fibrinolytic system. Acute exercise leads to a transient activation of the coagulation system, which is accompanied by an increase in the fibrinolytic capacity in healthy subjects. However, patients with ischemic heart disease, who cannot increase their fibrinolytic potential, may be at considerable risk for acute ischemic events if they are exposed to unaccustomed strenuous physical exertion. It is concluded that physical activity has profound effects on thrombogenic factors and that these mechanisms could contribute to its beneficial cardiovascular effects.

Leisure time physical activity, cardiorespiratory fitness, and plasma fibrinogen concentrations in nonsmoking middle-aged men

PURPOSE

The relationship of both leisure time physical activity and predicted maximum oxygen consumption (VO2max) with plasma fibrinogen concentration was examined within a cohort of employed middle-aged men.

METHODS

Analyses were performed on a subsample of 635 nonsmoking men (46.7 +/- 7.7 yr) who completed a preventive medical assessment between 1992 and 1996.

RESULTS

Among nonsmokers, mean age-adjusted fibrinogen concentration decreased significantly with higher physical activity index (PAL) categories and quartiles of predicted VO2max (mL x kg(-1) x min(-1)) (both P = 0.001). Mean age-adjusted plasma fibrinogen concentrations were significantly different (P < 0.05) between inactive and vigorous PAI groups and extreme quartiles of predicted VO2max (mL x kg(-1) x min(-1)). These relationships were no longer significant after adjustment for the confounding effect of other ischemic heart disease risk factors. Stepwise multiple regression analyses showed that age, sum of skinfolds, and blood leukocyte count were the strongest predictors of plasma fibrinogen concentration.

CONCLUSION

These data do not confirm a significant independent association of both physical activity and predicted VO2max (mL x kg(-1) x min(-1)) with fibrinogen concentrations among nonsmoking middle-aged men of similar high social class.

Fibrinogen and cardiovascular risk

The hypothesis that fibrinogen is closely related to cardiovascular risk has been strengthened through the results of various lines of research, which this review will aim to unravel. Several prospective epidemiological studies convincingly show elevated fibrinogen to represent a major, independent cardiovascular risk factor. Cross-sectional studies strongly associate fibrinogen and conventional cardiovascular risk factors. Clinical cohort studies demonstrate that increased fibrinogen is also a risk factor for the sequelae of cardiovascular disease. Our knowledge about the determinants of the variable plasma level of fibrinogen in health and disease is incomplete. Understanding of the mechanisms that might be involved in the atherothrombogenic action of fibrinogen is also fragmentary. Fibrinogen strongly affects blood coagulation, blood rheology and platelet aggregation. In addition, it has direct effects on the vascular wall and is a prominent acute phase reactant. All of these phenomena might constitute pathophysiological mechanisms involved in the association between fibrinogen and cardiovascular events. Their relative importance is unclear at present. Even though many crucial questions await conclusive answers, little doubt exists that fibrinogen represents a major, independent risk factor.

Leisure-time physical activity but not work-related physical activity is associated with decreased plasma viscosity. Results from a large population sample

BACKGROUND

Regular leisure-time physical activity (LTPA) is inversely associated with coronary heart disease (CHD). This has been mainly explained by its impact on traditional CHD risk factors, but more recently it was also shown to lower fibrinogen, which largely determines plasma viscosity. No data on the effect of work activity (WA) on plasma viscosity have been published.

METHODS AND RESULTS

We studied the relationship between self-reported LTPA or WA and plasma viscosity as well as other CHD risk factors in 3522 men and women age 25 to 64 years. Physical activity was assessed by questionnaire. LTPA was inversely associated with plasma viscosity in both sexes. The unadjusted mean differences in plasma viscosity in men between no activity and the highest activity were 0.024 mPa.s (95% confidence interval [CI], 0.016 to 0.032 mPa.s, P < .001) during winter and 0.024 mPa.s (95% CI, 0.016 to 0.031 mPa.s, P < .001) during summer. After adjustment for age, cholesterol, smoking, blood pressure, body mass index, and years of education, mean differences decreased but still remained substantial and statistically significant (0.010 mPa.s; 95% CI, 0.003 to 0.018 mPa.s [P = .009] for winter activity; and 0.010 mPa.s; 95% CI, 0.002 to 0.017 mPa.s [P = .011] for summer activity). Similar results were found in women. WA showed no appreciable association with plasma viscosity after controlling for the covariates.

CONCLUSIONS

LTPA is inversely associated with plasma viscosity, independent of other risk factors, whereas WA shows no material effect in men and women. Decreased plasma viscosity may represent one mechanism through which LTPA confers a decrease of CHD risk.

Fibrinogen levels and exercise. Is there a relationship?

Haemostatic disturbances associated with elevated plasma fibrinogen levels have been implicated in coronary heart disease. Changes involving plasma fibrinogen levels have been reported after acute exercise. However, the results reported have sometimes been controversial, due to differences in the populations studied, exercise protocols and testing procedures, and the analytical methods employed for the assessment of plasma fibrinogen levels. The influence of physical training on plasma fibrinogen levels is more controversial and less well known. Cross-sectional studies suggest that regular exercise reduces plasma fibrinogen concentration. However, the influence of training programmes on plasma fibrinogen levels is less well studied and the available data are still poor with conflicting results being reported. This lack of evidence warrants further investigations in order to clarify the exact effects of acute exercise and physical training on plasma fibrinogen levels in normal healthy individuals and patients.

The acute rise in plasma fibrinogen concentration with exercise is influenced by the G-453-A polymorphism of the beta-fibrinogen gene

We have investigated the effects of chronic physical training and acute intensive exercise on plasma fibrinogen levels and the relationship of these responses to beta-fibrinogen G-453-A polymorphism genotype. One hundred fifty-six male British Army recruits were studied at the start of their 10-week basic training, which emphasizes physical fitness. Cohorts were restudied between 0.5 and 5 days after a major 2-day strenuous military exercise (ME) undertaken in their final week of training. Changes in fibrinogen concentration were adjusted for the effects of age, body mass index, and smoking history. Compared with baseline values, fibrinogen concentrations were significantly lower (11.9%, P=.04) at day 5 after ME, consistent with the beneficial effect of training. However, they were higher on days 1 through 3 after ME (suggesting an "acute-phase" response to strenuous exercise) and were maximal on days 1 and 2 (27.2%, P<.001 and 37.1%, P<.001 respectively). Fibrinogen genotype was available in 149 individuals. As expected from previous studies, men with one or more fibrinogen gene A-453 alleles had plasma fibrinogen concentration slightly but significantly higher at baseline (4.5%, P=.11). During the acute-phase response (days 2 and 3), however, the degree of rise was strongly related to the presence of the A allele, being 26.7+/-5.4% (mean+/-SE), 36.5+/-11.0%, and 89.2+/-30.7 for the GG, GA, and AA genotypes, respectively (P=.01). These results confirm that chronic exercise training lowers plasma fibrinogen levels, that intensive exercise generates an acute-phase rise in levels, and that this acute response is strongly influenced by the G/A polymorphism of the beta-fibrinogen gene.

Regular exercise reduces fibrinogen levels: a review of longitudinal studies

Fibrinogen can be considered as a major cardiovascular risk factor. Therefore there is a growing interest in methods to lower its plasma level. This paper is aimed at reviewing the data investigating the effects of regular exercise on plasma fibrinogen levels. Cross-sectional studies strongly suggest that regular exercise will reduce fibrinogen levels, and longitudinal data confirm this. The average decrease achieved by regular endurance exercise over several months is around 0.4 g/l. It can be extrapolated that this corresponds to a substantial decrease in risk of coronary heart disease. It is concluded that regular exercise is the most practicable approach known to date to lower plasma fibrinogen levels.

The role of fibrinogen as a cardiovascular risk factor

Several epidemiological studies have produced longitudinal data identifying fibrinogen as a major cardiovascular risk factor. Cross-sectional results show strong associations between fibrinogen and a variety of demographic variables, cardiovascular risk factors, or diseases. Clinical cohort studies demonstrate that fibrinogen might also be a risk factor for the sequelae of cardiovascular disease. Knowledge about the determinants of the plasma level of fibrinogen in health and disease is as yet incomplete. Understanding of the mechanisms leading to the atherothrombogenic action of fibrinogen is also fragmentary. Fibrinogen strongly affects blood coagulation, blood rheology and platelet aggregation; in addition fibrinogen and its metabolites have direct effects on the vascular wall. Finally, fibrinogen is a prominent acute phase protein. All of these phenomena might provide some insight into the pathophysiological mechanisms involved. It is concluded that fibrinogen represents a major, independent risk factor that should now be included into the cardiovascular risk profile.