Exercise and cardiovascular disease: a new perspective

The Influence of Exercise on Oxidative Stress after Spinal Cord Injury: A Narrative Review

Spinal cord injury (SCI) is an irreversible disease resulting in partial or total loss of sensory and motor function. The pathophysiology of SCI is characterized by an initial primary injury phase followed by a secondary phase in which reactive oxygen species (ROSs) and associated oxidative stress play hallmark roles. Physical exercise is an indispensable means of promoting psychophysical well-being and improving quality of life. It positively influences the neuromuscular, cardiovascular, respiratory, and immune systems. Moreover, exercise may provide a mechanism to regulate the variation and equilibrium between pro-oxidants and antioxidants. After a brief overview of spinal cord anatomy and the different types of spinal cord injury, the purpose of this review is to investigate the evidence regarding the effect of exercise on oxidative stress among individuals with SCI.

Aging, aerobic exercise, and cardiovascular health: Barriers, alternative strategies and future directions

Age-associated cardiovascular (CV) dysfunction, namely arterial dysfunction, is a key antecedent to the development of CV disease (CVD). Arterial dysfunction with aging is characterized by impaired vascular endothelial function and stiffening of the large elastic arteries, each of which is an independent predictor of CVD. These processes are largely mediated by an excess production of reactive oxygen species (ROS) and an increase in chronic, low-grade inflammation that ultimately leads to a reduction in bioavailability of the vasodilatory molecule nitric oxide. Additionally, there are other fundamental aging mechanisms that may contribute to excessive ROS and inflammation termed the "hallmarks of aging"; these additional mechanisms of arterial dysfunction may represent therapeutic targets for improving CV health with aging. Aerobic exercise is the most well-known and effective intervention to prevent and treat the effects of aging on CV dysfunction. However, the majority of mid-life and older (ML/O) adults do not meet recommended exercise guidelines due to traditional barriers to aerobic exercise, such as reduced leisure time, motivation, or access to fitness facilities. Therefore, it is a biomedical research priority to develop and implement time- and resource-efficient alternative strategies to aerobic exercise to reduce the burden of CVD in ML/O adults. Alternative strategies that mimic or are inspired by aerobic exercise, that target pathways specific to the fundamental mechanisms of aging, represent a promising approach to accomplish this goal.

The Effect of 13 Weeks Long-Distance Bicycle Riding on Inflammatory Response Indicators Related to Joint Cartilage and Muscle Damage

This study was to investigate the effects of 13 weeks of long-distance cycling on biomarkers of joint cartilage, muscle damage and inflammation. All subjects in this study were seven participants of the “One Korea New-Eurasia Peace Cycle Expedition”, in which they rode cycles from Berlin, Germany to Seoul, Korea for thirteen weeks. The total course of the expedition was divided into three sub-courses: course 1 (from Berlin to Moscow), course 2 (from Moscow to Ulaanbaatar) and course 3 (from Ulaanbaatar to Seoul). All the selected participants rode 87.4 km/day (course 1), 70.4 km/day (course 2) and 57.6 km/day (course 3) on average, respectively. We collected their blood samples before the expedition in Seoul (S1), after course 1 in Moscow (M), after course 2 in Ulaanbaatar (U) and after the expedition in Seoul (S2), to analyze biomarkers of joint cartilage damage (Cartilage Oligomeric Matrix Protein; COMP), muscle damage (Creatine Phosphokinase; CPK, Lactate Dehydrogenase; LDH, Myoglobin), inflammation (Interleukin-6; IL-6, Interleukin-1β; IL-1β, Tumor Necrosis Factor-α; TNF-α, C-Reactive Protein; CRP) and stress hormone (Cortisol). According to this result, COMP (S1; 188.37 ± 46.68 ng/mL) showed a significant increase after the expedition course 1 (M; 246.69 ± 51.69 ng/mL, p = 0.012) and course 2 (U; 237.09 ± 62.57 ng/mL, p = 0.047), and recovered to the stable state after expedition course 3 (S2; 218.46 ± 34.78. p = 0.047). Biomarkers of muscle damage (CPK, LDH and Myoglobin) and inflammation (IL-6, IL-1β, TNF-α and CRP) were not significantly changed in all courses, but CRP (S1; 1.07 ± 0.76 ng/mL) showed a tendency to decrease after the expedition course 1 (M; 0.3 ± 0.1 mg/mL, p = 0.044). Lastly, the Cortisol level significantly increased in all courses (per p < 0.05), but the Cortisol level after expedition course 3 (S2; 21.00 ± 3.65 mg/mL) was lower than that of after the expedition course 1 (M; 24.23 ± 2.47 mg/mL, p = 0.028). In summary, it seems that repetitive and continuous 50−90 km/day of cycling can increase joint cartilage damage risk and stress hormone temporarily. However, this result suggests that the appropriate intensity of cycling for thirteen weeks does not increase physical damage, and rather enhances the human body to adapt to exercise training.

Synergistic effects of exercise and catalase overexpression on gut microbiome

Exercise influences metabolic parameters in part by modulating redox stress and as recently suggested, by affecting the gut microbiome. However, whether excess endogenous antioxidant potentiates or interferes with the beneficial effects of exercise on the gut microbiome is not known. A comparison of the gut microbiome of C57Bl6 (C57/WT) mice to the 'stress-less' catalase overexpressing mice models ([Tg(CAT)± ] and Bob-Cat), that were either exercised or remained sedentary, showed differences in both alpha and beta diversity. The significant variation was explained by genotypes along with exercise, suggesting a synergistic relationship between exercise and genotypic traits. Linear discriminant analysis effect size (LEfSe) analysis also revealed differential taxa within the exercised/genotype cohorts in contrast to those within sedentary/genotype cohorts. Functional pathway predictions from PICRUSt2 showed enrichment for the metabolism of short-chain fatty acids, butanoate and propanoate pathways in exercised groups. Spearman correlations between enriched taxa and metabolic parameters showed correlations with body or fat weight in some of the cohorts. However, there were significant correlations of differential taxa among all cohorts against parameters that predict energy metabolism, such as respiratory exchange ratio and energy expenditure. Overall, our study showed that there was a synergistic beneficial influence of antioxidant overexpression and exercise on the gut microbiome.

OxLDL as an Inducer of a Metabolic Shift in Cancer Cells

Recent evidence established a link between disturbed lipid metabolism and increased risk for cancer. One of the most prominent features related to disturbed lipid metabolism is an increased production of oxidized low-density-lipoproteins (oxLDL), which results from elevated oxidative stress. OxLDL is known to have detrimental effects on healthy cells and plays a primary role in diseases related to the metabolic syndrome. Nevertheless, so far, the exact role of oxLDL in cancer cell metabolism is not yet known. To examine changes in metabolic profile induced by oxLDL, pancreatic KLM-1 cells were treated with oxLDL in a concentration- (25 or 50 µg/ml) and/or time-dependent (4 hr or 8 hr) manner and the impact of oxLDL on oxygen consumption rates (OCR) as well as extracellular acidification rates (ECAR) was analyzed using Seahorse technology. Subsequently, to establish the link between oxLDL and glycolysis, stabilization of the master regulator hypoxia-inducible factor 1-alpha (HIF-1α) was measured by means of Western blot. Furthermore, autophagic responses were assessed by measuring protein levels of the autophagosomal marker LC3B-II. Finally, the therapeutic potential of natural anti-oxLDL IgM antibodies in reversing these effects was tested. Incubation of KLM-1 cells with oxLDL shifted the energy balance towards a more glycolytic phenotype, which is an important hallmark of cancer cells. These data were supported by measurement of increased oxLDL-mediated HIF-1α stabilization. In line, oxLDL incubation also increased the levels of LC3B-II, suggesting an elevated autophagic response. Importantly, antibodies against oxLDL were able to reverse these oxLDL-mediated metabolic effects. Our data provides a novel proof-of-concept that oxLDL induces a shift in energy balance. These data not only support a role for oxLDL in the progression of cancer but also suggest the possibility of targeting oxLDL as a therapeutic option in cancer.

Role of Regular Physical Activity in Neuroprotection against Acute Ischemia

One of the major obstacles that prevents an effective therapeutic intervention against ischemic stroke is the lack of neuroprotective agents able to reduce neuronal damage; this results in frequent evolution towards a long-term disability with limited alternatives available to aid in recovery. Nevertheless, various treatment options have shown clinical efficacy. Neurotrophins such as brain-derived neurotrophic factor (BDNF), widely produced throughout the brain, but also in distant tissues such as the muscle, have demonstrated regenerative properties with the potential to restore damaged neural tissue. Neurotrophins play a significant role in both protection and recovery of function following neurological diseases such as ischemic stroke or traumatic brain injury. Unfortunately, the efficacy of exogenous administration of these neurotrophins is limited by rapid degradation with subsequent poor half-life and a lack of blood-brain-barrier permeability. Regular exercise seems to be a therapeutic approach able to induce the activation of several pathways related to the neurotrophins release. Exercise, furthermore, reduces the infarct volume in the ischemic brain and ameliorates motor function in animal models increasing astrocyte proliferation, inducing angiogenesis and reducing neuronal apoptosis and oxidative stress. One of the most critical issues is to identify the relationship between neurotrophins and myokines, newly discovered skeletal muscle-derived factors released during and after exercise able to exert several biological functions. Various myokines (e.g., Insulin-Like Growth Factor 1, Irisin) have recently shown their ability to protects against neuronal injury in cerebral ischemia models, suggesting that these substances may influence the degree of neuronal damage in part via inhibiting inflammatory signaling pathways. The aim of this narrative review is to examine the main experimental data available to date on the neuroprotective and anti-ischemic role of regular exercise, analyzing also the possible role played by neurotrophins and myokines.

The effectiveness of military physical exercise on irisin concentrations and oxidative stress among male healthy volunteers

Background Irisin, a newly discovered hormone, is secreted into the circulation from skeletal muscles in response to physical exercise. The biochemical parameters related to irisin secretion have not been sufficiently investigated yet. The aim of this study was to examine the effectiveness of exercise on the level of irisin and its correlation with biochemical and oxidative stress parameters. Materials and methods In this pre- and post-test observational study, 39 healthy male volunteers from a military training setting were followed up on between September and November 2015. The individuals who were included in this study were between 22 and 27 years old with an average age of 24. Those with inflammatory disorders or chronic diseases such as diabetes mellitus were excluded from the study. The parameters were measured at the baseline, at 4 weeks, and at 8 weeks of intervention. Results The study found that the systolic and diastolic blood pressures substantially decreased after 8 weeks of intervention. The cholesterol-to-HDL ratio and glucose levels were significantly higher at the baseline compared to 8 weeks. Total protein and albumin were significantly higher following 4 weeks (0.25 and 0.21 g/dL) and 8 weeks (0.32 and 0.16 g/dL), respectively. Meanwhile, total globulin and irisin increased following 8 weeks of the intervention by only 0.16 g/dL and 0.41 μg/mL, respectively. The high sensitivity C-reactive protein (hs-CRP) decreased following 8 weeks (-0.81 μg/mL). The protein carbonyl (PC) decreased following 4 weeks by only 0.34 nmol/L. Conclusions This study demonstrated that military training enhanced irisin hormone secretion following 8 weeks of military exercise.

Modifiable lifestyle risk factors and C-reactive protein in patients with coronary artery disease: Implications for an anti-inflammatory treatment target population

BACKGROUND

Modifiable lifestyle risk factors (modRF) of coronary artery disease (CAD) are associated with increased inflammation represented by elevated C-reactive protein (CRP) levels. Lifestyle changes may influence the inflammatory burden in patients with CAD, relevantly modifying the target population for emerging anti-inflammatory compounds.

AIMS

The aims of this study were to analyse the association of modRF and CRP levels in CAD patients, and to define a potential target population for anti-inflammatory treatment with and without the optimisation of modRF.

METHODS

We included all patients with angiographically documented CAD from the observational cohort study INTERCATH. Patients with recent myocardial infarction, malignancy, infectious disease, and pre-existing immunosuppressive medication including a history of solid organ transplantation were excluded. Overweight (body mass index (BMI) ≥ 25 kg/m2), smoking, lack of physical activity (PA; <1.5 h/week), and poor diet (≤12 points of an established Mediterranean diet score (MDS), range 0-28 points) were considered as modRF. CRP was measured by a high-sensitivity assay (hsCRP) at baseline. We performed multivariable linear regressions with log-transformed hsCRP as the dependent variable. Based on these associations, we calculated potential hsCRP levels for each patient, assuming optimisation of the individual modRF.

RESULTS

Of 1014 patients, 737 (73%) were male, the mean age was 69 years, and 483 (48%) had an hsCRP ≥ 2 mg/l. ModRF were significantly overrepresented in patients with hsCRP ≥ 2 mg/l compared to patients with an hsCRP < 2 mg/l (BMI ≥ 25 kg/m2: 76% vs 61%; PA < 1.5 h/week: 69% vs 57%; MDS ≤ 12: 46% vs 37%; smoking: 61% vs 54%; p < 0.05 for all). hsCRP increased with the incremental number of modRF present (median hsCRP values for N = 0, 1, 2, 3, and 4 modRF: 1.1, 1.0, 1.6, 2.4, 2.8 mg/l, p < 0.001). Multivariable linear regression adjusting for age, sex, intake of lipid-lowering medication, and diabetes mellitus revealed independent associations between log-transformed hsCRP and all modRF (BMI ≥ 25 kg/m2: exp(ß) = 1.55, p < 0.001; PA < 1.5 h/week: exp(ß) = 1.33, p < 0.001; MDS ≤ 12: exp(ß) = 1.18, p = 0.018; smoking: exp(ß) = 1.18, p = 0.019). Individual recalculation of hsCRP levels assuming optimisation of modRF identified 183 out of 483 (38%) patients with hsCRP ≥ 2 mg/l who could achieve an hsCRP < 2 mg/l via lifestyle changes.

CONCLUSION

modRF are strongly and independently associated with CRP levels in patients with CAD. A relevant portion of CAD patients with high inflammatory burden could achieve an hsCRP < 2 mg/l by lifestyle changes alone. This should be considered both in view of the cost and side-effects of pharmacological anti-inflammatory treatment and for the design of future clinical trials in this field.

Effect of Exercise on Behavioral Symptoms and Pain in Patients With Dementia Living in Nursing Homes

OBJECTIVES

Examine the effects of a 6-month exercise intervention on neuropsychiatric symptoms, pain, and medication consumption in older people with dementia (PWD) living in nursing homes (NH).

METHODS

Ninety-one older PWD living in NH performed a 6-month structured exercise intervention (n = 44) or a social activity intervention (n = 47). Neuropsychiatric symptoms were measured by the neuropsychiatric inventory (NPI), pain was assessed using the Algoplus scale, and dementia-related drug prescriptions were obtained for all participants.

RESULTS

Between-group analysis found a nonsignificant difference that could be of clinical relevance: a 4-point difference in the NPI and 1.3-point difference in the reduction of the number of medications favoring exercisers. No significant differences were found for pain, and a trend was found for an increase in medication consumption in the social group.

CONCLUSION

Exercise effects did not differ from social intervention effects on neuropsychiatric symptoms, pain, and medication consumption in older PWD living in NH.

Does Physical Activity-Based Intervention Improve Systemic Proinflammatory Cytokine Levels in Overweight or Obese Children and Adolescents? Insights from a Meta-Analysis of Randomized Control Trials

OBJECTIVES

The purpose of this research was to conduct a meta-analysis of the role that physical activity (PA) plays in influencing the critical proinflammatory cytokine levels associated with overweight/obese children and adolescents to explore the effectiveness of exercise intervention within this population.

METHODS

With searches of the PubMed, EMBASE, and CENTRAL databases, we updated our meta-analysis up to November 2018. The randomized controlled trials (RCT) evaluated the ability of exercise training to increase the following factors in children and/or adolescents classified as obese or overweight: tumor necrosis factor (TNF)-α, interleukin (IL)-6, and C-reactive protein (CRP).

RESULTS

Eleven RCT comprising 623 children and/or adolescents who were obese or overweight (i.e., 393 with PA and 230 controls) were suitable for use in this study. The meta-analysis showed that PA in general was associated with a significant reduction of CRP levels (mean difference = -0.45 mg/L, p = 0.02) in overweight/obese children and adolescents. Based on 115 overweight and obese youths, this study suggests that PA does not significantly mitigate IL-6 levels (mean difference = -0.39 pg/mL, p = 0.08), although there was a trend towards a reduction. Additionally, no close connection was observed between PA and TNF-α levels at 0.04 pg/mL (p = 0.78). Moreover, meta-regression analysis revealed a statistical association between CPR levels and changes in BMI or changes in adiponectin; likewise, IL-6 levels dramatically impacted the effect of exercise on changes in adiponectin.

CONCLUSIONS

PA was associated with significantly reduced CRP levels, whereas there was no significant association with IL-6 or TNF-α in overweight/obese children or adolescents; however, there was a trend towards a reduction of IL-6.

Changes in oxidized LDL during a half marathon in athletes with spinal cord injuries

Introduction:

We reported previously that exercise significantly increases plasma adrenaline and oxidized low-density lipoprotein (oxLDL) in healthy subjects but not in persons with spinal cord injury (SCI). Since oxLDL and adrenaline levels are associated with oxidant/antioxidant balance, and exercise training elicits production of reactive oxygen species, we elucidated the effects of exercise on adrenaline, oxidant/antioxidant balance and oxLDL in individuals with SCI.

Case Presentation:

Eight subjects with cervical spinal cord injury (CSCI) and nine subjects with lower lesion of SCI (lower SCI (LSCI)) participated in a wheelchair half marathon race, and blood samples were collected before (pre), immediately after (post) and 1 h after the race (post 1 h). The blood samples were used to determine adrenaline, derivatives of reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP), both as markers for oxidant/antioxidant balance.

Discussion:

Pre-serum oxLDL levels were 147.2±8.1 and 97.0±10.4 U l⁻¹ (mean±s.e.m.) in LCSI and CSCI subjects, respectively, and remained stable throughout the study. Adrenaline levels were higher in LSCI athletes than in CSCI athletes, especially post half marathon. Serum d-ROMs level did not change between pre and post in both groups. The mean BAP was significantly higher in LSCI than in CSCI subjects (2574±94.6 vs 2118±94.6 μmol l⁻¹) at post, whereas the oxidative stress index (d-ROMs/BAP) was similar in the two groups throughout the study. In conclusion, exercise did not increase the d-ROMs or d-ROMs/BAP ratio in CSCI and LSCI subjects. The lack of increase in the plasma oxLDL level in SCI subjects was not due to the lack of response of adrenaline to exercise.

Arterial Thickness and Immunometabolism: The Mediating role of Chronic Exercise

Metabolic alterations and cardiovascular diseases, such as atherosclerosis, are associated with lifestyle modifications, particularly the increase of physical inactivity and poor eating habits, which contribute to one of the main causes of death in modern times. Cardiovascular diseases are positively correlated with several illnesses, such as obesity, hypertension and dyslipidemia, and these disorders are known to contribute to changes in immune cells, cytokines and metabolism. Atherosclerosis is a chronic inflammatory disease characterized by the formation of lipid plaques and fibrous tissue (atheroma) in the artery walls and this process is related to the oxidation of LDL-c (low density lipoprotein) and the formation of a particle, termed LDLox, which can generate toxic injury to the vessel wall. In this atherogenic process there is an inflammatory response generated by the injury in the vascular endothelium, which in itself is able to express and secrete a variety of molecules, such as myeloid colony-stimulating factors (M-CSF), monocyte chemotactic protein-1 (MCP-1) and tumor necrosis factor alpha (TNF-α), that act as activators of the immune system. Therefore, the main purpose of this review is to highlight the immuno-metabolic alterations involving the thickening and stiffness of arteries observed in atherosclerosis, and how chronic exercise can act as an anti-inflammatory and anti-atherogenic approach.

Acute modification in plasma lipid levels in ultramarathon runners

We aimed to evaluate the effects of a 24-h ultramarathon, an aerobic test of high physical load, on lipid profile and apolipoproteins B (ApoB) and A1 (ApoA1) levels, minimally modified low-density lipoprotein (LDL), and oxidised LDL. Prospective evaluation of 16 male athletes who participated in an ultramarathon run, where the objective was to run the greatest distance possible in 24 h. Fourteen participants completed the run. The mean distance achieved was 133.1 km (maximum of 169.6 km). There was a trend in reduction of triglycerides and total cholesterol (P = 0.06 and 0.05, respectively), without significant modifications in high-density lipoprotein, LDL and ApoA1 levels (P = 0.16; 0.55 and 0.67). There was a marked reduction in ApoB levels (P < 0.001), correlated directly to the distance covered (Pearson R = 0.68). Accordingly, an increase in the LDL/ApoB ratio was observed. The stress of this physical activity was not associated to an increase in minimally modified LDL or oxidised LDL. Lipid profile levels were not acutely altered by prolonged physical activity. Similarly, there was no evidence of greater oxidation of LDL over a 24-h period of physical activity. The reduction in ApoB was directly proportional to the distance covered, suggesting an acute positive change in phenotype of LDL molecules.

MAP kinase phosphatase DUSP1 is overexpressed in obese humans and modulated by physical exercise

Chronic low-grade inflammation and dysregulation of the stress defense system are cardinal features of obesity, a major risk factor for the development of insulin resistance and diabetes. Dual-specificity protein phosphatase 1 (DUSP1), known also as MAP kinase phosphatase 1 (MKP1), is implicated in metabolism and energy expenditure. Mice lacking DUSP1 are resistant to high-fat diet-induced obesity. However, the expression of DUSP1 has not been investigated in human obesity. In the current study, we compared the expression pattern of DUSP1 between lean and obese nondiabetic human subjects using subcutaneous adipose tissue (SAT) and peripheral blood mononuclear cells (PBMCs). The levels of DUSP1 mRNA and protein were significantly increased in obese subjects with concomitant decrease in the phosphorylation of p38 MAPK (p-p38 MAPK) and PGC-1α and an increase in the levels of phospho-JNK (p-JNK) and phospho-ERK (p-ERK). Moreover, obese subjects had higher levels of circulating DUSP1 protein that correlated positively with various obesity indicators, triglycerides, glucagon, insulin, leptin, and PAI-1 (P < 0.05) but negatively with V̇O(2max) and high-density lipoprotein (P < 0.05). The observation that DUSP1 was overexpressed in obese subjects prompted us to investigate whether physical exercise could reduce its expression. In this study, we report for the first time that physical exercise significantly attenuated the expression of DUSP1 in both the SAT and PBMCs, with a parallel increase in the expression of PGC-1α and a reduction in the levels of p-JNK and p-ERK along with attenuated inflammatory response. Collectively, our data suggest that DUSP1 upregulation is strongly linked to adiposity and that physical exercise modulates its expression. This gives further evidence that exercise might be useful as a strategy for managing obesity and preventing its associated complications.

Endurance exercise accelerates myocardial tissue oxygenation recovery and reduces ischemia reperfusion injury in mice

Exercise training offers cardioprotection against ischemia and reperfusion (I/R) injury. However, few essential signals have been identified to underscore the protection from injury. In the present study, we hypothesized that exercise-induced acceleration of myocardial tissue oxygenation recovery contributes to this protection. C57BL/6 mice (4 weeks old) were trained on treadmills for 45 min/day at a treading rate of 15 m/min for 8 weeks. At the end of 8-week exercise training, mice underwent 30-min left anterior descending coronary artery occlusion followed by 60-min or 24-h reperfusion. Electron paramagnetic resonance oximetry was performed to measure myocardial tissue oxygenation. Western immunoblotting analyses, gene transfection, and myography were examined. The oximetry study demonstrated that exercise markedly shortened myocardial tissue oxygenation recovery time following reperfusion. Exercise training up-regulated Kir6.1 protein expression (a subunit of ATP-sensitive K(+)channel on vascular smooth muscle cells, VSMC sarc-K(ATP)) and protected the heart from I/R injury. In vivo gene transfer of dominant negative Kir6.1AAA prolonged the recovery time and enlarged infarct size. In addition, transfection of Kir6.1AAA increased the stiffness and reduced the relaxation capacity in the vasculature. Together, our study demonstrated that exercise training up-regulated Kir6.1, improved tissue oxygenation recovery, and protected the heart against I/R injury. This exercise-induced cardioprotective mechanism may provide a potential therapeutic intervention targeting VSMC sarc-K(ATP) channels and reperfusion recovery.

Physical exercise reduces the expression of RANTES and its CCR5 receptor in the adipose tissue of obese humans

RANTES and its CCR5 receptor trigger inflammation and its progression to insulin resistance in obese. In the present study, we investigated for the first time the effect of physical exercise on the expression of RANTES and CCR5 in obese humans. Fifty-seven adult nondiabetic subjects (17 lean and 40 obese) were enrolled in a 3-month supervised physical exercise. RANTES and CCR5 expressions were measured in PBMCs and subcutaneous adipose tissue before and after exercise. Circulating plasma levels of RANTES were also investigated. There was a significant increase in RANTES and CCR5 expression in the subcutaneous adipose tissue of obese compared to lean. In PBMCs, however, while the levels of RANTES mRNA and protein were comparable between both groups, CCR5 mRNA was downregulated in obese subjects (P < 0.05). Physical exercise significantly reduced the expression of both RANTES and CCR5 (P < 0.05) in the adipose tissue of obese individuals with a concomitant decrease in the levels of the inflammatory markers TNF-α, IL-6, and P-JNK. Circulating RANTES correlated negatively with anti-inflammatory IL-1ra (P = 0.001) and positively with proinflammatory IP-10 and TBARS levels (P < 0.05). Therefore, physical exercise may provide an effective approach for combating the deleterious effects associated with obesity through RANTES signaling in the adipose tissue.

Impact of endovascular therapy on oxidative stress in patients with peripheral artery disease

BACKGROUND

Atherosclerosis is believed to be caused by oxidative stress. Endovascular therapy (EVT) is effective for claudication of patients with peripheral artery disease (PAD). However, its effect on oxidative stress in PAD patients is unknown. Here, the impact of EVT on oxidative stress in PAD patients is investigated.

METHODS AND RESULTS

Twenty-five PAD patients (Rutherford stage II or III) who underwent EVT were enrolled. The levels of diacron-reactive oxygen metabolite (d-ROM; an oxidative stress marker), ankle-brachial index (ABI), and maximum walking distance at baseline and at 3 months after EVT were measured. As compared with baseline values, the maximum walking distance and ABI improved significantly after EVT (109.9±104.2 vs. 313.7±271.8m, P<0.0001; 0.61±0.15 vs. 0.91±0.13m, P<0.0001, respectively). The improved exercise capacity and arterial flow induced a significant decrease in d-ROM levels (from 472.8±64.8 to 390.2±46.7U.CARR; P<0.0001). The decrease in d-ROM levels after EVT was more prominent in PAD patients with a high baseline d-ROM level. The increased ABI (r=0.524, P=0.0007) and maximum walking distance (r=-0.416, P=0.039) after EVT were significantly correlated with the decreased d-ROM levels.

CONCLUSIONS

The improved exercise capacity and peripheral blood flow induced by EVT decreases oxidative stress in PAD patients.

The thioredoxin system as a therapeutic target in human health and disease

The thioredoxin (Trx) system comprises Trx, truncated Trx (Trx-80), Trx reductase, and NADPH, besides a natural Trx inhibitor, the thioredoxin-interacting protein (TXNIP). This system is essential for maintaining the balance of the cellular redox status, and it is involved in the regulation of redox signaling. It is also pivotal for growth promotion, neuroprotection, inflammatory modulation, antiapoptosis, immune function, and atherosclerosis. As an ubiquitous and multifunctional protein, Trx is expressed in all forms of life, executing its function through its antioxidative, protein-reducing, and signal-transducing activities. In this review, the biological properties of the Trx system are highlighted, and its implications in several human diseases are discussed, including cardiovascular diseases, heart failure, stroke, inflammation, metabolic syndrome, neurodegenerative diseases, arthritis, and cancer. The last chapter addresses the emerging therapeutic approaches targeting the Trx system in human diseases.

Analysis of oxidative stress during the menstrual cycle

BACKGROUND

Few data concerning the oxidative stress (OS) in plasma during the entire menstrual cycle of eumenorrheic women are available.

METHODS

OS was assessed in 20 healthy volunteers during the phase of the menstrual cycle by determining the plasmatic hydroperoxides levels (d-ROMs test). The assessment was performed every three days, starting from the first day (t1) up the end of the menstrual phase (t27). Concomitantly, the estrogen (E2) and progestin (P4) levels were determined at the same time intervals.

RESULTS

From a base value (t1) of 284 +/- 38.0 CARR.U., which is essentially within the normal range (<300 Carratelli units or CARR.U.), the OS levels progressively increased to 378 +/- 115 CARR.U. at t15, and then slightly decreased over the subsequent time but with average values >300 CARR.U. Analysis of the E2 levels showed that the maximum OS values were noticed near the estrogen peak, while remaining above the base levels, and then decreased during the progestin phase until returning to normal at the end of the menstrual cycle.

CONCLUSIONS

It may concludes that the healthy women go into OS for 2/3 of the menstrual cycle.

Vitamin E differentially affects short term exercise induced changes in oxidative stress, lipids, and inflammatory markers

BACKGROUND AND AIM

Physical activity or exercise is a proven deterrent of cardiovascular diseases. The purpose of this study was to examine whether vitamin E supplementation interfere with the potential benefits of exercise.

METHODS AND RESULTS

A total of 455 apparently healthy men and women were recruited, for a 2-month aerobic/cardiovascular exercise program. Subjects were randomly assigned for soft gel vitamin E or placebo (800 IU), and required to give blood at 0, 2, 4 and 8 weeks of exercise. Levels of lipid and markers of oxidative stress and inflammation were measured along with the VO2 and duration time spent on treadmill. Statistical analysis did not show significant changes in the levels of lipids and markers of oxidative stress and inflammation. Favorable trends among both of the randomization groups were observed in lipids, and some of the oxidative stress and inflammatory markers. This study also established several interesting correlations between VO2, and lipids on one hand and markers of oxidation and inflammation on the other hand. Reduction in LDL levels positively associated with increased levels of MCP-1 (P < 0.008) among placebo group, and also decreased hCRP levels strongly correlated with the increases in VO2 (P < 0.0004) among the placebo, and vitamin E subjects (P < 0.01).

CONCLUSIONS

Exercise training induces oxidative stress might be instrumental in favorable lipid reduction and markers of oxidative stress and inflammation. However interestingly, vitamin E didn't demonstrate favorable effects on the level of oxidative stress and inflammation associated with exercise.

Combined effects of exercise and soy isoflavone diet on paraoxonase, nitric oxide and aortic apoptosis in ovariectomized rats

Menopause is associated with an increased risk of cardiovascular disease (CVD). Exercise and soy isoflavone diets have been suggested to reduce the risk of CVD in postmenopausal women. We investigated the effects of exercise, or combined exercise and soy isoflavone diet, on plasma lipid profiles, paraoxonase (PON), nitric oxide (NO) and apoptosis in the aorta of ovariectomized (OVX) rats. Thirty-two female Sprague-Dawley rats were divided into four groups: OVX with general diet (OVX-GD), OVX with isoflavone diet (OVX-ISO), OVX-GD with exercise training (OVX-ET) and OVX-ISO with exercise training (OVX-ISO+ET). The experimental rats undertook treadmill training (30 min/day, 4 days/week) and/or were supplied a soy isoflavone diet (added to the experimental diet at 2.39 mg/g protein) for 12 weeks. Body weight and levels of total cholesterol (TC), triglyceride (TG), LDL-cholesterol (LDL-C) increased in the OVX rats and HDL-C decreased. These effects were reduced by exercise and/or soy isoflavone supplementation. PON and NO activities were higher in the OVX-ISO+ET group than in the OVX-GD group. In addition, this group had lower caspase-9 and -3 and higher Bcl-2 expression, and there was less aortic apoptotic cell death. These results suggest that a combination of exercise and a soy isoflavone diet has beneficial effects in terms of protecting against cardiovascular risk factors by controlling lipid profiles and the related enzyme, PON, as well as NO activity and apoptosis of the aorta in OVX rats.

Superoxide dismutases: role in redox signaling, vascular function, and diseases

Excessive reactive oxygen species Revised abstract, especially superoxide anion (O₂•-), play important roles in the pathogenesis of many cardiovascular diseases, including hypertension and atherosclerosis. Superoxide dismutases (SODs) are the major antioxidant defense systems against (O₂•-), which consist of three isoforms of SOD in mammals: the cytoplasmic Cu/ZnSOD (SOD1), the mitochondrial MnSOD (SOD2), and the extracellular Cu/ZnSOD (SOD3), all of which require catalytic metal (Cu or Mn) for their activation. Recent evidence suggests that in each subcellular location, SODs catalyze the conversion of (O₂•-), H2O2, which may participate in cell signaling. In addition, SODs play a critical role in inhibiting oxidative inactivation of nitric oxide, thereby preventing peroxynitrite formation and endothelial and mitochondrial dysfunction. The importance of each SOD isoform is further illustrated by studies from the use of genetically altered mice and viral-mediated gene transfer. Given the essential role of SODs in cardiovascular disease, the concept of antioxidant therapies, that is, reinforcement of endogenous antioxidant defenses to more effectively protect against oxidative stress, is of substantial interest. However, the clinical evidence remains controversial. In this review, we will update the role of each SOD in vascular biologies, physiologies, and pathophysiologies such as atherosclerosis, hypertension, and angiogenesis. Because of the importance of metal cofactors in the activity of SODs, we will also discuss how each SOD obtains catalytic metal in the active sites. Finally, we will discuss the development of future SOD-dependent therapeutic strategies.

Inflammatory cytokine profiles during exercise in obese, diabetic, and healthy children

OBJECTIVE

Modulation of inflammatory status is considered a key component of the overall health effects of exercise. This may be especially relevant in children with obesity (Ob) or type 1 diabetes (T1DM), in which an imbalance between pro- and anti-inflammatory mediators could accelerate onset and progression of cardiovascular complications. To date, exercise-induced alterations in immuno-modulatory mediators in Ob and T1DM children remain largely unknown.

METHODS

In this study, we monitored the kinetic profiles of 8 pro-and anti-inflammatory cytokines (TNF-a, IL-6, IL-2, IL-8, IL-5, IL-13, IL-10, IL-4) during a standardized exercise challenge (ten 2-min cycling bouts at 80% VO2max, separated by 1-min intervals) in 23 Ob (12 females, 11 males), 23 T1DM (10 females and 13 males) patients and 20 healthy (CL, 10 females and 10 males) children. Blood glucose of T1DM patients was kept in the 4.4-6.1 mM range for at least 90 minute prior to and during exercise. Blood samples were drawn at rest and after every other exercise bout.

RESULTS

In Ob, TNF-a and IL-2 were significantly greater (p<0.0167) as compared to T1DM and CL, both at baseline and throughout exercise. All other variables, while not significant, were quantitatively elevated in Ob vs. CL. In T1DM, IL-4 and IL-8 levels were similar to Ob, IL-2 and TNF-a similar to CL, and IL-6, IL-5, IL-13, IL-4 levels were intermediate between the Ob and CL groups.

CONCLUSIONS

During exercise, therefore, both Ob and T1DM children displayed exaggerated pro-inflammatory responses, although with clearly different magnitude and involved mediators. Our data support the necessity to identify specific exercise formats through which each at-risk pediatric population can draw maximal beneficial health effects.

Assessment of the activity of an oral contraceptive on the levels of oxidative stress and changes in oxidative stress after co-treatment with two different types of physiological modulators with antioxidant action

BACKGROUND

The aims of this research were to document the nature of oxidative stress (OS) while taking an estrogen/progestagen-combined oral contraceptive (OC) and to evaluate the action of two different products composed of a combination of antioxidant, vitamins and natural products in physiological quantity and classified as antioxidant/food supplement. For this reason, the two products are classified as physiological modulators (PM), able to restore the balance between antioxidants and reactive oxygen species in the organism.

STUDY DESIGN

The Reactive Oxygen Metabolites-derived compound test, a photometric assay that measures the hydroperoxides levels in biological fluids, was used to determine the OS. OS was analyzed every 3 days (from t(1) to t(27)) for 28 days on 10 healthy volunteers during three successive OC treatment cycles with a contraceptive (Microgynon®: ethinylestradiol 50 mcg plus levonorgestrel 125 mcg). In the first cycle, the OC was administered by itself; in the successive two cycles, the OC was administered in association in an open crossover study with two different types of PMs with antioxidant action. The main difference in the composition of the two products is the presence/absence of catechins from green tea.

RESULTS

With just OC treatment, all the volunteers showed an increase in the OS values from 240±22.3 (mean±SD) Carratelli Units. (normal value) up to values >400 Carratelli Units (severe OS), then returned to normal when the OC therapy was suspended. The concomitant use of the two PMs showed that only the product containing green tea catechins was able to reduce the OS values, on average, by approximately 50% (t test p<.05).

CONCLUSION

We conclude that to control the OS generated by OC, specific types of physiological modulators are needed.

Reducing oxidized lipids to prevent cardiovascular disease

Despite significant success in reducing plasma cholesterol, especially low-density lipoprotein cholesterol, risks for cardiovascular disease (CVD) complications remain. Among these risks are circulating levels of oxidative modified lipoproteins, primarily oxidized low-density lipoproteins (oxLDL). The evidence supporting oxLDL as a potential target for therapeutic management to reduce metabolic complications and CVD events is reviewed in this report.

Physical inactivity and cardiovascular risk: baseline observations from men and premenopausal women

INTRODUCTION

Physical activity or exercise is a proven deterrent of cardiovascular (CV) diseases.

PURPOSE

In this study, we examined the relationships between baseline values of parameters related to physical activity and known markers of CV disease, including markers of oxidative stress.

METHODS

A total of 455 healthy men and women between the ages of 18 and 50 were recruited to participate in the study. Levels of lipids/lipoproteins and markers of oxidative stress and inflammation were measured along with the VO(2) and duration time spent on treadmill.

RESULTS

Women, in general, had a significantly (P<0.0001) higher plasma high density lipoprotein (1.51+/-0.30 mmol/l), decreased (P<0.0001) low density lipoprotein (LDL) (2.75+/-0.66 mmol/l), and decreased (P<0.0001) triglycerides levels (2.09+/-0.85 mmol/l), compared with males (1.21+/-0.23 mmol/l, 2.92+/-0.81 mmol/l, and 3.02+/-1.34 mmol/l, respectively). There was a direct correlation between the levels of plasma LDL and the levels oxidized LDL levels (P<0.0001) in both men and women. Despite a better antiatherogenic lipid profile, the levels of C-reactive protein in women were significantly (P<0.0001) elevated (3.78+/-3.66 ng/ml) as compared with those in men (1.82+/-2.37 ng/ml).

CONCLUSION

These results suggest intrinsic sex differences between men and women in relation to atherogenic risk.

Is exercise training an effective therapy targeting endothelial dysfunction and vascular wall inflammation?

There is an increasing evidence that endothelial dysfunction and vascular wall inflammation are present in all stages of atherosclerosis. Atherosclerosis does not have to necessarily progress to an acute clinical event. Several therapeutic strategies exist, such as exercise training, which mitigates endothelial dysfunction and inflammation. Exercise training consistently improves the nitric oxide bioavailability, and the number of endothelial progenitor cells, and also diminishes the level of inflammatory markers, namely pro-inflammatory cytokines and C-reactive protein. However, the mechanisms by which exercise improves endothelial function in coronary artery disease patients are not fully clarified. Several mechanisms have been proposed to explain the positive effect of exercise on the disease progression. They include the decrease in cytokine production by the adipose tissue, skeletal muscles, endothelial cells, and blood mononuclear cells, and also, the increase in the bioavailability of nitric oxide, antioxidant defences, and regenerative capacity of endothelium. This study aims to provide a critical review of the literature linking exercise, inflammation, and endothelial dysfunction in coronary artery patients, and to discuss the potential mechanisms behind the exercise-training improvement of endothelial function and inflammatory status.

Inflammatory markers and visceral fat are inversely associated with maximal oxygen consumption in women with polycystic ovary syndrome (PCOS)

BACKGROUND

We investigated whether several different inflammatory markers including C-reactive protein (CRP) and fibrinogen and white blood cells (WBCs) count, are associated with maximal oxygen consumption (VO(2 max)) in women with polycystic ovary syndrome (PCOS).

METHODS

In PCOS women (n = 124, 24.1 +/- 4.5 year-old) VO(2 max) was measured during symptom-limited cardiopulmonary exercise test. Abdominal fat distribution was determined by ultrasound. Physical activity level was assessed by a standardized questionnaire. CRP was measured by immunoassays, fibrinogen by the Clauss method, and WBCs count with a Coulter counter.

RESULTS

Pearson's analysis showed a significant correlation between VO(2 max) and logCRP (r = -0.437, P < 0.001), fibrinogen (r = -0.479, P < 0.001), and WBCs count (r = -0.438, P < 0.001). Multivariable logistic regression model showed that age (beta = -0.127, P = 0.005), AUC(INS )(beta = -0.335, P < 0.001), HDL-C (beta = 0.390, P < 0.001), physical activity score (beta = 0.238, P = 0.002), visceral fat (beta =-0.184), P = 0.023), FAI (beta = -0.291, P = 0.028); CRP (beta = -0.216, P = 0.011), fibrinogen (beta = -0.113, P = 0.008) and WBCs count (beta = -0.177, P < 0.001) were significantly associated with VO(2 max).

CONCLUSIONS

Acute-phase reactants, such as CRP and fibrinogen, and WBCs count were independently and inversely associated with a direct measure of cardiorespiratory fitness (VO(2 max)) in women with PCOS, even after adjustment for physical activity level and other potential confounding factors. These findings add to the growing body of evidence linking inflammation to cardiorespiratory fitness in PCOS women.

Lipid peroxidation and decomposition--conflicting roles in plaque vulnerability and stability

The low density lipoprotein (LDL) oxidation hypothesis has generated considerable interest in oxidative stress and how it might affect atherosclerosis. However, the failure of antioxidants, particularly vitamin E, to affect the progression of the disease in humans has convinced even staunch supporters of the hypothesis to take a step backwards and reconsider alternatives. Preponderant evidence for the hypothesis came from animal antioxidant intervention studies. In this review we point out basic differences between animal and human atherosclerosis development and suggest that human disease starts where animal studies end. While initial oxidative steps in the generation of early fatty streak lesions might be common, the differences might be in the steps involved in the decomposition of peroxidized lipids into aldehydes and their further oxidation into carboxylic acids. We suggest that these steps may not be amenable to attenuation by antioxidants and antioxidants might actually counter the stabilization of plaque by preventing the formation of carboxylic acids which are anti-inflammatory in nature. The formation of such dicarboxylic acids may also be conducive to plaque stabilization by trapping calcium. We suggest that agents that would prevent the decomposition of lipid peroxides and promote the formation and removal of lipid hydroxides, such as paraoxonase (PON 1) or apo A1/high density lipoprotein (HDL) might be more conducive to plaque regression.

Markers of inflammation are inversely associated with V̇o2 max in asymptomatic men

We investigated whether markers of inflammation, including a cytokine (IL-6), acute-phase reactants [C-reactive protein (CRP) and fibrinogen], and white blood cell (WBC) count are associated with maximal O2 consumption (V̇o2 max) in men without coronary heart disease (CHD). In asymptomatic men ( n = 172, 51 ± 9.3 yr old), V̇o2 max was measured during a symptom-limited graded treadmill exercise test. Physical activity level was assessed by a standardized questionnaire. IL-6 and CRP were measured by immunoassays, fibrinogen by the Clauss method, and WBC count with a Coulter counter. IL-6 and CRP were logarithmically transformed to reduce skewness. Multivariable regression was used to assess whether markers of inflammation were associated with V̇o2 max after adjustment for age, body mass index, CHD risk factors, and lifestyle variables (physical activity level, percent body fat, and alcohol intake). V̇o2 max was 34.5 ml·kg−1·min−1 (SD 6.1). Log IL-6 ( r = −0.38, P < 0.001), log CRP ( r = −0.40, P < 0.001), fibrinogen ( r = −0.42, P < 0.001), and WBC count ( r = −0.22, P = 0.004) were each correlated with V̇o2 max. In separate multivariable linear regression models that adjusted for age, body mass index, CHD risk factors, and lifestyle variables, log IL-6 [β-coeff = −1.66 ± 0.63 (SE), P = 0.010], log CRP [β-coeff = −0.99 ± 0.33 (SE), P = 0.003], fibrinogen [β-coeff = −1.51 ± 0.44 (SE), P = 0.001], and WBC count [β-coeff = −0.52 ± 0.30 (SE), P = 0.088] were each inversely associated with V̇o2 max. In conclusion, higher circulating levels of IL-6, CRP, and fibrinogen are independently associated with lower V̇o2 max in asymptomatic men.

Effect of exercise training on in vitro LDL oxidation and free radical-induced hemolysis: the HERITAGE Family Study

Oxidant stress and overproduction of reactive oxygen species (ROS) contribute to the development of cardiovascular disease. Oxidative modifications of low-density lipoproteins (LDL) are thought to play an early and critical role in atherogenesis. LDL oxidation can be reproduced in vitro, but results usually show a large interindividual variation not entirely explained by the environment. Free radical-induced hemolysis is also proposed to reveal the overall antioxidant capacity. The roles of genetic factors and exercise on the variability of both measures were investigated. The study was conducted in 146 healthy individuals from 28 families participating in a 20-week exercise-training program. In addition to important biological and environmental influences on variation, significant familial aggregation was detected in all oxidation measures. Exercise did not significantly modify the LDL oxidation parameters, but significantly increased resistance was observed in the free radical-induced hemolysis, especially in women, this effect was not observed in smokers. In total, the findings suggest the presence of familial effects in the response to ex vivo oxidation. Further, smoking negates the beneficial effect of exercise training on erythrocyte resistance to free radical-induced hemolysis. These observations emphasize the importance of context in the evaluation of exercise and oxidant stress.

Role of exercise intensities in oxidized low-density lipoprotein-mediated redox status of monocyte in men

Exercise significantly influences the progression of atherosclerosis. Oxidized LDL (ox-LDL), as a stimulator of oxidative stress, facilitates monocyte-related atherogenesis. This study investigates how exercise intensity impacts ox-LDL-mediated redox status of monocytes. Twenty-five sedentary healthy men exercised mildly, moderately, and heavily (i.e., 40, 60, and 80% maximal oxygen consumption, respectively) on a bicycle ergometer. Reactive oxygen species (ROS) production, cytosolic and mitochondrial superoxide dismutase (c-SOD and m-SOD, respectively) activities, and total and reduced-form γ-glutamylcysteinyl glycine (t-GSH and r-GSH, respectively) contents in monocytes mediated by ox-LDL were measured. This experiment obtained the following findings: 1) ox-LDL increased monocyte ROS production and was accompanied by decreased c-SOD and m-SOD activities, as well as t-GSH and r-GSH contents, whereas treating monocytes with diphenyleneiodonium (DPI) (a NADPH oxidase inhibitor) or rotenone/2-thenoyltrifluoroacetone (TTFA) (mitochondrial complex I/II inhibitors) hindered ox-LDL-induced monocyte ROS production; 2) production of ROS and reduction of m-SOD activity and r-GSH content in monocyte by ox-LDL were enhanced by heavy exercise and depressed by mild and moderate exercise; and 3) heavy exercise augmented the inhibition of ox-LDL-induced monocyte ROS production by DPI and rotenone/TTFA, whereas these DPI- and rotenone/TTFA-mediated monocyte ROS productions were unchanged in response to mild and moderate exercise. We conclude that heavy exercise increases ox-LDL-induced monocyte ROS production, possibly by decreasing m-SOD activity and r-GSH content in monocytes. However, mild and moderate exercise likely protects individuals against suppression of anti-oxidative capacity of monocyte by ox-LDL.

Exercise prescription and thrombogenesis

Lifestyle habits, such as exercise, may significantly influence risk of major vascular thrombotic events. The risk of primary cardiac arrest has been shown to transiently increase during vigorous exercise, whereas regular moderate-intensity exercise is associated with an overall reduced risk of cardiovascular diseases. What are the mechanisms underlying these paradoxical effects of vigorous exercise versus exercise training on thrombotic modification? This review analyzes research regarding effects and their underlying mechanisms of acute exercise, endurance training, and deconditioning on platelets, coagulation, and fibrinolysis. Evidence suggests that (i) light, acute exercise ( < or = 49% VO(2 max)) does not affect platelet reactivity and coagulation and increases fibrinolytic activity; (ii) moderate, acute exercise (50 to approximately 74% VO(2 max)) suppresses platelet reactivity and enhances fibrinolysis, which remains unchanged in the coagulation system; and, (iii) strenuous, acute exercise ( > or = 75% VO(2 max)) enhances both platelet reactivity and coagulation, simultaneously promoting fibrinolytic activity. Therefore, moderate exercise is likely a safe and effective exercise dosage for minimizing risk of cardiovascular diseases by inducing beneficial anti-thrombotic changes. Moreover, moderate-intensity exercise training reduces platelet reactivity and enhances fibrinolysis at rest, also attenuating enhanced platelet reactivity and augmenting hyper-fibrinolytic activity during strenuous exercise. However, these favorable effects of exercise training on thrombotic modification return to a pre-training state after a period of deconditioning. These findings can aid in determining appropriate exercise regimes to prevent early thrombotic events and further hinder the cardiovascular disease progression.

Aerobic exercise, lipoproteins, and cardiovascular disease: benefits and possible risks

Aerobic exercise has been shown to reduce the risk of cardiovascular disease (CVD). This reduction is proportional to the intensity of the exercise. The reduction in CVD risk is at least partially mediated by changes in circulating lipoproteins resulting from adaptive changes in enzymes involved in their metabolism. Specifically, aerobic exercise is associated with reductions in low density lipoprotein (LDL), total cholesterol and triacylglycerol (TAG), and increases in high density lipoprotein (HDL). Exposure to oxygen can oxidatively damage LDL. Oxidized LDL is a risk factor for atherosclerosis. Although aerobic exercise can cause oxidative damage, there are adaptive changes resulting from chronic exercise that result in lower rather than higher levels of oxidized LDL.

Endothelial function in post-menopausal former elite athletes

OBJECTIVE

To characterize endothelial function in postmenopausal former elite athletes in comparison to sedentary controls and to study the influence of hormone replacement therapy (HRT) on endothelial function in these groups of women.

DESIGN

Cross-sectional study.

SETTING

Research unit at a university hospital.

PARTICIPANTS

Twenty postmenopausal former elite but still active endurance female athletes and 19 age-matched sedentary controls. The group of athletes and control subjects were each subdivided into two groups on the basis of utilization or non-utilization of HRT involving estrogen and gestagen.

METHODS

Flow-mediated vasodilatation (FMD) was employed as an indicator of endothelial function. Fasting blood samples were analyzed for lipids and body composition determined by dual-energy x-ray absorptiometry.

MAIN OUTCOME MEASURES

FMD, blood lipids and body composition.

RESULTS

Former elite athletes not utilizing HRT demonstrated the highest FMD of all four subgroups, their values being significantly higher than those of control subjects not utilizing HRT (P < 0.05), whereas this difference was not seen between the subgroups of athletes and control subjects using HRT. Serum levels of cholesterol and low-density lipoprotein (LDL) and the percentage of fat mass were significantly lower in the former elite athletes than in the control group (P < 0.05 in all cases). However, these variables were not related to FMD.

CONCLUSION

This investigation documents enhanced endothelial function in postmenopausal former elite endurance athletes not utilizing HRT, whereas the use of HRT equalizes FMD in former athletes and sedentary control subjects. Our findings suggest that long-term strenuous exercise has beneficial effects on endothelial function in postmenopausal women but that no further improvement can be obtained with HRT.

Exercise training improves low-density lipoprotein oxidability in untrained subjects with coronary artery disease

Exercise training improves low-density lipoprotein oxidability in untrained subjects with coronary artery disease.

OBJECTIVE

To test the hypothesis that regular exercise alters low-density lipoprotein (LDL) oxidability in patients with coronary artery disease.

DESIGN

Longitudinal study.

SETTING

General hospital and community.

PARTICIPANTS

Thirteen patients.

INTERVENTIONS

Training program comprising running bouts twice weekly over 2 months.

MAIN OUTCOME MEASURES

Plasma lipid profile, oxidized LDL, and rate (Ox(rate)) and amount (Ox(amount)) of LDL reaction products were measured at baseline and after 2 months of training. Brachial artery endothelium-dependent and -independent vasodilation was assessed by use of ultrasound.

RESULTS

Lipid profile and oxidized LDL remained unchanged, but mean Ox(rate) and Ox(amount) +/- standard deviation were reduced from 2.5+/-1.5nmol.mgLDL(-1).min(-1) and 120.3+/-75.3nmol/mgLDL at baseline to 0.4+/-0.2nmol.mgLDL(-1).min(-1) and 21.3+/-11.4nmol/mgLDL after training (P<.05), respectively. Brachial artery vasodilation was suggested to be improved, but statistical significance was not reached in the small cohort under study.

CONCLUSIONS

Aerobic training enhances the resistance of LDL to oxidation in patients with coronary artery disease, which may play a role in the favorable effects of exercise.

HDL capacity to inhibit LDL oxidation in well-trained triathletes

Physical activity is known to play a cardioprotective role. Nevertheless, a paradox seems to arise when considering that aerobic exercise enhances oxidative stress. In previous works, we showed that free radical formation during physical activity was counteracted by an increase in antioxidant defenses. Low density lipoprotein (LDL) oxidation is a crucial step in atherosclerosis, process that can be inhibited by high density lipoprotein (HDL) through its oxidable components or associated enzymes like paraoxonase (PON) and platelet-activating factor acetylhydrolase (PAF-AH). In this study, we evaluated copper-induced oxidation in isolated LDL and HDL fractions, and the effect of HDL on LDL oxidation in samples from well trained amateur athletes who were participating in an ultra-distance triathlon (n=18) in comparison with healthy sedentary controls (n=18). PON and PAF-AH activities and PON phenotype were also evaluated. The oxidability of isolated lipoproteins, as well as HDL antioxidant capacity, was similar in both groups of subjects. After classification by paraoxonase phenotype, only sportsmen belonging to the QR phenotype showed higher HDL susceptibility to in vitro oxidation (thiobarbituric reactive substances, TBARS) than controls (p<0.05). HDL oxidability exhibited a positive correlation with its triglyceride content (r=0.58; p<0.01). Similarly, HDL capacity to inhibit LDL oxidation was increased in athletes (p<0.05) which was positively associated with HDL oxidability (HDL-TBARS: r=0.55, p<0.005; HDL-lag time: r=0.45, p<0.01; HDL-D max: r=0.35, p<0.05). In conclusion, regular aerobic exercise was associated to a more efficient antioxidant function played by HDL from PON-QR carriers, which could constitute an adaptive response to the increased oxidative stress.

Exercise training prevents the inflammatory response to hypoxia in cremaster venules

Systemic hypoxia produces microvascular inflammation in several tissues, including skeletal muscle. Exercise training (ET) has been shown to reduce the inflammatory component of several diseases. Alternatively, ET could influence hypoxia-induced inflammation by improving tissue oxygenation or increasing mechanical antiadhesive forces at the leukocyte-endothelial interface. The effect of 5 wk of treadmill ET on hypoxia-induced microvascular inflammation was studied in the cremaster microcirculation of rats using intravital microscopy. In untrained rats, hypoxia (arterial Po2 = 32.3 ± 2.1 Torr) increased leukocyte-endothelial adherence from 2.3 ± 0.4 to 10.2 ± 0.3 leukocytes per 100 μm of venule ( P < 0.05) and was accompanied by extravasation of FITC-labeled albumin after 4 h of hypoxia (extra-/intravascular fluorescence intensity ratio = 0.50 ± 0.07). These responses were attenuated in ET (leukocyte adherence was 1.5 ± 0.4 during normoxia and 1.8 ± 0.7 leukocytes per 100 μm venule after 10 min of hypoxia; extra-/intravascular fluorescence intensity ratio = 0.11 ± 0.02; P < 0.05 vs. untrained) despite similar reductions of arterial (32.4 ± 1.8 Torr) and microvascular Po2 (measured with an oxyphor-quenching method) in both groups. Shear rate decreased during hypoxia to similar extents in ET and untrained rats. In addition, circulating blood leukocyte count was similar in ET and untrained rats. The effects of ET on hypoxia-induced leukocyte-endothelial adherence remained up to 4 wk after discontinuing training. Thus ET attenuated hypoxia-induced inflammation despite similar effects of hypoxia on tissue Po2, venular shear rate, and circulating leukocyte count.

The Effects of Physical Activity on Serum C-Reactive Protein and Inflammatory Markers

Physical activity is associated with a reduced incidence of coronary disease, but the mechanisms mediating this effect are not defined. There has been considerable recent interest in inflammation in the pathogenesis of cardiovascular disease. Some of the beneficial role of physical activity may result from its effects on the inflammatory process. We searched PubMed for articles published between 1975 through May 2004 using the terms exercise, physical activity, or physical fitness combined with C-reactive protein, inflammation, inflammatory markers, or cytokines. The review revealed 19 articles on the acute inflammatory response to exercise, 18 on cross-sectional comparisons of subjects by activity levels, and 5 examining prospectively the effects of exercise training on the inflammatory process. Exercise produces a short-term, inflammatory response, whereas both cross-sectional comparisons and longitudinal exercise training studies demonstrate a long-term "anti-inflammatory" effect. This anti-inflammatory response may contribute to the beneficial effects of habitual physical activity.

Exercise might favor reverse cholesterol transport and lipoprotein clearance: potential mechanism for its anti-atherosclerotic effects

Livers of C57 BL/6 mice exercised for 2 weeks showed a dramatic increase in scavenger receptor B1 (SR-B1), CD36 and low density lipoprotein (LDL) receptor and a decrease in acetyl LDL receptor gene expression. These effects on lipoprotein receptors are reminiscent of the effects mediated by peroxisome proliferator-activated receptor (PPARgamma) ligands.

Differential effects of exercise on aortic mitochondria

Routine exercise is widely recognized as cardioprotective. Exercise induces a variety of effects within the cardiovasculature, including decreased mitochondrial damage and improved aerobic capacity. It has been generally thought that the transient increase in oxidative stress associated with exercise initiates cardioprotective processes. Somewhat paradoxically, increased oxidative stress associated with cardiovascular disease (CVD) risk factors is thought to play an important role in the promotion and development of CVD. Hence, it is possible that CVD risk factors that increase oxidative stress (e.g., hypercholesterolemia) may modulate the cardioprotective effects of exercise. In this regard, the interaction between CVD risk factors and exercise on atherosclerotic lesion development and basal oxidant load is less defined. To determine the influence of preexistent hypercholesterolemia on cardioprotective effects of exercise, atherosclerotic lesion formation, oxidant load, mitochondrial damage, protein nitration (3-nitrotyrosine levels), and mitochondrial enzyme activities were determined in aortic tissues from normocholesterolemic (C57 control) and hypercholesterolemic [apoliprotein E-deficient (apoE(-/-))] mice after 16 wk of regular exercise. In normocholesterolemic mice, regular exercise was associated with decreased mitochondrial damage and oxidant load and increased SOD2 and adenine nucleotide translocator activities. Exercise did not decrease endogenous oxidant load and mitochondrial damage in hypercholesterolemic mice and did not reduce atherosclerotic lesion development. These data are consistent with the notion that CVD risk factors associated with increased oxidative stress can alter the benefits of exercise and that mitochondrial damage appears to be correlated with the cardiovascular effects of exercise.

Effects of exercise training and detraining on oxidized low-density lipoprotein-potentiated platelet function in men

OBJECTIVE

To investigate how exercise training and detraining affect oxidized low-density lipoprotein (Ox-LDL)-potentiated platelet function in men.

DESIGN

Cohort study.

SETTING

Department of physical medicine and rehabilitation.

PARTICIPANTS

Ten sedentary men (mean age +/- standard error of the mean, 21.6+/-0.2 y) who did not engage in any regular physical activity for at least 1 year before the study.

INTERVENTIONS

Subjects cycled on an ergometer at about 50% of maximal oxygen consumption for 30 minutes daily, 5 days a week, for 8 weeks, then detrained for 12 weeks.

MAIN OUTCOME MEASURES

During the experimental period, blood samples from the subjects were collected before and immediately after a progressive exercise test (ie, strenuous, acute exercise) every 4 weeks. The following measurements were taken when the subjects were at rest and immediately after exercise: plasma lipid profile, plasma Ox-LDL level, and platelet aggregation and intracellular calcium concentration ([Ca2+]i) elevation induced by adenosine disphosphate (ADP) alone or simultaneous ADP and Ox-LDL addition.

RESULTS

Analytical results indicated that: (1) plasma total cholesterol and LDL levels were reduced after exercise training from 151+/-7 mg/dL and 58+/-2 mg/dL to 133+/-6 mg/dL and 46+/-2 mg/dL (P<.05), respectively, whereas the plasma Ox-LDL level remained unchanged; (2) platelet aggregation and [Ca2+]i elevation promoted by 100 microg/mL of Ox-LDL were significantly increased from 70%+/-5% and 91%+/-7% of resting level to 108%+/-4% and 125%+/-3% after strenuous, acute exercise (P<.05); (3) exercise training decreased resting and postexercise 100 microg/mL Ox-LDL-potentiated platelet aggregation (ie, 31%+/-4% and 82%+/-4%, respectively; P<.05) and [Ca2+]i elevation (ie, 35%+/-6% and 71%+/-4%, respectively; P<.05); (4) detraining reversed the training effects on lipid profile and platelet function; and (5) treating the platelet with L-arginine-inhibited Ox-LDL-potentiated platelet activation during the experimental period.

CONCLUSIONS

Our results suggest that 8 weeks of exercise training decreased the plasma LDL level, but failed to influence production of plasma Ox-LDL. Importantly, resting and exercise-induced Ox-LDL-potentiated platelet activation was decreased by exercise training. However, this was reversed by detraining to the pretraining level.

Estrogen, neutrophils and oxidation

The potential role of estrogens in the prevention of cardiovascular disease (CVD) is still under debate. Previous studies from our laboratory have shown that estradiol may act as a pro oxidant at physiological concentrations, enhancing peroxidase-mediated oxidation of low density lipoprotein (LDL). In the present study, we show that physiological concentrations of estradiol enhance fMLP-mediated neutrophil degranulation and oxidative stress markers. For example, 10 nM estradiol increased myeloperoxidase (MPO), elastase, and superoxide release by 19.9 +/- 9.6% (p = 0.006), 16.3 +/- 5.2% (p = 0.09), and 36.1 +/- 19.5% (p = 0.05), respectively. The enhancement of neutrophil degranulation by estradiol resulted in an increase in the formation of LDL oxidation markers such as conjugated dienes and thiobarbituric acid-reactive substances (20.7 +/- 7.2%, p = 0.04). Thus, estradiol can act as a pro oxidant, promoting neutrophil degranulation as well as reacting with MPO to enhance the oxidation of LDL. This mechanism supports our hypothesis that oxidative stress may be beneficial towards the prevention of CVD both by promoting plasma oxidation of LDL, with its subsequent clearance by the liver, as well as by inducing a threshold antioxidant defense in the arteries. Our study also suggests that estradiol by promoting oxidation in the plasma is beneficial in preventing CVD.

Enhanced cholesterol efflux promotion in well-trained soccer players

It is widely accepted that aerobic physical activity is associated with a less atherogenic lipid and lipoprotein profile and, consequently, with a reduced cardiovascular risk. Both cross-sectional studies and prospective-interventional trials show that the most frequent modification observed consists of a slight but significant increase in high-density lipoprotein cholesterol (HDL-C) levels. Nevertheless, only few studies made an attempt to elucidate if this quantitative modification was accompanied by an improvement in any of HDL antiatherogenic functions. The purpose of this study was to evaluate the main steps of reverse cholesterol transport, the best known antiatherogenic function performed by HDL, in a group of well-trained soccer players (n = 35) in comparison to sedentary controls (n = 15). Average HDL-C levels were 12.5% higher in the sportsmen, in large part because of greater HDL2-C concentration. No statistically significant differences were observed in the other lipid- and lipoprotein-related parameters. The capacity to promote cholesterol efflux from Fu5AH cells was significantly higher in the soccer players than in the control individuals (20.5% +/- 0.4% v 15.9% +/- 1.2%, respectively, P < .001). However, lecithin:cholesterol acyltransferase (LCAT; 2.6 +/- 0.9 v 1.4 +/- 0.3%/mL.h, respectively) and cholesteryl ester transfer protein (CETP; 69.5 +/- 8.3 v 62.7 +/- 14.8%/mL.h, respectively) activities did not reach statistically significant difference between both groups. Correlation analysis showed that cholesterol efflux induced by serum samples was directly related to HDL-C (r = 0.59, P < .001), HDL2-C (r = 0.37, P < .01), and lipoprotein (Lp)A-I (r = 0.44, P < .05). On the other hand, negative correlations were observed with waist/hip ratio (r = -0.36, P < .05), low-density lipoprotein cholesterol (LDL-C; r = -0.33, P < .05), apolipoprotein B (apo B; r = -0.42, P < .05), and LpA-I;A-II (r = -0.51, P < .005). In conclusion, the well-known cardioprotective benefit of regular exercise could be based, at least in part, on a less atherogenic lipid and lipoprotein profile and an enhanced cellular cholesterol efflux.

Weight loss and race modulate nitric oxide metabolism in overweight women

Weight reduction is associated with a decrease in the risk of developing cardiovascular disease. We hypothesized that, given the central role of reactive oxygen and nitrogen species in vascular biology, changes in nitric oxide (NO) metabolism contribute to benefits of weight loss. In a controlled weight loss trial involving overweight (body mass index (BMI) = 27-30 kg/m(2)), otherwise healthy premenopausal Caucasian and African-American women, serum levels of nitrite and nitrate, as an index of NO production, and protein 3-nitrotyrosine and myeloperoxidase (MPO), as markers of inflammation, were determined. Testing was performed before and after reduction to normal body weight (BMI < 25) under standardized conditions, with controlled diet, and following 1 month of weight maintenance. After weight loss there was an increase in nitrite and nitrate, and levels were higher among African-American women relative to Caucasian counterparts. Whereas weight loss was associated with a decrease in 3-nitrotyrosine in Caucasian women, no change was observed among African-Americans. Furthermore, MPO levels increased in response to weight loss for African-Americans, but did not change in Caucasian women. These data indicate that vascular production of reactive nitrogen species can be modulated by race and weight loss and highlight important racial differences in these responses and are discussed in the context of risk for developing vascular disease.

Exercise, stress, and inflammation in the growing child: from the bench to the playground

PURPOSE OF REVIEW

It is becoming increasingly clear that physical activity in children plays a critical role in growth and development, therapy for certain chronic diseases and disabilities, and in the pediatric origins of a variety of bone, metabolic, and cardiovascular diseases. New mechanistic insights have created the opportunity for a phase shift in understanding of the links between exercise and health in the context of the growing child.

RECENT FINDINGS

Exercise even in healthy children profoundly alters stress, immune, and inflammatory mediators including peripheral blood mononuclear cells and circulating pro- and anti-inflammatory cytokines (like interleukin-6). Moreover, exercise even in healthy adults stimulates the production of reactive oxygen species (ROS) and mediators that attenuate them. Oxidative stress, in turn, alters growth and stress mediators. Both ROS and stress/inflammatory factors interact with powerful growth mediators like growth hormone and insulinlike growth factor-I. These findings suggest specific ways in which the balance between pro- and anti-inflammatory, catabolic, and anabolic factors associated with exercise can influence health and growth in children.

SUMMARY

To address the current epidemic of physical inactivity and obesity in children and to optimize the therapeutic effects of exercise in children with disease and disability will require real changes in environments (eg, schools and playgrounds); innovative approaches to rehabilitation of children with chronic disease and disability; and enlightened training of child health professionals. Identifying novel exercise mechanisms involving stress, inflammation, and growth factors will help guide these efforts.

The effects of acute exercise on neutrophils and plasma oxidative stress

PURPOSE

To investigate the influence of intensity versus total energy expenditure on neutrophilia and blood oxidative stress to acute exercise.

METHODS

Nine males (18-30 yr) completed one maximal (Max) and three submaximal exercise sessions: 1) 45 min at 10% above (LT+) lactate threshold (LT), 2) 45 min at 10% below (LT-) LT, and 3) 10% below LT until caloric expenditure equaled the 10%+ trial (LT-kcal). Blood was sampled before (PRE), immediately (POST), 1 h, and 2 h after exercise to measure neutrophils, myeloperoxidase, superoxide (O(2)-), neutrophil activation (O(2)-/neutrophils), ascorbic acid, uric acid, malondialdehyde, and lipid hydroperoxides.

RESULTS

Intensity-dependent neutrophilia occurred POST exercise with significant increases (P <or= 0.05) after Max and LT+. A second neutrophilia wave occurred 2 h postexercise. Superoxide was elevated POST (Max) and 2 h post (Max and LT+). In contrast, O(2)-/neutrophils was increased at 2 h only (Max and LT+). These data indicate that immediately postexercise, total neutrophil number rather than activation best represents neutrophil-generated reactive species within blood. POST Max, ascorbic acid and uric acid were decreased indicating a blood oxidative stress occurred. Alternately, total energy expenditure was not related to any marker of neutrophilia or oxidative stress.

CONCLUSION

Exercise intensity plays a major role in postexercise blood oxidative stress, whereas total exercise energy expenditure does not. Further, neutrophils recruited into circulation during exercise may impose a threshold dependent oxidative stress in blood plasma after exercise.