Diagnostic Indicators of ECG for Coronary Slow Flow Phenomenon; a Systematic Review and Meta-Analysis.

Introduction: Currently, epicardial coronary angiography is still the only diagnostic tool for Coronary Slow Flow Phenomenon (CSFP). This study aimed to systematically review studies that compared Electrocardiogram (ECG) findings between patients with and without CSFP. Methods: Using relevant key terms, we systematically searched MEDLINE, Scopus, Embase, and Web of Science to find relevant studies up to February 5th, 2023. Effect sizes in each study were calculated as mean differences and crude odds ratio; then, random-effect models using inverse variance and Mantel-Haenszel methods were used to pool standardized mean differences (SMD) and crude odds ratios, respectively. Results: Thirty-two eligible articles with a total sample size of 3,937 patients (2,069 with CSFP) were included. CSFP patients had higher P-wave maximum (Pmax) (SMD: 1.02 (95% confidence interval (CI): 0.29 - 1.76); p=0.006) and P-dispersion (Pd) (SMD: 1.63 (95% CI: 0.99 - 2.27); p<0.001) compared to the control group. CSFP group also showed significantly longer QT wave maximum duration (SMD: 0.69 (95% CI: 0.33 - 1.06); p<0.001), uncorrected QTd (SMD: 1.89(95% CI: 0.67 - 3.11); p=0.002), and corrected dispersion (QTcd) (SMD: 1.63 (95% CI: 1.09 - 2.17), p<0.001). The frontal QRS-T angle was significantly higher in the CSFP group in comparison with the control group (SMD: 1.18 (95% CI: 0.31 - 2.04; p=0.007). While CSFP patients had a significantly higher T-peak to T-end (Tp-e) (SMD:1.71 (95% CI: 0.91, 2.52), p<0.001), no significant difference was noted between groups in terms of Tp-e to QT (p=0.16) and corrected QT ratios (p=0.07). Conclusion: Our findings suggest several ECG parameters, such as P max, Pd, QT, QTc, QTd, QTcd, Tp-e, and frontal QRS-T angle, may be prolonged in CSFP patients, and they could be employed as diagnostic indicators of CSFP before angiography.

Post-acute midterm follow-up cardiac MRI findings and clinical outcomes in patients with COVID-19 vaccine-associated myocarditis: a comprehensive systematic review and meta-analysis.

PURPOSE: Although previous investigations revealed favourable in-hospital outcomes of COVID-19 vaccine-related myocarditis, the mid-term prognosis is still unclear. Hence, we aim to summarise existing evidence on the follow-up imaging and clinical findings in patients with COVID-19 vaccine-related myocarditis. METHODS: We performed a systematic search in online databases using relevant key terms covering COVID-19 vaccine, myocarditis, follow-up, and cardiac MRI. We included all observational studies that reported cardiac MRI findings of patients with myocarditis following COVID-19 vaccination in both acute and follow-up phases. Data on clinical outcomes and cardiac MRI findings were extracted and pooled using a random-effect model. RESULTS: A total of 27 studies (126 patients) met our eligibility criteria. At the time of follow-up, myocarditis symptoms were resolved in all patients, but abnormal electrocardiography and elevated troponin levels were detected in 18.7% and 3.8% of them, respectively. Median imaging follow-up times varied from 3 to 6.3 months. On follow-up cardiac MRI, the persistence of LGE was observed in 76% (95%CI: 62 to 85%), but its extension declined compared to the baseline in almost all patients. Persistent LGE was accompanied by myocardial edoema in six patients, and it was consistent with myocardial fibrosis (LGE without edoema) in the remaining cases. Mean changes (95%CI) of cardiac MRI left ventricular ejection fraction (LVEF) (%) was +2.97 (+1.59 to +4.34) from baseline. CONCLUSION: In conclusion, although most patients likely experience favourable clinical outcomes without serious complications, cardiac MRI abnormalities, mainly LGE, may persist in a notable proportion of them beyond the acute phase.

Neuromuscular diseases associated with COVID-19 vaccines: a systematic review and pooled analysis of 258 patients.

BACKGROUND: Neuromuscular diseases (NMD) emerged as one of the main side effects of the COVID-19 vaccination. We pooled and summarized the evidence on the clinical features and outcomes of NMD associated with COVID-19 vaccination. METHODS: We comprehensively searched three databases, Medline, Embase, and Scopus, using the key terms covering "Neuromuscular disease" AND "COVID-19 vaccine", and pooled the individual patient data extracted from the included studies. RESULTS: A total of 258 NMD cases following COVID-19 have been reported globally, of which 171 cases were Guillain-Barré syndrome (GBS), 40 Parsonage-Turner syndrome (PTS), 22 Myasthenia Gravis (MG), 19 facial nerve palsy (FNP), 5 single fiber neuropathy, and 1 Tolosa-Hunt syndrome. All (100%) SFN patients and 58% of FNP patients were female; in the remaining NMDs, patients were predominantly male, including MG (82%), GBS (63%), and PTS (62.5%). The median time from vaccine to symptom was less than 2 weeks in all groups. Symptoms mainly appeared following the first dose of vector vaccine, but there was no specific pattern for mRNA-based. CONCLUSION: COVID-19 vaccines might induce some NMDs, mainly in adults. The age distribution and gender characteristics of affected patients may differ based on the NMD type. About two-thirds of the cases probably occur less than 2 weeks after vaccination.

Clinical features and outcomes of Myasthenia Gravis associated with COVID-19 vaccines: A systematic review and pooled analysis.

BACKGROUNDS: Myasthenia Gravis (MG), a chronic neuromuscular junction disorder, emerged as one of the serious side effects of the Coronavirus Disease 2019 (COVID-19) vaccination. We aimed to summarize the findings of studies on the clinical features and outcomes of COVID-19 vaccination-associated MG. METHODS: We performed a systematic search on 3 databases, Medline, Embase, and Scopus, using the query "COVID-19 vaccine" and "Myasthenia Gravis." Patients' data, including clinical data, MG subtype, vaccine type, and vaccine dose number, were extracted from the eligible studies. RESULTS: A total of 20 COVID-19 vaccination-related MGs have been reported worldwide. The median (interquartile range) age was 64 (51, 75) years; 85% (17/20) of them were male, and 70% (14/20) of patients had received messenger RNA-based vaccines. The most common symptoms, in order of frequency, were binocular diplopia (8/11) and ptosis (4/11); the median (interquartile range) time from vaccine to MG symptoms was 6 (2, 7.5) days. Repetitive nerve stimulation showed abnormal decrement in 85% (11/13) of patients, and all 4 patients getting single-fiber electromyography showed an abnormal finding. Nine out of twelve patients with data on clinical outcomes experienced partial/complete improvement of symptoms within 1 month. CONCLUSION: MG cases after the COVID-19 vaccine are more likely to occur among males and adults older than 50 years. Our pooled cohort data suggest MG symptoms appear within 2 weeks after receiving the vaccine. The presenting symptoms in MG cases associated with COVID-19 vaccine are possibly similar to non-vaccination related MGs. Most patients are expected to experience partial/complete improvement within 1 month.

COVID-19 Associated Fulminant Myocarditis in a Fully-Vaccinated Female: A Case Report with Clinical Follow-up.

Background: Myocarditis is considered a serious adverse event after COVID-19 infection. The risk and severity of myocarditis after COVID-19 disease decreased significantly in the vaccinated population. We present a case of cardiac magnetic resonance proven fulminant myocarditis following COVID-19 disease in a young female who was previously vaccinated with 2 doses of the BIBP (Sinopharm) vaccine. Case summary: A 29-year-old female was referred to the hospital with acute chest pain, dyspnea, and nausea. Her electrocardiogram revealed ST-segment elevation in anterolateral leads with reciprocal changes in inferior leads. She was primarily diagnosed with ST-elevation myocardial infarction following spontaneous coronary artery dissection (SCAD) according to her age and gender. Her coronary angiography was normal. RT-PCR nasopharyngeal swab was positive for SARS-COV-2 infection. According to her history and excluding coronary artery diseases, she was clinically diagnosed with myocarditis and received corticosteroids, IVIG, and colchicine. She was discharged in a favorable condition after 11 days of hospitalization. Cardiac magnetic resonance imaging confirmed the diagnosis of myocarditis according to the updated lake Louise criteria. On her 4-month follow-up, she was asymptomatic, and her echocardiography showed improvement in biventricular function. Discussion: The diagnosis of myocarditis caused by COVID-19 infection may be challenging as the symptoms of myocarditis, and COVID-19 disease may overlap. It should be considered when patients have acute chest pain, palpitation, elevated cardiac biomarkers, and new abnormalities in ECG or echocardiography. Cardiac MRI is a non-invasive gold standard modality for diagnosing and follow-up of myocarditis and should be used in clinically suspected myocarditis. The long-term course of myocarditis following COVID-19 disease is still unclear, but some evidence suggests it may have a favorable mid-term outcome.

Efficacy and safety of intracoronary epinephrine for the management of the no-reflow phenomenon following percutaneous coronary interventions: a systematic-review study.

BACKGROUND: Currently, no pharmacological or device-based intervention has been fully proven to reverse the no-reflow phenomenon. OBJECTIVES: To assess the efficacy and safety of intracoronary (IC) epinephrine in the management of no-reflow phenomenon following percutaneous coronary intervention (PCI), either as first-line treatment or after the failure of conventional agents. DESIGN: Systematic review. DATA SOURCES AND METHODS: PubMed and Scopus databases were systematically searched up to 28 May 2022, with additional manual search on the Google Scholar and review of the reference lists of the relevant studies to identify all published studies. Cohort studies, case series, and interventional studies written in English which evaluated the efficacy and safety of IC epinephrine in patients with no-flow phenomenon were included in our review. RESULTS: Six of the 646 articles identified in the initial search met our inclusion criteria. IC epinephrine was used either as a first-line treatment [two randomized clinical trials (RCTs)] or after the failure of conventional agents (two cohort studies and two case series) for restoring the coronary flow, mainly after primary PCI. As first-line therapy, IC epinephrine successfully restored coronary flow in over 90% of patients in both RCTs, which significantly outperformed IC adenosine (78%) but lagged behind combination of verapamil and tirofiban (100%) in this regard. In the refractory no-flow phenomenon, successful reperfusion [thrombolysis in myocardial infarction (TIMI) flow grade = 3] was achieved in three out of four patients after the administration of IC epinephrine based on the results from both case series. Their findings were confirmed by a recent cohort study that further compared IC epinephrine with IC adenosine and found significant differences between them in terms of efficacy [% TIMI flow grade 3: (69.1% versus 52.7%, respectively; p value = 0.04)] and 1-year major adverse cardiac event (MACE) outcomes (11.3% versus 26.7%, respectively; p value ⩽ 0.01). Overall, malignant ventricular arrhythmias were reported in none of the patients treated with IC epinephrine. CONCLUSION: Results from available evidence suggest that IC epinephrine might be an effective and safe agent in managing the no-reflow phenomenon.

Utility of electrocardiogram to predict the occurrence of the no-reflow phenomenon in patients undergoing primary percutaneous coronary intervention (PPCI): a systematic review and meta-analysis.

Background: The no-reflow phenomenon affects about one out of five patients undergoing Primary Percutaneous Coronary Intervention (PPCI). As the prolonged no-reflow phenomenon is linked with unfavorable outcomes, making early recognition is crucial for effective management and improved clinical outcomes in these patients. Our review study aimed to determine whether electrocardiogram (ECG) findings before PCI could serve as predictors for the occurrence of the no-reflow phenomenon. Methods and materials: We systematically searched MEDLINE, Scopus, and Embase to identify relevant studies. The random-effect model using inverse variance and Mantel-Haenszel methods were used to pool the standardized mean differences (SMD) and odds ratios (OR), respectively. Result: Sixteen eligible articles (1,473 cases and 4,264 controls) were included in this study. Based on our meta-analysis of baseline ECG findings, the no-reflow group compared to the control group significantly had a higher frequency of fragmented QRS complexes (fQRS) (OR (95% CI): 1.35 (0.32-2.38), P-value = 0.01), and Q-waves (OR (95% CI): 1.97 (1.01-2.94), P-value <0.001). Also, a longer QRS duration (QRSD) (SMD (95% CI): 0.72 (0.21, 1.23), p-value <0.001) and R wave peak time (RWPT) (SMD (95% CI): 1.36 (0.8, 1.93), P < 0.001) were seen in the no-reflow group. The two groups had no significant difference regarding P wave peak time (PWPT), and P wave maximum duration (Pmax) on baseline ECG. Conclusion: Our findings suggest that prolonged QRSD, delayed RWPT, higher fQRS prevalence, and the presence of a Q wave on baseline ECG may predict the occurrence of the no-reflow phenomenon in patients undergoing PPCI.

Cardiac MRI Findings in COVID-19 Vaccine-Related Myocarditis: A Pooled Analysis of 468 Patients.

Understanding the pattern and severity of myocarditis caused by the coronavirus disease 2019 (COVID-19) vaccine is imperative for improving the care of the patients, and cardiac evaluation by MRI plays a key role in this regard. Our systematic review and meta-analysis aimed to summarize cardiac MRI findings in COVID-19 vaccine-related myocarditis. We performed a comprehensive systematic review of literature in PubMed, Scopus, and Google Scholar databases using key terms covering COVID-19 vaccine, myocarditis, and cardiac MRI. Individual-level patient data (IPD) and aggregated-level data (AD) studies were pooled through a two-stage analysis method. For this purpose, all IPD were first gathered into a single data set and reduced to AD, and then this AD (from IPD studies) was pooled with existing AD (from the AD studies) using fixed/random effect models. I2 was used to assess the degree of heterogeneity, and the prespecified level of statistical significance (P value for heterogeneity) was <0.1. Based on meta-analysis of 102 studies (n = 468 patients), 79% (95% confidence interval [CI]: 54%-97%) of patients fulfilled Lake Louise criteria (LLC) for diagnosis of myocarditis. Cardiac MRI abnormalities included elevated T2 in 72% (95% CI: 50%-90%), myocardial late gadolinium enhancement (LGE) in 93% (95% CI: 83%-99%; nearly all with a subepicardial and/or midwall pattern), impaired left ventricular ejection fraction (LVEF) (<50%) in 4% (95% CI: 1.0%-9.0%). Moreover, elevated T1 and extracellular volume fraction (ECV) (>30), reported only by some IPD studies, were detected in 74.5% (76/102) and 32% (16/50) of patients, respectively. In conclusion, our findings may suggest that over two-thirds of patients with clinically suspected myocarditis following COVID-19 vaccination meet the LLC. COVID-19 vaccine-associated myocarditis may show a similar pattern compared to other acute myocarditis entities. Notably, preserved LVEF is probably a common finding in these patients. EVIDENCE LEVEL: 4 TECHNICAL EFFICACY: Stage 3.

Effect of herbal antioxidant-rich formula on improvement of antioxidant defense system and heat shock protein-70 expression in recreational female athletes: A randomized controlled trial.

BACKGROUND: The aim of the present study was to evaluate the effect of natural antioxidant formula (blend of herbs: ginger root, cinnamon bark and raw almond fruit powder, rosemary leaf powder, and honey) on oxidative status, antioxidant enzyme activity, and relative heat shock protein (HSP-70) expression in recreational female athletes. MATERIALS AND METHODS: Eighteen female participants trained for 4 weeks and randomly received either antioxidant formula (FormEX) (n = 8) or placebo (PlcEX) (n = 10) in a randomized controlled trial. Blood samples were obtained 1-h before, 1 h and 24 h postexercise to measure malondialdehyde (MDA), total antioxidant capacity (TAC), superoxide dismutase (SOD), glutathione peroxidases (GPx), and HSP70 mRNA expression. Data analysis was performed using 2 (treatment = grouping factor) ×6 (time = within-factor) repeated measurements analysis of variance or generalized estimating equations (GEE) test. We used the independent t-test to evaluate any significant differences for real-time polymerase chain reaction data. RESULTS: Antioxidant formula increased the relative HSP-70 mRNA expression more than Plc-EX group in all time points (P = 0.001). The time main effect was significant with regard to TAC and SOD concentrations (P = 0.001 and 0.002, respectively). However, there were no statistically significant differences between groups for TAC, SOD, and MDA (P = 0.25, 0.06, and 0.38, respectively). Neither the time main effect for MDA nor time and intervention interaction was not statistically significant for MDA, TAC, and SOD (P = 0.19, 0.13, and 0.10, respectively). GEE results for GPx showed that there were no significant differences between the groups (P = 0.11). CONCLUSION: The results presented herein revealed that natural antioxidant rich formula had variable effects on oxidative status. However, in contrast to many antioxidant supplements, this formulation increases the HSP-70 mRNA expression which might improve the antioxidant ability of cells in the long-term period and exercise-induced adaptation.

Effect of aerobic training on nerve conduction in men with type 2 diabetes and peripheral neuropathy: A randomized controlled trial.

OBJECTIVE: Peripheral neuropathy (PN) is one of the long-term complications of diabetes. Few studies have investigated the role of regular exercise on diabetic PN. We examined the effect of aerobic training on nerve conduction velocity and action potential amplitude in the lower limbs of men with type 2 diabetes and PN. METHODS: In a randomized controlled study, 24 volunteers diagnosed with diabetic PN were randomly assigned to exercise or control groups. Aerobic training consisted of 20-45min walking or running at 50-70% of heart rate reserve for three sessions per week over 12weeks. Before and 48h after the experimental period, nerve conduction studies were performed and blood samples were taken to be analyzed for HbA1c, fasting and 2h postprandial glucose concentration. Data were analyzed using repeated-measures ANOVA at significance level of P<0.05. RESULTS: Sural sensory nerve conduction velocity (NCV) in the exercise group significantly increased (from 35.2±4.3m/s to 37.3±6.2m/s) compared to the control group (P=0.007). Changes in peroneal and tibial motor NCV and nerve action potential amplitude (NAPA) in all nerves studied were not different between groups (P>0.05). Moreover, HbA1c decreased to a greater extent in the exercise group compared to the control (P=0.014). CONCLUSION: Aerobic exercise training may have the potential to hinder the progression of diabetic PN by improving NCV. Given the sparse evidence in this domain, exercise-related mechanisms need to be studied in the future.

Effects of creatine supplementation along with resistance training on urinary formaldehyde and serum enzymes in wrestlers.

BACKGROUND: Formaldehyde is a cytotoxic agent produced from creatine through a metabolic pathway, and in this regard, it has been claimed that creatine supplementation could be cytotoxic. Even though the cytotoxic effects of creatine supplementation have been widely studied, yet little is known about how resistance training can alter these toxic effects. This study aimed to determine the effects of short-term creatine supplementation plus resistance training on the level of urinary formaldehyde and concentrations of serum enzymes in young male wrestlers. METHODS: In a double-blind design twenty-one subjects were randomized into creatine supplementation (Cr), creatine supplementation plus resistance training (Cr + T) and placebo plus resistance training (Pl + T) groups. Participants ingested creatine (0.3 g/kg/day) or placebo for 7 days. The training protocol consisted of 3 sessions in one week, each session including three sets of 6-9 repetitions at 80-85% of one-repetition maximum for whole-body exercise. Urine and blood samples were collected at baseline and at the end of the supplementation. RESULTS: Creatine supplementation significantly increased the excretion rate of urinary formaldehyde in the Cr and Cr + T groups by 63.4% and 30.4%, respectively (P<0.05), indicating that resistance training could partially lower this rate by 17.7%. No significant differences were detected in the levels of serum enzymes across time and groups (P>0.05). CONCLUSIONS: These findings indicate that resistance training may lower the increase of urinary formaldehyde excretion induced by creatine supplementation, suggesting that creatine consumption could be relatively less toxic when combined with resistance training.

The Effects of Caffeine Supplements on Exercise-Induced Oxidative Damages.

BACKGROUND: There is an interaction between oxidative equilibrium and anti-oxidants in oxidative stress. Therefore, oxidative stress has an effect on intercellular oxidation and causes atrophy and is an underlying factor in many diseases. OBJECTIVES: The aim of this study was to investigate the effect of running downhill and the short-term effect of caffeine supplementation on oxidative stress in non-athletic men. PATIENTS AND METHODS: Twenty men, aged 25 - 28 years, from Tabriz, Iran were been selected and divided in two homogeneous groups of 10 men: the supplementation group and the placebo group. In the next stage, groups received caffeine supplementation (caffeine capsules at a dose of 5 mg/kg of body weight daily for 14 days) or placebo (5 mg/kg of dextrose during supplementation) and ran downhill (30 minutes of treadmill running with a slope of -10 degrees with 65% maximal oxygen consumption); blood sampling was also performed. RESULTS: Anti-oxidant capacity by the ferric reducing ability of plasma (FRAP) techniques and serum malondialdehyde (MDA) were measured by the thiobarbituric acid (TBA) method, while the total number of thiol molecules (TTM) with Hu and DNA damage was evaluated using ELISA. CONCLUSIONS: The results of this study indicated that running downhill caused significant changes in all measured parameters, but the short-term caffeine supplementation did not have a significant effect on the indices of oxidative stress or DNA damage measured.

Effect of coenzyme Q10 supplementation on exercise-induced response of inflammatory indicators and blood lactate in male runners.

BACKGROUND: Heavy exercise cause muscle damage associated with production of inflammatory agents. The purpose of present study was to determine the effect of acute and 14-day Coenzyme Q10 supplementation on inflammatory, blood lactate and muscle damage in male middle-distance runners. METHODS: Eighteen male middle-distance runners in a randomized and quasi experimental study were allocated into two equal groups: supplement group (n=9, Coenzyme Q10: 5mg/kg/day) and placebo group (n= 9, Dextrose: 5mg/kg/day). After acute (1day) and 14-day supplementation, all subjects were participated in a training like running (competitive 3000 meters). Blood samples were obtained in the four phases: one hour before and 18-24 hours after two running protocols. Lactate, serum interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), C-reactive protein (CRP) and creatine kinase (CK) were analyzed. Repeated ANOVA and Bonferuni as a post hoc tests were used to determine the changes in four stages. Differences between groups were determined by t-test. RESULTS: The results showed that acute and short-term Coenzyme Q10 supplementation had not significant effect on basal parameters. The acute coenzyme Q10 supplementation attenuated only the exercise-induced increase in response of the plasma CRP. The short-term (14-day) coenzyme Q10 supplementation attenuated the exercise-induced increase in response of the lactate, serum interleukin- 6, tumor necrosis factor-alpha, and CRP in male middle-distance runners. However, the acute and short-term coenzyme Q10 supplementation had not any significant effect on the exerciseinduced increase response of total serum creatine kinase. CONCLUSION: Based on the present results, it can be concluded that the 14-day coenzyme Q10 supplementation (5mg.kg-1.day-1) is more effective than the acute supplementation to overcome the exercise-induced adverse responses in some oxidative, inflammatory and biochemical parameters. Therefore, short-term coenzyme Q10 supplementation is recommended to reduce exercise-induced adverse consequences.

Effect of endurance training and cinnamon supplementation on post-exercise oxidative responses in rats.

Despite the preventative and therapeutic effects of regular exercise, exhaustive exercise may be harmful to health. The present study aimed to determine the protective effect of endurance training and cinnamon bark extract (CBE) supplementation on oxidative responses induced by an exhaustive exercise schedule in rats. The rats were randomly divided into the following five groups of 6; control sedentary (Con/Sed), control exercised (Con/Ex), trained exercised (Tr/Ex), supplemented exercised (Sup/Ex), and trained, supplemented and exercised (Tr/Sup/Ex). Animals in exercise groups ran on a rodent treadmill for an 8-week endurance training program. At the end of the experiment, blood samples were collected and (MDA) and total thiol (TT) levels were measured in plasma. Glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (CAT) activities were determined in soleus muscles. Results showed significant increases in SOD activity and malondealdehyde (MDA) levels in the soleus muscles and serum of exercised rats fed with the normal diet. The exhaustive exercise also induced a decrease in serum total thiol level and GPX activity. Elevated levels of total thiol and total antioxidant capacity (TAC) and reduced serum MDA levels were found in the Sup/Ex and Tr/Sup/Ex groups. CAT and GPX activities increased by CBE treatment in trained rats. Regular training increased CAT and GPX activities in the Tr/Sup/Ex group. CAT, GPX and SOD activities were not affected by the CBE treatment in untrained rats. Results suggest that additional use of regular training and CBE supplementation increase TAC and protect healthy male rats against oxidative damage induced by exhaustive exercise.

Effect of short- and long-term strength exercise on cardiac oxidative stress and performance in rat

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Increase in heart metabolism during severe exercise facilitates production of ROS and result in oxidative stress. Due to shortage of information, the effect of chronic strength exercise on oxidative stress and contractile function of the heart was assessed to explore the threshold for oxidative stress in this kind of exercise training. Male Wistar rats (80) were divided into two test groups exercised 1 and 3 months and two control groups without exercise. Strength exercise was carried by wearing a Canvas Jacket with weights and forced rats to lift the weights. Rats were exercised at 70% of maximum lifted weight 6 days/week, four times/day, and 12 repetitions each time. Finally, the hearts of ten rats/group were homogenized and (..) (AU)

Effect of short- and long-term strength exercise on cardiac oxidative stress and performance in rat.

Increase in heart metabolism during severe exercise facilitates production of ROS and result in oxidative stress. Due to shortage of information, the effect of chronic strength exercise on oxidative stress and contractile function of the heart was assessed to explore the threshold for oxidative stress in this kind of exercise training. Male Wistar rats (80) were divided into two test groups exercised 1 and 3 months and two control groups without exercise. Strength exercise was carried by wearing a Canvas Jacket with weights and forced rats to lift the weights. Rats were exercised at 70% of maximum lifted weight 6 days/week, four times/day, and 12 repetitions each time. Finally, the hearts of ten rats/group were homogenized and MDA, SOD, GPX, and catalase (CAT) were determined by ELISA method. In other ten rats/group, left ventricle systolic and end diastolic pressures (LVSP and LVEDP) and contractility indices (LVDP and +dp/dt max) and relaxation velocity (-dp/dt max) were recorded. The coronary outflow was collected. Short- and long-term strength exercise increased heart weight and heart/BW ratio (P < 0.05). In the 3-month exercise group, basal heart rate decreased (P < 0.05). LVEDP did not change but LVDP, +dp/dt max, -dp/dt max, and coronary flow significantly increased in both exercise groups (P < 0.05). None of MDA or SOD, GPX, and CAT significantly changed. The results showed that sub-maximal chronic strength exercise improves heart efficiency without increase in oxidative stress index or decrease in antioxidant defense capacity. These imply that long-time strength exercise up to this intensity is safe for cardiac health.

Effect of moderate aerobic cycling on some systemic inflammatory markers in healthy active collegiate men.

BACKGROUND: Based on the inconsistency of some previous results related to moderate exercise effects on systemic inflammatory responses, this study was conducted to determine the effects of 45 minutes of moderate aerobic cycling on inflammatory markers, interleukin-6 (IL-6), interleukin-10 (IL-10), C-reactive protein (CRP), and leucocyte counts in young active men. METHODS: Ten healthy, active collegiate men (aged 21.03 ± 1.2 years, body fat 12.04 ± 2.72% and VO(2)max 59.6 ± 2.4 mL/kg/min) in a quasiexperimental pre/post design, participated in an acute, moderate cycling protocol at an intensity of 50% VO(2)max for 45 minutes. The inflammatory markers (serum IL-6, IL-10, CRP, and peripheral blood leucocyte counts), along with cortisol and epinephrine, were examined before and after the protocol. Data were expressed as mean (± SD) and analyzed by paired t-test using SPSS15 at α ≤ 0.05. RESULTS: The results showed that serum IL-6, IL-10, CRP, total leukocyte counts, and stress hormones (epinephrine and cortisol) were significantly increased following 45 minutes of moderate cycling in active collegiate men (P < 0.001). However, all pre- and post-measurements were in the population range. CONCLUSION: Based on the present results, it can be concluded that moderate cycling is not only sufficient to induce systemic inflammation in active collegiate men, but also appears to be safe from an immunological point of view.

Effect of regular aerobic exercise with ozone exposure on peripheral leukocyte populations in Wistar male rats.

BACKGROUND: The immune system in endurance athletes may be at risk for deleterious effects of gasous pollutants such as ambient ozone. Therefore, this study was performed to assess the effect of regular aerobic exercise with ozone exposure on peripheral leukocytes populations in male Wistar rats. METHODS: Twenty eight 8 weeks old rats were selected and randomly divided into four groups of ozone-unexposed and untrained (control or group 1, n = 6), ozone-exposed and untrained (group 2, n = 6), ozone-unexposed and trained (group 3, n = 8), ozone-exposed and trained (group 4, n = 8). All animals in groups 3 and 4 were regularly running (20 m/min, 30 min/day) on a treadmill for 7 weeks (5 day/week). After the last ozone exposure [0.3 ppm, 30 min per sessions], blood samples were obtained from the cardiac puncture and hematological parameters as well as blood lactate were measured using automatic analyzers. Data were expressed as means (± SD) and analyzed by ANOVA and Pearson's correlation tests at p < 0.05. RESULTS: All the hematological parameters differences (except RBC and hemoglobin rate) were significantly higher in the trained groups (p < 0.001). However, ozone-induced leukocytosis in the trained (but not in the sedentary) rats was statistically higher than in the counterpart groups. CONCLUSIONS: Repeated acute ozone exposure has more additive effect on peripheral leukocyte counts in active animals. But, more researches are needed to identify effects of ozone exposure on other components of the immune system in athletes and non-athletes.