Frequency of exercise-induced ST-T-segment deviations and cardiac arrhythmias in recreational endurance athletes during a marathon race: results of the prospective observational Berlin Beat of Running study

Cardiovascular Disease Risk Factor Profile of Experienced Male Amateur Marathon Runners: A Systematic Review

CONTEXT

Male amateur marathon runners represent a unique subset of the population who may be at increased risk of cardiovascular disease (CVD) due to their underlying risk factors and their involvement in vigorous exercise such as marathon running.

OBJECTIVE

To assess the modifiable risk factors (MRFs) of CVD in experienced male amateur marathon runners and health interventions on CVD risk factors.

DATA SOURCES

CINAHL, Cochrane Library, Embase, Medline, and SPORTDiscus.

STUDY SELECTION

Studies selected according to the inclusion criteria.

STUDY DESIGN

Systematic review.

LEVEL OF EVIDENCE

Level 3.

DATA EXTRACTION

The publication dates included were from June 1, 2008 to February 29, 2020.Published primary epidemiological, observational, randomized controlled trial (RCT) and/or non-RCT studies assessing the MRFs of CVD and health interventions on CVD risk factors in male amateur marathon runners aged ≥18 years and written in the English language were included in the review.

RESULTS

Five studies met the inclusion criteria for analysis. These included male amateur marathon runners (n = 862), aged 42 to 77 years. Hypertension, hyperlipidemia, smoking, and alcohol use were MRFs positively associated with an increased risk of coronary atherosclerosis found in a subset of male marathon runners. No studies examined health interventions on CVD risk factors in any of the included studies. All 5 studies were of good quality from the National Heart, Lung, and Blood Institute quality assessment tools used. The risk of bias was low to moderate.

CONCLUSION

There is a paucity of observational studies evaluating the CVD MRFs. Negative lifestyle behaviors exist within this population despite their engagement in physical exercise through marathon running. Marathon running does not negate the long-term effects caused by past negative lifestyle behaviors. This systematic review identifies that this population may not be aware of their possible risk of atherosclerosis and, consequently, CVD.

Evaluation of the electrocardiogram RV5 /V6 criteria in the diagnosis of left ventricular hypertrophy in marathon runners

To assess the value of electrocardiogram (ECG) RV5/V6 criteria for diagnosing left ventricular hypertrophy (LVH) in marathons. A total of 112 marathon runners who met the requirements for "Class A1" events certified by the Chinese Athletics Association in Changzhou City were selected, and their general clinical information was collected. ECG examinations were performed using a Fukuda FX7402 Cardimax Comprehensive Electrocardiograph Automatic Analyser, whereas routine cardiac ultrasound examinations were performed using a Philips EPIQ 7C echocardiography system. Real-time 3-dimensional echocardiography (RT-3DE) was performed to acquire 3-dimensional images of the left ventricle and to calculate the left ventricular mass index (LVMI). According to the LVMI criteria of the American Society of Echocardiography for the diagnosis of LVH, the participants were divided into an LVMI normal group (n = 96) and an LVH group (n = 16). The correlation between the ECG RV5/V6 criteria and LVH in marathon runners was analysed using multiple linear regression stratified by sex and compared with the Cornell (SV3 + RaVL), modified Cornell (SD + RaVL), Sokolow-Lyon (SV1 + RV5/V6), Peguero-Lo Presti (SD + SV4), SV1, SV3, SV4, and SD criteria. In marathon runners, the ECG parameters SV3 + RaVL, SD + RaVL, SV1 + RV5/V6, SD + SV4, SV3, SD, and RV5/V6 were able to identify LVH (all p < .05). When stratified by sex, linear regression analysis revealed that a significantly higher number of ECG RV5/V6 criteria were evident in the LVH group than in the LVMI normal group (p < .05), both with no adjustment and after initial adjustment (including age and body mass index), as well as after full adjustment (including age, body mass index, interventricular septal thickness, left ventricular end-diastolic diameter, left ventricular posterior wall thickness, and history of hypertension). Additionally, curve fitting showed that the ECG RV5/V6 values increased with increasing LVMI in marathon runners, exhibiting a nearly linear positive correlation. In conclusions, the ECG RV5/V6 criteria were correlated with LVH in marathon runners.

The association between marathon running and high-sensitivity cardiac troponin: A systematic review and meta-analysis

BACKGROUND

Marathon running is an extreme sport with a distance of about 42 kilometers. Its relationship to high-sensitivity cardiac troponin (hs-cTn) remains controversial.

OBJECTIVE

As the gold standard for detecting myocardial injury, the trends of hs-cTn before and after a marathon were investigated and analyzed.

METHODS

A literature search was conducted in PubMed, EMBASE, and Cochrane Library databases by combing the keywords marathon and troponin, and studies regarding high-sensitivity cardiac troponin I (hs-cTnI) and high-sensitivity cardiac troponin T (hs-cTnT) concentrations before and after marathon running (not for half-marathon and ultra-marathon) were included. "Quality Assessment Tool for Before-After (Pre-Post) Studies With No Control Group" were used to assess the risk of bias. Statistical analysis was performed using Review Manager, presenting data as mean values and 95% confidence intervals (CIs). Sensitivity analysis and subgroup analysis were performed if there was high heterogeneity among studies based on I2 statistic.

RESULTS

A total of 13 studies involving 824 marathoners were included in this systematic review and meta-analysis. Both hs-cTnI (MD 68.79 ng/L, [95% CI 53.22, 84.37], p< 0.001) and hs-cTnT (MD 42.91 ng/L, [95% CI 30.39, 55.43], p< 0.001) were elevated after running a marathon, but the concentration of hs-cTnT returned to baseline after 72 to 96 h post-race (MD 0.11 ng/L, [95% CI -1.30, 1.52], p= 0.88). The results of subgroup analysis demonstrated that the 99th percentile upper reference limit of hs-cTnT might be the source of heterogeneity.

CONCLUSION

The concentrations of hs-cTnI and hs-cTnT were increased after marathon running, but the change of hs-cTnT is usually not seen as irreversible myocardial injury.

ST-T segment changes in prehospital emergency physicians in the field: a prospective observational trial

Aims

Due to time-critical decision-making, physical strain and the uncontrolled environment, prehospital emergency management is frequently associated with high levels of stress in medical personnel. Stress has been known to cause ischemia like changes in electrocardiograms (ECGs), including arrhythmias and deviations in ST-T segments. There is a lack of knowledge regarding the occurrence of changes in ST-T segments in prehospital emergency physicians. We hypothesized that ST-T segment deviations occur in prehospital emergency physicians in the field.

Methods

In this prospective observational trial, ST-T segments of emergency physicians were recorded using 12-lead Holter ECGs. The primary outcome parameter was defined as the incidence of ST-T segment changes greater than 0.1 mV in two corresponding leads for more than 30 s per 100 rescue missions. The secondary outcomes included T-wave inversions and ST-segment changes shorter than 30 s or smaller than 0.1 mV. Surrogate parameters of stress were measured using the NASA-Task Load Index and cognitive appraisal, and their correlation with ST-T segment changes were also assessed.

Results

Data from 20 physicians in 36 shifts (18 days, 18 nights) including 208 missions were analysed. Seventy percent of previously healthy emergency physicians had at least one ECG abnormality; the mean duration of these changes was 30 s. Significantly more missions with ECG changes were found during night than day shifts (39 vs. 17%, p < 0.001). Forty-nine ECG changes occurred between missions. No ST-T segment changes > 30 s and > 0.1 mV were found. Two ST-T segment changes < 30 s or < 0.1 mV (each during missions) and 122 episodes of T-wave inversions (74 during missions) were identified. ECG changes were found to be associated with alarms when asleep and NASA task load index.

Conclusion

ECG changes are frequent and occur in most healthy prehospital emergency physicians. Even when occurring for less than 30 s, such changes are important signs for high levels of stress. The long-term impact of these changes needs further investigation.

Trial registration The trial was registered at ClinicalTrials.gov (NCT04003883) on 1.7.2019: https://clinicaltrials.gov/ct2/show/NCT04003883?term=emergency+physician&rank=2

Extracellular Inflammasome Particles Are Released After Marathon Running and Induce Proinflammatory Effects in Endothelial Cells

Objectives: The intracellular NLRP3 inflammasome is an important regulator of sterile inflammation. Recent data suggest that inflammasome particles can be released into circulation. The effects of exercise on circulating extracellular apoptosis-associated speck-like protein (ASC) particles and their effects on endothelial cells are not known.

Methods: We established a flow cytometric method to quantitate extracellular ASC specks in human serum. ASC specks were quantitated in 52 marathon runners 24–72 h before, immediately after, and again 24–58 h after the run. For mechanistic characterization, NLRP3 inflammasome particles were isolated from a stable mutant NLRP3 (p.D303N)-YFP HEK cell line and used to treat primary human coronary artery endothelial cells.

Results: Athletes showed a significant increase in serum concentration of circulating ASC specks immediately after the marathon (+52% compared with the baseline, p < 0.05) and a decrease during the follow-up after 24–58 h (12% reduction compared with immediately after the run, p < 0.01). Confocal microscopy revealed that human endothelial cells can internalize extracellular NLRP3 inflammasome particles. After internalization, endothelial cells showed an inflammatory response with a higher expression of the cell adhesion molecule ICAM1 (6.9-fold, p < 0.05) and increased adhesion of monocytes (1.5-fold, p < 0.05).

Conclusion: These findings identify extracellular inflammasome particles as novel systemic mediators of cell–cell communication that are transiently increased after acute extensive exercise with a high mechanical muscular load.

Initial evaluation of a novel electrocardiography sensor-embedded fabric wear during a full marathon

Sudden cardiac accident (SCA) during a marathon is a concern due to the popularity of the sport. Preventive strategies, such as cardiac screening and deployment of automated external defibrillators have controversial cost-effectiveness. We investigated the feasibility of use of a new electrocardiography (ECG) sensor-embedded fabric wear (SFW) during a marathon as a novel preventive strategy against SCA. Twenty healthy volunteers participated in a full marathon race. They were equipped with a SFW hitoe® with a transmitter connected via Bluetooth to a standard smartphone for continuous ECG recording. All data were stored in a smartphone and used to analyze the data acquisition rate. The adequate data acquisition rate was > 90% in 13, 30-90% in 3, and < 10% in 4 runners. All of 4 runners with poorly recorded data were female. Inadequate data acquisition was significantly associated with the early phase of the race compared with the mid phase (P = 0.007). Except for 3 runners with poor heart rate data, automated software calculation was significantly associated with manual analysis for both the mean (P < 0.001) and maximum (P = 0.014) heart rate. We tested the feasibility of continuously recording cardiac data during a marathon using a new ECG sensor-embedded wearable device. Although data from 65% of runners were adequately recorded, female runners and the early phase of the race tended to have poor data acquisition. Further improvements in device ergonomics and software are necessary to improve ability to detect abnormal ECGs that may precede SCA.

Marathon race performance increases the amount of particulate matter deposited in the respiratory system of runners: an incentive for "clean air marathon runs"

Background

In the last decades, marathon running has become a popular form of physical activity among people around the world. It should be noticed that the main marathon races are performed in large cities, where air quality varies considerably. It is well established that breathing polluted air results in a number of harmful effects to the human body. However, there have been no studies to show the impact of marathon run performance on the amount of the deposition of varied fractions of airborne particulate matter (PM) in the respiratory tract of runners. This is why the present study sought to determine the impact of marathon run performance in the air of varying quality on the deposition of the PM₁, PM_2.5, PM₁₀ in the respiratory tract in humans.

Methods

The PM₁, PM_2.5 and PM₁₀ deposition was determined in an “average runner” (with marathon performance time 4 h: 30 min) and in an “elite marathon runner” (with marathon performance time 2 h: 00 min) at rest, and during a marathon race, based on own measurements of the PM content in the air and the size-resolved DF(d) profile concept.

Results

We have shown that breathing air containing 50 µg m⁻³ PM₁₀ (a borderline value according to the 2006 WHO standard - still valid) at minute ventilation (V_E) equal to 8 L min⁻¹ when at rest, resulted in PM₁₀deposition rate of approximately 9 µg h⁻¹, but a marathon run of an average marathon runner with the V_E = 62 L min⁻¹ increased the deposition rate up to 45 µg h⁻¹. In the elite runner, marathon run with the V_E= 115 L min⁻¹ increased PM₁₀ deposition rate to 83 µg h⁻¹. Interestingly, breathing the air containing 50 µg m⁻³of PM₁₀ at the V_E = 115 L min⁻¹by the elite marathon runner during the race resulted in the same PM₁₀deposition rate as the breathing highly polluted air containing as much as 466 µg m⁻³ of PM₁₀ when at rest. Furthermore, the total PM₁₀ deposition in the respiratory tract during a marathon race in average runners is about 22% greater (203 / 166 = 1.22) than in elite runners. According to our calculations, the concentration of PM₁₀in the air during a marathon race that would allow one not to exceed the PM₁₀ deposition rate of 9 µg h⁻¹should be lower than 10 µg m⁻³ in the case of an average runner, and it should be lower than 5.5 µg m⁻³ in the case of an elite runner.

Conclusions

We conclude that a marathon run drastically increases the rate of deposition of the airborne PM in the respiratory tract of the runners, as a consequence of the huge V_E generated during the race. A decrease of the PM content in the air attenuates this rate. Based on our calculations, we postulate that the PM₁₀ content in the air during a “clean air marathon run”, involving elite marathon runners, should be below 5.5 µg m⁻³.

Prevalence of abnormal and borderline electrocardiogram changes in 13, 079 Chinese amateur marathon runners

BACKGROUND

The 12-lead electrocardiogram (ECG) has been adopted as an important component of preparticipation cardiovascular screening. However, there are still controversies in the screening and few studies with a large sample size have reported the results of ECGs of marathon runners. Therefore, the purpose of this study was to assess the prevalence of normal, borderline, and abnormal ECG changes in marathon runners.

METHODS

The 12-lead ECG data of 13,079 amateur marathon runners between the ages of 18 and 35 years were included for analysis. The prevalence of ECG abnormalities among different gender groups was compared with chi-square tests.

RESULTS

In terms of training-related changes, sinus bradycardia, sinus arrhythmia, and left ventricular high voltage were found in approximately 15, 5, and 3.28% of the participants, respectively. The incidence of right axis deviation in the marathon runners was 1.78%, which was slightly higher than the incidence of left axis deviation (0.88%). No more than 0.1% of the amateur marathon runners exhibited ST-segment depression, T wave inversion (TWI), premature ventricular contraction, pathologic Q waves, and prolonged QT interval.

CONCLUSIONS

Training-related ECG changes, including sinus bradycardia, sinus arrhythmia, and left ventricular high voltage, were common in amateur marathon runners. Most abnormal ECG changes, including ST-segment depression, TWI, premature ventricular contraction, pathologic Q waves, and prolonged QT interval, were infrequently found in amateur marathon runners. The data also suggested Chinese amateur marathon runners may have a relatively lower prevalence of ECG abnormalities than black and white runners.

Electrocardiographic Changes in Male and Female Amateur Marathon Runners: A Comparison Study

Physical training is gaining popularity among amateurs. Males and females exhibit different cardiac adaptation to exercise. The aim of the study was to compare the incidence of electrocardiographic abnormalities before and after the marathon between sexes. 12-lead electrocardiogram was performed in 40 male (39±8 years) and 27 female (40±7 years) amateur runners: 2-3 weeks before (Stage 1) and immediately after (Stage 2) the marathon. Abnormalities in the resting (Stage 1) and exercise (Stage 2) electrocardiograms were compared between sexes. At rest left atrial enlargement was more frequent in females than males (48 vs. 20%; p<0.05). The incidence of right atrial enlargement was significantly more common at Stage 2 than 1, both in men (43 vs. 0%; p<0.001) and in women (48 vs. 4%; p=0.001). Significant increase of P-wave amplitude was found in male runners after the marathon (0.12±0.05 vs. 0.21±0.09 mV; p<0.001 Stage 1 vs. 2), but was absent in females. QTc prolongation was observed in both sexes, however to a higher degree in males (p<0.05 for the interaction stage and sex). Although both male and female amateur marathon runners exhibit abnormalities in resting and exercise electrocardiograms, men present more exercise-induced electrocardiographic changes, which might indicate a higher propensity for post-marathon arrhythmias. Electrocardiographic screening in amateurs should be considered.

Electrocardiographic Responses Following Live-Fire Firefighting Drills

OBJECTIVE

Firefighting-related environmental and physiological factors associated with cardiovascular strain may promote arrhythmias and myocardial ischemia, which induce sudden cardiac events (SCE) in susceptible individuals. The present study evaluated electrocardiographic (ECG) changes that may reflect increased SCE risk following simulated live-firefighting.

METHODS

Using a repeated measures design, ECG tracings from 32 firefighters were recorded 12-hours post-firefighting in a residential structure and compared with a 12-hour control period.

RESULTS

Ventricular arrhythmias were present in 20%, and ST segment changes indicative of myocardial ischemia in 16%, of firefighters 12-hours post-firefighting that were not detected in the control period.

CONCLUSION

Live-firefighting induces significant ECG changes that include ventricular arrhythmias and ST segment changes, which may reflect myocardial ischemia. The implications of such ECG changes explaining increased cardiovascular risk in firefighters warrants further research.

Prevalence of Myocardial Fibrosis in Intensive Endurance Training Athletes: A Systematic Review and Meta-Analysis

Objective: To review the published literature reporting on the incidence of myocardial fibrosis (MF) in high-intensity endurance athletes measured by late gadolinium enhancement (LGE) with cardiac magnetic resonance imaging (CMR). Methods: Five databases (PubMed, Cochrane Controlled Trials Register, EMBASE, Web of Science, and SPORTDiscus) were searched to obtain case cohort studies published before November 10, 2019. From 96 abstracts or reports extracted, 18 full-text articles were reviewed. The incidence of LGE was reported as outcome measures. Subgroup analysis was performed by age (under or above 50 years). Pooled estimates were obtained using a fixed-effects model. Results: After a full-text assessment, 12 studies involving 1,359 participants were included for analysis. Among them, 163/772 participants in the endurance athletes group showed LGE positive, compared with 19/587 participants in the comparison group. The results of the meta-analysis suggested that the prevalence of LGE was higher in the athletes group with long-term endurance exercise (OR 7.20;95%CI: 4.51-11.49). In addition, the same conclusion was drawn after the stratification of age. Conclusions: The available evidence demonstrates that high-intensity endurance athletes is associated with an increased incidence of LGE positive.

Usability of Wearable Devices With a Novel Cardiac Force Index for Estimating the Dynamic Cardiac Function: Observational Study

Background

Long-distance running can be a form of stress to the heart. Technological improvements combined with the public’s gradual turn toward mobile health (mHealth), self-health, and exercise effectiveness have resulted in the widespread use of wearable exercise products. The monitoring of dynamic cardiac function changes during running and running performance should be further studied.

Objective

We investigated the relationship between dynamic cardiac function changes and finish time for 3000-meter runs. Using a wearable device based on a novel cardiac force index (CFI), we explored potential correlations among 3000-meter runners with stronger and weaker cardiac functions during running.

Methods

This study used the American product BioHarness 3.0 (Zephyr Technology Corporation), which can measure basic physiological parameters including heart rate, respiratory rate, temperature, maximum oxygen consumption, and activity. We investigated the correlations among new physiological parameters, including CFI = weight * activity / heart rate, cardiac force ratio (CFR) = CFI of running / CFI of walking, and finish times for 3000-meter runs.

Results

The results showed that waist circumference, smoking, and CFI were the significant factors for qualifying in the 3000-meter run. The prediction model was as follows: ln (3000 meters running performance pass probability / fail results probability) = –2.702 – 0.096 × [waist circumference] – 1.827 × [smoke] + 0.020 × [ACi7]. If smoking and the ACi7 were controlled, contestants with a larger waist circumference tended to fail the qualification based on the formula above. If waist circumference and ACi7 were controlled, smokers tended to fail more often than nonsmokers. Finally, we investigated a new calculation method for monitoring cardiac status during exercise that uses the CFI of walking for the runner as a reference to obtain the ratio between the cardiac force of exercise and that of walking (CFR) to provide a standard for determining if the heart is capable of exercise. A relationship is documented between the CFR and the performance of 3000-meter runs in a healthy 22-year-old person. During the running period, data are obtained while participant slowly runs 3000 meters, and the relationship between the CFR and time is plotted. The runner’s CFR varies with changes in activity. Since the runner’s acceleration increases, the CFR quickly increases to an explosive peak, indicating the runner’s explosive power. At this period, the CFI revealed a 3-fold increase (CFR=3) in a strong heart. After a time lapse, the CFR is approximately 2.5 during an endurance period until finishing the 3000-meter run. Similar correlation is found in a runner with a weak heart, with the CFR at the beginning period being 4 and approximately 2.5 thereafter.

Conclusions

In conclusion, the study results suggested that measuring the real-time CFR changes could be used in a prediction model for 3000-meter running performance.

Unraveling the steroid hormone response in male marathon runners: Correlation of running time with aldosterone and progesterone

Marathon running is a physical and psychological stressor. We aimed to characterize the response of nine steroid hormones, which include estradiol, progesterone, testosterone, cortisol, aldosterone, 17-hydroxyprogesterone, cortisone, androstenedione, and dehydroepiandrosterone sulfate, to marathon running and their association with performance. Blood samples of sixty men (age: 49.3 ± 5.9 years) who participated in the Berlin marathon were collected within 3 days before, within 30 min and within 58 h after the end of the marathon. The nine steroid hormones in serum were quantified using liquid chromatography-tandem mass spectrometry. The responses of nine steroid hormones to marathon running were characterized. Aldosterone (fold change: 8.5), progesterone (fold change: 6.6), and cortisol (fold change: 3.7) showed significant increases within 30 min after the marathon (all p < 0.0001). Estradiol but not testosterone increased in the male runners. Marathon running time was significantly related to aldosterone increase (beta=-0.238, p = 0.008) and progesterone increase (beta=-0.192, p = 0.036) in addition to body mass index, self-reported training distance, and age. Serum progesterone correlated with aldosterone and cortisol (r = 0.81 and r = 0.92, respectively, p < 0.001). Progesterone, as a precursor hormone, is increased after the completion of marathon running in association with the increase of aldosterone and cortisol. These findings reveal a contribution of progesterone during the response to the psycho-physical stress of marathon running in males.

Is Endurance Exercise Safe? The Myth of Pheidippides

With the increase in participation in endurance events in the general population, patient concern may arise as to whether endurance exercise is safe. Acute but not chronic increases in blood urea nitrogen, creatinine, and urine albumin occur in endurance exercise. Iron-deficiency anemia may be observed in female athletes. Upper respiratory illness is increased in elite athletes but decreased in intense recreational athletes. No convincing evidence of developing osteoarthritis exists. Common gastrointestinal symptoms occur and isolated reports of gastrointestinal bleeding exist. Nevi are increased and the minimal erythematous dose is decreased. Exercising in the presence of air pollution has negative pulmonary effects, but overall, benefit exists. Numerous reports pertain to the cardiovascular system. The risk of cardiac arrest increases during exercise, troponin is elevated after exercise, and a predisposition for atrial fibrillation exists. Ventricular myocardial scar formation as assessed by gadolinium enhancement on magnetic resonance imaging is inconsistently observed, and increased coronary plaque of a more stable variety is reported. Left ventricular compliance is chronically increased and no decrease in longevity is found. Although some concerns exist, endurance exercise is safe.

2706 km cycling in 2 weeks: effects on cardiac function in 6 elderly male athletes

OBJECTIVES

Physiological effects of exercise on trained and untrained individuals have been studied extensively. Typically, young or middle-aged individuals are examined before and after short periods of vigorous exertion.

METHODS

We studied 6 elderly male athletes (61 ± 8 years (mean ± SD); baseline [Formula: see text]O₂max 48 ± 5 ml·kg^-1·min^-1) with focus on cardiac function and biomarkers following 14 consecutive days of moderate intensity exercise. Cardiac dimensions, function, biomarkers, and other measures of cardiovascular health were examined at baseline and 2 and 28 h after the last day of cycling a total of 2706 km.

RESULTS

Data collected after the cessation of exercise on the 14th day revealed significant increases in average size of the left atrium (3.5 ± 0.4 to 4.0 ± 0.3 cm; p = 0.02) and left ventricular end systolic volume (47 ± 2 to 52 ± 5 ml; p = 0.004), with no other significant changes in cardiac size or function. Small, transient increases in cardiac biomarkers (troponin T, creatine kinase myocardial band, and N-terminal pro-brain natriuretic peptide) (p < 0.01) were observed 2 h after completion of cycling but no changes in systolic (including strain-analyses) or diastolic cardiac function were observed at rest. [Formula: see text]O₂max was significantly lower at the 28 h time point than at baseline (p < 0.02). Plasma concentrations of total- (p < 0.01) and low-density lipoprotein-cholesterol (p < 0.01) were markedly lower after exercise. Systolic blood pressure was unchanged, but diastolic pressure was significantly lower after exercise than at baseline.

CONCLUSIONS

The results suggest that repeated moderate intensity exercise in elderly men was associated with a transient increase in cardiac biomarkers while cardiac function remained unaltered. A favorable reduction in blood lipids and diastolic blood pressure were seen for >28 h after the end of activity. An unexplained symptomless severe plasma hyponatremia developed in 3 of 6 subjects 28 h after the end of activity.

Marathon running increases circulating endothelial- and thrombocyte-derived microparticles

Background Acute vascular effects of high intensity physical activity are incompletely characterized. Circulating microparticles are cellular markers for vascular activation and damage. Methods Microparticles were analysed in 99 marathon runners (49 ± 6 years, 22% female) of the prospective Berlin Beat of Running study. Blood samples were taken within three days before, immediately after and within two days after the marathon run. Endothelial-derived microparticles were labelled with CD144, CD31 and CD62E, platelet-derived microparticles with CD62P and CD42b, leukocyte-derived microparticles with CD45 and monocyte-derived microparticles with CD14. Results Marathon running induced leukocytosis (5.9 ± 0.1 to 14.8 ± 0.3 10⁹/l, p < 0.0001) and increased platelet counts (239 ± 4.6 to 281 ± 5.9 10⁹/l, p < 0.0001) immediately after the marathon. Blood monocytes increased and lymphocytes decreased after the run ( p < 0.0001). Endothelial-derived microparticles were acutely increased ( p = 0.008) due to a 23% increase of apoptotic endothelial-derived microparticles ( p = 0.007) and returned to baseline within two days after the marathon. Thrombocyte-derived microparticles acutely increased by 38% accompanied by an increase in activated and apoptotic thrombocyte-derived microparticles ( p ≤ 0.0001) each. Both monocyte- and leukocyte-derived microparticles were decreased immediately after marathon run ( p < 0.0001) and remained below baseline until day 2. Troponin T increased from 12 to 32 ng/l ( p < 0.0001) immediately after the run and returned to baseline after two days. Conclusion Circulating apoptotic endothelial- and thrombocyte-derived microparticles increased after marathon running consistent with an acute pro-thrombotic and pro-inflammatory state. Exercise-induced vascular damage reflected by microparticles could indicate potential mechanisms of post-exertional cardiovascular complications. Further studies are warranted to investigate microparticles as markers to identify individuals prone to such complications.