Effects of a long-distance run on cardiac markers in healthy athletes

Assessment of cardiovascular risk and physical activity: the role of cardiac-specific biomarkers in the general population and athletes

The first part of this Inter-Society Document describes the mechanisms involved in the development of cardiovascular diseases, particularly arterial hypertension, in adults and the elderly. It will also examine how consistent physical exercise during adolescence and adulthood can help maintain blood pressure levels and prevent progression to symptomatic heart failure. The discussion will include experimental and clinical evidence on the use of specific exercise programs for preventing and controlling cardiovascular diseases in adults and the elderly. In the second part, the clinical relevance of cardiac-specific biomarkers in assessing cardiovascular risk in the general adult population will be examined, with a focus on individuals engaged in sports activities. This section will review recent studies that suggest a significant role of biomarkers in assessing cardiovascular risk, particularly the presence of cardiac damage, in athletes who participate in high-intensity sports. Finally, the document will discuss the potential of using cardiac-specific biomarkers to monitor the effectiveness of personalized physical activity programs (Adapted Physical Activity, APA). These programs are prescribed for specific situations, such as chronic diseases or physical disabilities, including cardiovascular diseases. The purposes of this Inter-Society Document are the following: 1) to discuss the close pathophysiological relationship between physical activity levels (ranging from sedentary behavior to competitive sports), age categories (from adolescence to elderly age), and the development of cardiovascular diseases; 2) to review in detail the experimental and clinical evidences supporting the role of cardiac biomarkers in identifying athletes and individuals of general population at higher cardiovascular risk; 3) to stimulate scientific societies and organizations to develop specific multicenter studies that may take into account the role of cardiac biomarkers in subjects who follow specific exercise programs in order to monitor their cardiovascular risk.

Exercise Training, Cardiac Biomarkers, and Cardiorespiratory Fitness in Type 2 Diabetes: The HART-D Study

Background

High-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) are cardiac biomarkers commonly detected in adults with type 2 diabetes (T2D) and are associated with heart failure risk.

Objectives

The purpose of this study was to evaluate the effects of exercise training (ET) on hs-cTnT and NT-proBNP and evaluate the associations of these biomarkers with cardiorespiratory fitness among adults with T2D.

Methods

Participants of the HART-D (Health Benefits of Aerobic and Resistance Training in Individuals with Type 2 Diabetes) trial who were randomly assigned to one of 3 ET groups or a non-exercise control group were included. Cardiac biomarkers and cardiorespiratory fitness (evaluated by peak oxygen uptake [VO2peak]) were assessed at baseline and after 9 months. The effects of ET (3 ET groups pooled) vs non-exercise control on hs-cTnT and NT-proBNP were assessed using separate analysis of covariance models. Multivariable-adjusted linear regression was performed to identify factors associated with follow-up biomarkers and ΔVO2peak.

Results

The present study included 166 participants randomized to the ET (n = 135) and non-exercise control (n = 31) groups. Compared with the non-exercise control, ET did not significantly change hs-cTnT or NT-proBNP. In adjusted analysis, each ET group and ΔVO2peak were not significantly associated with hs-cTnT or NT-proBNP levels on follow-up. Among individuals in the ET group, baseline hs-cTnT was inversely associated with ΔVO2peak [per 1 SD higher log (hs-cTnT): β = -0.08 (95% CI = -0.15 to -0.01)].

Conclusions

Among individuals with T2D, ET did not modify cardiac biomarkers. Higher baseline hs-cTnT was associated with blunted cardiorespiratory fitness improvement in response to exercise.

Hsp90 as a Myokine: Its Association with Systemic Inflammation after Exercise Interventions in Patients with Myositis and Healthy Subjects

Compelling evidence supports the health benefits of physical exercise on the immune system, possibly through the molecules secreted by the skeletal muscles known as myokines. Herein, we assessed the impact of exercise interventions on plasma Heat shock protein 90 (Hsp90) levels in 27 patients with idiopathic inflammatory myopathies (IIM) compared with 23 IIM patients treated with standard-of-care immunosuppressive therapy only, and in 18 healthy subjects undergoing strenuous eccentric exercise, and their associations with the traditional serum markers of muscle damage and inflammation. In contrast to IIM patients treated with pharmacotherapy only, in whom we demonstrated a significant decrease in Hsp90 over 24 weeks, the 24-week exercise program resulted in a stabilization of Hsp90 levels. These changes in Hsp90 levels were associated with changes in several inflammatory cytokines/chemokines involved in the pathogenesis of IIM or muscle regeneration in general. Strenuous eccentric exercise in healthy volunteers induced a brief increase in Hsp90 levels with a subsequent return to baseline levels at 14 days after the exercise, with less pronounced correlations to systemic inflammation. In this study, we identified Hsp90 as a potential myokine and mediator for exercise-induced immune response and as a potential biomarker predicting improvement after physiotherapy in muscle endurance in IIM.

Cardiac Troponin-T Release After Sport and Differences by Age, Sex, Training Type, Volume, and Intensity: A Critical Review

BACKGROUND

Postexercise release of cardiac troponin (cTn) is a well-known phenomenon, although the influence of various confounders remains unclear. The aim of this critical review was to analyze the postexercise release of cTn according to age, sex, different types of sport, exercise intensity and duration, and training level.

DATA SOURCES

A literature search was performed within the National Library of Medicine using the following keywords: cTn, peak, release, and exercise. The search was further refined by adding the keywords athletes, children/adolescents, and sport.

MAIN RESULTS

For final analysis, 52 studies were included: 43 adult studies, 4 pediatric studies, and 5 with a mixed population of adults and children. Several studies have investigated the kinetics of cTn response after exercise with different biomarkers. The current evidence suggests that sport intensity and duration have significant effects on postexercise cTn elevation, whereas the influence of the type of sport, age, and sex have been not completely defined yet. Most data were obtained during endurance races, whereas evidence is limited (or almost absent), particularly for mixed sports. Data on young adults and professional athletes are limited. Finally, studies on women are extremely limited, and those for non-White are absent.

CONCLUSIONS

Postexercise release of cTn can be observed both in young and master athletes and usually represents a physiological phenomenon; however, more rarely, it may unmask a subclinical cardiac disease. The influence of different confounders (age, sex, sport type/intensity/duration, and training level) should be better clarified to establish individualized ranges of normality for postexercise cTn elevation.

The effects of a 50 km ultramarathon race on high sensitivity cardiac troponin I and NT-proBNP in highly trained athletes

BACKGROUND

High sensitivity cardiac troponins I (hs-cTnI) and T (hs-cTnT) and natriuretic peptides (BNP and NT-proBNP) are universally recognized as cardiac reference biomarkers in patients with acute coronary syndromes and heart failure respectively. However, while on one hand the high sensitivity methods of cardiac biomarkers have provided answers to fundamental pathophysiological and clinical questions in patients with heart disease, less information is available on their assessment in paraphysiological conditions, such as high intensity exercise in healthy athletes. The aim of this study was to evaluate hs-cTnI and NT-proBNP in highly trained runners after a 50 km ultramarathon.

METHODS

We have enrolled 20 highly trained male athletes who have run a 50 km ultramarathon. Blood samples were collected 2 hours before the start of the race (T0) and 20 minutes after the end of the race (T1). The blood concentrations of hs-cTnI and NT-proBNP measured before the race were within reference intervals in all runners.

RESULTS

Hs-cTnI significantly increased after the end of the race (median: 19 ng/L [IQR: 12.5-25.75] versus 6 ng/L [IQR: 4.25-8.0]; P<0.001), in three cases over the upper reference limit (URL) of 34 ng/L. NT-proBNP also significantly increased (median: 78 ng/L [IQR: 68.25-87.75] versus 22 ng/L [IQR: 18.25-26.75]; P<0.001). Three other athletes reached concentration over the URL (125 ng/L).

CONCLUSIONS

Our study showed a significant increase in hs-cTnI and NT-proBNP in highly trained athletes after a 50 km ultramarathon race, and 30% of runners had the values of cardiac biomarkers above URL. More studies with a larger number of athletes will be needed to better understand the effects of intense exercise on the heart of trained athletes.

Blood Biomarkers of Recovery Efficiency in Soccer Players

Physical exercise strongly affects human metabolism and causes biochemical changes. This study aimed to investigate the relationship between routine plasma biomarker levels and recovery efficiency in soccer players during an entire competitive match season. The players participating in the study were divided into a midfielder/defender group (seven midfielders and seven defenders) and a goalie/substitute group (six persons—goalkeepers and players with a short cumulative match-time). The fasting capillary blood samples were taken 17–24 h after each competitive match. The blood plasma was used to determine the creatinine, urea, alkaline phosphatase, creatine kinase, lactate dehydrogenase, aspartate and alanine aminotransferase, iron and magnesium levels of the athletes. The levels of (AST) (aspartate aminotransferase), (ALT) (alanine aminotransferase) and (Cr) creatinine were higher in the midfielder/defender group than in the control group, but only AST and Cr significantly varied over time (AST decreased, and Cr increased with time). The (LDH) (lactate dehydrogenase) activity and urea level were significantly lower in the midfielder/defender group than in the goalie/substitute group, and it significantly varied over time (LDH decreased, and urea increased with time). No differences in the (CK) creatine kinase and (ALP) alkaline phosphatase activities between the groups was found, although CK increased significantly with time in the midfielder/defender group (particularly midfielders in the spring round). In midfielders, the AST activity and the iron level were significantly lower in the spring than in the autumn round. On the contrary, ALT, CK, urea and magnesium levels were significantly higher in the spring than in autumn round. A long-term measurement of biochemical parameters in elite soccer players indicated that AST, CK, LDH and creatinine levels, when analyzed together, could constitute a useful set of markers for monitoring recovery periods.

A Randomized Controlled Trial Investigating the Effects of Undulatory, Staggered, and Linear Load Manipulations in Aerobic Training on Oxygen Supply, Muscle Injury, and Metabolism in Male Recreational Runners

Background

Taper is considered as a strategy to avoid overtraining and increase peak performance in athletes. Because aerobic exercise increases the level and duration of independence during the lifespan, the participation of recreational athletes has increased in running events around the world. However, the effects of using load reduction in their training and aerobic performance are still not well known.

Objectives

Our goal was to compare load manipulations, using tapering-like periods in the end of recreational athletes training evaluating alterations in oxygen supply, muscle injury, and metabolism markers.

Methods

Healthy males (n = 88, 20–35 years old) were randomly distributed in groups using a combination of two mesocycles of 4 weeks, undulatory and staggered, with two daily microcycles, undulatory and linear. Undulatory-undulatory (Und-Und) and undulatory-linear (Und-Lin) groups had load reduction in the final week of training while the staggered-undulatory (Sta-Und) and staggered-linear (Sta-Lin) groups did not. Cardiorespiratory capacity (V̇O_2max), body mass index (BMI), and body fat % were evaluated. Blood samples were also collected to analyze hematocrit (Ht), mean corpuscular hemoglobin (MCHC), circulating levels of hemoglobin (Hb), creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea (U), cortisol (C), free testosterone (FT), and free T/C ratio.

Results

After 8 weeks of training, Und-Und had the highest trend to increase V̇O_2max. Both Und-Und and Sta-Lin reduced body fat %. Und-Und showed a significant increase in MCHC, T and Free T/C ratio, a positive trend to increase Ht% and Hb levels, and a trend to decrease CK, LDH, and C circulating levels. Sta-Lin presented a trend to decrease Ht% and Hb levels, a significant increase in CK, LDH, AST, ALT circulating levels, and a decrease in Free T/C ratio.

Conclusion

The use of daily undulatory training load provides better gains for aerobic fitness while the use of staggered load, mainly associated with linear load, promotes inadequate recovery in recreational runners.

Cardiac Biomarker Release After Exercise in Healthy Children and Adolescents: A Systematic Review and Meta-Analysis

PURPOSE

The authors evaluated the impact of acute exercise and 24-hour recovery on serum concentration of cardiac troponins T and I (cTnT and cTnI) and N-terminal fragment of the prohormone brain natriuretic peptide (NT-proBNP) in healthy children and adolescents. The authors also determined the proportion of participants exceeding the upper reference limits and acute myocardial infarction cutoff for each assay.

METHOD

Web of Science, SPORTDiscus, MEDLINE, ScienceDirect, and Scopus databases were systematically searched up to November 2017. Studies were screened and quality-assessed; the data was systematically extracted and analyzed.

RESULTS

From 751 studies initially identified, 14 met the inclusion criteria for data extraction. All 3 biomarkers were increased significantly after exercise. A decrease from postexercise to 24 hours was noted in cTnT and cTnI, although this decrease was only statistically significant for cTnT. The upper reference limit was exceeded by 76% of participants for cTnT, a 51% for cTnI, and a 13% for NT-proBNP. Furthermore, the cutoff value for acute myocardial infarction was exceeded by 39% for cTnT and a 11% for cTnI. Postexercise peak values of cTnT were associated with duration and intensity (Q₍₃₎ = 28.3, P < .001) while NT-proBNP peak values were associated with duration (Q₍₂₎ = 11.9, P = .003).

CONCLUSION

Exercise results in the appearance of elevated levels of cTnT, cTnI, and NT-proBNP in children and adolescents. Postexercise elevations of cTnT and NT-proBNP are associated with exercise duration and intensity.

Acute Responses of Novel Cardiac Biomarkers to a 24-h Ultra-Marathon

The aim of the present study was to examine the acute effect of an ultra-endurance performance on N-terminal pro-brain natriuretic peptide (NT-proBNP), cardiac specific troponin T (cTnT), creatinine kinase-myocardial band (CK-MB), high sensitive C-reactive protein (hsCRP), ischemia modified albumin (IMA), heart-type fatty acid binding protein (H-FABP) and cardiovascular function. Cardiac biomarkers were evaluated in 14 male ultra-marathoners (age 40 ± 12 years) during a 24 h ultra-marathon at five points (i.e., Pre-race; Marathon, 12-h run, 24-h run, and 48-h post-race). All subjects underwent baseline echocardiography assessment at least 10 days prior to the ultra-marathon and 48 h post-race. The average distance covered during the race was 149.4 ± 33.0 km. Running the ultra-marathon led to a progressive increase in hsCRP and H-FABP concentrations (p < 0.001). CK-MB and cTnT levels were higher after a 24-h run compared to pre-race (p < 0.05). Diastolic function was altered post-race characterized by a reduction in peak early to late diastolic filling (p < 0.01). Running an ultra-marathon significantly stimulates specific cardiac biomarkers; however, the dynamic of secretion of biomarkers linked to myocardium ischemia were differentially regulated during the ultra-marathon race. It is suggested that both exercise duration and intensity play a crucial role in cardiovascular adaptive mechanisms and cause risk of cardiac stress in ultra-marathoners.

Impact of a Soccer Game on Cardiac Biomarkers in Adolescent Players

PURPOSE

Biochemical markers such as cardiac troponin I (cTnI) and N-terminal pro B-type natriuretic peptide (NT-proBNP) have become indispensable tools for the diagnosis of myocardial injury, providing highly sensitive and specific information about cardiac cell damage and wall stress. The purpose of the present research was to examine the response of cardiac biomarkers to a soccer game in adolescent male soccer players.

METHODS

Twenty-two trained adolescent male soccer players (14-16 y) were selected in a purposive manner. Blood samples were taken before, immediately after, and 2 and 24 hours after the game for the determination of cTnI and NT-proBNP.

RESULTS

Serum concentration of cTnI and NT-proBNP increased immediately and 2 hours after the soccer game (P < .001). After 24 hours, the levels of cTnI dropped but remained above baseline (P = .002), whereas serum NT-proBNP levels returned to baseline. At no time point did any of the values exceed the upper reference value.

CONCLUSIONS

This is the first study to investigate the acute responses of cardiac biomarkers to a soccer game in adolescent male players. The postgame elevation of cardiac biomarkers and their rapid recovery are indicative of a physiological rather than a pathological response.

Biochemical, physiological, and performance response of a functional watermelon juice enriched in L-citrulline during a half-marathon race

Background: Watermelon is a rich natural source of l-citrulline. This non-essential amino acid increases exercise performance.

Objective: Evaluate the effect of Fashion watermelon juice enriched in l-citrulline (CWJ) (3.45 g per 500 mL) in physical performance and biochemical markers after a half-marathon race.

Design: A randomised, double blind, crossover design where 2 h after drinking 500 mL of CWJ or placebo (PLA, beverage without l-citrulline) amateur male runners performed two half-marathon races. Jump height, heart rate and rating of perceived exertion were evaluated before and after the races. Moreover, muscle soreness and plasma markers of muscle damage and metabolism were evaluated for 72 h after the races.

Results: Muscle soreness perception was significantly lower from 24 to 72 h after the race with CWJ beverage. Immediately after the races, runners under CWJ condition showed plasma lactate and glucose concentrations significantly lower and higher lactate dehydrogenase and l-arginine concentration than runners under PLA. A maintenance of jump heights after the races under CWJ supplementation was found, decreasing significantly with PLA.

Conclusion: A single Fashion watermelon juice enriched in l-citrulline dose diminished muscle soreness perception from 24 to 72 h after the race and maintained lower concentrations of plasma lactate after an exhausting exercise.

Troponin and exercise

Cardiac troponins are the preferred biomarkers in diagnostic of myocardial infarction, but these markers also can rise in response to exercise. Multiple studies have assessed troponins post-exercise, but the results have varied and there have been disagreements about the mechanism of troponin release. The aim of this paper was to review the literature, and to consider factors and mechanisms regarding exercise-induced increase of troponin. 145 studies were found after a search in pubmed and inclusion of additional articles found in the reference list of the first articles. Results showed that troponin rises in 0-100% of subjects after prolonged heavy exercise like marathon, but also after short-term and intermittent exercise like 30min of running and basketball. The variation can be due to factors like intensity, age, training experience, variation in sample size, blood sample timing and troponin assay. The pattern of troponin level post-exercise corresponds to release from the cytosolic compartment of cardiomyocytes. Increased membrane permeability might be caused by production of reactive oxygen species or alterations in calcium, pH, glucose/fat metabolism or in communication between integrins. Other suggested mechanisms are increased cardiovascular stress, inflammation, vasculitis, release of troponin degradation products in "blebs", dehydration, impaired renal clearance and expression of cardiac troponin in skeletal muscle. It can be concluded that both heavy and light exercise may cause elevated troponin, which have to be considered when patient are suspected to have a myocardial infarction. Several factors probably influence post-exercise levels of troponin, but the mechanism of release is most likely physiologic.

The Effects of Exercise on Natriuretic Peptides in Individuals without Heart Failure

Cardiac natriuretic peptides (NPs) play an important role in the regulation of energy expenditure in skeletal muscle and adipose tissue. A systematic review on the effects of exercise on NPs in patients with heart failure reported that aerobic and resistance training reduced NPs; however, the effects of exercise on NPs and the underlying mechanism of exercise-induced NP secretion in subjects without heart failure remain unknown. In athletes and young, healthy subjects, the NP concentration at rest is not elevated, but strenuous endurance exercise significantly increases NPs. The exercise-induced increase in NPs may be caused by transient myocardial wall stress, cardiomyocyte metabolic changes, or neuroendocrinological response, which may have cytoprotective and growth-regulating effects on the heart. On the other hand, in elderly, overweight/obese subjects, and patients with hypertension, NP concentrations also increase during exercise; however, NP secretion may be more susceptible to cardiac stress compared to young, healthy individuals. Recent studies have shown that NPs are associated with thermogenesis in fat tissue and oxidative capacity in skeletal muscles. NPs may also have a protective role for skeletal muscle in humans, although further studies are warranted to elucidate the physiological mechanism of exercise-induced NP secretion.

Biomarker Changes after Strenuous Exercise Can Mimic Pulmonary Embolism and Cardiac Injury—A Metaanalysis of 45 Studies

BACKGROUND

Biomarkers are well established for diagnosis of myocardial infarction [cardiac troponins, high-sensitivity cardiac troponins (hs-cTn)], exclusion of acute and chronic heart failure [B-type natriuretic peptide (BNP), N-terminal proBNP (NT-proBNP)] and venous thromboembolism (d-dimers). Several studies have demonstrated acute increases in cardiac biomarkers and altered cardiac function after strenuous sports that can pretend a cardiovascular emergency and interfere with state-of-the-art clinical assessment.

METHODS

We performed a systematic review and metaanalysis of biomarker and cardiovascular imaging changes after endurance exercise. We searched for observational studies published in the English language from 1997 to 2014 that assessed these biomarkers or cardiac function and morphology directly after endurance exercise. Of 1787 identified abstracts, 45 studies were included.

RESULTS

Across all studies cardiac troponin T (cTnT) exceeded the cutoff value (0.01 ng/mL) in 51% (95% CI, 37%–64%) of participants. The measured pooled changes from baseline for high-sensitivity cTnT (hs-cTnT) were +26 ng/L (95% CI, 5.2–46.0), for cTnI +40 ng/L (95% CI, 21.4; 58.0), for BNP +10 ng/L (95% CI, 4.3; 16.6), for NT-proBNP +67 ng/L (95% CI, 49.9; 84.7), and for d-dimer +262 ng/mL (95% CI, 165.9; 358.7). Right ventricular end diastolic diameter increased and right ventricular ejection fraction as well as the ratio of the early to late transmitral flow velocities decreased after exercise, while no significant changes were observed in left ventricular ejection fraction.

CONCLUSIONS

Current cardiovascular biomarkers (cTnT, hs-cTnT, BNP, NT-proBNP, and d-dimer) that are used in clinical diagnosis of pulmonary embolism, acute coronary syndrome, and heart failure are prone to alterations due to strenuous exercise. Hence, it is necessary to take previous physical exercise into account when a cardiac emergency is suspected.

The effect of elapsed time on cardiac troponin-T (cTnT) degradation and its relation to postmortem interval in cases of electrocution

BACKGROUND

The estimation of postmortem interval (PMI) is of paramount importance for the police in their investigation when arriving at the scene of a questionable death. The aim of present study is to evaluate the effect of elapsed time on cardiac Troponin-T degradation and its association with PMI in cases of death due to electrocution.

METHODS

Cardiac tissue samples were collected from medico-legal autopsies, after informed consent from the relatives. The cases included were the subjects of electrocution without any prior history of disease who died in the hospital and their exact time of death was known. The analysis involves extraction of the protein at room temperature for different time periods (∼5, 26, 50, 84, 132, 157, 180, 205 and 230 Hrs), separation by SDS-PAGE and visualization by Western blot using cTnT specific monoclonal antibodies.

RESULTS

The results specify a characteristic banding pattern amongst human cadavers (n = 5), a pseudo-linear relationship between percent cTnT degraded and the time since death (R(2) = 0.87, p = 0.0001) was observed. The area of the bands within a lane was quantified by scanning and digitizing the image using Gel Doc (Universal Hood II).

CONCLUSIONS

The post-mortem Troponin-T fragmentation observed in this study reveals a sequential, time-dependent process with the potential for use as a predictor of PMI in cases of electrocution.

Gender- and sex-specific sports-related injury research in emergency medicine: a consensus on future research direction and focused application

Title IX, the commercialization of sports, the social change in sports participation, and the response to the obesity epidemic have contributed to the rapid proliferation of participation in both competitive organized sports and nontraditional athletic events. As a consequence, emergency physicians are regularly involved in the acute diagnosis, management, disposition, and counseling of a broad range of sports-related pathology. Three important and highly publicized mechanisms of injury in sports relevant to emergency medicine (EM) include concussion, heat illness, and sudden cardiac death. In conjunction with the 2014 Academic Emergency Medicine consensus conference "Gender-specific Research in Emergency Care: Investigate, Understand, and Translate How Gender Affects Patient Outcomes," a consensus group consisting of experts in EM, emergency neurology, sports medicine, and public health convened to deliberate and develop research questions that could ultimately advance the field of sports medicine and allow for meaningful application in the emergency department (ED) clinical setting. Sex differences in injury risk, diagnosis, ED treatment, and counseling are identified in each of these themes. This article presents the consensus-based priority research agenda.

Acute changes to biomarkers as a consequence of prolonged strenuous running

BACKGROUND

A single bout of strenuous running exercise results in perturbations to numerous biomarkers. An understanding of these is important when analysing samples from individuals who have recently performed such exercise.

METHODS

A literature search was undertaken using the search terms, exercise, marathon and delayed onset of muscle soreness. The search was then refined using the terms for key biomarkers known to be altered by exercise.

RESULTS

The magnitude of changes to biomarkers is proportional to the severity of the running bout. Familiar, moderate intensity running exercise produces brief transient changes in common biomarkers such as lactate, whereas more severe bouts of running exercise, such as marathons and ultra-marathon events can produce changes to biomarkers that are normally associated with pathology of the muscles, liver and heart. Examples being changes to concentrations and/or activity of myoglobin, leucocytes, creatine kinase, bilirubin, cardiac troponins, lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase. While persisting for longer, these changes are also transient and full recovery occurs within days, without any apparent long-term adverse consequences. Additionally, unfamiliar exercise involving forceful eccentric muscle contractions, such as running downhill, can cause increases in creatine kinase and delayed onset of muscle soreness that peaks 36-72 h after the exercise bout.

CONCLUSIONS

Strenuous running exercise can produce changes to biomarkers that are normally associated with disease and injury, but these do not necessarily reflect chronic pathology.

Brain natriuretic peptide and NT-proBNP levels reflect pulmonary artery systolic pressure in trekkers at high altitude

Our objective was to evaluate the utility of the natriuretic peptides BNP (brain natriuretic peptide) and NT-proBNP as markers of pulmonary artery systolic pressure (PASP) in trekkers ascending to high altitude (HA). 20 participants had BNP and NT-proBNP assayed and simultaneous echocardiographic assessment of PASP performed during a trek to 5150 m. PASP increased significantly (p=0.006) with ascent from 24+/-4 to 39+/-11 mm Hg at 5150 m. At 5150 m those with a PASP>/=40 mm Hg (n=8) (versus those with PASP<40 mm Hg) had higher post-exercise BNP (pg/ml): 54.5+/-36 vs. 13.4+/-17 (p=0.012). Their resting BNP at 5150 m was also higher: 57.3+/-43.4 vs. 12.6+/-13 (p=0.017). In those with a pathological (>/=400 pg/ml) rise in NT-proBNP at 5150 m (n=4) PASP was significantly higher: 45.9+/-7.5 vs. 32.2+/-6.2 mm Hg (p=0.015). BNP and NT-proBNP may reflect elevated PASP, a central feature of high altitude pulmonary oedema, at HA.

Leukocyte chemotactic cytokine and leukocyte subset responses during ultra-marathon running

PURPOSE

The aim of this study was to assess leukocyte chemotactic cytokine and leukocyte subset responses during ultra-marathon running. Leukocyte chemokines such as interleukin (IL)-8, interferon gamma-induced protein-10 (IP-10), regulated upon activation, normal T-cell expressed and secreted (RANTES), and eotaxin are involved in leukocyte recruitment.

METHODS

Among 60 male amateur endurance runner volunteers, 18 finished the course (a 308 km continuous race from Kanghwado to Kangneung, South Korea). Their average age, height, and body mass were 52.8 ± 5.0 years, 167.6 ± 5.2 cm, and 64.5 ± 1.2 kg, respectively. Blood samples were collected at 0, 100, 200, and 308 km during the race for analysis of white blood cells and serum concentrations of IL-8, IP-10, RANTES, eotaxin, IL-6, creatine kinase (CK), and C-reactive protein (CRP).

RESULTS

Muscle and liver damage indicators (IL-6, CK, and CRP) were maximally elevated as a result of marathon running. Total leukocytes, neutrophils, and monocytes increased significantly during the event (leukocytosis, neutrophilia, and monocytosis, respectively). However, lymphocytes and eosinophils decreased significantly during the event (lymphopenia and eosinopenia, respectively). Serum levels of the neutrophil chemokine IL-8 increased maximally at 100 km and were maintained. Monocyte-lymphocyte chemokine IP-10 concentration decreased during the latter part of the race. The eosinophil chemokine eotaxin decreased gradually during the race, and no difference was observed in eosinophil chemokine RANTES levels.

CONCLUSION

These observations indicate that prolonged endurance ultra-marathon running was associated with significant systemic inflammation and perturbation in leukocyte subsets. Leukocyte chemotactic cytokines such as IL-8, IP-10, eotaxin showed similar patterns of responses in related leukocyte subsets, but RANTES did not.

Effect of endurance and strength exercise on release of brain natriuretic peptide

Objectives:

The aim of this study was to investigate the effects of 8-week endurance and resistance exercise training on release of brain natriuretic peptide.

Materials and Methods:

Study population was categorized into 4 groups: Group-1 (n = 6) consisted of sedentary individuals who volunteered to complete 8-weeks of endurance exercise; Group-2 (n=6) consisted of sedentary individuals who volunteered to complete 8-weaks of resistance exercise. Three blood samples [for Terminal pro BNP (NT-Pro-BNP)] were taken before, immediately after exercise and after 8 weeks of exercise training.

Results:

NT-Pro BNP was significantly increased immediately after endurance exercise [from 37.9 ± 1.4 pg/ml to 52.1 ±1.5 pg/ml; P = 0.002] and was decreased to 23.2 ± 9.3 pg/ml after 8 weeks of endurance exercise [P = 0.013]. On the other hand, NT-Pro BNP showed no significant changes immediately after resistance exercise [from 26.6 ± 4.9 pg/ml to 24.1 ±4.5 pg/ml; P = 0.553]. In contrast, NT-Pro BNP was significantly increased to 39.5 ±1.6 pg/ml after 8 weeks of resistance exercise [P = 0.012].

Conclusion:

Endurance exercise training reduces circulating NT-Pro BNP concentration, which is likely a marker of reduced ventricular wall tension and improved myocardial function. In contrast, strength exercise induces significant increase in NT-Pro BNP, which could be partially attributed to myocardial damage.

Metabolic markers in sports medicine

Physical exercise induces adaptations in metabolism considered beneficial for health. Athletic performance is linked to adaptations, training, and correct nutrition in individuals with genetic traits that can facilitate such adaptations. Intense and continuous exercise, training, and competitions, however, can induce changes in the serum concentrations of numerous laboratory parameters. When these modifications, especially elevated laboratory levels, result outside the reference range, further examinations are ordered or participation in training and competition is discontinued or sports practice loses its appeal. In order to correctly interpret commonly used laboratory data, laboratory professionals and sport physicians need to know the behavior of laboratory parameters during and after practice and competition. We reviewed the literature on liver, kidney, muscle, heart, energy, and bone parameters in athletes with a view to increase the knowledge about clinical chemistry applied to sport and to stimulate studies in this field. In liver metabolism, the interpretation of serum aminotransferases concentration in athletes should consider the release of aspartate aminotransferase (AST) from muscle and of alanine aminotransferase (ALT) mainly from the liver, when bilirubin can be elevated because of continuous hemolysis, which is typical of exercise. Muscle metabolism parameters such as creatine kinase (CK) are typically increased after exercise. This parameter can be used to interpret the physiological release of CK from muscle, its altered release due to rhabdomyolysis, or incomplete recovery due to overreaching or trauma. Cardiac markers are released during exercise, and especially endurance training. Increases in these markers should not simply be interpreted as a signal of cardiac damage or wall stress but rather as a sign of regulation of myocardial adaptation. Renal function can be followed in athletes by measuring serum creatinine concentration, but it should be interpreted considering the athlete's body-mass index (BMI) and phase of the competitive season; use of cystatin C could be a reliable alternative to creatinine. Exercise and training induce adaptations in glucose metabolism which improve glucose utilization in athletes and are beneficial for reducing insulin insensitivity in nonathletes. Glucose metabolism differs slightly for different sports disciplines, as revealed in laboratory levels. Sport activities induce a blood lipid profile superior to that of sedentary subjects. There are few reports for a definitive conclusion, however. The differences between athletes and sedentary subjects are mainly due to high-density lipoprotein cholesterol (HDLC) concentrations in physically active individuals, although some differences among sport disciplines exist. The effect of sports on serum and urinary markers for bone metabolism is not univocal; further studies are needed to establish the real and effective influence of sport on bone turnover and especially to establish its beneficial effect.

Marathon running as a cause of troponin elevation: a systematic review and meta-analysis

BACKGROUND

Cardiac troponin (cTn) has high sensitivity and specificity for myocardial injury in acute coronary syndrome. Our objective was to review the published literature regarding the incidence of cTn elevations in marathon runners.

METHODS

Systematic review and meta-analysis of observational studies published before September 2009. We included studies of patients who had completed a marathon and had serum cTn levels within 24 hours. The primary outcome was the odds ratio for conversion of a normal pre-marathon cTn to an elevated post-marathon cTn. Secondary outcomes included the pooled prevalence of cTn elevation and comparison of the odds ratio for post-marathon elevation of cTnI versus cTnT.

RESULTS

Sixteen studies of 939 participants met criteria for inclusion. The mean age was 39 ± 4 years and patients were 74 ± 14% male. There were 6 pre-marathon cTn elevations and 579 post-race elevations. The pooled odds ratio for converting from a normal pre-race to an elevated post-race cTn was 51.84 (95% CI 16-168, I² = 66%, P < 0.001). The pooled incidence of a post-marathon cTn elevation was 51% (95% CI 33-69, I² = 98%, P < 0.001) of all runners. For the primary outcome there was no significant publication bias. Age and gender were not associated, but publication date and assay sensitivity was associated with cTn elevation. cTnI was less commonly elevated versus cTnT.

CONCLUSIONS

The available data demonstrate that cTn levels are frequently elevated after a marathon with unclear cardiovascular significance. This elevation of cTn appears to be consistent among a diverse patient population.

Myocardial infarction & sudden death in recreational master marathon runners

This review of the current literature on myocardial infarction and sudden death in recreational master marathon runners aims to help raise awareness of the scope of the problem to primary care providers, and to provide guidelines for educating and screening in recreational master marathon runners.

The response of circulating brain natriuretic peptide to academic stress in college students

Brain natriuretic peptide (BNP), a cardiac peptide, has been implicated in the regulation of hypothalamic-pituitary-adrenocortical (HPA) responses to psychological stressors. The influence of academic stress on circulating concentration of the N-terminal fragment of BNP precursor (NT-proBNP), and in relation to the stress hormone (cortisol) response was studied in 170 college students undergoing major examinations. Just prior to the examination, we measured self-estimated stress level, systolic, and diastolic blood pressure (SBP, DBP), heart rate (HR), plasma levels of cortisol, and NT-proBNP. These parameters were compared to the participants' baseline measurements, taken at the same hour of a different 'control day', without a major examination to induce stress. Hemodynamic variables (SBP, DBP, and HR) increased on the examination day compared with baseline values ( p < 0.001). Circulating cortisol concentration increased before examinations (+42%, p < 0.001). The response to stress was marked by a significant decrease in plasma NT-proBNP concentration (-40%, p < 0.001). We found in males a significant interaction between the cortisol elevation with examination stress and the NT-proBNP reduction ( p = 0.02). In response to academic stress, the plasma cortisol elevation was accompanied by a marked reduction in plasma NT-proBNP level. These data may indicate that mental stress entails an interface between the HPA axis and the peripheral natriuretic peptide system, leading to reciprocating changes in circulating levels of the corresponding hormones.

A 246-km continuous running race causes significant changes in bone metabolism

BACKGROUND

Regular physical exercise exerts a favorable effect on the skeleton. However, excessive physical exercise may have detrimental effects. A low bone mineral density (BMD) has been registered in highly trained runners. The aim of the present study was to evaluate potential effects of the Spartathlon, an annual ultramarathon race of 246 km, on bone metabolism.

METHODS

Venous blood samples were taken before and within 15 min after the end of the race as well as three days after the start of the race. The following variables of bone metabolism were studied: osteocalcin (Oc), cross-linked-C-telopeptide of type I collagen (CTX), osteoprotegerin (OPG), and its ligand, receptor activator of nuclear factor kappaB ligand (RANKL).

RESULTS

Blood samples were taken from 18 runners (16 men and 2 women) at the three time points. The median time taken by the runners to complete the race was 32 h and 52 min. Serum levels of CTX were significantly increased immediately after the race as well as three days after the start of the race compared with the time prior to the race. Oc was transiently suppressed after the race. Serum levels of RANKL and OPG were increased three days after the start of the race compared to the time before the start of the race.

CONCLUSIONS

This study showed that an ultra-distance run of nearly 250 km induced changes in RANK/RANKL/OPG interaction, which suggests a transient uncoupling of bone metabolism, increased bone resorption, and suppressed bone formation.

Predisposing factors and consequences of elevated biomarker levels in long-distance runners aged >or=55 years

Cardiac biomarkers play an important role in the diagnosis of cardiovascular disease. Elevated levels can be seen in the context of strenuous exercise. We studied this phenomenon in senior endurance runners. We included 185 participants (61.1 +/- 5 years; 29% women) at a 30-km cross-country race who were self-reportedly in excellent health. Before and after the race, the creatinine, N-terminal pro-brain natriuretic peptide (NT-proBNP), and troponin T were analyzed, and participation in the number of previous races and the race duration were recorded. NT-proBNP increased from 53 ng/L (interquartile range 31 to 89) to 121 ng/L (interquartile range 79 to 184) and troponin T from undetectable to 0.01 microg/L (interquartile range 0.01 to 0.04). The independent predictors of a large NT-proBNP increase were (1) greater levels present at baseline, (2) a greater increase in creatinine (both p <0.001), (3) older age (p = 0.01), and (4) a longer race duration (p <0.05). Troponin T elevation was independently predicted by (1) older age (p = 0.01), (2) a greater increase in creatinine, and (3) participation in fewer previous races (both p <0.05). Of the 15 runners with an elevated (>194 ng/L) baseline NT-proBNP level (8.1% of 185), 4 were found to have serious cardiovascular disease (2.2% of whole sample). Of these 4 patients, 1 died from sudden cardiac death within months after the race. In conclusion, biomarker elevation occurs commonly in senior runners. A high baseline NT-proBNP is predictive of a large release during exercise, suggesting that the factors that control the at rest levels also determine its release with exertion. Troponin T elevation was seen in less-experienced participants. A small group of very ill runners were identified by NT-proBNP analysis.

Myocardial function in older male amateur marathon runners: assessment by tissue Doppler echocardiography, speckle tracking, and cardiac biomarkers

BACKGROUND

Participation of older men in endurance races continues to increase. Recent studies on marathon runners raised concerns about a transient myocardial dysfunction and damage. The aim of our study was to compare the extent of marathon-induced myocardial dysfunction in young and older runners and to identify its potential correlation to elevated cardiac biomarkers.

METHODS

Twenty-eight older (aged 60-72 years) and 50 younger (22-59 years) male amateur athletes who participated in the 2006 Berlin Marathon were included in the study and examined by echocardiography (including tissue Doppler and speckle tracking echocardiography) and blood tests (including troponin T [TnT], N-terminal pro brain natriuretic peptide [NT-proBNP]) before, immediately after, and 2 weeks after the race.

RESULTS

Immediately after the marathon, there was no sign of systolic myocardial dysfunction (increase in fractional shortening, baseline 39.9% +/- 7.6% vs post 46.8% +/- 9.2%, P < .001, unchanged septal basal longitudinal 2-dimensional strain: 17.1% +/- 2.9%, 17.7% +/- 3.2%, P = .11). As a marker of diastolic function, E/E' was not altered significantly (7.6 +/- 2.1, 8.7 +/- 3.5, P = .15). The deceleration time of E and E' decreased in both groups immediately after the race, indicating a transient adaptation of diastolic myocardial function. Strain of the right ventricular free wall was decreased in the mid and apical segments after the race in both groups with normalization during follow-up. Tricuspid annular plane systolic excursion was not altered. Some 53.8% of all runners had increases in TnT or NT-proBNP after the race. Some 32% of controls and 29% of older runners had elevated levels of NT-proBNP (P = .75, TnT: 44% vs 29% P = .18). There was no correlation between NT-proBNP and TnT increase. The increases in biomarkers were not correlated to echocardiography parameters of systolic, diastolic, or right-sided heart dysfunction or to age, training level, running time, or renal function. All parameters returned to normal ranges after 2 weeks.

CONCLUSION

Left ventricular systolic function is preserved after a marathon in older runners. There are right ventricular functional changes as a sign of prolonged myocardial work load. There is no significant difference between older and young runners regarding transient diastolic dysfunction or biomarker release. The latter is not associated with echocardiography parameters of myocardial dysfunction.

Magnitude, reproducibility, and association with baseline cardiac function of cardiac biomarker release in long-distance runners aged > or =55 years

Cardiac biomarker release after endurance exercise has been described in young athletes. Although older athletes are increasingly active in such sports, they have not previously been studied. Therefore, the aim of this study was to assess the magnitude and reproducibility of biomarker release in athletes aged > or =55 years. Forty-three healthy athletes (mean age 61 +/- 3.6 years) were assessed before and immediately after a 30-km cross-country race and studied with echocardiography at rest. The median N-terminal pro-brain natriuretic peptide (NT-proBNP; normal <194 ng/L) level was 42 ng/L (interquartile range 30 to 95) at baseline and 191 ng/L (interquartile range 114 to 308) after the race. Troponin T (normal <0.03 microg/L) was elevated in 19 subjects (44%) after the race. Twenty-two subjects had also been studied 3 years before at the same race, using an identical test protocol. Between the 2 races, strong correlations were seen for individual runners' postrace biomarker levels (NT-proBNP: r = 0.82, log transformed data; troponin T: Spearman's rho = 0.84; p <0.001 for both). The coefficient of variation for NT-proBNP release was 8.1%. Levels of NT-proBNP after the race were correlated with levels at baseline (r = 0.93, p <0.001) and with left ventricular mass index (r = 0.32, p = 0.03). Moreover, participants with elevated postrace NT-proBNP were significantly older (62.0 vs 59.8 years, p = 0.04). In conclusion, long-distance runners aged > or =55 years released NT-proBNP and troponin T in a reproducible fashion. The magnitude of NT-proBNP release during the race was correlated strongly with NT-proBNP baseline levels and was associated with left ventricular mass and age. These findings may suggest a potential adverse effect of long-distance running on cardiac function in certain participants in this age group.