30 research outputs found
Cardiac and renal function in a large cohort of amateur marathon runners
Background Participation of amateur runners in endurance races continues to
increase. Previous studies of marathon runners have raised concerns about
exercise-induced myocardial and renal dysfunction and damage. In our pooled
analysis, we aimed to characterize changes of cardiac and renal function after
marathon running in a large cohort of mostly elderly amateur marathon runners.
Methods A total of 167 participants of the BERLIN-MARATHON (female n = 89,
male n = 78; age = 50.3 ± 11.4 years) were included and cardiac and renal
function was analyzed prior to, immediately after and 2 weeks following the
race by echocardiography and blood tests (including cardiac troponin T, NT-
proBNP and cystatin C). Results Among the runners, 58% exhibited a significant
increase in cardiac biomarkers after completion of the marathon. Overall, the
changes in echocardiographic parameters for systolic or diastolic left and
right ventricular function did not indicate relevant myocardial dysfunction.
Notably, 30% of all participants showed >25% decrease in cystatin C-estimated
glomerular filtration rate (GFR) from baseline directly after the marathon; in
8%, we observed a decline of more than 50%. All cardiac and renal parameters
returned to baseline ranges within 2 weeks after the marathon. Conclusions The
increase in cardiac biomarkers after completing a marathon was not accompanied
by relevant cardiac dysfunction as assessed by echocardiography. After the
race, a high proportion of runners experienced a decrease in cystatin
C-estimated GFR, which is suggestive of transient, exercise-related alteration
of renal function. However, we did not observe persistent detrimental effects
on renal function
results of the prospective observational Berlin Beat of Running study
Objectives: While regular physical exercise has many health benefits,
strenuous physical exercise may have a negative impact on cardiac function.
The ‘Berlin Beat of Running’ study focused on feasibility and diagnostic value
of continuous ECG monitoring in recreational endurance athletes during a
marathon race. We hypothesised that cardiac arrhythmias and especially atrial
fibrillation are frequently found in a cohort of recreational endurance
athletes. The main secondary hypothesis was that pathological laboratory
findings in these athletes are (in part) associated with cardiac arrhythmias.
Design: Prospective observational cohort study including healthy volunteers.
Setting and participants: One hundred and nine experienced marathon runners
wore a portable ECG recorder during a marathon race in Berlin, Germany.
Athletes underwent blood tests 2–3 days prior, directly after and 1–2 days
after the race. Results: Overall, 108 athletes (median 48 years (IQR 45–53),
24% women) completed the marathon in 249±43 min. Blinded ECG analysis revealed
abnormal findings during the marathon in 18 (16.8%) athletes. Ten (9.3%)
athletes had at least one episode of non-sustained ventricular tachycardia,
one of whom had atrial fibrillation; eight (7.5%) individuals showed transient
ST-T-segment deviations. Abnormal ECG findings were associated with advanced
age (OR 1.11 per year, 95% CI 1.01 to 1.23), while sex and cardiovascular risk
profile had no impact. Directly after the race, high-sensitive troponin T was
elevated in 18 (16.7%) athletes and associated with ST-T-segment deviation (OR
9.9, 95% CI 1.9 to 51.5), while age, sex and cardiovascular risk profile had
no impact. Conclusions: ECG monitoring during a marathon is feasible. Abnormal
ECG findings were present in every sixth athlete. Exercise-induced transient
ST-T-segment deviations were associated with elevated high-sensitive troponin
T (hsTnT) values. Trial registration: ClinicalTrials.gov NCT01428778; Results
The Preventable Causes of Death in the United States: Comparative Risk Assessment of Dietary, Lifestyle, and Metabolic Risk Factors
Majid Ezzati and colleagues examine US data on risk factor exposures and disease-specific mortality and find that smoking and hypertension, which both have effective interventions, are responsible for the largest number of deaths
Poly-beta-hydroxy alkanoate and the support of river biofilm metabolism following radical changes in environmental conditions
Endogenous carbon reserves such as poly-beta-hydroxy alkanoate (PHA) can sustain microbial viability during conditions of nutrient deprivation. Microbial extracellular enzyme activities under one set of environmental conditions might be wholly inappropriate for another, and thus PHA might also serve as an energy source as the biofilm acclimates to a changed environment. In order to test this hypothesis, radical changes in environmental conditions were imposed upon river biofilms by transferring them between three rivers of acid, circum-neutral and alkaline pH. The findings supported the hypothesis; each of the transfers resulted in reduced PHA levels, while the physiology of the biofilm (metabolic activity, population density, phosphatase & glucosidase activities) acclimated to the environmental conditions of the recipient site. The greatest PHA depletion was observed when the magnitude of the imposed change resulted in an inability of phosphatase enzyme to respond to the change. The implicit greater dependence on the reserves of PHA, is similarly consistent with the hypothesis