Jennifer Adam

Circulating microRNA-126 increases after different forms of endurance exercise in healthy adults

Background MicroRNAs (miRNAs) are small non-coding molecules regulating gene expression. Recently circulating miRNAs could be detected in the plasma, serving as novel biomarkers. Different forms of exercise mobilize progenitor cells from the bone marrow, helping in tissue repair. Data of different forms of exercise on endothelial cell damage are lacking. The aim of the study was to evaluate the impact of different exercise modalities on the plasma concentration of miRNA-126, as a marker for endothelial damage. Methods The plasma concentration of miRNA-126 and miRNA-133 (marker for muscle damage) was assessed by qRT-PCR analysis in plasma samples from healthy individuals performing one of the following exercise tests: (1) maximal symptom-limited exercise test, (2) bicycling for 4 h, (3) running a marathon, and (4) resistance exercise. Results A maximal symptom-limited exercise test resulted in a significant increase of circulating miRNA-126 at maximum power (2.1-fold versus begin), whereas the concentration of miRNA-133 remained unchanged. In line, four hours of cycling increased plasma concentration of miRNA-126 with a maximum 30 minutes after begin (4.6-fold versus begin) without an impact on miRNA-133 concentration. Finishing a marathon race resulted in an increase of miRNA-126 and miRNA-133. In contrast, eccentric resistance training led to an isolated increase of miRNA-133 level (2.1-fold versus begin) with unchanged miRNA-126. Conclusion Different endurance exercise protocols lead to damage of the endothelial cell layer as evident by an increase in miRNA-126. On the other hand, resistance exercise has no impact on the endothelial cells, but leads to a destruction of muscular cells.

Coronary Collateral Growth Induced by Physical Exercise Results of the Impact of Intensive Exercise Training on Coronary Collateral Circulation in Patients With Stable Coronary Artery Disease (EXCITE) Trial

Background— A well-developed coronary collateral circulation provides a potential source of blood supply in coronary artery disease. However, the prognostic importance and functional relevance of coronary collaterals is controversial with the association between exercise training and collateral growth still unclear. Methods and Results— This prospective, open-label study randomly assigned 60 patients with significant coronary artery disease (fractional flow reserve ⩽0.75) to high-intensity exercise (group A, 20 patients) or moderate-intensity exercise (group B, 20 patients) for 4 weeks or to a control group (group C, 20 patients). The primary end point was the change of the coronary collateral flow index (CFI) after 4 weeks. Analysis was based on the intention to treat. After 4 weeks, baseline CFI increased significantly by 39.4% in group A (from 0.142±0.07 at beginning to 0.198±0.09 at 4 weeks) in comparison with 41.3% in group B (from 0.143±0.06 to 0.202±0.09), whereas CFI in the control group remained unchanged (0.7%, from 0.149±0.09 to 0.150±0.08). High-intensity exercise did not lead to a greater CFI than moderate-intensity training. After 4 weeks, exercise capacity, VO2 peak and ischemic threshold increased significantly in group A and group B in comparison with group C with no difference between group A and group B. Conclusions— A significant improvement in CFI was demonstrated in response to moderate- and high-intensity exercise performed for 10 hours per week. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01209637.

Coronary Collateral Growth Induced by Physical Exercise: Results of the Leipzig EXerCIse Training versus MEdical Management in Patients With Stable Coronary Artery Disease (EXCITE) Trial

Background— A well-developed coronary collateral circulation provides a potential source of blood supply in coronary artery disease. However, the prognostic importance and functional relevance of coronary collaterals is controversial with the association between exercise training and collateral growth still unclear. Methods and Results— This prospective, open-label study randomly assigned 60 patients with significant coronary artery disease (fractional flow reserve ⩽0.75) to high-intensity exercise (group A, 20 patients) or moderate-intensity exercise (group B, 20 patients) for 4 weeks or to a control group (group C, 20 patients). The primary end point was the change of the coronary collateral flow index (CFI) after 4 weeks. Analysis was based on the intention to treat. After 4 weeks, baseline CFI increased significantly by 39.4% in group A (from 0.142±0.07 at beginning to 0.198±0.09 at 4 weeks) in comparison with 41.3% in group B (from 0.143±0.06 to 0.202±0.09), whereas CFI in the control group remained unchanged (0.7%, from 0.149±0.09 to 0.150±0.08). High-intensity exercise did not lead to a greater CFI than moderate-intensity training. After 4 weeks, exercise capacity, VO2 peak and ischemic threshold increased significantly in group A and group B in comparison with group C with no difference between group A and group B. Conclusions— A significant improvement in CFI was demonstrated in response to moderate- and high-intensity exercise performed for 10 hours per week. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01209637.

Impact of different exercise training modalities on the coronary collateral circulation and plaque composition in patients with significant coronary artery disease (EXCITE trial): study protocol for a randomized controlled trial

BackgroundExercise training (ET) in addition to optimal medical therapy (OMT) in patients with stable coronary artery disease (CAD) has been demonstrated to be superior to percutaneous coronary interventions (PCI) with respect to the composite endpoint of death, myocardial infarction, stroke, revascularization and hospitalization due to worsening of angina. One mechanism leading to this superiority discussed in the literature is the increase in coronary collateral blood flow due to ET. Until now, data demonstrating the positive effect of ET on the collateral blood flow and the functional capacity of the coronary collateral circulation are still lacking.Methods/designThe EXCITE trial is a three-armed randomized, prospective, single-center, open-label, controlled study enrolling 60 patients with stable CAD and at least one significant coronary stenosis (fractional flow reserve ≤0.75). The study is designed to compare the influence and efficacy of two different 4-week ET programs [high-intensity interval trainings (IT) versus moderate-intensity exercise training (MT) in addition to OMT] versus OMT only on collateral blood flow (CBF). The primary efficacy endpoint is the change of the CBF of the target vessel after 4 weeks as assessed by coronary catheterization with a pressure wire during interruption of the antegrade flow of the target vessel by balloon occlusion. Secondary endpoints include the change in plaque composition as assessed by intravascular ultrasound (IVUS) after 4 weeks, myocardial perfusion as analyzed in MRI after 4 weeks and 12 months, peak oxygen uptake (V02 peak), change in endothelial function and biomarkers after 4 weeks, 3, 6 and 12 months. The safety endpoint addresses major adverse cardiovascular events (death from cardiovascular cause, myocardial infarction, stroke, TIA, target vessel revascularization or hospitalization) after 12 months.DiscussionThe trial investigates whether ET for 4 weeks increases the CBF in patients with significant CAD compared to a sedentary control group. It also examines the impact of two intensities of ET on the CBF as well as the histological plaque composition. The trial started recruitment in June 2009 and will complete recruitment until June 2012. First results are expected in December 2012 (4-week follow-up), final results (12-month long-term secondary endpoint) in December 2013.Trial registrationClinical trial registration information-URL: http://www.clinicaltrials.gov.Unique identifier: NCT01209637

Endothelial Function in Children and Adolescents Is Mainly Influenced by Age, Sex and Physical Activity ― An Analysis of Reactive Hyperemic Peripheral Artery Tonometry ―

BACKGROUND As adolescents rarely experience cardiovascular events, surrogate markers of atherosclerosis are useful to justify and monitor effects of primary prevention and therapy of risk factors. Endothelial function assessed by reactive hyperemic peripheral arterial tonometry (RH-PAT) resulting in a reactive hyperemic index (RHI) is a noninvasive method with limited data for use in children and adolescents.Methods and Results:We performed a total of 931 RHI measurements in 445 high-school students, aged 10-17 years, over a time period of 5 years. Students were randomized by class to 60 min physical exercise (PE) at school daily (intervention group), or 2 units of 45-min PE weekly (control group). To characterize the factors influencing the RHI, anthropometry, cardiopulmonary exercise testing, blood cholesterol and quality of life were assessed and used to build mixed linear models. Main influential factors were age, with an increase of RHI from 1.53±0.42 in the youngest to 1.96±0.59 in the oldest students, sex, with higher values in girls, and physical activity. This increase adjusted by age and sex was estimated as 0.11 [0.08, 0.14] per year. RHI was higher in the intervention group by 0.09 [-0.05, 0.23] in comparison with the control group. CONCLUSIONS If RH-PAT is used in research or as a clinical tool in adolescents, the shown age- and sex-dependence of RHI have to be taken in account.

Long term impact of one daily unit of physical exercise at school on cardiovascular risk factors in school children

Background Obesity and physical inactivity in children correlate with the presence of cardiovascular risk factors. The aim of this prospective, randomised, interventional study was to examine the long term impact of additional physical exercise lessons at school on fitness and cardiovascular risk factors. Methods We randomly assigned 366 5th and 6th grade students class-wise into an intervention group that participated in one-daily physical exercise unit at school and a control group, participating in conventional school sports twice a week. The intervention duration was 4 years. At baseline and yearly follow-up, anthropometric measurements, body coordination tests, spiroergometry, questionnaires and blood samples were performed. Results A total of 236 children qualified for analysis of the intervention effect after 4 years. At the beginning students of the intervention and control groups had similar values for fitness assessed by peak oxygen uptake. Peak oxygen uptake was significantly better in the intervention group at first and second follow-up. After 4 years we found no difference in fitness any longer. Students in the intervention group were more likely to have healthy body mass index percentiles in comparison to the control group (within 10th to 90th percentile: intervention 86.4%, control 78.2%, P = 0.13). Conclusion Over a period of 1–2 years, additional physical exercise lessons at school resulted in an improvement of fitness. However, long-term follow-up failed to demonstrate ongoing improvement of performance in the intervention compared with the control group. Nevertheless, the intervention group had lower rates of body mass index above the 90th percentile throughout the entire follow-up. Therefore more physical exercise units at school seem justified.

Reliability of the calculated maximal lactate steady state in amateur cyclists

Complex performance diagnostics in sports medicine should contain maximal aerobic and maximal anaerobic performance. The requirements on appropriate stress protocols are high. To validate a test protocol quality criteria like objectivity and reliability are necessary. Therefore, the present study was performed in intention to analyze the reliability of maximal lactate production rate (V.Lamax) by using a sprint test, maximum oxygen consumption (V.O2max) by using a ramp test and, based on these data, resulting power in calculated maximum lactate-steady-state (PMLSS) especially for amateur cyclists. All subjects (n = 23, age 26 ± 4 years) were leisure cyclists. At three different days they completed first a sprint test to approximate V.Lamax. After 60 min of recreation time a ramp test to assess V.O2max was performed. The results of V.Lamax-test and V.O2max-test and the body weight were used to calculate PMLSS for all subjects. The intra class correlation (ICC) for V.Lamax and V.O2max was 0.904 and 0.987, respectively, coefficient of variation (CV) was 6.3% and 2.1%, respectively. Between the measurements the reliable change index of 0.11 mmol·l -1s -1 for V.Lamax and 3.3 mlkg -1min -1 for V.O2max achieved significance. The mean of the calculated PMLSS was 237 ± 72 W with an RCI of 9 W and reached with ICC = 0.985 a very high reliability. Both metabolic performance tests and the calculated PMLSS are reliable for leisure cyclists.

Impact of Weight Reduction During Adolescence on Parameters of Cardiac Geometry and Function in Obese Children

Childhood obesity is associated with changes in myocardial geometry and function indicating early onset of unfavorable alterations of the myocardium [(1,2)][1]. The value of those studies is limited by a cross-sectional study design. We aimed to assess the impact of weight reduction on temporal

Gender-dependent association of diabetes mellitus with mortality in patients undergoing transcatheter aortic valve replacement

BackgroundDiabetes mellitus (DM) is a risk factor for cardiovascular disease. However, its effect on procedural and follow-up performance after transcatheter aortic valve replacement (TAVR) remains controversial.Methods and resultsWe performed an observational study of all consecutive patients treated with a transfemoral TAVR in a single-center cohort (n = 1818). All patients were stratified by diabetes status and gender. All-cause 3-year mortality was the primary endpoint. Male patients with DM were identified to have substantially increased 3-year mortality [125/314 (39.8%)] compared to males without DM [142/478 (29.7%), p < 0.01]. Male patients with DM had significantly higher 3-year mortality in comparison to female patients with (p < 0.01) or without DM (p < 0.01). There was no difference in 3-year mortality for female patients with [135/465 (29.0%)] and without DM [151/554 (27.3%); p = 0.70]. This increase in mortality in male DM patients was triggered by both cardiovascular and non-cardiovascular mortality. Furthermore, DM served as an independent predictor of 3-year mortality after TAVR selectively only in men. The interaction between male gender and diabetes mellitus was identified as an independent predictor of 3-year mortality [HR 1.88 (1.25; 2.82); p < 0.01]. DM did not affect 30-day mortality for the overall cohort and for males.ConclusionMales with DM are a high-risk subgroup of patients after TAVR and require close medical attention including aggressive therapy of modifiable risk factors. Intensified diabetes management may improve long-term survival after TAVR.