Exercise-induced changes in miRNA expression in coronary artery disease.

OBJECTIVES: Micro ribonucleic acids (miRNAs) are small non-coding RNA molecules that control gene expression by translational inhibition. Exercise has been shown to affect several miRNAs' expression in healthy subjects, but this has not yet been studied in patients with coronary artery disease (CAD). Since exercise training confers beneficial long-term effects and may also trigger acute coronary events, it is of utmost interest to be able to identify those who are risk for untoward effects. Therefore, we set out to assess miRNA expression in response to maximal ergospirometry in patients with CAD. METHODS: Total RNA was extracted from blood drawn immediately before and 5 min after maximal cycle-ergospirometry (10 male and 10 female CAD patients). A qRT-PCR was performed for 187 target miRNAs associated with endothelial function/dysfunction, cardiovascular disease, myocardial infarction, and sudden cardiac death. RESULTS: In response to a maximal ergospirometry, 33 miRNAs significantly changed their expression levels. Of these miRNAs 16 were significantly differently expressed between gender. Using multi-variance analysis, nine miRNAs (let-7e-5p; miR-1; miR-19b-1-5p; miR-103a-3p; miR-148b-3p; miR-181b-5p; miR-188-5p; miR-423-5p; miR-874-3p) showed significantly different responses to maximal ergospirometry between genders. CONCLUSIONS: We report for the first time that in patients with CAD, miRNA expression is amenable to maximal ergospirometry and that the extent of changes differs between genders. Affected by exercise and gender were miRNAs that are associated, among others, with pathways for glucose metabolism, oxidative stress, and angiogenesis. Future studies should assess whether disease-specific miRNA expression in response to maximal exercise might serve as a marker for patient outcome.

Acute Effects of Winter Sports and Indoor Cycling on Arterial Stiffness.

Sedentary lifestyle predisposes to endothelial dysfunction, increased arterial stiffness and cardiovascular diseases, all of which can be positively modified by regular physical exercise training. A decrease in physical activity during winter months coincides with higher rates of cardiovascular events. In order to identify winter sports suitable to overcome this seasonal exercise deficit and thus contribute to cardiovascular health, it was the aim of this study to compare immediate effects of cross-country skiing (XCS) and alpine skiing (AS) on arterial stiffness as an alternative to indoor cycling (IC). After baseline assessment, eighteen healthy subjects performed one session of XCS, AS, and IC in randomized order. Pulse wave analysis was conducted (Mobil-o-Graph®) before and 10-min after exercise. Parameters of arterial stiffness and wave reflection were reduced after XCS and IC, but not after AS: central systolic blood pressure (IC: -8.0 ± 5.4 mmHg; p < 0.001), amplitude of the backward pressure wave (IC: -1.4 ± 2.7 mmHg; p < 0.05), reflection coefficient (XCS: -6.0 ± 7.8%; IC: -5.7 ± 8.1%; both p < 0.1), and pulse wave velocity (IC by -0.19 ± 0.27 m/s; p < 0.01). Higher exercise intensities correlated with greater reductions of arterial stiffness (all p < 0.05). Single sessions of XCS, IC but not AS led to comparable improvement in arterial stiffness, which was even more pronounced during higher exercise intensities. With regard to arterial stiffness, IC and XCS emerge as more effective to counteract the winter exercise deficit and thus the deleterious cardiovascular effects of a sedentary lifestyle.

A Comparison between Alpine Skiing, Cross-Country Skiing and Indoor Cycling on Cardiorespiratory and Metabolic Response.

Since physical inactivity especially prevails during winter months, we set out to identify outdoor alternatives to indoor cycling (IC) by comparing the metabolic and cardiorespiratory responses during alpine skiing (AS), cross-country skiing (XCS) and IC and analyse the effects of sex, age and fitness level in this comparison. Twenty one healthy subjects performed alpine skiing (AS), cross-country skiing (XCS), and IC. Oxygen uptake (VO2), total energy expenditure (EE), heart rate (HR), lactate, blood glucose and rate of perceived exertion (RPE) were determined during three 4-min stages of low, moderate and high intensity. During XCS and IC VO2max and EE were higher than during AS. At least 2½ hours of AS are necessary to reach the same EE as during one hour of XCS or IC. HR, VO2, lactate, and RPEarms were highest during XCS, whereas RPEwhole-body was similar and RPElegs lower than during AS and IC, respectively. Weight adjusted VO2 and EE were higher in men than in women while fitness level had no effect. Male, fit and young participants were able to increase their EE and VO2 values more pronounced. Both AS and XCS can be individually tailored to serve as alternatives to IC and may thus help to overcome the winter activity deficit. XCS was found to be the most effective activity for generating a high EE and VO2 while AS was the most demanding activity for the legs. Key pointsDuring cross-country skiing and indoor cycling VO2max and energy expenditure were higher than during alpine skiingApproximately 2½ hours of alpine skiing are necessary to reach the same energy expenditure of one hour of cross-country skiing or indoor cycling.Alpine skiing and cross-country skiing can be individually tailored to serve as sports alternatives in winter to activity deficit.By applying different skiing modes as parallel ski steering, carving long radii and short turn skiing, metabolic and cardiorespiratory response can be increased during alpine skiing.Male, fit and young participants were able to increase their energy expenditure and VO2 more pronounced with an increase in intensity compared with their counterparts.

Exercise responsive micro ribonucleic acids identify patients with coronary artery disease.

AIMS: Exercise is a trigger for acute coronary events especially in the untrained. Identifying subjects at risk remains a challenge. We set out to assess whether a distinct pattern of micro ribonucleic acids (miRNAs) expressed in response to an acute bout of all-out exercise might exist that would allow discrimination between health and disease. METHODS: Twenty healthy subjects and 20 patients with coronary artery disease (CAD) performed an all-out cycle ergometry. Total RNA was extracted from blood drawn before and after exercise. Each blood sample was analysed for 187 target miRNAs by quantitative reverse transcription polymerase chain reaction. RESULTS: At baseline, 18 miRNAs allowed discrimination between healthy subjects and CAD patients. In response to an acute all-out exercise in healthy subjects 51 miRNAs and in CAD patients 60 miRNAs were significantly modulated (all p < 0.05). Using logistic regression analysis, a unique pattern of pre-exercise miR-150-5p, post-exercise miR-101-3p, miR-141-3p and miR-200b-3p together with maximal oxygen uptake and maximal power corrected for bodyweight allowed discrimination between healthy subjects and CAD patients with an accuracy of 92.5%. CONCLUSION: In this most comprehensive analysis of exercise effects on circulating miRNAs to date we demonstrate for the first time that a distinct combination of miRNAs together with variables of exercise capacity allow robust discrimination between healthy subjects and CAD patients. We postulate that miRNAs may eventually serve as biomarkers to identify patients with CAD and possibly even those at risk of exercise-induced cardiac events.

Alpine Skiing as Winter-Time High-Intensity Training.

INTRODUCTION: To counteract the winter activity deficit, we set out to analyze cardiorespiratory and metabolic responses of two high-intensity training (HIT) protocols during alpine skiing (AS), cross-country skiing (XCS), and indoor cycling (IC) and the effects of sex, age, and fitness level in this comparison. METHODS: Nineteen healthy subjects (two age and fitness groups, both sexes) performed AS, XCS, and IC with measurements of oxygen uptake (V˙O2), energy expenditure (EE), HR, lactate, blood glucose and rate of perceived exertion, determined during 4 min of continuous HIT (HITc: 90% HRmax for XCS and IC or short turn skiing during AS) or 10-min intermittent HIT [HITint: 5 × 1 min high intensity (>90% HRmax or short turn skiing), 1 min active recovery]. RESULTS: During all three exercise modes and irrespective of HIT protocols, sex, age, and fitness, participants were able to reach exercise intensities >90% HRmax and >84% V˙O2max. In all exercise modes 10-min of HITint with a 10-min postexercise O2 consumption phase resulted in greater mean EE per minute compared to 4-min HITc with 10 min postexercise O2 consumption. When applying the same HIT loading and recovery pattern to all three exercise modes, EE during approximately 1:15 h of AS was equivalent to about 1:00 h of either XCS or IC. CONCLUSIONS: Across all exercise modes and HIT protocols, high cardiorespiratory and metabolic responses were achieved regardless of age, sex, or fitness. EE during AS can be maximized by choosing the skiing mode "short turn skiing" in combination with an HITint to prolong the duration of continuous high-intensity loading during each descent. Therefore, all exercise modes and both HIT protocols are applicable and feasible in a broad spectrum of healthy subjects.

Effects of a 12-week alpine skiing intervention on endothelial progenitor cells, peripheral arterial tone and endothelial biomarkers in the elderly.

OBJECTIVE: Endothelial dysfunction occurs early during atherogenesis and it can be normalized by exercise training. Unfortunately, patients' compliance with exercise prescription remains low, often because the given choices do not appeal to them. In Alpine regions, skiing is a popular mode of exercise, and therefore we set out to assess whether it can induce antiatherogenic effects. METHODS: We randomized 42 subjects into a group of 12weeks of guided skiing (intervention group, IG, n=22; 12 males/10 females; age: 66.6±2.1years) or a control group (CG, n=20; 10 males/10 females; age: 67.3±4.4years). Early (CD3-CD34+CD45+) and late endothelial progenitor cells (EPCs; CD45dimCD34+KDR+ peripheral blood mononuclear cells, PBMCs), peripheral arterial tonometry and endothelial biomarkers were assessed at the beginning and end of the study. RESULTS: In the IG, participants completed 28.5±2.6 skiing days at an average heart rate of 72.7±8.5% of their maximum heart rate. Changes in early (IG: +0.001±0.001% PBMC; CG: -0.001±0.001% PBMC; IG vs. CG: p<0.001) but not late EPCs differed significantly. Changes in peripheral arterial tone differed significantly between IG (Reactive Hyperemia Index: +0.18±0.76) and CG (-0.39±0.85; p=0.045), as did homocysteine (IG: -1.3±1.3µmol/l; CG: -0.4±1.4µmol/l; p=0.037) while other endothelial biomarkers remained essentially unchanged. CONCLUSIONS: This study shows that skiing induces several beneficial effects on markers of atherogenesis including EPCs, peripheral arterial tone and homocysteine. Our findings suggest that recreational alpine skiing may serve as a further mode of preventive exercise training, which might result in improved compliance with current recommendations.