Change In VO2peak Research Articles

Depressive symptoms interfere with the improvement in exercise capacity by cardiac rehabilitation after left ventricular assist device implantation.

Although depressive symptoms are associated with an increased risk of readmission after left ventricular assist device (LVAD) implantation, it is unclear whether they affect the efficacy of exercise-based cardiac rehabilitation (EBCR). This study aimed to investigate the effect of depressive symptoms on EBCR efficacy. We analyzed 48 patients who participated in EBCR after LVAD implantation (mean age 45±12years; 60% male). Patients were classified into two groups using the Zung Self-Rating Depression Scale (SDS): depressive group (SDS ≥40, n=27) and non-depressive group (SDS <40, n=21). We examined changes in peak oxygen uptake (VO2 ), knee extensor muscular strength (KEMS), and quality of life (QOL) during EBCR using analysis of covariance. Although baseline characteristics were similar between the two groups, the non-depressive group was less likely to receive diuretics (22% vs. 52%, p=0.030). Peak VO2 , KEMS, and QOL significantly increased over time in both groups (all p<0.05). The depressive group had a significantly lower change in peak VO2 than the non-depressive group (2.7 vs. 1.6ml/kg/min; mean difference: -1.1ml/kg/min, 95% confidence interval [CI]: -0.045 to -2.17; p=0.041, d=0.59). There was no between-group difference regarding the change in KEMS or QOL. Adjusting for the baseline value, a significant difference between groups was observed only in peak VO2 (p=0.045). Although EBCR significantly improved exercise capacity after LVAD implantation, depressive symptoms interfered with this improvement. Further studies are needed to determine whether psychological interventions for depression, in addition to EBCR, would improve the response to EBCR after LVAD implantation.

Moderate-intensity exercise training or high-intensity interval training to improve aerobic fitness during exercise prehabilitation in patients planned for elective abdominal cancer surgery?

Low preoperative aerobic fitness is associated with an increased risk of postoperative complications and delayed recovery in patients with abdominal cancer. Surgical prehabilitation aims to increase aerobic fitness preoperatively to improve patient- and treatment-related outcomes. However, an optimal physical exercise training program that is effective within the short time period available for prehabilitation (<6 weeks) has not yet been established. In this comparative review, studies (n = 8) evaluating the effect of short-term (<6 weeks) moderate-intensity exercise training (MIET) or high-intensity interval training (HIIT) on objectively measured aerobic fitness were summarized. The content of exercise interventions was critically appraised regarding the frequency, intensity, time, type, volume, and – monitoring of – progression (FITT-VP) principles. Three out of four studies evaluating HIIT showed statistically significant improvements in oxygen uptake at peak exercise (VO2peak) by more than 4.9%, the coefficient of variation for VO2peak. None of the two studies investigating short-term MIET showed statistically significant pre-post changes in VO2peak. Although short-term HIIT seems to be a promising intervention, concise description of performed exercise based on the FITT-VP principles was rather inconsistent in studies. Hence, interpretation of the results is challenging, and a translation into practical recommendations is premature. More emphasis should be given to individual responses to physical exercise training. Therefore, adequate risk assessment, personalized physical exercise training prescription using the FITT-VP principles, full reporting of physical exercise training adherence, and objective monitoring of training progression and recovery is needed to ensure for a personalized and effective physical exercise training program within a multimodal prehabilitation program.

Predictors for one-year outcomes of cardiorespiratory fitness and cardiovascular risk factor control after cardiac rehabilitation in elderly patients: The EU-CaRE study.

Studies on effectiveness of cardiac rehabilitation (CR) in elderly cardiovascular disease patients are rare, and it is unknown, which patients benefit most. We aimed to identify predictors for 1-year outcomes of cardiorespiratory fitness and CV risk factor (CVRF) control in patients after completing CR programs offered across seven European countries. Cardiovascular disease patients with minimal age 65 years who participated in comprehensive CR were included in this observational study. Peak oxygen uptake (VO2), body mass index (BMI), resting systolic blood pressure (BPsys), and low-density lipoprotein-cholesterol (LDL-C) were assessed before CR (T0), at termination of CR (T1), and 12 months after start of CR (T2). Predictors for changes were identified by multivariate regression models. Data was available from 1241 out of 1633 EU-CaRE patients. The strongest predictor for improvement in peak VO2 was open chest surgery, with a nearly four-fold increase in surgery compared to non-surgery patients. In patients after surgery, age, female sex, physical inactivity and time from index event to T0 were negative predictors for improvement in peak VO2. In patients without surgery, previous acute coronary syndrome and higher exercise capacity at T0 were the only negative predictors. Neither number of attended training sessions nor duration of CR were significantly associated with change in peak VO2. Non-surgery patients were more likely to achieve risk factor targets (BPsys, LDL-C, BMI) than surgery patients. In a previously understudied population of elderly CR patients, time between index event and start of CR in surgery and disease severity in non-surgery patients were the most important predictors for long-term improvement of peak VO2. Non-surgery patients had better CVRF control.

Effects of Aerobic Exercise Training on Systemic Biomarkers and Cognition in Late Middle-Aged Adults at Risk for Alzheimer's Disease.

Increasing evidence indicates that physical activity and exercise training may delay or prevent the onset of Alzheimer’s disease (AD). However, systemic biomarkers that can measure exercise effects on brain function and that link to relevant metabolic responses are lacking. To begin to address this issue, we utilized blood samples of 23 asymptomatic late middle-aged adults, with familial and genetic risk for AD (mean age 65 years old, 50% female) who underwent 26 weeks of supervised treadmill training. Systemic biomarkers implicated in learning and memory, including the myokine Cathepsin B (CTSB), brain-derived neurotrophic factor (BDNF), and klotho, as well as metabolomics were evaluated. Here we show that aerobic exercise training increases plasma CTSB and that changes in CTSB, but not BDNF or klotho, correlate with cognitive performance. BDNF levels decreased with exercise training. Klotho levels were unchanged by training, but closely associated with change in VO2peak. Metabolomic analysis revealed increased levels of polyunsaturated free fatty acids (PUFAs), reductions in ceramides, sphingo- and phospholipids, as well as changes in gut microbiome metabolites and redox homeostasis, with exercise. Multiple metabolites (~30%) correlated with changes in BDNF, but not CSTB or klotho. The positive association between CTSB and cognition, and the modulation of lipid metabolites implicated in dementia, support the beneficial effects of exercise training on brain function. Overall, our analyses indicate metabolic regulation of exercise-induced plasma BDNF changes and provide evidence that CTSB is a marker of cognitive changes in late middle-aged adults at risk for dementia.

Peak oxygen consumption achieved at the end of cardiac rehabilitation predicts long-term survival in patients with coronary heart disease

Cardiac rehabilitation (CR) improves survival in patients with coronary heart disease (CHD), which is largely mediated by the improvements in cardiorespiratory fitness (CRF) defined as peak oxygen consumption (VO2). Therefore, measuring CRF is essential to predict long-term outcomes in this population. It is unclear, however, whether peak VO2 achieved at the end of CR (END-peak VO2) predicts survival or whether the changes of CRF achieved during CR provide a greater prognostic value. To determine whether END-peak VO2 independently predicts long-term survival in patients with CHD undergoing CR. We also aimed at identifying cut-offs for END-peak VO2 that could be used in clinical practice. Retrospective analysis of 853 patients with CHD referred to CR who completed a maximal cardiopulmonary exercise test. Survival analysis was performed to examine the risk of all-cause mortality (average follow-up years: 6.65) based on peak VO2. The Contal and O'Quigley's method was used to determine the optimal cut-off of END-peak VO2 based on the log-rank statistic. END-peak VO2 was inversely associated with mortality risk [hazard ratio (HR) = 0.84; 95% confidence interval (CI) = 0.78-0.90], independent of changes in peak VO2 adjusted for the baseline peak VO2. The estimated cut-off of END-peak VO2 at ≥17.6 mL/kg/min best predicted the survival with high predictive accuracy and patients with END-peak VO2 under the cut-off had a greater risk of mortality (HR = 2.93; 95% CI = 1.81-4.74). In patient with CHD undergoing CR, END-peak VO2 is an independent predictor for long-term survival. Studies utilizing higher intensity CR programmes, with and without pharmacologic strategies, to increase peak VO2 to a greater degree in those achieving a suboptimal END-peak VO2, are urgently needed.

Effects of resistance training on metabolic and cardiovascular responses to a maximal cardiopulmonary exercise test in Parkinson`s disease.

ABSTRACT:Objective:To evaluate the effects of resistance training on metabolic and cardiovascular responses during maximal cardiopulmonary exercise testing in patients with Parkinson’s disease.Methods:Twenty-four patients with Parkinson’s disease (modified Hoehn and Yahr stages 2 to 3) were randomly assigned to one of two groups: Control or Resistance Training. Patients in the Resistance Training Group completed an exercise program consisting of five resistance exercises (two to four sets of six to 12 repetitions maximum per set) twice a week. Patients in the Control Group maintained their usual lifestyle. Oxygen uptake, systolic blood pressure and heart rate were assessed at rest and during cycle ergometer-based maximal cardiopulmonary exercise testing at baseline and at 12 weeks. Assessments during exercise were conducted at absolute submaximal intensity (slope of the linear regression line between physiological variables and absolute workloads), at relative submaximal intensity (anaerobic threshold and respiratory compensation point) and at maximal intensity (maximal exercise). Muscle strength was also evaluated.Results:Both groups had similar increase in peak oxygen uptake after 12 weeks of training. Heart rate and systolic blood pressure measured at absolute and relative submaximal intensities and at maximal exercise intensity did not change in any of the groups. Muscle strength increased in the Resistance Training but not in the Control Group after 12 weeks.Conclusion:Resistance training increases muscle strength but does not change metabolic and cardiovascular responses during maximal cardiopulmonary exercise testing in patients with Parkinson’s disease without cardiovascular comorbidities.

Circulating microRNA as predictors for exercise response in heart failure with reduced ejection fraction.

Exercise training is a powerful adjunctive therapy in patients with heart failure with reduced ejection fraction (HFrEF), but ca. 55% of patients fail to improve VO2peak. We hypothesize that circulating microRNAs (miRNAs), as epigenetic determinants of VO2peak, can distinguish exercise responders (ER) from exercise non-responders (ENR). We analysed 377 miRNAs in 18 male HFrEF patients (9 ER and 9 ENR) prior to 15 weeks of exercise training using a miRNA array. ER and ENR were defined as change in VO2peak of >20% or <6%, respectively. First, unsupervised clustering analysis of the miRNA pattern was performed. Second, differential expression of miRNA in ER and ENR was analysed and related to percent change in VO2peak. Third, a gene set enrichment analysis was conducted to detect targeted genes and pathways. Baseline characteristics and training volume were similar between ER and ENR. Unsupervised clustering analysis of miRNAs distinguished ER from ENR with 83% accuracy. A total of 57 miRNAs were differentially expressed in ENR vs. ER. A panel of seven miRNAs up-regulated in ENR (Let-7b, miR-23a, miR-140, miR-146a, miR-191, miR-210, and miR-339-5p) correlated with %changeVO2peak (all P < 0.05) and predicted ENR with area under the receiver operating characteristic curves ≥0.77. Multiple pathways involved in exercise adaptation processes were identified. A fingerprint of seven miRNAs involved in exercise adaptation processes is highly correlated with VO2peak trainability in HFrEF, which holds promise for the prediction of training response and patient-targeted exercise prescription.

Endothelin-1 and peak oxygen consumption in patients with heart failure with preserved ejection fraction

BackgroundMechanisms of exercise intolerance in patients with heart failure with preserved ejection fraction (HFpEF) are not well understood. Pulmonary hypertension, a common accompaniment in patients with HFpEF, is associated with poor outcomes. While Endothelin -1 (ET-1) plays a mechanistic role in pulmonary hypertension, its role in exercise intolerance in HFpEF is not well established. ObjectiveTo explore the association between plasma ET-1 levels and maximal oxygen consumption (pVO2), and their changes over 24 weeks in HFpEF. MethodsThis is a post-hoc analysis of the Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in Heart Failure with Preserved Ejection Fraction (RELAX) trial. We performed linear regressions to assess the relationship between plasma ET-1 and pVO2. We also used linear regressions to determine whether ET-1 was associated with change in peak VO2 (ΔpVO2). ResultsA total of 210 patients were included. Baseline plasma ET-1 levels were associated with older age, higher NT-proBNP levels, higher serum creatinine levels, and higher prevalence of atrial fibrillation. Patients with higher ET1 levels also had higher plasma galectin-3 and CITP levels. After multiple adjustments, baseline ET1 levels were associated with lower pVO2 (β -0.927, SE 0.196, p < 0.001). Over 24 weeks, the change in ET1 levels was associated with the change in pVO2 (multivariable adjusted β -0.415, SE 0.115, p = 0.018). Baseline ET1 levels did not modify the effect of sildenafil on change in peak VO2. ConclusionsPlasma ET1 levels are significantly associated with lower exercise oxygen consumption both at baseline and longitudinally over 24 weeks. Future studies should explore Endothelin-1 antagonism to improve exercise tolerance in HFpEF.

One-Year Aerobic Exercise Reduced Carotid Arterial Stiffness and Increased Cerebral Blood Flow in Amnestic Mild Cognitive Impairment.

Central arterial stiffness and brain hypoperfusion are emerging risk factors of Alzheimer's disease (AD). Aerobic exercise training (AET) may improve central arterial stiffness and brain perfusion. To investigate the effects of AET on central arterial stiffness and cerebral blood flow (CBF) in patients with amnestic mild cognitive impairment (MCI), a prodromal stage of AD. This is a proof-of-concept, randomized controlled trial that assigned 70 amnestic MCI patients into a 12-month program of moderate-to-vigorous AET or stretching-and-toning (SAT) intervention. Carotid β-stiffness index and CBF were measured by color-coded duplex ultrasonography and applanation tonometry. Total CBF was measured as the sum of CBF from both the internal carotid and vertebral arteries, and divided by total brain tissue mass assessed with MRI to obtain normalized CBF (nCBF). Episodic memory and executive function were assessed using standard neuropsychological tests (CVLT-II and D-KEFS). Changes in cardiorespiratory fitness were measured by peak oxygen uptake (VO2peak). Total 48 patients (29 in SAT and 19 in AET) were completed one-year training. AET improved VO2peak, decreased carotid β-stiffness index and CBF pulsatility, and increased nCBF. Changes in VO2peak were associated positively with changes in nCBF (r = 0.388, p = 0.034) and negatively with carotid β-stiffness index (r = -0.418, p = 0.007) and CBF pulsatility (r = -0.400, p = 0.014). Decreases in carotid β-stiffness were associated with increases in cerebral perfusion (r = -0.494, p = 0.003). AET effects on cognitive performance were minimal compared with SAT. AET reduced central arterial stiffness and increased CBF which may precede its effects on neurocognitive function in patients with MCI.

Interindividual variation in cardiometabolic health outcomes following 6months of endurance training in youth at risk of type 2 diabetes mellitus.

This study determined the interindividual variation in the cardiometabolic response to 6months of moderate or vigorous intensity exercise training (ET) among youth at risk for type 2 diabetes mellitus. Youth were randomized to moderate intensity ET (45-55% heart rate reserve; n = 31), vigorous intensity ET (70-85% heart rate reserve; n = 37), or control (n = 36). Only those attending ≥70% of ET sessions were included. Cardiometabolic measures included insulin sensitivity, hepatic triglyceride content, visceral adipose area, and cardiorespiratory fitness. The contribution of ET to interindividual variation was determined using the standard deviation of individual responses (SDIR) and considered meaningful if the SDIR surpassed the smallest worthwhile difference (SWD), calculated as 0.2× the standard deviation of the control group baseline values. ET meaningfully contributed to the interindividual variation among changes in peak oxygen uptake following moderate (SDIR: 2.04) and vigorous (SDIR: 3.43) ET (SWD: 1.17 mL·kgfat free mass-1·min-1), body fat percentage and hepatic triglyceride content following moderate-intensity ET (SDIR: 1.64, SWD: 1.05%; SDIR: 10.08, SWD: 1.06%, respectively), and visceral fat mass following vigorous ET (SDIR: 11.06, SWD: 7.13 cm2). Variation in the changes in insulin sensitivity were not influenced by ET. The contribution of ET to interindividual variation appears to be influenced by the desired outcome and prescribed intensity. Trial registration at ClinicalTrials.gov (identifier no.: NCT00755547). Novelty: The contribution of exercise to interindividual variation following training depends on the outcome and exercise intensity. Increasing exercise intensity does not systematically reduce non-response among youth at risk for type 2 diabetes.

HIIT Models in Addition to Training Load and Heart Rate Variability Are Related With Physiological and Performance Adaptations After 10-Weeks of Training in Young Futsal Players.

IntroductionThe present study aimed to investigate the effects of two high-intensity interval training (HIIT) shuttle-run-based models, over 10 weeks on aerobic, anaerobic, and neuromuscular parameters, and the association of the training load and heart rate variability (HRV) with the change in the measures in young futsal players.MethodsEleven young male futsal players (age: 18.5 ± 1.1 years; body mass: 70.5 ± 5.7 kg) participated in this study. This pre-post study design was performed during a typical 10 weeks training period. HIIT sessions were conducted at 86% (HIIT86; n = 6) and 100% (HIIT100; n = 5) of peak speed of the FIET. Additionally, friendly and official matches, technical-tactical and strength-power training sessions were performed. Before and after the training period, all players performed the FIET, treadmill incremental, repeated sprint ability (RSA), sprint 15-m, and vertical jump tests (CMJ and SJ), and the HRV was measured. Training load (TL) was monitored using the session rating of perceived effort. Data analysis was carried out using Bayesian inference methods.ResultsThe HIIT86 model showed clear improvements for the peak oxygen uptake (VO2peak), peak speed in the treadmill incremental test, first and second ventilatory thresholds, RSA best and mean times, CMJ, and SJ. The HIIT100 model presented distinct advances in VO2peak, peak speed in the treadmill incremental test, RSA mean time, and CMJ. Between HIIT models comparisons showed more favorable probabilities of improvement for HIIT86 than HIIT100 model in all parameters. TL data and HIIT models strongly explained the changes in the RSA mean and best times (R2 = 0.71 and 0.87, respectively), as well as HRV changes, and HIIT models explained positively VO2peak changes (R2 = 0.72). All other changes in the parameters were low to moderately explained.ConclusionThe HIIT86 proved to be more effective for improving aerobic, RSA, and neuromuscular parameters than HIIT100 during a typical 10-week futsal training period. So, strength and conditioning specialists prescribing shuttle-run intermittent exercises at submaximal intensities can manage the individual acceleration load imposed on athlete increasing or decreasing either the set duration or the frequency of change of direction during HIIT programming.

Cardiac rehabilitation program improves exercise capacity in heart transplantation recipients regardless of marginal donor factors.

Cardiac rehabilitation (CR) is recommended to improve exercise capacity after heart transplantation (HTx); however, the effects of marginal donor factors are unclear. Forty-one recipients participated in a 3-month CR program early after HTx (mean age 39 ± 14years; 88% male). Patients were divided into marginal (≥ 2 marginal donor factors; n = 24) and control groups (< 2 marginal donor factors; n = 17). We examined donor and recipient factors related to change in peak oxygen uptake (peak VO2) during the CR program using multiple linear regression analysis. Baseline characteristics were similar between groups, although the mean age was higher in the marginal group (43 ± 13 vs. 34 ± 14years, p = 0.043). Peak VO2 and knee extensor muscular strength (KEMS) improved significantly in both groups (p < 0.05), but there were no observed inter-group differences. Multiple analysis revealed change in KEMS (β = 0.52, 95% CI = 0.023-1.01) as an independent predictor of change in peak VO2 after adjustment for recipients' age, sex, and CR attendance frequency (adjusted R2 = 0.25, p = 0.0084), whereas marginal donor factors were not a predictor (p = 0.76). The CR program improved exercise capacity in HTx recipients regardless of marginal donor factors, suggesting that recipients of marginal donor hearts should be referred to CR programs.

Abstract 16003: Genetic Variation Associated With Favorable Exercise Response in Patients With Systolic Heart Failure: A Hf-action Trial Substudy

Background: Exercise has shown benefit in patients with systolic heart failure, including in the clinical trial Heart Failure: A Controlled Trial Investigating Outcomes of Exercise Training (HF-ACTION). There is heterogeneity in who derives benefit from exercise, and the biologic mechanisms of favorable response to exercise in systolic heart failure are not well understood. Hypothesis: Genetic variation is an underlying factor influencing heterogeneity in response to exercise in patients with systolic heart failure. Methods: The HF-ACTION trial randomized individuals with systolic heart failure (left ventricular ejection fraction &lt;35%) to supervised exercise versus usual care. In this study, we performed a genome wide association study (GWAS) in the HF-ACTION biorepository using the Axiom Biobank1 genotyping array (13,403,591 single nucleotide polymorphisms [SNPs] after quality control on directly genotyped and 1000 genomes imputed data), in N=377 study subjects who completed the supervised exercise arm. Using change in peak VO2 as our outcome, we ran within-ancestry GWASes, modeling SNP effects as both additive and dominant, and conducted across-ancestry meta-analysis within each genetic model. Results: Five loci met genome-wide significance in the European ancestry analyses, 5 loci in the African ancestry, and 8 in the meta-analyses. The two most significantly associated loci across both additive and dominant meta-analysis models were rs111577308 located in the histone acetylation for transcription elongator complex 3 gene ( ELP3, p=1.212x10 -9 ) and rs75444785 located in the phosphodiesterase 4D gene ( PDE4D , p=1.565x10 -9 ). ELP3 is responsible for histone modifications related to DNA transcription factor complexes, and PDE4D is involved in cyclic AMP cell signaling. In silico analysis of these loci showed that they are in linkage with regions associated with skeletal muscle and peripheral vascular disease phenotypes. Conclusions: Using a genome-wide association study in a well-phenotyped clinical trial of exercise in systolic heart failure, we found common genetic variants in genes involved in DNA transcription histone modification and cyclic AMP cell signaling that are associated with a more favorable response to exercise.

Age-related change in peak oxygen uptake and the association to change in cardiovascular risk factor levels. The HUNT Study, Norway

Abstract Background Cardiorespiratory fitness (CRF) is established as an important prognostic factor for future health, and specifically for cardiovascular disease. Few large studies have examined the longitudinal change in the gold-standard measure of CRF, namely peak oxygen uptake (VO2peak), in free-living populations. Purpose To assess the age-related change in absolute and relative VO2peakin a previously healthy population sample, and to assess the influence of leisure-time physical activity (LTPA) on age-related change in VO2peak. Furthermore, we wanted to assess the association between longitudinal change of VO2peak and change of cardiovascular risk factor levels. Methods Participants in the third wave of the Nord-Trøndelag Health Study (HUNT3, 2006–2008) free from cardiovascular, malignant, and pulmonary disease, and no use of antihypertensive medication were invited to cardiopulmonary exercise testing (CPET). Of the 4,656 participants completing a VO2peak test in HUNT3 1,505 performed a second CPET in HUNT4 (2017–2019). Anthropometric measures, blood samples, and self-reported questionnaires for leisure-time physical activity (LTPA) e.g was gathered at both time points. Linear mixed models were used to explore absolute (L/min) and relative (mL/kg/min) changes in VO2peak by age, sex and LTPA. The effect of age, sex, and LTPA (low, moderate, or high intensity and minutes of LTPA per week) on change in VO2peak was explored, and age, sex, and baseline VO2peak-adjusted linear regression models (excluding participants with relevant medication use from analyses) were used to assess the effect of change in VO2peak on change of cardiovascular risk factors. Results Average 10-year decline in relative VO2peak was 3.9 mL/kg/min (10%) in women and 5.5 mL/kg/min (12%) in men, increasing from a mean 3% in those 20 to 30 years old to about 20% in those 70 to 80 years old. The same pattern of a non-linear, accelerating decline in VO2peak was also found in results from the linear mixed models as illustrated in Figure 1, with a steeper decline for men. Both minutes and intensity of LTPA was associated with higher absolute and relative VO2peak, but the effect of LTPA on age-related decline in VO2peak diminished with age. A lower decline in relative VO2peak was associated with favourable changes of HDL cholesterol, total cholesterol (and the ratio to HDL cholesterol), triglycerides, systolic and diastolic blood pressure, and resting heart rate. Conclusions The decline in absolute and relative VO2peak is non-linear, accelerates with age, and is more pronounced in men. LTPA attenuated the decline in VO2peak, but the effect diminished with high age. Maintaining VO2peak was associated with favourable changes in cardiovascular risk factor levels. Measures to maintain a higher VO2peak on the populational level may convey significant societal health benefits through cardiovascular risk reduction. Figure 1 Funding Acknowledgement Type of funding source: Public hospital(s). Main funding source(s): The Liaison Committee for Education, Research and Innovation in Central Norway

The effect of an acute exercise bout on plasme miRNA and its relation with cardiovascular adaptation to exercise training in heart failure

Abstract Background Exercise training (ET) improves aerobic capacity (VO2peak) in heart failure with reduced ejection fraction (HFrEF), but the individual response is highly variable. Underlying mechanisms of this variability are still not fully elucidated yet. Specific miRNA might be involved in cardiovascular adaptation to exercise, as changes in miRNA levels with repetitive acute exercise bouts have been described. miR-23a, -140, -146a, -191 and -210 have been related to aerobic capacity, endothelial function and angiogenesis. Purpose First, to evaluate if vascular function-associated miRNAs are related to vascular function and aerobic capacity in HFrEF patients. Second, to evaluate the effect of a single exercise bout on the miR profile. Third, to evaluate if miRNA changes in response to acute exercise are related to aerobic and vascular response to training. Methods Plasma levels of miR-23a, -140, -146a, -191 and -210 were analyzed using RT-qPCR in 24 HFrEF patients, before and immediately after a cardiopulmonary exercise test (CPET) and repeated after 15 weeks of ET. At baseline and after 15 weeks, VO2peak, flow-mediated dilation (FMD), pulsed wave velocity (PWV) and heart rate-corrected augmentation index (Aix@75) were recorded. Results In this prospective study, 24 HFrEF patients were included. Mean age was 56.9±12.9 years, mean left ventricular ejection fraction 31.7±7.0% and median adherence to ET was 41 sessions (30–43). Mean percent change in VO2peak was 2.86% (±13.5), in Aix@75 −9.8% (±80.9), in FMD 79.1% (±223.7) and in PWV −3.1% (±11.2), however these changes were not significant compared to baseline (p&amp;gt;0.05). At baseline, none of the miRNA were correlated with percent change in VO2peak (all p&amp;gt;0.05), however, miR-140 showed a trend towards correlation (r=−0.385, p=0.063). miR-191was significantly correlated with Aix@75 at baseline and after 15 weeks (respectively r=0.588, p=0.013 and r=0.609, p=0.006) and miR-23a was significantly correlated with FMD at baseline and showed a trend at 15 weeks (respectively r=0.462, p=0.040 and r=0.417, p=0.076). An acute exercise bout resulted in a significant decrease of miR-191 (1.82 before and 1.58 after CPET; 14% decrease, p=0.043). This change was significantly correlated with percent change in Aix@75 (r=−0.730, p=0.005) after ET. In a linear regression model adjusted for age, change in miR-191 significantly predicted percent change in Aix@75 (B=−84.5, p=0.043). Conclusion In HFrEF patients, plasma levels of miR-191 significantly decrease in response to an acute exercise bout. Baseline levels of vascular function-associated miRNAs were correlated with arterial stiffness and endothelial function before and after exercise training, which may suggest that these miRNAs are implicated in the vascular adaptations due to repetitive acute exercise bouts. However, these findings need to be validated in larger cohorts. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Fund for scientific research-Flanders (FWO)

The impact of age and socioeconomic factors on response to exercise training in patients with ischemic heart disease, heart failure and after valve replacement

Abstract The impact of baseline characteristics on response to exercise training in patients with ischemic heart disease. Background Exercise training improves peak oxygen uptake, an important predictor of mortality in patients with coronary artery disease (CAD). Unfortunately, some patients do not response with an increase in peak oxygen uptake after exercise training. If it is possible to identify these patients it would be possible to tailor their exercise training. Purpose To investigate if baseline characteristics can predict response to exercise training in patients with heart disease. Methods A retrospective analysis of 1443 CAD patients (age 64±11 y (mean (±SD)), 74% male, participated and completed an eight-week supervised outpatient exercise intervention with two weekly training sessions of 1.5 hours with high intensity interval- (&amp;gt;80% of VO2peak) and resistance training. Patient characteristics were entered in the local database as the patients entered cardiac rehabilitation (CR). VO2peak was assessed before and after CR using a cardiopulmonary exercise test (CPET) with a maximal symptom limited bicycle ergometer test. Breathing gases were collected and analysed breath-by-breath. Each test aimed at physical exhaustion and a respiratory exchange ratio of more than 1.1 to ensure the validity of the CPET test. Patients were divided into responders defined as an improvement in aerobic capacity (change in VO2peak) after CR and non-responders if no improvement (change in VO2peak of 0.0ml/kg/min or less) post CR. We performed a multivariable logistic regression analysis using responders vs. non-responders as the endpoint. Explanatory variables were identified according to previous literature and comprised the following variables; age, sex, baseline VO2peak, tobacco use, diabetes, COPD, revascularization, working status, educational attainment, ethnicity and hypercholesteremia. Results 1097 patients were responders and 346 (24%) non-responders to the exercise training despite no difference in attendance. Logistic regression analysis of responders vs. non-responders in relation to baseline characteristics are shown in the table. Conclusion In summarize, 24% of these heart patients were exercise non-responders. High baseline VO2peak, older age, having COPD, being on disability pension, low educational attainment and non-western ethnicity were predictors of training non-response. Identification of patients with a large likelihood of non-response is a beginning towards patient tailored exercise programmes. Baseline characteristics in responders. CABG: coronary artery bypass graft; COPD: chronic obstructive pulmonary disease; PCI: percutaneous coronary intervention; SD: standard deviation; VO2peak: change in peak oxygen uptake. P-values of &amp;lt;0.05 are considered significant and shown in bold. 95% confidence intervals are shown in last column. Funding Acknowledgement Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Helsefonden

Serotonin 1A agonist and cardiopulmonary improvements with whole-body exercise in acute, high-level spinal cord injury: a retrospective analysis.

High-level spinal cord injury (SCI) can result in spinal and supraspinal respiratory control deficits leading to insufficient ventilatory responses to exercise and training-related adaptations. We hypothesized a serotonin agonist, known to improve respiratory function in animal models, would improve adaptations to whole-body functional electrical stimulation (FES) exercise training in patients with acute high-level SCI. We identified 10 patients (< 2years of injury with SCI from C4 to T3) in our program who had performed 6 months of FES-row training while on Buspirone (29 ± 17mg/day) between 2012 and 2018. We also identified well-matched individuals who trained for six months but not on Buspirone (n = 11). A peak incremental FES-rowing exercise test and resting pulmonary function test had been performed before and after training. Those on Buspirone demonstrated greater increases in peak oxygen consumption (VO2peak: + 0.24 ± 0.23 vs. + 0.10 ± 0.13 L/min, p = 0.08) and peak ventilation (VEpeak: + 6.5 ± 8.1 vs. -0.7 ± 6.9 L/min, p < 0.05) compared to control. In addition, changes in VO2peak and VEpeak were correlated across all patients (r = 0.63, p < 0.01), but most strongly in those on Buspirone (r = 0.85, p < 0.01). Furthermore, changes in respiratory function correlated with increased peak tidal volume in the Buspirone group (r > 0.66, p < 0.05). These results suggest Buspirone improves cardiorespiratory adaptations to FES-exercise training in individuals with acute, high-level SCI. The strong association between increases in ventilatory and aerobic capacities suggests improved respiratory function is a mechanism; however, controlled studies are needed to determine if this preliminary finding is reproducible.

Effects of 2 Models of Aquatic Exercise Training on Cardiorespiratory Responses of Patients With Type 2 Diabetes: The Diabetes and Aquatic Training Study—A Randomized Controlled Trial

There are a lack of clinical trials with suitable methodological quality that compare aquatic exercise training types in type 2 diabetes (T2D) treatment. This study aimed to compare the effects of aerobic and combined aquatic training on cardiorespiratory outcomes in patients with T2D. Untrained patients with T2D were randomized to receive an aerobic aquatic training, a combined aquatic training, or a procedure control in 3 weekly sessions for 15 weeks. The sessions were 50 minutes long. The intensities were from 85% to 100% of heart rate of anaerobic threshold and at maximal velocity for aerobic and resistance parts, respectively. Resting heart rate, peak oxygen uptake (VO2peak), and oxygen uptake corresponding to second ventilatory threshold and its relation with VO2peak were evaluated. Participants were 59.0 (8.2) years old and 51% women. Intervention groups increased in VO2peak (aerobic aquatic training group: 4.48mL·kg-1·min-1, P = .004; combined aquatic training group: 5.27mL·kg-1·min-1; P = .006) and oxygen uptake corresponding to second ventilatory threshold, whereas the control group presented an increase in oxygen uptake corresponding to second ventilatory threshold and minimal change in VO2peak. Aerobic and combined aquatic exercise interventions improve the cardiorespiratory fitness of patients with T2D.

Age-related change in peak oxygen uptake and change of cardiovascular risk factors. The HUNT Study

BackgroundLarge longitudinal studies on change in directly measured peak oxygen uptake (VO2peak) is lacking, and its significance for change of cardiovascular risk factors is uncertain. We aimed to assess ten-year change in VO2peak and the influence of leisure-time physical activity (LTPA), and the association between change in VO2peak and change in cardiovascular risk factors. Methods and resultsA healthy general population sample had their VO2peak directly measured in two (n = 1431) surveys of the Nord-Trøndelag Health Study (HUNT3; 2006–2008 and HUNT4; 2017–19).Average ten-year decline in VO2peak was non-linear and progressed from 3% in the third to about 20% in the eight decade in life and was more pronounced in men. The fit linear mixed models including an additional 2,933 observations from subjects participating only in HUNT3 showed similar age-related decline. Self-reported adherence to LTPA recommendations was associated with better maintenance of VO2peak, with intensity seemingly more important than minutes of LTPA with higher age. Adjusted linear regression analyses showed that one mL/kg/min better maintenance of VO2peak was associated with favorable changes of individual cardiovascular risk factors (all p ≤ 0.002). Using logistic regression one mL/kg/min better maintenance of VO2peak was associated with lower adjusted odds ratio of hypertension (0.95 95% CI 0.92 to 0.98), dyslipidemia (0.92 95% CI 0.89 to 0.94), and metabolic syndrome (0.86 95% CI 0.83 to 0.90) at follow-up. ConclusionsAlthough VO2peak declines progressively with age, performing LTPA and especially high-intensity LTPA is associated with less decline. Maintaining VO2peak is associated with an improved cardiovascular risk profile.

Effects of detraining on cardiorespiratory fitness of individuals with chronic stroke

ABSTRACT Background Aerobic training can improve cardiorespiratory fitness in individuals after stroke. However, the effects of short-term and long-term detraining are not well known. Objective To determine the effects of short-term (1-month) and long-term (6-month) detraining on cardiorespiratory fitness (VO2peak) of individuals after stroke, who participated in aerobic training. Methods A cohort study was developed. Twenty adults (57 ± 11 years old) with stroke were included. After completing an outpatient aerobic training, participants were divided into gain group (VO2peak increase >1.3 ml.kg−1.min−1 from before to immediately after the training) or non-gain group (VO2peak change ≤1.3 ml.kg−1.min−1). Cardiorespiratory fitness (VO2peak), obtained by the cardiopulmonary exercise test was assessed one and 6 months after the end of the training (short- and long-term detraining, respectively), or collected retrospectively from patient chart (before and after the training). Results There was found a significant interaction effect (time*group) for VO2peak (F= 6.108;p < 0,001). Higher values in the VO2peak observed in the gain group with the aerobic training (F = 25.86; p< .001) were significantly reduced with short-term detraining, reaching values similar to that observed before the training and to that of the non-gain group (F = 14.81;p= .001). Both groups had similar VO2peak values within long-term detraining (F = 2.70;p= .12), with no significant differences from the values observed before the training and after short-term detraining (0.11 ≤ p≤ 1.00). Conclusions Detraining on cardiorespiratory fitness of individuals after chronic stroke occurred within only 1 month. Therefore, it is important to maintain aerobic training throughout life.