Lifelong endurance exercise and its relation with coronary atherosclerosis

AIMS

The impact of long-term endurance sport participation (on top of a healthy lifestyle) on coronary atherosclerosis and acute cardiac events remains controversial.

METHODS AND RESULTS

The Master@Heart study is a well-balanced prospective observational cohort study. Overall, 191 lifelong master endurance athletes, 191 late-onset athletes (endurance sports initiation after 30 years of age), and 176 healthy non-athletes, all male with a low cardiovascular risk profile, were included. Peak oxygen uptake quantified fitness. The primary endpoint was the prevalence of coronary plaques (calcified, mixed, and non-calcified) on computed tomography coronary angiography. Analyses were corrected for multiple cardiovascular risk factors. The median age was 55 (50-60) years in all groups. Lifelong and late-onset athletes had higher peak oxygen uptake than non-athletes [159 (143-177) vs. 155 (138-169) vs. 122 (108-138) % predicted]. Lifelong endurance sports was associated with having ≥1 coronary plaque [odds ratio (OR) 1.86, 95% confidence interval (CI) 1.17-2.94], ≥ 1 proximal plaque (OR 1.96, 95% CI 1.24-3.11), ≥ 1 calcified plaques (OR 1.58, 95% CI 1.01-2.49), ≥ 1 calcified proximal plaque (OR 2.07, 95% CI 1.28-3.35), ≥ 1 non-calcified plaque (OR 1.95, 95% CI 1.12-3.40), ≥ 1 non-calcified proximal plaque (OR 2.80, 95% CI 1.39-5.65), and ≥1 mixed plaque (OR 1.78, 95% CI 1.06-2.99) as compared to a healthy non-athletic lifestyle.

CONCLUSION

Lifelong endurance sport participation is not associated with a more favourable coronary plaque composition compared to a healthy lifestyle. Lifelong endurance athletes had more coronary plaques, including more non-calcified plaques in proximal segments, than fit and healthy individuals with a similarly low cardiovascular risk profile. Longitudinal research is needed to reconcile these findings with the risk of cardiovascular events at the higher end of the endurance exercise spectrum.

Plasma-Derived microRNAs Are Influenced by Acute and Chronic Exercise in Patients With Heart Failure With Reduced Ejection Fraction

Background: Exercise training improves VO₂peak in heart failure with reduced ejection fraction (HFrEF), but the effect is highly variable as it is dependent on peripheral adaptations. We evaluated changes in plasma-derived miRNAs by acute and chronic exercise to investigate whether these can mechanistically be involved in the variability of exercise-induced adaptations.

Methods: Twenty-five male HFrEF patients (left ventricular ejection fraction < 40%, New York Heart Association class ≥ II) participated in a 15-week combined strength and aerobic training program. The effect of training on plasma miRNA levels was compared to 21 male age-matched sedentary HFrEF controls. Additionally, the effect of a single acute exercise bout on plasma miRNA levels was assessed. Levels of 5 miRNAs involved in pathways relevant for exercise adaptation (miR-23a, miR-140, miR-146a, miR-191, and miR-210) were quantified using RT-qPCR and correlated with cardiopulmonary exercise test (CPET), echocardiographic, vascular function, and muscle strength variables.

Results: Expression levels of miR-146a decreased with training compared to controls. Acute exercise resulted in a decrease in miR-191 before, but not after training. Baseline miR-23a predicted change in VO₂peak independent of age and left ventricular ejection fraction (LVEF). Baseline miR-140 was independently correlated with change in load at the respiratory compensation point and change in body mass index, and baseline miR-146a with change in left ventricular mass index.

Conclusion: Plasma-derived miRNAs may reflect the underlying mechanisms of exercise-induced adaptation. In HFrEF patients, baseline miR-23a predicted VO₂peak response to training. Several miRNAs were influenced by acute or repeated exercise. These findings warrant exploration in larger patient populations and further mechanistic in vitro studies on their molecular involvement.

miR-181c level predicts response to exercise training in patients with heart failure and preserved ejection fraction: an analysis of the OptimEx-Clin trial

AIMS

In patients with heart failure with preserved ejection fraction (HFpEF), exercise training improves the quality of life and aerobic capacity (peakV·O2). Up to 55% of HF patients, however, show no increase in peakV·O2 despite adequate training. We hypothesized that circulating microRNAs (miRNAs) can distinguish exercise low responders (LR) from exercise high responders (HR) among HFpEF patients.

METHODS AND RESULTS

We selected HFpEF patients from the Optimizing Exercise Training in Prevention and Treatment of Diastolic HF (OptimEx) study which attended ≥70% of training sessions during 3 months (n = 51). Patients were defined as HR with a change in peakV·O2 above median (6.4%), and LR as below median (n = 30 and n = 21, respectively). Clinical, ergospirometric, and echocardiographic characteristics were similar between LR and HR. We performed an miRNA array (n = 377 miRNAs) in 14 age- and sex-matched patients. A total of 10 miRNAs were upregulated in LR, of which 4 correlated with peakV·O2. Validation in the remaining 37 patients indicated that high miR-181c predicted reduced peakV·O2 response (multiple linear regression, β = -2.60, P = 0.011), and LR status (multiple logistic regression, odds ratio = 0.48, P = 0.010), independent of age, sex, body mass index, and resting heart rate. Furthermore, miR-181c decreased in LR after exercise training (P-group = 0.030, P-time = 0.048, P-interaction = 0.037). An in silico pathway analysis identified several downstream targets involved in exercise adaptation.

CONCLUSIONS

Circulating miR-181c is a marker of the response to exercise training in HFpEF patients. High miR-181c levels can aid in identifying LR prior to training, providing the possibility for individualized management.

Assessment of vascular function in formerly pre-eclamptic women as a novel marker of future cardiovascular risk

Funding Acknowledgements

Type of funding sources: None.

Background

Women with a history of pre-eclampsia (PE) are at increased risk of cardiovascular disease (CVD). The association between PE and CVD in later life may be explained by vascular dysfunction, either pre-existing or elicited by PE.  Several small studies have shown that vascular dysfunction may persist for years in some patients, indicator of future CVD risk, while other studies could not confirm these findings.

Purpose

In this longitudinal prospective cohort study, we aim to comprehensively assess vascular function in previously pre-eclamptic women (early (&lt;34 weeks) and late (&gt;34 weeks)) and healthy controls. We hypothesize that vascular dysfunction is both more persistent and pronounced in early PE compared to late PE since different pathophysiologic mechanisms underlie both subtypes of PE.

Methods

For this first analysis, 63 PE patients were compared to 16 non-pregnant healthy controls.  Endothelial function was determined by flow-mediated dilatation (FMD), modified FMD (mFMD) and low-flow mediated constriction (L-FMC). Arterial stiffness was assessed by carotid-femoral pulse wave velocity (cfPWV) and augmentation index using pulse wave analysis of the brachial artery, and corrected for heart-rate (Aix75).

Results

Average post-partum period was 11 months (1.4-111.5 months). Thirty-five presented with early PE, 28 with late PE.

In the total PE group, FMD was significantly decreased compared to healthy controls (7.1 ± 2.8 vs 8.9 ± 3.8; p = 0.037), but no difference between early and late PE was observed. Likewise, Aix75 remained elevated after PE (16.5 ± 11.5 vs 5.8 ± 10.1; p &lt; 0.001), again, without difference between early and late PE.  cfPWV was not different after PE compared to healthy controls (p &gt; 0.05) but was significantly higher in the early PE group compared to the late PE group (6.9 ± 1.0 vs 6.4 ± 1.0;  p = 0.045).

Conclusion

Even in the postpartum, PE is characterized by overt and persisting endothelial dysfunction and arterial stiffness. Arterial stiffness is more pronounced in early PE compared to late PE.

This reaffirms that PE has consequences beyond placental impairment and that the persisting vascular impairment in the postpartum could reflect the risk of CVD later in life.

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

AIMS

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).

METHODS AND RESULTS

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.

CONCLUSION

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.

A systematic literature review on the effects of exercise on human Toll-like receptor expression

BACKGROUND

Toll-like receptors (TLRs) are a family of transmembrane pattern recognition receptors that are mainly expressed on immune cells. Recognition of various exogenous and endogenous molecular patterns activates the TLR signalling cascade, which orchestrates an inflammatory immune response. Dysfunctional immune responses, including aberrant TLR signalling, are increasingly implicated in the associations between sedentarism, chronic low-grade systemic inflammation and various non-communicable diseases. Conversely, exercise exerts anti-inflammatory effects, which could be conferred through its immunomodulatory properties, potentially affecting TLRs. This study aims to systematically review the effects of exercise on human TLR expression.

METHOD

A systematic literature search of Pubmed, Embase, The Cochrane Library and SPORTDiscus for articles addressing the impact of exercise (as isolated intervention) on TLRs in humans was conducted, ending in February 2020.

RESULTS

A total of 66 articles were included. The publications were categorised according to exercise modality and duration: acute resistance exercise (4 studies), acute aerobic exercise (26 studies), resistance training program (9 studies), aerobic training program (16 studies), combined (i.e. resistance and aerobic) training program (8 studies) and chronic exercise not otherwise classifiable (9 studies). Five articles investigated more than one of the aforementioned exercise categories. Several trends could be discerned with regard to the TLR response in the different exercise categories. Acute resistance exercise seemed to elicit TLR upregulation, whereas acute aerobic exercise had less activating potential with the majority of responses being neutral or, especially in healthy participants, downregulatory. Chronic resistance and combined exercise programs predominantly resulted in unaltered or decreased TLR levels. In the chronic aerobic exercise category, mixed effects were observed, but the majority of measurements demonstrated unchanged TLR expression.

CONCLUSION

Currently published research supports an interplay between exercise and TLR signalling, which seems to depend on the characteristics of the exercise. However, there was large heterogeneity in the study designs and methodologies. Therefore, additional research is required to further corroborate these findings, to define its pathophysiological implications and to elucidate the mechanism(s) linking exercise to TLR signalling.

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

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&gt;0.05).

At baseline, none of the miRNA were correlated with percent change in VO2peak (all p&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 Effect of Exercise Training During Pregnancy to Improve Maternal Vascular Health: Focus on Gestational Hypertensive Disorders

Hypertensive disorders of pregnancy, including gestational hypertension and pre-eclampsia, occur in up to 10% of pregnancies and are associated with increased life-long cardiovascular risk. Physical activity improves cardiovascular health in pregnancy and may lower the risk of developing hypertensive disorders of pregnancy. However, a minority of pregnant women comply with the recommended level of physical activity. Adequate knowledge on the physiological effects of exercise in healthy pregnancy could help to overcome potential barriers as pregnancy is a unique window of opportunity to improve health outcomes for both mother and child. In this mini review, we discuss structural and functional vascular adaptations during healthy and hypertensive pregnancies, we elaborate on the effects of exercise on the vasculature and review the safety and existing evidence of exercise training as preventive therapy for gestational hypertensive disorders.

Exercise training in women with cardiovascular disease: Differential response and barriers - review and perspective

BACKGROUND

Exercise-based cardiac rehabilitation has a class 1A recommendation in coronary artery disease and heart failure based on its beneficial effects on mortality, morbidity and quality of life. However, the inter-individual response to exercise training is highly variable and influenced by both training and patient characteristics. Notably, men and women display a different training response, even when accounting for age, height and lean muscle mass. Most studies investigating exercise effects on various physiological outcomes focus on male patients. Because women are understudied, the scientific evidence for tailored exercise prescription in women is still limited.

METHODS

This narrative review summarises: (a) the underlying physiological determinants of the response to exercise training in women with cardiovascular disease, in which women rely more on fat than on carbohydrate oxidation during exercise, have lower aerobic capacities and smaller increases in cardiac function during exercise; (b) the benefits and barriers of exercise in women, in whom improving cardiometabolic risk and quality of life is weighed against socioeconomic and psychological needs; and (c) the relevance of different clinical endpoints in exercise trials such as maximum oxygen uptake, morbidity, mortality, training characteristics, quality of life and metabolic or vascular endpoints.

RESULTS

Finally, we provide a perspective on how to improve referral, enrolment and adherence to exercise training in women, with structured approaches to inform the referring physician as well as the patient, and offering more flexible, gender-tailored or tele/smartphone-based programmes while addressing the socioeconomic and psychological needs of the patients. This may ultimately improve the admission, adherence and outcome of exercise-based cardiac rehabilitation in women.