Potential mechanisms linking high-volume exercise with coronary artery calcification

Biomarkers of aging: from molecules and surrogates to physiology and function

Many countries face an unprecedented challenge in aging demographics. This has led to an exponential growth in research on aging, which, coupled to a massive financial influx of funding in the private and public sectors, has resulted in seminal insights into the underpinnings of this biological process. However, critical validation in humans has been hampered by the limited translatability of results obtained in model organisms, additionally confined by the need for extremely time-consuming clinical studies in the ostensible absence of robust biomarkers that would allow monitoring in shorter time frames. In the future, molecular parameters might hold great promise in this regard. In contrast, biomarkers centered on function, resilience, and frailty are available at the present time, with proven predictive value for morbidity and mortality. In this review, the current knowledge of molecular and physiological aspects of human aging, potential antiaging strategies, and the basis, evidence, and potential application of physiological biomarkers in human aging are discussed.

Exercise intensity and mortality in overweight and obese patients with chronic kidney disease: longitudinal analysis (1999-2016)

BACKGROUND

Chronic kidney disease (CKD) and overweight/obesity are significant global public health issues. Appropriate free-time physical activity (PA) is essential for overweight/obese patients with chronic kidney disease, but specific guidelines are lacking. The present study was conducted to determine the association between PA and all-cause mortality in these patients.

METHODS

Data from 3,434 overweight/obese adults with CKD from the 1999-2016 National Health and Nutrition Examination Surveys were analyzed. Associations between clinical/laboratory findings and PA intensity (moderate and vigorous) were investigated. The all-cause mortality of patients in different PA categories were compared by Kaplan-Meier analysis. Factors associated with all-cause mortality were determined using a Cox proportional hazards model. A restricted cubic spline was employed to obtain a more flexible and detailed representation of the relationship between PA intensity and all-cause mortality, with better predictive capability.

RESULTS

The Kaplan-Meier analysis revealed that greater all-cause mortality was associated with < 10 min/week moderate/vigorous PA (log-rank p < 0.001). A greater survival probability was associated with ≥ 150 min/week vigorous PA or 10-149 min/week moderate PA (log-rank p < 0.001). Age, gender, vigorous PA, smoking status, alcohol consumption, diabetes status, eGFR, serum albumin level, uric acid level, and blood urea nitrogen level were identified as factors associated independently with mortality in the Cox proportional hazards analysis. The restricted cubic splines revealed that these relationships were non-linear (all p < 0.05). Kaplan-Meier analysis of data from patients who engaged in 10-450 min/week moderate/vigorous PA revealed significant differences between the 0-74-min/week and other vigorous PA groups (all log-rank p < 0.001).

CONCLUSIONS

Extended durations of vigorous PA are associated with reduced all-cause mortality in overweight/obese patients with CKD. Clinicians should recommend vigorous free-time PA to these patients, and public health interventions should target this goal to maximize patient health.

A new perspective on cardiovascular function and dysfunction during endurance exercise: identifying the primary cause of cardiovascular risk

Exercise mechanical efficiency typically falls within the range of approximately 20 to 25%. This means that a great part of the metabolic energy converted to generate movement is released as heat. Therefore, the rise in core temperature during endurance exercise in humans is proportional to generated work. Cutaneous vasodilation occurs when the core temperature threshold is reached. The rise in heart rate in response to thermal stress is a cardiovascular response that increases cardiac output and skin blood flow. The cardiovascular response during endurance exercise is a complex phenomenon potentially influenced by the involvement of nitric oxide in active thermoregulatory vasodilation. Excessive exercise can create high oxidative stress by disrupting the balance between free radicals' production and scavenging, resulting in impaired cardiovascular function. The above considerations are related to the severity and duration of endurance exercise. The first focus of this narrative review is to provide an updated understanding of cardiovascular function during endurance exercise. We aim to explore the potential role of oxidative stress in causing cardiovascular dysfunction during endurance exercise from a fresh perspective. Additionally, we aim to identify the primary factors contributing to cardiovascular risk during strenuous prolonged exercise by highlighting recent progress in this area, which may shed light on previously unexplained physiological responses. To ascertain the effect of endurance exercise on cardiovascular function and dysfunction, a narrative review of the literature was undertaken using PubMed, ScienceDirect, Medline, Google Scholar, and Scopus. The review highlighted that high oxidative stress (due to high levels of catecholamines, shear stress, immune system activation, and renal dysfunction) leads to a rise in platelet aggregation during endurance exercise. Importantly, we clearly revealed for the first time that endothelial damage, vasoconstriction, and blood coagulation (inducing thrombosis) are potentially the primary factors of cardiovascular dysfunction and myocardial infarction during and/or following endurance exercise.

Myocardial Fibrosis in Young and Veteran Athletes: Evidence from a Systematic Review of the Current Literature

Background: Exercise is associated with several cardiac adaptations that can enhance one's cardiac output and allow one to sustain a higher level of oxygen demand for prolonged periods. However, adverse cardiac remodelling, such as myocardial fibrosis, has been identified in athletes engaging in long-term endurance exercise. Cardiac magnetic resonance (CMR) imaging is considered the noninvasive gold standard for its detection and quantification. This review seeks to highlight factors that contribute to the development of myocardial fibrosis in athletes and provide insights into the assessment and interpretation of myocardial fibrosis in athletes. Methods: A literature search was performed using the PubMed/Medline database and Google Scholar for publications that assessed myocardial fibrosis in athletes using CMR. Results: A total of 21 studies involving 1642 endurance athletes were included in the analysis, and myocardial fibrosis was found in 378 of 1595 athletes. A higher prevalence was seen in athletes with cardiac remodelling compared to control subjects (23.7 vs. 3.3%, p < 0.001). Similarly, we found that young endurance athletes had a significantly higher prevalence than veteran athletes (27.7 vs. 19.9%, p < 0.001), while male and female athletes were similar (19.7 vs. 16.4%, p = 0.207). Major myocardial fibrosis (nonischaemic and ischaemic patterns) was predominately observed in veteran athletes, particularly in males and infrequently in young athletes. The right ventricular insertion point was the most common fibrosis location, occurring in the majority of female (96%) and young athletes (84%). Myocardial native T1 values were significantly lower in athletes at 1.5 T (p < 0.001) and 3 T (p = 0.004), although they had similar extracellular volume values to those of control groups. Conclusions: The development of myocardial fibrosis in athletes appears to be a multifactorial process, with genetics, hormones, the exercise dose, and an adverse cardiovascular risk profile playing key roles. Major myocardial fibrosis is not a benign finding and warrants a comprehensive evaluation and follow-up regarding potential cardiac disease.

The Serum NLRP1 Level and Coronary Artery Calcification: From Association to Development of a Risk-Prediction Nomogram

Background

To investigate the correlation between inflammasomes and coronary artery calcification (CAC), and develop and validating a nomogram for predicting the risk of CAC in patients with coronary artery disease (CAD).

Methods

A total of 626 patients with CAD at the Affiliated Hospital of Xuzhou Medical University were enrolled in this study. The patients were divided into the calcification group and the non-calcification group based on the assessment of coronary calcification. We constructed a training set and a validation set through random assignment. The least absolute shrinkage and selection operator (LASSO) regression and multivariate analysis were performed to identify independent risk factors of CAC in patients with CAD. Based on these independent predictors, we developed a web-based dynamic nomogram prediction model. The area under the receiver operating characteristic curve (AUC-ROC), calibration curves, and decision curve analysis (DCA) were used to evaluate this nomogram.

Results

Age, smoking, diabetes mellitus (DM), hyperlipidemia, the serum level of nucleotide-binding oligomerization domain (NOD)-like receptor protein 1 (NLRP1), alkaline phosphatase (ALP) and triglycerides (TG) were identified as independent risk factors of CAC. The AUC-ROC of the nomogram is 0.881 (95% confidence interval (CI): 0.850-0.912) in the training set and 0.825 (95% CI: 0.760-0.876) in the validation set, implying high discriminative ability. Satisfactory performance of this model was confirmed using calibration curves and DCA.

Conclusions

The serum NLRP1 level is an independent predictor of CAC. We established a web-based dynamic nomogram, providing a more accurate estimation and comprehensive perspective for predicting the risk of CAC in patients with CAD.

Associations Between Visceral Fat, Abdominal Muscle, and Coronary Artery Calcification: A Cross-Sectional Analysis of the Multi-Ethnic Study of Atherosclerosis

The associations of body composition components, including muscle and adipose tissue, and markers of subclinical coronary artery disease are unclear. We examined the relation between abdominal computed tomography (CT)-derived measures of the area and density of fat and muscle with coronary artery calcification (CAC), using data from the Multi-Ethnic Study of Atherosclerosis (MESA). A total of 1,974 randomly selected MESA participants free of coronary heart disease underwent abdominal CT scans at examinations 2 or 3, with the resulting images interrogated for abdominal body composition. Using 6 cross-sectional slices spanning L2 to L5, the Medical Imaging Processing Analysis and Visualization software was used to determine abdominal muscle and fat composition using appropriate Hounsfield units ranges. CT chest scans were used to obtain CAC scores, calculated using the Agatston method and spatially weighted calcium score. Multivariable linear and logistic regression analyses were performed to assess the relation between abdominal visceral fat and muscle area and density to prevalent CAC. A total of 1,089 participants had a CAC >0, with an average CAC score of 310. In the fully adjusted model, for every 10-cm2 increase in visceral fat area, the likelihood of having a CAC greater than 0 increased by 0.60% (p <0.001). In the minimally adjusted model, abdominal muscle area was significantly associated with CAC >0, which became nonsignificant in the fully adjusted model. For the density of visceral fat, every 1-Hounsfield unit increase (less lipid-dense fat tissue), the likelihood of having a CAC score >0 decreased by 0.29% (p <0.05). No significant relation was observed between density of abdominal muscle and CAC >0. A greater area and higher lipid density of abdominal visceral fat were associated with an increased likelihood of having CAC, whereas there was no significant relation between abdominal muscle area or density and CAC. The quantity and the quality of fat have associations, with an important marker of subclinical atherosclerosis, CAC, and their significance with respect to cardiovascular outcomes, require further evaluation.

Physical Activity, Cardiorespiratory Fitness and Atherosclerotic Cardiovascular Disease: Part 1

Background

The cardioprotective benefits and prognostic significance of regular moderate-to-vigorous physical activity (PA), increased cardiorespiratory fitness (CRF), or both are often underappreciated by the medical community and the patients they serve. Individuals with low CRF are two to three times more likely to die prematurely from atherosclerotic cardiovascular disease (CVD), than their fitter counterparts when matched for risk factor profile or coronary artery calcium (CAC) score. Accordingly, part 1 of this 2-part review examines these relations and the potential underlying mechanisms of benefit (e.g., exercise preconditioning) on atherosclerotic CVD, with specific reference to gait speed and mortality, CRF and PA as separate risk factors, and the relation between CRF and/or PA on attenuating the adverse impact of an elevated CAC score, as well as potentially favorably modifying CAC morphology, and on incident atrial fibrillation, all-cause and cardiovascular mortality, and on sudden cardiac death (SCD).

Summary

We explore the underappreciated cardioprotective effects of regular PA and CRF. Part 1 examines how CRF and PA reduce the risk of premature death from atherosclerotic CVD by investigating their roles as separate risk factors, the potential underlying mechanisms of benefit, and their impact on gait speed, mortality, and atrial fibrillation. The review also addresses how CRF and PA may mitigate the adverse impact of an elevated CAC score, potentially modifying CAC morphology, and reduce the risk of SCD.

Key Messages

Regular PA and high CRF are essential for reducing the risk of premature death from CVD and mitigating the negative impact of elevated CAC scores. Additionally, they provide significant protection against SCD and atrial fibrillation, emphasizing their broad cardioprotective effects.