Cardiovascular Risk Markers and Cognitive Performance in Children

Look into my eyes: What can eye-based measures tell us about the relationship between physical activity and cognitive performance?

BACKGROUND

There is a growing interest to understand the neurobiological mechanisms that drive the positive associations of physical activity and fitness with measures of cognitive performance. To better understand those mechanisms, several studies have employed eye-based measures (e.g., eye movement measures such as saccades, pupillary measures such as pupil dilation, and vascular measures such as retinal vessel diameter) deemed to be proxies for specific neurobiological mechanisms. However, there is currently no systematic review providing a comprehensive overview of these studies in the field of exercise-cognition science. Thus, this review aimed to address that gap in the literature.

METHODS

To identify eligible studies, we searched 5 electronic databases on October 23, 2022. Two researchers independently extracted data and assessed the risk of bias using a modified version of the Tool for the assEssment of Study qualiTy and reporting in EXercise (TESTEX scale, for interventional studies) and the critical appraisal tool from the Joanna Briggs Institute (for cross-sectional studies).

RESULTS

Our systematic review (n = 35 studies) offers the following main findings: (a) there is insufficient evidence available to draw solid conclusions concerning gaze-fixation-based measures; (b) the evidence that pupillometric measures, which are a proxy for the noradrenergic system, can explain the positive effect of acute exercise and cardiorespiratory fitness on cognitive performance is mixed; (c) physical training- or fitness-related changes of the cerebrovascular system (operationalized via changes in retinal vasculature) are, in general, positively associated with cognitive performance improvements; (d) acute and chronic physical exercises show a positive effect based on an oculomotor-based measure of executive function (operationalized via antisaccade tasks); and (e) the positive association between cardiorespiratory fitness and cognitive performance is partly mediated by the dopaminergic system (operationalized via spontaneous eye-blink rate).

CONCLUSION

This systematic review offers confirmation that eye-based measures can provide valuable insight into the neurobiological mechanisms that may drive positive associations between physical activity and fitness and measures of cognitive performance. However, due to the limited number of studies utilizing specific methods for obtaining eye-based measures (e.g., pupillometry, retinal vessel analysis, spontaneous eye blink rate) or investigating a possible dose-response relationship, further research is necessary before more nuanced conclusions can be drawn. Given that eye-based measures are economical and non-invasive, we hope this review will foster the future application of eye-based measures in the field of exercise-cognition science.

Knowledge gaps and future directions in cognitive functions in children and adolescents with primary arterial hypertension: A systematic review

Arterial hypertension (AH) among adults is known to be associated with worse cognitive outcomes. Similarly, children and adolescents with AH could be expected to underperform during neuropsychological evaluations when compared with healthy peers. Our aims were to review the existing literature on cognitive functioning among children and adolescents with primary AH and to identify what additional evidence may be needed to substantiate the impact of hypertension on poor cognitive outcomes in this population. We conducted a systematic review of articles in PubMed and Web of Science published before 17 January 2022, reporting on cognitive testing among children and adolescents with primary AH. From 1,316 records, 13 were included in the review-7 used battery-testing while other employed indirect measures of cognitive functions. Most of the studies reported worse results among individuals with AH. Results of two prospective trials suggested that cognitive functioning may improve after starting antihypertensive treatment. Ambulatory blood pressure monitoring was shown to be more strongly related to cognitive testing results than office measures of blood pressure. Significant confounders, namely obesity and sleep apnea, were identified throughout the studies. Our review indicates that evidence relating AH with poor cognitive functioning among youth is usually based on indirect measures of executive functions (e.g., questionnaires) rather than objective neuropsychological tests. Future prospective trials set to test different cognitive domains in children and adolescents undergoing treatment for AH are endorsed and should consider using standardized neuropsychological batteries as well as adjust the assessing results for obesity and sleep disorders.

Vascular biomarkers in the prevention of childhood cardiovascular risk: From concept to clinical implementation

Vascular biomarkers allow for non-invasive assessment of vascular structure and function and have been shown to be surrogates for cardiovascular (CV) outcome in adults. They reflect the cumulative risk of a plethora of single CV risk factors, such as obesity and hypertension, on the arterial wall. The process of atherosclerosis oftentimes has its origin in childhood and tracks into adulthood. Obesity-related CV risk in childhood is a main determinant of manifest CV disease and adverse outcome in adulthood. To date, prevention strategies are directed toward the detection and reduction of CV disease in adulthood. This review updates and puts into perspective the potential use of vascular biomarkers in children. With reference to the concept of early vascular aging in adults, it elaborates on the role of vascular biomarkers for CV risk stratification in children. The concept of primordial vascular aging implies that young children be screened for vascular health, in an attempt to timely detect subclinical atherosclerosis and initiate treatment strategies to reverse vascular damage in a period of life with high probability for risk regression. The evidence for the validity of macro- and microvascular candidate biomarkers as screening tools of CV risk in children is reviewed, and limitations as well as remaining research gaps are highlighted. Furthermore, an overview on the effects of exercise treatment on vascular biomarkers is given. Vascular biomarkers susceptible to lifestyle or drug treatment have the potential to qualify as monitoring tools to guide clinicians. This review discusses evidence for vascular biomarkers to optimize screening of childhood CV risk from initial concepts to potential future clinical implementation in cardiovascular prevention.

Exercise types and working memory components during development

Working memory is crucial to learning and academic success. Exercise has been found to benefit working memory in late life, but its effects during cognitive development are less clear. Building on findings that working memory is supported by the motor system, we highlight the sensitivity of different working memory components to acute and long-term exercise in children and adolescents. We also consider how the specific skill demands of endurance and coordinative exercise influence this sensitivity. Distinct effects of these exercise types are further linked with neurocognitive and neuroendocrine pathways. Our review suggests long-term rather than acute benefits of exercise for children and adolescents' working memory, which are more pronounced and specific for exercise with high coordinative demands.