Exercise-associated prevention of adult cardiovascular disease in children and adolescents: monocytes, molecular mechanisms, and a call for discovery

KLB and NOX4 expression levels as potential blood-based transcriptional biomarkers of physical activity in children

Insufficient physical activity (PA) in children is considered one of the major contributors to obesity and cardiometabolic complications later in life. Although regular exercise may contribute to disease prevention and health promotion, reliable early biomarkers are required to objectively discern people performing low PA from those who exercise enough. Here, we aimed to identify potential transcript-based biomarkers through the analysis of a whole-genome microarray in peripheral blood cells (PBC) from physically less active (n = 10) comparing with more active (n = 10) children. A set of genes differentially expressed (p < 0.01, Limma test) in less physically active children were identified, including the down-regulation of genes related to cardiometabolic benefits and improved skeletal function (KLB, NOX4, and SYPL2), and the up-regulation of genes whose elevated expression levels are associated with metabolic complications (IRX5, UBD, and MGP). The analysis of the enriched pathways significantly affected by PA levels were those associated with protein catabolism, skeletal morphogenesis, and wound healing, among others, which may suggest a differential impact of low PA on these processes. Microarray analysis comparing children according to their usual PA has revealed potential PBC transcript-based biomarkers that may be useful in early discerning children expending high sedentary time and its associated negative consequences.

Acute, but not chronic, aerobic exercise alters the impact of ex vivo LDL and fatty acid stimulation on monocytes and macrophages from healthy, young adults

BACKGROUND

Elevated low-density lipoprotein (LDL) and triglyceride concentrations are associated with future cardiovascular risk in young adults. Conversely, chronic physical activity is generally accepted to reduce CVD risk. Atherosclerosis is a major underlying cause of CVD, and atherogenesis is mediated by peripheral monocytes and monocyte-derived macrophages. The study aimed to determine if an individual's physical activity level impacts the phenotype of monocytes and monocyte-derived macrophages when stimulated with LDL and fatty acid ex vivo.

METHODS

Peripheral blood mononuclear cells (PBMCs) were obtained from healthy, young adults of differing physical activity levels before and after a single bout of moderate intensity exercise (25 min at 60% of VO_2peak). PBMCs were stimulated with LDL and palmitate ex vivo prior to differentiation into macrophages. Monocyte subset percentages and monocyte-derived macrophage expression of phenotypic (CD86, CD206) and functional (CCR2, ERK 1/2) markers were evaluated by flow cytometry.

RESULTS

Compared to baseline, ex vivo LDL and palmitate stimulation decreased (p = 0.038) non-classical monocyte percentage from 24.7 ± 3.2 to 21.5 ± 2.6% in all participants. When ex vivo lipid stimulation was preceded by acute exercise, non-classical monocyte percentage was similar to baseline levels (p = 0.670, 25.8 ± 2.15%). Macrophage CD86/CD206 was increased from 1.30 ± 0.14 to 1.68 ± 0.19 when preceded by acute exercise in all participants. No differences were observed between participants of differing physical activity levels.

CONCLUSIONS

Findings suggest that acute exercise modulates monocyte phenotype after LDL and palmitate stimulation in a protective manner, however, chronic physical activity does not alter monocyte/macrophage responses to any experimental condition in this population.

Pediatric Cardiopulmonary Exercise Testing: Interoperability Through Domain Analysis Modeling and a National Survey

PURPOSE

The electronic health record, data science advances, and dynamic environmental and infectious threats to child health highlight the need for harmonized and interoperable approaches to pediatric cardiopulmonary exercise testing (CPET). Accordingly, we developed a terminology harmonization in exercise medicine and exercise science domain analysis model (THEMES DAM) to structure CPET data elements.

METHODS

THEMES DAM identified 114 data elements, including participant information, calibration, equipment, protocols, laboratory personnel, encouragement strategies, and analysis procedures. We used the THEMES DAM, vetted by the international data standards organization HL7, to construct a current-state survey of pediatric CPET centers in the United States. Forty-eight of 101 centers responded to a questionnaire covering seven major topic areas (38 items).

RESULTS

Centers predominantly performed between 100 and 500 tests annually. Cardiac disease represented 55% of referrals. Almost all centers calibrated gas concentrations and flow daily, but 42% never calibrated their treadmill or cycle ergometers. All centers measured V̇O2peakbut calculated differently. Centers used a variety of protocols (e.g., for treadmill: 61%, Bruce; 43%, modified Bruce; 59%, other); 44% calculated CPET slopes from submaximal portions of CPET (e.g., V̇O2-HR). All centers verbally encouraged participants, but only 40% used a standardized approach. The interpretation of CPET was done by physicians (60%), exercise physiologists (25%), exercise technicians (10%), nurses (1%), or others (4%). Ninety-one percent would agree to collaborate in multicenter research, 89% to establish dynamic reference values, and 83% to better interpret CPET.

CONCLUSIONS

The survey data and the implementation of THEMES DAM could accelerate interoperability across multiple centers. This would facilitate a nimble approach to create pediatric reference values responsive to the constantly changing health environment and stimulate novel approaches to CPET research and clinical application.

Melatonin in Early Nutrition: Long-Term Effects on Cardiovascular System

Breastfeeding protects against adverse cardiovascular outcomes in the long term. Melatonin is an active molecule that is present in the breast milk produced at night beginning in the first stages of lactation. This indoleamine appears to be a relevant contributor to the benefits of breast milk because it can affect infant health in several ways. The melatonin concentration in breast milk varies in a circadian pattern, making breast milk a chrononutrient. The consumption of melatonin can induce the first circadian stimulation in the infant's body at an age when his/her own circadian machinery is not functioning yet. This molecule is also a powerful antioxidant with the ability to act on infant cells directly as a scavenger and indirectly by lowering oxidant molecule production and enhancing the antioxidant capacity of the body. Melatonin also participates in regulating inflammation. Furthermore, melatonin can participate in shaping the gut microbiota composition, richness, and variation over time, also modulating which molecules are absorbed by the host. In all these ways, melatonin from breast milk influences weight gain in infants, limiting the development of obesity and comorbidities in the long term, and it can help shape the ideal cellular environment for the development of the infant's cardiovascular system.