The development of atherosclerotic lesions and endothelial cell damage can originate during early childhood. Endothelial cells produce and release vasodilatory chemicals, which dictate the artery’s ability to vasodilate or vasoconstrict. Brachial artery FMD is a non-invasive, reproducible and a sensitive technique used to detect changes in arterial diameter and is correlated with coronary artery endothelial function. Cross-sectional studies have indicated increases in arterial diameter in children between the ages of 6-18 years however, a longitudinal, observational design study has not been conducted to understand how arterial diameters and FMD change over time in children, with considerations for the influences of physical activity and sex. The purpose of this study was to understand the impact of age and sex on arterial diameter and FMD and investigate the effects of habitual moderate-to-vigorous physical activity (MVPA) during both the school-age and preschool years on endothelial function trajectories during the school-age years. Over three years, 418 children between 3-5 years old participated in the HOPP study annually, and 279 of these children attended the lab when they were between 6-12 years old for an additional 3 annual visits in the SKIP study. Habitual MVPA was measured for 7 days in both the HOPP and SKIP studies each year, and FMD was measured each year during SKIP. Linear mixed-effects modeling was implemented to study the trend in FMD and the influence of chronological and biological age, sex and MVPA on arterial function; effects are reported as unstandardized estimates (Est). Boys had larger baseline and peak brachial artery diameters compared to girls (p<0.001). Girls had larger brachial artery FMD compared to boys (6.82±3.39 vs. 6.23±3.50 %, p<0.001). There was an effect of MVPA in the SKIP study on allometrically scaled FMD (Est. -0.017, p=0.03), but not on relative FMD (Est. -0.01, p=0.17). MVPA in the preschool years did not predict school-aged scaled FMD (Est. 0.11, p=0.24) or FMD (Est. -0.003, p=0.64). The observed trends in brachial artery diameter and FMD are in-line with expected changes in growth and maturation in children. Children who engaged in more habitual MVPA during the childhood years, but not the preschool years, demonstrated changes endothelial function during the school-age years. / Thesis / Master of Science (MSc) / It is clear that preliminary signs of atherosclerosis begin during the early years of childhood, and typically precede the development of future cardiovascular disease. Engaging in habitual physical activity at higher intensities, has been shown to positively influence cardiovascular health, specifically in central and peripheral arteries. This study sought to investigate the trends in vascular heath over time in children and examine the effect of moderate-to-vigorous physical activity engagement during the preschool years on vascular health during the school-age years. Our results suggest that as children age, their arteries get bigger in size and that school-aged girls have elevated vascular function when compared to boys. Children who engage in greater amounts of moderate-to-vigorous physical activity during their school-age years does not influence measures of vascular health. Additionally, engagement in habitual moderate to vigorous physical activity during the preschool years does not impact these vascular health relationships during the school-age years.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/24937 |
| Date | January 2019 |
| Creators | Bacauanu, Joey |
| Contributors | MacDonald, Maureen, Kinesiology |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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