James A. Janssen

Rationale, design and methods for the RIGHT Track Health Study: pathways from childhood self-regulation to cardiovascular risk in adolescence

BackgroundCardiovascular risk factors during adolescence—including obesity, elevated lipids, altered glucose metabolism, hypertension, and elevated low-grade inflammation—is cause for serious concern and potentially impacts subsequent morbidity and mortality. Despite the importance of these cardiovascular risk factors, very little is known about their developmental origins in childhood. In addition, since adolescence is a time when individuals are navigating major life changes and gaining increasing autonomy from their parents or parental figures, it is a period when control over their own health behaviors (e.g. drug use, sleep, nutrition) also increases. The primary aim of this paper is to describe the rationale, design and methods for the RIGHT Track Health Study. This study examines self-regulation as a key factor in the development of cardiovascular risk, and further explores health behaviors as an explanatory mechanism of this association. We also examine potential moderators (e.g. psychosocial adversities such as harsh parenting) of this association.Method/designRIGHT Track is a longitudinal study that investigates social and emotional development. The RIGHT Track Health Study prospectively follows participants from age 2 through young adulthood in an effort to understand how self-regulatory behavior throughout childhood alters the trajectories of various cardiovascular risk factors during late adolescence via health behaviors. Individuals from RIGHT Track were re-contacted and invited to participate in adolescent data collection (~16.5, 17.5 and 18+ years old). Individuals completed assessments of body composition, anthropometric indicators, fitness testing (via peak oxygen consumption), heart rate variability during orthostatic challenge, 7-day accelerometry for physical activity and sleep, 24-h dietary recalls, and blood analysis for biomarkers related to metabolic syndrome, inflammatory status and various hormones and cytokines. Individuals also completed extensive self-report measures on diet and eating regulation, physical activity and sedentary behaviors, sleep, substance use, medical history, medication use and a laboratory-day checklist, which chronicled previous day activities and menstrual information for female participants.DiscussionInsights emerging from this analysis can help researchers and public health policy administrators target intervention efforts in early childhood, when preventing chronic disease is most cost-effective and behavior is more malleable.

Vagal Regulation of Cardiac Function in Early Childhood and Cardiovascular Risk in Adolescence

Objective Poor behavioral self-regulation in the first 2 decades of life has been identified as an important precursor of disease risk in adulthood. However, physiological regulation has not been well studied as a disease risk factor before adulthood. We tested whether physiological regulation at the age of 2 years, in the form of vagal regulation of cardiac function (indexed by respiratory sinus arrhythmia [RSA] change), would predict three indicators of cardiovascular risk at the age of 16 years (diastolic and systolic blood pressure and body mass index). Methods Data came from 229 children who participated in a community-based longitudinal study. At the age of 2 years, children were assessed for RSA baseline and RSA change (ln(ms)2) in response to a series of challenge tasks. These same children were assessed again at the age of 16 years for diastolic and systolic blood pressure (millimeters of mercury), height (meters), and weight (kilogram). Results Regression analyses revealed that less RSA withdrawal at the age of 2 years predicted higher diastolic blood pressure at the age of 16 years, adjusting for demographic characteristics (B = −3.07, M [S E] = 1.12, p = .006). Follow-up analyses demonstrated that these predictions extended to clinically significant levels of diastolic prehypertension (odds ratio = 0.43, 95% confidence interval = 0.22–0.89). RSA withdrawal did not significantly predict adolescent body mass index or systolic blood pressure. Conclusions Vagal regulation of cardiac function in early childhood predicts select indicators of cardiovascular risk 14 years later. Early signs of attenuated vagal regulation could indicate an increased risk for elevated blood pressure before adulthood. Future research should test biological, behavioral, and psychological mechanisms underlying these long-term predictions.

The effects of low-intensity cycling on cognitive performance following sleep deprivation

This study examined the effect of 24h of sleep deprivation on cognitive performance and assessed the effect of acute exercise on cognitive performance following sleep deprivation. Young, active, healthy adults (n=24, 14 males) were randomized to control (age=24.7±3.7years, BMI=27.2±7.0) or exercise (age=25.3±3.3years, BMI=25.6±5.1) groups. Cognitive testing included a 5-min psychomotor vigilance task (PVT), three memory tasks with increasing cognitive load, and performance of the PVT a second time. On morning one, cognitive testing followed a typical nights sleep. Following 24-h of sustained wakefulness, cognitive testing was conducted again prior to and after the acute intervention. Participants in the exercise condition performed low-intensity cycling (∼40%HRR) for 15-min and those in the control condition sat quietly on the bike for 15-min. t-Tests revealed sleep deprivation negatively affected performance on the PVT, but did not affect memory performance. Following the acute intervention, there were no cognitive performance differences between the exercise and rested conditions. We provide support for previous literature suggesting that during simple tasks, sleep deprivation has negative effects on cognitive performance. Importantly, in contrast to previous literature which has shown multiple bouts of exercise adding to cognitive detriment when combined with sleep deprivation, our results did not reveal any further detriments to cognitive performance from a single-bout of exercise following sleep deprivation.