Sleep characteristics and cardiovascular risk in children and adolescents: an enumerative review

Abstract

Cardiovascular risk factors develop in childhood and adolescence. This enumerative review addresses whether sleep characteristics, including sleep duration, continuity, quality, and daytime sleepiness, are associated with cardiovascular risk factors in young people. Thirty-nine studies were identified, which examined the following risk factors: metabolic syndrome, glucose and insulin, lipids, blood pressure, and cardiovascular responses to psychological stressors. Due to the availability of other reviews, 16 longitudinal studies of obesity published in 2011 and later were also included in this report. Excluded from the review were studies of participants with suspected or diagnosed sleep disorders and reports from sleep deprivation experiments. Combining studies, evidence was strongest for obesity, followed by glucose, insulin, blood pressure (especially ambulatory blood pressure), and parasympathetic responses to psychological stressors. There was little evidence for metabolic syndrome cluster, lipids, and blood pressure responses to psychological stressors. The more positive associations were obtained for studies that incorporated objective measures of sleep and that included adolescents. The foundational evidence is almost entirely cross-sectional, except for work on obesity. In summary, available evidence suggests that the associations between sleep characteristics and cardiovascular risk vary by risk factor. It is time to conduct studies to determine antecedent and consequent relationships, and to expand risk factors to include markers of inflammation.

Keywords: Blood pressure; Cardiovascular risk factors; Children; Lipids; Obesity; Sleep.

Figure 1

a. Flow diagram of study selection for sleep and cardiovascular risk factors. Note: Included studies had a) had a mean sample age of 24 or younger, and b) investigated sleep duration, continuity, quality, timing, or sleepiness in relation to one or more of the cardiometabolic risk factors (metabolic syndrome, glucose/insulin, lipids, blood pressure, cardiovascular stress responses). We also included studies on sleep architecture when available. Excluded from review were total or partial sleep deprivation experiments and studies that focused exclusively on clinical samples or participants with sleep disorders. b. Flow diagram of longitudinal study selection for sleep and obesity. Note: Included studies a) had a mean sample age of 24 or younger, b) were published in 2011 or later c) were not included in recent reviews of sleep and obesity in youth, and d) used a longitudinal design to examine sleep as a predictor of body mass index or adiposity. Excluded from review were total or partial sleep deprivation experiments and studies that focused exclusively on clinical samples or participants with sleep disorders.

Figure 1

a. Flow diagram of study selection for sleep and cardiovascular risk factors. Note: Included studies had a) had a mean sample age of 24 or younger, and b) investigated sleep duration, continuity, quality, timing, or sleepiness in relation to one or more of the cardiometabolic risk factors (metabolic syndrome, glucose/insulin, lipids, blood pressure, cardiovascular stress responses). We also included studies on sleep architecture when available. Excluded from review were total or partial sleep deprivation experiments and studies that focused exclusively on clinical samples or participants with sleep disorders. b. Flow diagram of longitudinal study selection for sleep and obesity. Note: Included studies a) had a mean sample age of 24 or younger, b) were published in 2011 or later c) were not included in recent reviews of sleep and obesity in youth, and d) used a longitudinal design to examine sleep as a predictor of body mass index or adiposity. Excluded from review were total or partial sleep deprivation experiments and studies that focused exclusively on clinical samples or participants with sleep disorders.