Poor Sleep and Cardiovascular Function in Children

We investigated whether sleep quantity and quality were related to 24-hour ambulatory blood pressure (ABP) and cardiovascular reactivity in children. We studied term-born, healthy 8-year-olds (SD = 1.4 years) without sleep-disordered breathing (231 and 265 children provided valid data for analyses of ABP and cardiovascular reactivity, respectively). Sleep was registered with an actigraph for six nights on average (SD = 1.2, range = 3–13 nights). ABP was measured for 24-hours (41% non-school days) with an oscillometric device. The children underwent the Trier Social Stress Test for Children during which blood pressure, electrocardiography and thoracic impedance were recorded and processed offline to give measures of cardiovascular and autonomic function. Neither quantity nor quality of sleep was related to 24-hour ABP or cardiovascular reactivity after accounting for major covariates (sex, age, height, body mass index and parental education). Although lower sympathetic nervous system activation and higher cardiac activation under stress were found in the group of children who slept for short duration when they were compared to the average sleep duration group, these associations were not significant after correction for multiple testing and were not seen in linear regression models of the effects of sleep duration. These findings do not support the mainstream of epidemiological findings, derived from samples more heterogeneous in age, sociodemographic characteristics and health, suggesting that poor sleep is associated with an unhealthy cardiovascular phenotype.