Sleep problems and cardiovascular function in children

OBJECTIVE: To assess the associations of sleep problems with 24-hour ambulatory blood pressure and cardiovascular reactivity in children. METHODS: Sleep problems in 285 term-born, healthy 8-year-olds (mean [standard deviation] = 8.1 [0.3] years) were measured with a parent-rated Sleep Disturbance Scale for Children. Ambulatory blood pressure (n = 241) was measured for 24 hours (41% nonschool days) with an oscillometric device. The children (n = 274) 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. RESULTS: No associations were found between sleep problems and 24-hour ambulatory blood pressure. Children with sleep breathing disorders (n = 5) had higher baseline sympathetic vascular activity (p = .014) and higher heart rate (p = .044) and sympathetic cardiac activity (p = .031) in reaction to stress. Children with disorders of excessive somnolence (n = 55) had higher baseline parasympathetic activity (p = .016). None of the associations remained significant after controlling for multiple testing. CONCLUSIONS: Our results suggest that in a healthy community sample of prepubertal children, sleep problems are not associated with an unhealthy cardiovascular phenotype at this age. However, associations may be underestimated because of the low prevalence of sleep breathing disorders in this sample and may not generalize to older populations.