SLEEP REACTIVITY AND PARASYMPATHETIC CONTROL WHEN RETURNING TO SLEEP
PublisherThe University of Arizona.
AbstractInsomnia is among the most common health problems and is associated with lower parasympathetic control. Sleep reactivity is associated with development of chronic insomnia. The purpose of this study was to examine whether sleep reactivity is associated with parasympathetic control in response to a sleep-relevant stressor. Parasympathetic control was operationalized using respiratory sinus arrhythmia (RSA). Sleep reactivity was operationalized as a score of 14 or higher on the Ford Insomnia Response to Stress Test (FIRST). Participants were 33 healthy young adults required to adhere to a fixed eight-hour sleep schedule for three nights before an in-laboratory sleep study. Physiological signals were recorded for two five-minute baseline periods of resting wakefulness prior to lights out. Participants were woken after the first five minutes of contiguous N2 sleep in the third NREM period and kept awake for 15 minutes, then allowed to return to sleep. In a multiple linear regression, the interaction between baseline RSA and sleep reactivity predicted RSA when returning to sleep. Individuals with high sleep reactivity had relatively low parasympathetic control when returning to sleep. People with high sleep reactivity may benefit from interventions to increase parasympathetic control during awakenings from sleep.