Differences in cardiac vagal modulation and cortisol response in adolescents with and without Autism Spectrum Disorder

Abstract

BackgroundPrevious research pointed towards a need of enhanced understanding of cardiac vagal modulation during resting and stress conditions in individuals with Autism Spectrum Disorder (ASD). This cross-sectional study addressed the following hypotheses: lower values of cardiac vagal modulation will be found in adolescents with ASD in comparison to typically developing (TD) peers; different levels of cardiac vagal reactivity and recovery will be found in adolescents with ASD. In addition, exploratory analyses examined the possible association between cardiac vagal modulation and psychosocial functioning and baseline cortisol levels. MethodsAge and sex matched groups of adolescents (13–17 year) with ASD (n = 47) and TD peers (n = 47) were included. Heart rate, breathing frequency and cortisol levels were determined during baseline and a standardized stress-provoking assessment. Behavioral data concerning autism and behavioral characteristics were collected prior to the assessment. ResultsAdolescents with ASD displayed lower levels of cardiac vagal modulation during baseline and stress-provocation compared to their TD peers. However, levels of cardiac vagal reactivity and recovery were similar across groups. Exploratory analyses indicated weak to moderate associations between the level of cardiac vagal modulation and self- and parent-reported measures of autism characteristics and psychosocial functioning in adolescents with ASD. No significant associations were found between baseline cortisol levels and cardiac vagal modulation in both groups. ConclusionThese findings suggest a parasympathetic hypo-activity in adolescents with ASD and, although the level of reactivity and recovery was the same as TD peers, this hypo-activity might be related to several aspects of psychosocial functioning.