Heart Rate Variability in Children With Autism Spectrum Disorder and Associations With Medication and Symptom Severity

Abstract

Decreased heart rate variability (HRV) is considered a common marker of autonomic dysfunction that contributes to poor health outcomes. While some studies have suggested that children with autism spectrum disorder (ASD) show reduced HRV, research is yet to consider whether this may be associated with medication use and symptom severity. This study examined the relationship between resting state HRV, medication use and symptom severity in children diagnosed with ASD. Children with ASD (N = 86), aged between 3 and 12 years (M = 8.09), were compared to 44 neurotypical children of similar age (M = 7.15). Laboratory assessment of HRV involved 5 min of non‐invasive baseline electrocardiogram assessments while participants viewed an age‐appropriate non‐verbal animated video. Time‐domain and frequency‐domain HRV measures were analyzed. ASD symptom severity was assessed using the Autism Diagnostic Observation Schedule‐Second Edition (ADOS‐2) and Social Responsiveness Scale (SRS‐2). Results indicated that children with ASD exhibited reduced resting HRV relative to neurotypical children. Subsequent analyses within the ASD group suggested that this group difference was greater in children who were taking psychotropic medication (N = 36). Our data also provides tentative evidence of a relationship between HRV and social impairment symptoms in children with ASD, with more severe repetitive behaviors (as measured by the ADOS‐2) associated with decreased resting HRV. Overall, these findings suggest that HRV may be atypical in children with ASD and suggest the importance of exploring HRV as a risk factor for cardiovascular health in this group. Lay Summary Cardiac activity, such as heart rate variability (HRV), can provide insight into the autonomic nervous system. This study reports on the association between resting‐state HRV and autonomic nervous system activity in young children with autism spectrum disorder (ASD) compared to neurotypical children. These results may help us understand what underlies autonomic nervous system dysfunction and the potential pathophysiological mechanisms leading to increased cardiovascular risk in ASD.

Heart Rate Variability in Schizophrenia and Autism

“…The majority of the studies measuring HRV in autism focused on children and adolescents find relatively consistent effects. For the few reports in adults, similar reductions are reported (35), particularly when under social (36), or sensory stimulation (37), reflecting impaired emotion regulation (38), worse inhibitory control (39), and more symptoms (40). HRV has also been found to mediate task performance (speed at responding to a cue) and this relationship differs subtly between autism and ADHD suggesting some specificity with diagnosis (41).…”

Autism Spectrum Disorder in Children Is Not Associated With Abnormal Autonomic Nervous System Function: Hypothesis and Theory

“…Contrary to their expectations, the autonomic responsiveness to the Stroop test was the same for the ASD and control group (60). Thapa et al confirmed this in autistic children: no differences in heart rate, RMSSD, nor high-frequency power were observed in children not on psychotropic medication, compared to a control group (61). Hence, medication is likely a major factor in the higher heart rate found in ASD groups.…”

The autism-associated Meis2 gene is necessary for cardiac baroreflex regulation in mice

“…The barore ex is associated with some pathological conditions 48,51 , but only recently, imbalance of cardiac autonomic regulation in patients with intellectual disabilities and ASD is emerging [7][8][9][10][11][12][13][14][15][16][17][18][19] . However, the origins of dysautonomia in ASD is still unclear and somehow controversial with highly variable pro les depending on the studies.…”