Stress reactivity as a moderator of family stress, physical and mental health, and functional impairment for children with sickle cell disease.

OBJECTIVE: To evaluate whether autonomic nervous system (ANS) reactivity modifies the relation between family stress, and physical and mental health, and functional impairment for children with sickle cell disease.
METHODS: Thirty-eight 5-to 8-year old children with sickle cell disease completed a 20-minute ANS reactivity protocol measuring respiratory sinus arrhythmia and pre-ejection period during comparison and challenge tasks in social, cognitive, sensory, and emotion domains. Domain-specific reactivity was calculated as the difference between challenge and comparison tasks; overall reactivity was calculated across domains as the mean of the difference scores. ANS profile scores combined the overall respiratory sinus arrhythmia and pre-ejection period reactivity scores. Caregivers completed measures of family stress, child physical and mental health symptoms, and functional impairment.
RESULTS: Family stress was associated with child functional impairment whereas overall and cognitive ANS reactivity was associated with co-morbid internalizing and externalizing mental health symptoms. Interaction models showed that children with the classic ANS profile (parasympathetic inhibition and sympathetic activation) in the cognitive and emotion domains were most vulnerable to the effects of stress, with more functional impairment and injuries when family stress was high, controlling for age, sex, and parent education.
CONCLUSION: The costs to patients and families in diminished quality of life and to the health care system could be reduced by further exploration of strategies to identify children with sickle cell disease who are most vulnerable under conditions of high family stress and heightened psychobiologic reactivity.