Objective: A functional promoter polymorphism in the monoamine oxidase A (MAOA) gene has been implicated in neuropsychiatric disorders and also moderates the association between early-life stress and mental disorders, which often co-occur with cardiovascular disease. No study has examined the relationship between MAOA genotype, childhood trauma, and subclinical atherosclerosis. The objective of this investigation was to examine whether childhood trauma moderates the association between MAOA genotype and subclinical atherosclerosis.
Methods: A sample including 289 middle-aged male twin pairs was studied. Subclinical atherosclerosis was assessed by brachial flow-mediated dilation (FMD) using ultrasound. Childhood trauma, before age 18 years, was measured with the Early Trauma Inventory and included physical, emotional, and sexual abuse as well as general trauma. Generalized estimating equation models were used to test the main and interactive effects of the MAOA genotype and each domain of childhood trauma on FMD, adjusting for known risk factors.
Results: General trauma was the most prevalent childhood trauma (28.4%), followed by physical abuse (25.0%), emotional abuse (19.4%), and sexual abuse (11.6%). MAOA genotype was not associated with any domain of childhood trauma. There was no significant evidence for a main effect for the MAOA genotype (β = .02, p = .82) or childhood trauma (.005 < β < .10, p > .54) FMD. However, a significant interaction was observed between MAOA genotype and physical (β interaction = .37, p = .026) or emotional abuse (β interaction = .43, p = .025) on subclinical atherosclerosis.
Conclusions: Childhood trauma modulates the impact of MAOA variant on subclinical atherosclerosis, independent of traditional cardiovascular risk factors.
Keywords: MAOA genotype; childhood trauma; gene × environment interaction; subclinical atherosclerosis; twin study.