Exposure to life stresses can lead to diminution in the capacity of stress response systems to mount a robust response to new challenges, with blunting of dynamic range – the spread between maximal attainable and minimal resting levels. We investigate the association between early life adversity and the dynamic range of adult diurnal cortisol secretion.
In 35-86 year-old adults, cortisol assayed from 16 saliva samples over four consecutive days was used to compute diurnal dynamic range and area under the curve (AUC). Economic adversity in childhood was indexed by recalled parental education, family welfare dependence, and perceived financial status; and childhood social adversity by parental separation, death, and abuse.
Adjusted for age, gender, and race/ethnicity, both childhood adversities were strongly associated with smaller adult cortisol diurnal dynamic range, but not with AUC. The association with cortisol dynamic range was explained by adult social and economic variables.
Early life adversity appears to leave a long-term imprint on cortisol secretion dynamics, reducing diurnal dynamic range without increasing total secretion. This points to the importance of examining the adaptation capacity of physiological systems when studying the impact of early life and chronic stresses on adult health.