Final Published Version
Inter-individual variability in metrics of hypothalamic-pituitary-adrenocortical (HPA) activity, such asthe slope of the diurnal decline in cortisol, cortisol awakening response (CAR), and total cortisol out-put, have been found to associate inversely with trait ratings of extraversion and positive affect (E/PA)and positively with neuroticism and negative affect (N/NA) in some, but not all, investigations. Theseinconsistencies may partly reflect varied intensity of cortisol sampling among studies and reliance onself-rated traits, which are subject to reporting biases and limitations of introspection. Here, we furtherexamined dispositional correlates of HPA activity in 490 healthy, employed midlife volunteers (M age = 43years; 54% Female; 86% white). Trait ratings were requested from participants and 2 participant-electedinformants using the Positive and Negative Affect Schedule (PANAS) and Extraversion and Neuroticismdimensions of NEO personality inventories. CAR was assessed as percent increase in cortisol levels fromawakening to 30 min after awakening; and the diurnal slope and total output of cortisol [Area Underthe Curve (AUC)] were determined from cortisol measurements taken at awakening, +4 and +9 h later,and bedtime, across 3 workdays. Structural equation modeling was used to estimate multi-informantE/PA and N/NA factors. We used 3 days of measurement as indicators to model each of the three latentcortisol factors (slope, CAR, and AUC). With the two latent emotionality and three latent cortisol indicesincluded there was good fit to the data ( 2(200)= 278.38, p = 0.0002; RMSEA = 0.028, 90% CI = 0.02–0.04;CFI/TLI = 0.97/0.96; SRMR = 0.04). After controlling for covariates (age, sex, race), results showed higherlatent E/PA associated with a steeper diurnal slope (Standardized ˇ = −0.19, p = 0.02) and smaller CAR(Standardized ˇ = −0.26, p = 0.004), whereas N/NA did not associate with any cortisol metric (Standard-ized ˇ’s = −0.12 to 0.13, p’s = 0.10 to 0.53). These findings suggest that positive emotionality may be moreclosely associated with indices of diurnal cortisol release than negative emotionality.
Miller et al. "Trait positive and negative emotionality differentially associate withdiurnal cortisol activity." Psychoneuroendocrinology 68 (2016); 177-185.