Author: Golden SH, et al. (2013) Psychoneuroendocrinology.
Cumulative cortisol burden is known to influence neuropsychiatric and metabolic disorders. Up to 18 salivary cortisol samples were collected over 3 days from 935 White, Hispanic, and Black individuals in the Multi-Ethnic Study of Atherosclerosis. Higher Cortisol Awakening Response (CAR) was associated with significantly lower wake-up cortisol and a higher early decline Area Under Curve (AUC) but was not associated with total cortisol AUC, or other diurnal cortisol curve components following multivariable adjustment. Total cortisol AUC was significantly and positively associated with wake-up cortisol, bedtime cortisol, and other AUC measures, following multivariable adjustment. Associations were similar by sex, race/ethnicity, and age categories. The researchers concluded that bedtime cortisol showed the strongest correlation with total cortisol AUC, suggesting it may be a marker of daily cortisol exposure.