Hic characteristics. The AUC for cortisol increased with age (P for trend 0.0003) and was Miransertib clinical trials higher in whites than minorities (P=0.002). There were no significant differences by site, gender, income, wealth or education. Figure 1 shows smoothed LOESS curves for cortisol daily profiles stratified by age, sex, race/ ethnicity and income/wealth. In general cortisol values were higher in older than in younger participants. This difference was most pronounced later in the day, suggesting flatter declinesPsychoneuroendocrinology. Author manuscript; available in PMC 2011 July 1.Hajat et al.Pageas age increased. Males generally had higher cortisol values than females, except later in the day, when values were similar or slightly higher for females. Cortisol levels were higher in whites than in blacks at wake-up and 30 minutes after wake-up, but blacks had a slower decline later in the day resulting in slightly higher levels than whites before bedtime. Hispanics j.addbeh.2012.10.012 tended to have lower cortisol levels than other groups overall. Persons in the lowest income/wealth category had less pronounced increases after wake-up and less steep declines later in the day. Table 2 shows percent differences in different aspects of the daily cortisol profile associated with race/ethnicity, and income/wealth. Separate estimates are shown for cortisol at wake-up and for three journal.pone.0174724 different portions of change over the day: (1) CAR or the morning rise (the increase between wake-up and 30 minutes), (2) the decline between 30 and 120 minutes after wake-up (henceforth referred to as “early decline”) and (3) the decline between 120 minutes after wake-up and bedtime (henceforth referred to as “late decline”). All estimates were obtained simultaneously from a piecewise linear mixed model and were adjusted for race/ ethnicity, income-wealth index, age, sex, day and wake-up time. Models adjusted for health behaviors (smoking, exercise and obesity), psychosocial factors (cynical hostility, depression, emotional support and chronic burden) and both health behaviors and psychosocial factors are also presented in Table 2. Positive percent differences in wake-up levels indicate higher cortisol levels. Positive percent differences in the CAR indicate a more pronounced or steeper increase and positive percent differences in the early or late decline indicate a less pronounced or flatter decline. In the minimally adjusted model (adjusted for age, sex, day, wake-up time, race/ethnicity and the income-wealth index) blacks and Hispanics had significantly lower levels of cortisol than whites at wake-up (-17.2 and -15.7 lower in blacks and Hispanics respectively, p <= 0.005 for both comparisons). They also had a less pronounced CAR than whites but these differences were not statistically significant. Both groups also had less pronounced early declines than whites (7.1 for blacks p-value 0.068 and 12.0 for Hispanic p-value <0.001). The late decline was also significantly less pronounced in blacks than in whites but in contrast Hispanics had a more pronounced late decline than whites, although differences in the late decline were very small. Adjustment for behavioral or psychosocial factors did not substantially modify point estimates, although reductions (e.g. in differences at wake-up) were observed. Overall, the general pattern of lower wake-up, less pronounced CAR and less steep early decline observed in Blacks and Hispanics compared to whites persisted after adjustment.