Background - Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is hypothesized to be an important pathway linking socioeconomic position and chronic disease.
Purpose - This paper tests the association between education and the diurnal rhythm of salivary control.
Methods - Up to 8 measures of cortisol (mean of 5.38 per respondent) over two days were obtained from 311 respondents aged 18-70, drawn from 2001-2002 Chicago Community Adult Health Study. Multi-level models with linear splines were used to estimate waking level, rates of cortisol decline, and area-under-the-curve over the day, by categories of education.
Results - Lower education (0-11 years) was associated with lower waking levels of cortisol, but not the rate of decline of cortisol, resulting in a higher area-under-the-curve for more educated respondents throughout the day.
Conclusions - This study found evidence of lower cortisol exposure among individuals with less education and thus does not support the hypothesis that less education is associated with chronic over-exposure to cortisol
