Gender differences in age-related changes in HPA axis reactivity

Possible differences between men and women in age-related patterns of hypothalamic–pituitary–adrenal (HPA) axis response to challenge were examined to test the hypothesis that women show greater age-related increase in HPA axis reactivity to challenge. Twenty-six younger subjects, 9 men and 17 women, ages 22–26 and 14 older subjects, 7 men and 7 women, ages 67–88 participated in the study. Patterns of change in salivary “free” cortisol were measured in response to a standardized, 30-minute cognitive challenge, administered individually to each subject beginning at 1600 h. Consistent with previous research, there was a significant main effect for age with respect to baseline cortisol: older age was associated with higher baseline cortisol ( P=