Diurnal cortisol secretion and 2-year changes in older adults' physical symptoms: the moderating roles of negative affect and sleep.

OBJECTIVE This study examined whether the association between cortisol secretion and changes in physical health symptoms would depend on other factors in a person's life. The authors expected that physical health effects would emerge particularly when cortisol disturbances co-occur in the context of high levels of trait negative affect or poor sleep. DESIGN Physical symptoms, diurnal cortisol secretion, affective tendencies, and sleep efficiency were assessed in a 2-yr longitudinal study of 184 older adults. MAIN OUTCOME MEASURE Two-year changes in physical symptoms. RESULTS High cortisol levels were associated with increases in physical symptoms, but only among participants who experienced high negative affect and poor sleep. CONCLUSION Elevated levels of cortisol secretion contribute to older adults' physical symptoms if they co-occur in the context of other emotional and behavioral problems. By contrast, cortisol disturbances may not influence physical symptoms among people who are emotionally well or engage in efficient sleep behaviors.