Humor attenuates the cortisol awakening response in healthy older men

This study examined the impact of an important factor contributing to successful aging, humor, on post-awakening cortisol levels among a group of 45 older men whose ages ranged from 64 years to 86 years (mean=73.6 years). Four saliva samples were collected from the participants for 2 days immediately after waking and every 15 min thereafter for three times. Cortisol data of the 2 days were aggregated for analysis. Two separate indices of cortisol awakening response reflecting the mean level of secretion and the rise from immediately to 45 min post-awakening, AUC(G) and AUC(I), were computed using the trapezoid formula. The relation of these two indices to humor (operationalized as coping) was examined in a multiple regression analysis while controlling for the effect of age, socioeconomic status, and self-esteem. Results indicated that higher humor scores were associated with lower AUC(G) but had no relation with AUC(I). Findings of the present study suggest that the hypothalamic-pituitary-adrenocortical axis is the major pathway whereby positive psychological dispositions, such as humor, exert their health effects in the aging population. Moreover, cortisol levels in the awakening period may be particularly sensitive to the influences of psychosocial factors.