Attenuated cortisol response to psychological stress but not to CRH or ergometry in young habitual smokers.

Salivary cortisol and heart rate responses to a) psychological stress (public speaking and mental arithmetic), b) human corticotropin-releasing hormone (hCRH), and c) bicycle ergometry until exhaustion were investigated in 10 smokers and 10 nonsmokers. Compared to d), an injection of physiological saline, psychological stress as well as hCRH resulted in significant elevations of salivary cortisol levels in the total group. Ergometry workload induced only moderately enhanced cortisol concentrations. Profound changes in heart rates were observed following bicycle ergometry [+83 beats per minure (bpm)] and after the psychological stress (+29 bpm). hCRH injection increased heart rate by 5 bpm while heart rates dropped after saline administration (-2 bpm). Smokers showed an attenuated cortisol response to the psychological stressor. Mean cortisol increases reached only one third in smokers compared to nonsmokers. Similarly, cortisol levels in smokers tended to be lower after hCRH injection; however, this difference was not statistically significant. Cortisol responses to ergometry did not differ between the two groups. Likewise, heart rates did not reveal different profiles in any of the three stimulations in smokers compared to nonsmokers.