Immediate and sustained effects of smoking on autonomic arousal in human subjects

The effects of smoking on sudomotor/autonomic activity were examined by measuring water transfer across the skin (sweat output) as an index of activity. Sweat output was measured in 14 subjects (11 male and 3 female) during the act of smoking and for about 60 min following this. Sweat output was measured in 5 (4 male, 1 female) controls over the same time period. Smoking had two effects on sweat output: In 12 subjects it caused an immediate increase in output; in 4 of these 12 the increase persisted for the duration of the recording period. In the other 2 subjects no increase was noted, but in no subject did smoking cause a decrease in sweat output. Mood state questionnaires were administered at the beginning and end of the experimental period. No clear association was found between scores on the mood questionnaires and the autonomic effects of smoking. In 2 subjects, transdermal blood flow was also measured during and after smoking. Smoking caused a decrease in blood flow in these subjects. These results are discussed in terms of the "arousal modulation" hypothesis of smoking.