Effects of cigarette smoking on short-term variability of blood pressure in smoking and non smoking healthy volunteers.

The present trial was planned to study the effects of smoking on short-term variability of blood pressure and on haemodynamic parameters after an overnight cessation and after one day of repeated smoking in healthy cigarette smoking volunteers, compared to a control group of non-smokers who were not asked to smoke. 40 healthy male volunteers, 20 smokers and 20 non-smokers, participated in an open study with two period of measurements over a single day (morning and afternoon). Blood pressure and heart rate were measured using standard and finger recordings over 6 min before and 10 min after smoking one cigarette (in smokers only). During the two periods, smokers were asked to smoke 4 cm of a cigarette containing 1 mg of nicotine in 2 min, and a blood sample was taken for a plasma nicotine assay. In the smoking group, smoking the first cigarette of the day caused a significant increase of systolic blood pressure (+7%), diastolic blood pressure (+10%) and heart rate (+25%). The blood pressure variability in the frequency range of the Mayer waves (66-129 mHz) was increased after an overnight cessation of smoking in the smoking group in comparison to the non-smokers, and decreased significantly after the first cigarette of the day (7.1 +/- 4.0 to 3.2 +/- 1.8 mmHg2; P < 0.01). The changes observed in the afternoon after continuous smoking were significantly less important (3.8 +/- 1.9 to 3.2 +/- 1.9 mmHg2; NS). In the non-smoking group, the different parameters remained stable between the different measurements. These results suggest that an overnight cessation of smoking in smoking subjects is associated with a increase in sympathetic activity to the vascular system in the morning, which is released by smoking the first cigarette. This effect of smoking is reduced in the afternoon after a continuous nicotinic impregnation.