AIMS: Passive smoking impairs the elasticity of the aorta in patients with coronary heart disease. We therefore studied the effect of passive smoking on wave reflection in the aorta, a marker of arterial stiffness, in healthy subjects.

METHOD: We examined the effects of acute exposure to passive smoking on blood pressure and the aortic pressure waveform in healthy young men (n = 10) and women (n = 11), aged 26 +/- 5 years (mean +/- SEM) compared with 12 healthy controls, aged 24 +/- 2 years (six female) who were exposed to room air. The aortic pressure waveform was derived with radial applanation tonometry (SphygmoCor, AtCor Medical, version 6.2) and the augmentation index, a measure of arterial wave reflection in the aorta, calculated. Blood pressure (Omron Model HEM-705 CP, Omron Corporation, Tokyo, Japan) and augmentation index were measured at baseline, 15, 30 and 60 min after exposure to environmental tobacco smoke (carbon monoxide 25-30 p.p.m. for 60 min) or room air.

RESULTS: Passive smoking was associated with an increase in brachial (124 +/- 4-137 +/- 3 mmHg, P < 0.01) and aortic systolic blood pressure (110 +/- 3-123 +/- 4 mmHg, P < 0.01) at 60 min in the male subjects only. The augmentation index increased from -1.7 +/- 5 to 14 +/- 5 at 60 min (P < 0.001) only in the male subjects. The transit time of the pulse did not change significantly. The change in augmentation index was independent of the increase in blood pressure. Brachial and aortic diastolic blood pressure and heart rate did not change significantly in either male or female subjects. No haemodynamic changes were observed in the control group.

CONCLUSIONS: Acute exposure to passive smoking has a deleterious effect on the arterial pressure waveform in healthy young males but not in females, suggesting a possible protection of female gender from functional changes in arteries.