Cigarette smoking decreases cerebral blood flow suggesting increased risk for stroke

Abstract

Effects of chronic cigarette smoking on cerebral blood flow were investigated by measuring gray matter blood flow (Fg) using 133Xe inhalation among 192 volunteers without cerebrovascular symptoms. There were 108 normal, healthy volunteers; 84 had risk factors for stroke (hypertension, hyperlipidemia, diabetes mellitus and/or heart disease). Of both risk and nonrisk groups, 75 were habitual smokers (0.5-3.5 packs/day for 25 yr). Comparisons of mean Fg values for both hemispheres showed significant reductions related to tobacco consumption and risk factors for stroke. Multiple-regression equations using smoking, age, risk and alcohol consumption indicated a combined R2 [proportion of the variability accounted for] value of 0.22. Smoking was a potent risk factor decreasing cerebral blood flow probably by enhancing cerebral arteriosclerosis. Chronic cigarette smoking in persons with other risk factors further reduced Fg values in an additive manner when compared with subjects who had corresponding risk factors who did not smoke.