Effect of chronic smoking on regional cerebral blood flow in asymptomatic individuals

Correlations between cigarette smoking and cerebral blood flow (CBF) were determined. The purpose of the present study was to determine whether the level of cigarette use is a significant predictor of regional CBF (rCBF) when age, gender, mean arterial blood pressure, total cholesterol, fasting blood glucose, hematocrit, and presence of ST-T change and left ventricular hypertrophy on electrocardiogram (ECG) are controlled. We studied a continuous sample of 40 asymptomatic individuals including 20 smokers and 20 nonsmokers. Subjects (mean age 66.2 yr) had an average smoking index of 456 +/- 485.1 (mean +/- standard deviation) [(Number of cigarette/d) x (years of smoking history)]. Regional CBF was measured using the intravenous 133Xe injection method. Simple linear regression and multivariate regression analyses were performed, which modeled regional cerebral blood flow as a function of smoking index and other cerebrovascular disease risk factors. The male-to-female ratio was higher in the group of smokers (18/2) than in the group of nonsmokers (2/18) (P < 0.01). The mean hematocrit of smokers was significantly higher than that of nonsmokers (P < 0.01). There were no significant differences in other variables tested between the two groups. Simple linear regression analysis demonstrated a significant negative correlation of smoking index with CBF in whole brain (r = -0.33; P < 0.05), the right hemisphere (r = -0.34; P < 0.05), right parietal cortex (r = -0.36; P < 0.05), right occipital cortex (r = -0.34; P < 0.05) and left parietal cortex (r = -0.33; P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)