Inverse relation between serum cotinine concentration and blood pressure in cigarette smokers.

Blood pressure is, on average, lower in cigarette smokers than in nonsmokers. In a cross-sectional study of 288 normotensive bus drivers, we found a significant inverse correlation between serum cotinine (the major metabolite of nicotine) and systolic and diastolic blood pressure that could not be accounted for by age, body weight, or alcohol consumption. Over the observed range of cotinine values, the average decrease in blood pressure was 10.7 and 7.0 mm Hg for systolic and diastolic blood pressures, respectively. We suggest that cotinine be measured to assess the influence of cigarette smoking in epidemiologic studies of blood pressure.