OBJECTIVE: To evaluate the effect of smoking on blood pressure trends during a 24-hour period, by analyzing the parameters of the ambulatory blood pressure monitoring (ABPM). METHODS: The results of 289 ABPM tests conducted on patients classified as smokers or nonsmokers were studied. The parameters analyzed were: mean 24-hour, daytime and nighttime systolic and diastolic blood pressure readings; nocturnal dipping of systolic and diastolic pressures and blood pressure load. The patients were classified in four groups according to whether or not they used antihypertensive medication: 1A - nonsmokers using medication; 1B - smokers using medication; 2A - nonsmokers not using medication; and 2B - smokers not using medication. Variables were expressed as minimum, maximum, median, mean and standard deviation values. Univariate analysis was used for comparing the smoking and nonsmoking groups. The significantly different variables from the groups were selected using multivariate analysis. The significance level adopted was 5%. RESULTS: Mean daytime systolic and diastolic blood pressures were significantly higher in the smokers, regardless of whether or not they used antihypertensive medication. Mean nocturnal blood pressure readings were similar between smokers and nonsmokers. Mean 24-hour systolic blood pressure readings were significantly higher in the smokers, regardless of whether or not they used antihypertensive medication. Nocturnal dipping was similar for all groups. Blood pressure loads were consistently and significantly higher in the smokers regardless of medication use. CONCLUSION: Mean daytime systolic and diastolic blood pressure readings were consistently higher in the smokers when compared to nonsmokers regardless of antihypertension medication use. Nocturnal dipping was similar for smokers and nonsmokers.
Smoking; blood pressure; blood pressure monitoring; hypertension
