Comparative study of cardiovascular function and ventricular premature complexes in smokers and nonsmokers during maximal treadmill exercise.

Maximal treadmill exercise tests were performed by 586 male members of the Indiana State Polic Force who were free of clinical evidence of cardiovascular disease. The study population was categorized into groups according to cigarette smoking experience and subgroups according to age and number of pack-years of exposure. There were 176 nonsmokers (30 percent), 268 current smokers (46 percent) and 142 former smokers who had abstained for at least 1 year (24 percent). No statistically significant differences were found in the prevalence of exercise-induced ventricular premature complexes when current smokers were compared with nonsmokers or former smokers either as a group or as subgroups classified by age. The duration of maximal exercise and the peak heart rate and systolic blood pressure during maximal exercise were compared for each group. The duration of maximal exercise was significantly shorter in smokers (P less than 0.001) and former smokers (P less than 0.005) than in nonsmokers. Maximal systolic blood pressure during exercise was greater in smokers than in nonsmokers (P less than 0.01) but did not differ significantly between nonsmokers and former smokers. Maximal heart rate during exercise was significantly lower in smokers (P less than 0.01) and former smokers (P less than 0.01) than in nonsmokers. In conclusion, there was a statistically significant difference in the duration of exercise and the maximal heart rate and systolic blood pressure attained during exercise between men who smoked and nonsmokers, but the prevalence of the exercise-induced ventricular premature complexes did not appear to be influenced by smoking habits.