Cardiopulmonary Function in Young Smokers

Abstract

Pulmonary function studies including pulmonary diffusing capacity (DL) and measurements of heart rate and oxygen consumption were carried out at rest and O2, dynamics, DL , and heart rate were determined during exercise in 18 house-staff physicians. Nine (mean BSA 1.97 M2; mean age 30[plus or minus]3 yrs) were smokers who had smoked at least 1 pack of cigarettes per day for 5 years and 9 had never smoked (mean BSA 2.03 M2; mean age 31[plus or minus]5 yrs). Oxygen consumption at rest and mean increased total O2 uptake for the exercise period were not different for the 2 groups, but the O2 debt accumulated and the per cent of the total increase in O2 uptake represented by the O2 debt were both greater in the group of smokers. DL was significantly lower in the group of smokers. The mean values for the other pulmonary function measurements were within normal limits in both groups, but there were differences between the 2 groups. Vital capacity, total lung capacity and inspiratory reserve volume were significantly larger in the non-smokers. Residual volume showed a tendency to be larger in non-smokers but the differences between the means were not actually within the probability level of < .05. These differences between smokers and non-smokers may not all be interrelated, but may be multiple effects of the same stimuli. Although the exact mechanisms by which these abnormalities occur have not been elucidated, they do appear to result from cigarette smoking.