Lung function in former intravenous drug abusers: the effect of ubiquitous cigarette smoking.

To determine whether former intravenous drug abusers (IVDAs) demonstrate reductions in pulmonary function, especially in the diffusing capacity (DLCO), after adjustment for the effects of their ubiquitous smoking habit. Knowledge of baseline DLCO in this high-risk group is important in evaluating the effects of human immunodeficiency virus (HIV) and ensuing opportunistic infections.Measurements of single-breath DLCO, forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV1) were compared with predictive values that adjust for the effects of smoking. Patients were 98 ambulatory former IVDAs regularly attending a methadone maintenance program (62 men and 36 women; 94 current smokers, two ex-smokers, and two nonsmokers).When adjusted for smoking, FEV1 and DLCO were no different in the study sample than in cross sections of the general population: mean FEV1 105% predicted (men) and 97% predicted (women), mean DLCO 95% predicted (men) and 99% predicted (women). Eleven percent of the IVDAs had abnormal values for DLCO; only one subject had a value less than 50% of predicted.Most former IVDAs who regularly attend an ambulatory methadone program have normal DLCO values when the effects of smoking are taken into account. A decrease in DLCO in such subjects is presumptive evidence of superimposed disease, most likely related to opportunistic infections or HIV-associated malignancy or alveolitis.

VIVO