title: Pulmonary function in identical twins: comparison of nonsmokers and smokers.
abstract: Forty-five apparently normal pairs of identical twins were given pulmonary function tests to determine the role of genetics in bronchial susceptibility to cigarette smoke. Maximal expiratory flow at 60 per cent of total lung capacity (Vmax60) was the best discriminator of smokers from nonsmokers among pairs in which one member smoked and the other did not. The intrapair difference of Vmax60 values in pairs in which both members smoked was the same as in pairs in which both members did not smoke. These data support the view that genetic factors are important in determining the vulnerability of the airways to cigarette smoke.
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D003011:Closing Volume; D005260:Female; D006801:Humans; D007320:Inspiratory Capacity; D008297:Male; D008448:Maximal Expiratory Flow Rate; D008449:Maximal Expiratory Flow-Volume Curves; D011247:Pregnancy; D011653:Pulmonary Diffusing Capacity; D012115:Residual Volume; D012119:Respiration; D012737:Sex Factors; D012907:Smoking / Q000503:physiopathology*; D014109:Total Lung Capacity; D014427:Twins; D014430:Twins, Monozygotic; D014797:Vital Capacity