Tracheobronchial submucous gland profiles in smokers and non-smokers.

We have recently presented a method of assessing the amount of submucous gland, expressed as volume per unit luminal surface area in the tracheobronchial tree. We have now applied this technique in the trachea, left main bronchus, left upper lobe bronchus, lingular bronchus and three generations of the inferior lingular bronchus in 14 non-smokers and 14 smokers. The results show that there was statistically significantly more gland in the smoking group than in the non-smoking group at all but the two most distal generations, so the technique could be used to assess the effects of inhaled pollutants in groups. Overlap between the cases in the two groups meant, however, that individual profiles could not be used diagnostically. Questions about why the profile has the shape it does and why it responds to cigarette smoke as it does are considered but cannot be answered with the data at present available.