Radiographic evaluation of the influence of age and smoking on thoracic and regional pulmonary dimensions

Chest roentgenograms were taken at full inspiration (TLC) and expiration (RV) in healthy, nonsmoking and smoking, young and old subjects in the upright posture. Linear distances (D) were measured in apicodiaphragmatic and transverse thoracic directions and extensions [(Dsub(TLC)-Dsub(RV))/Dsub(TLC) and (Dsub(TLC)-Dsub(RV))/Dsub(RV)] and volumes were calculated. In the apico-diaphragmatic direction a subdivision was made into an apico-fissural (A-F) distance and a fissuro-diaphragmatic (F-D) distance by means of the minor fissure. Overall volumes at TLC were identical in the four groups but differences were present in distances, extensions and volumes above and below the fissure. Aging caused mainly an increase in D(A-F) and a decrease in D(F-D) at TLC as well as at RV, indicating hyperinflation and airtrapping of the upper zone and hypoinflation and flattening of the lower zone. Smoking caused an increase in D(F-D) at RV, indicating airtrapping in the lower zone. In both groups E(F-Dsub(R)) was reduced, but in old subjects this was due to a decrease in regional TLC and in young smokers to an increase in regional RV. In old, smoking subjects a combination of the effects of aging and smoking was present. (orig.)