The Early Effect of Smoking on Spirometry and Transfer Factor

Cigarette smoking is one of the most important etiological risk factor in COPD and significantly increases progressive deteri­oration in lung function. When the relationship between lung function and emphysema was assessed, the best correlation was found between emphysema and transfer factor for carbon monoxide per litre alveolar volume in the lungs. The present study concerns the early effect of smoking on spirometry and transfer factor in asymptomatic smokers. This trial was carried out in a sample composed of men (39 non-smokers and 93 smokers) aged 22 to 45 years. Although the mean pulmonary function test parameters were all in the normal range, PEF, T_L,CO and Kq_O (T_l,CO/V_a) were significantly lower in smok­ers than in non-smokers. A significant correlation was found between smoking pack-year and FEF₇₅o_/o (r= -0,3153, p<0.005), T_l,CO (r= -0,2312, p<0.05), K_co (T_L,CO/V_A) (r= -0,4526, p<0.001). Kqq (T_l,CO/V_a) was found to be under 75% of the predicted value in 22 smokers with a history of smoking over 20 pack-years. In contusion, we hypothesize that even in nor­mal spirometric ranges, the measurement of carbon monox­ide transfer factor may be added to the laboratory tests in healthy smokers having more than 20 pack-years cigarette burden. Lower values may indicate the early destruction of the lungs and transfer factor may be used as an additional parameter to spirometry.