Smoking is the main risk factor for COPD. Oscillometry is a easy to perform, not time-consuming technique with low patient burden that provides detailed assessment of respiratory impedance (Z) measurement. The study aims were to evaluate Z as a means to detect early airway abnormalities in past smokers (PS) and active smokers (AS) compared to non-smokers (NS).
Methods
We included 7560 subjects (Age 18-82) of the Austrian LEAD general population cohort, a longitudinal single-centered, observational study. Z-measurements were obtained (Resmon Pro Full, Restech, Italy) as conducted by trained technicians. Resistance (R) and reactance (X) at 5 Hz were analysed as well as the area under X (AX) and frequency dependence of R (R5-R19). Data are reported as % of predicted (Berger et al., ERJ open 2021).
Smokers were subdivided by the number of pack years (PY).
Results
AS with > 10 PY had higher R5 values than NS and PS< 10 PY groups. In addition, this group has manifested higher AX than PS >10 PY. PS, irrespective of the number of PY, showed no Z differences compared to the NS (Table).
|
Parameter |
Non smokers N=3881 |
Past smoker, < 10 PY N=139 |
Past smoker, > 10 PY N=129 |
Smoker, < 10 PY N=2048 |
Smoker, > 10 PY N=1363 |
| R5 %pred | 84(70;103)* | 78 (64;94)* | 86(69;105) | 83(69;101)* | 88(74;108) |
| X5 %pred | 84(61;111) | 79(59;109) | 78(57;104) | 81(60; 111) | 86(62; 114) |
| AX %pred | 138 (80;232) | 117 (77;234) | 119(71;189)* | 141(82;256) | 146(83;256) |
| R5-R19 %pred | 73(-76;235) | 101 (-6;225) | 48(-83;218) | 70(-60;230) | 65(-97;218) |
* p<0.05 vs Smoker > 10 pack/years. Data are presented as median (IQR).
Conclusion
Oscillometry is a feasible approach to identify Z changes in active smokers.