Is there a correlation between the changes in airway inflammation and the changes in respiratory mechanics after vaping in patients with asthma?

Table 1 Linear regression between the difference in fraction exhaled Nitric Oxide (particles per billion) and the difference in pulmonary function tests and in impulse oscillometry before and after the vaping of one electronic cigarette

Conrol group (n = 25)
Variable	Unstandardized coefficients (B) (95%CI)	Standardised coefficients (r)	P value
diff_FEV1 (L)	0.004 (-0.009–0.016)	0.131	0.53
diff_FVC (L)	-0.004 (-0.021–0.014)	-0.089	0.67
diff_FEV1/FVC (%)	0.096 (-0.216–0.407)	0.131	0.53
diff_PEF (L/s)	-0.065 (-0.166–0.035)	-0.269	0.19
diff_FEF25-75 (L/s)	0.000 (-0.053–0.054)	0.004	0.99
diff_RV (L)	0.010 (-0.005–0.025)	0.281	0.17
diff_TLC (L)	0.001 (-0.018–0.019)	0.015	0.94
diff_Z5Hz (kPa/L/s)	0.000 (-0.006–0.006)	-0.012	0.96
diff_R5Hz (kPa/L/s)	-0.001 (-0.007–0.004)	-0.112	0.59
diff_R20Hz (kPa/L/s)	-0.001 (-0.006–0.000)	-0.044	0.84
Asthma group (N = 25)
diff_FEV1 (L)	-0.007 (-0.016–0.002)	-0.327	0.11
diff_FVC (L)	0.005 (-0.005–0.015)	0.203	0.33
diff_FEV1/FVC (%)	-0.027 (-0.173–0.119)	-0.080	0.71
diff_PEF (L/sec)	-0.010 (-0.087–0.066)	-0.059	0.78
diff_FEF25-75 (L/s)	-0.007 (-0.033–0.020)	-0.110	0.60
diff_RV (L)	0.027 (0.005–0.049)	0.465	0.019
diff_TLC (L)	0.018 (0.005–0.031)	0.519	0.008
diff_Z5Hz (kPa/L/s)	0.005 (0.000–0.010)	0.402	0.046
diff_R5Hz (kPa/L/s)	0.005 (0.000–0.010)	0.386	0.057
diff_R20Hz (kPa/L/s)	0.003 (0.000–0.006)	0.358	0.078

FeNO: Fractional exhaled Nitric Oxide; ppb: Particles per billion; EC: Electronic cigarette; N: Number; CI: Confidence intervals; diff: Difference; FEV1: Forced expiratory volume in 1 second; L: Liters; FVC: Forced vital capacity; PEF: Peak expiratory flow; sec: Second; FEF25-75: Forced expiratory flow between 25% and 75% of FVC; RV: Residual volume; TLC: Total lung capacity; Z5Hz: Respiratory impedance at 5 Hz; Hz: Hertz; kPa: Kilopascal, R5Hz; R20Hz: Respiratory resistance at 5, 20 Hz.