Table 1 Symptoms, vital signs, lung function and inflammation parameters at baseline and following a 60-min period of air or e-liquid vaping in non-asthmatic and asthmatic subjects
Healthy Volunteers (N = 20) | Asthmatic Volunteers (N = 10) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Placebo (no e-liquid) | Experimental (with e-liquid) | Placebo (no e-liquid) | Experimental (with e-liquid) | |||||||||
T0a | T60a | Mean difference (95% CI Lower-Upper) | T0a | T60a | Mean difference (95% CI Lower-Upper) | T0a | T60a | Mean difference (95% CI Lower-Upper) | T0a | T60a | Mean difference (95% CI Lower-Upper) | |
Symptoms | ||||||||||||
Cough | 0.1 ± 0.2 | 0.1 ± 0.2 | 0.025 (0.021 to 0.029) | 0.1 ± 0.2 | 0.2 ± 0.5 | 0.10 (0.09 to 0.11) | 0.1 ± 0.1 | 0 ± 0 | −0.05 (−0.05 to − 0.05) | 0.3 ± 0.9 | 0 ± 0 | −0.30 (−0.32 to − 0.28) |
Chest tightness | 0 ± 0 | 0.1 ± 0.2 | 0.050 (0.047 to 0.053) | 0 ± 0 | 0.4 ± 1.1 | 0.38 (0.36 to 0.39) | 0.1 ± 0.2 | 0.1 ± 0.2 | 0 (−0.01 to 0.01) | 0 ± 0 | 0.6 ± 0.8 | 0.60 (0.58 to 0.62) |
Breathlessness | 0 ± 0.1 | 0 ± 0.1 | 0 (−0.002 to 0.002) | 0.1 ± 0.2 | 0.2 ± 0.7 | 0.10 (0.09 to 0.11) | 0.1 ± 0.2 | 0 ± 0 | −0.10 (−0.10 to − 0.10) | 0.2 ± 0.4 | 0.2 ± 0.2 | −0.05 (−0.06 to − 0.04) |
Secretions | 0.1 ± 0.2 | 0.1 ± 0.2 | 0 (−0.004 to 0.004) | 0.1 ± 0.2 | 0.3 ± 0.7 | 0.25 (0.24 to 0.26) | 0 ± 0 | 0.2 ± 0.3 | 0.20 (0.19 to 0.21) | 0.4 ± 0.7 | 0.3 ± 0.6 | −0.10 (−0.11 to − 0.09) |
Wheezing | 0 ± 0 | 0 ± 0 | 0 (0 to 0) | 0 ± 0 | 0.1 ± 0.2 | 0.05 (0.05 to 0.05) | 0 ± 0 | 0 ± 0 | 0 (0 to 0) | 0.1 ± 0.3 | 0 ± 0 | −0.10 (−0.11 to − 0.09) |
Heart rate (beat/min) | 69 ± 9 | 63 ± 8 | −6.4 (−6.5 to − 6.2) | 69 ± 9 | 61 ± 10 | −11.4 (−11.6 to − 11.1) | 74 ± 10 | 69 ± 11 | −5.2 (−5.3 to − 5.1) | 78 ± 9 | 74 ± 10 | −4.3 (−4.4 to − 4.2) |
Saturation (% O2) | 98 ± 2 | 96 ± 7 | 0.25 (0.23 to 0.27) | 97 ± 3 | 98 ± 1 | 0.80 (0.77 to 0.83) | 98 ± 1 | 99 ± 1 | 0.40 (0.38 to 0.42) | 98 ± 1 | 98 ± 1 | 0.70 (0.68 to 0.72) |
Respiratory rate (respiration/min) | 16 ± 3 | 15 ± 3 | −0.80 (−0.83 to − 0.77) | 15 ± 3 | 15 ± 3 | 0.20 (0.15 to 0.25) | 14 ± 3 | 14 ± 3 | 0 (−0.04 to 0.04) | 17 ± 3 | 15 ± 3 | −1.80 (−1.84 to − 1.76) |
Spirometry | ||||||||||||
FEV1 (L) | 4.0 ± 0.7 | 4.0 ± 0.7 | 0.021 (0.020 to 0.021) | 3.9 ± 0.7 | 3.9 ± 0.7 | −0.021 (−0.022 to − 0.020) | 3.4 ± 0.4 | 3.4 ± 0.4 | −0.01 (−0.01 to − 0.01) | 3.4 ± 0.4 | 3.4 ± 0.4 | 0.014 (0.013 to 0.015) |
FVC (L) | 4.9 ± 0.9 | 4.9 ± 0.9 | 0.004 (0.002 to 0.005) | 4.9 ± 0.9 | 4.9 ± 0.9 | −0.043 (−0.044 to − 0.041) | 4.4 ± 0.8 | 4.3 ± 0.8 | −0.05 (−0.05 to − 0.05) | 4.4 ± 0.8 | 4.3 ± 0.8 | −0.069 (−0.070 to − 0.068) |
FEV1/FVC | 0.80 ± 0.05 | 0.81 ± 0.05 | 0.010 (−0.016 to 0.036) | 0.80 ± 0.05 | 0.81 ± 0.05 | 0.314 (0.296 to 0.332) | 0.78 ± 0.09 | 0.79 ± 0.08 | −1.10 (−1.13 to − 1.11) | 0.78 ± 0.08 | 0.79 ± 0.08 | 1.550 (1.516 to 1.584) |
FOT | ||||||||||||
R5 (cm H2O.s/L) | 2.656 ± 0.595 | 2.778 ± 0.688 | 0.121 (0.116 to 0.126) | 2.766 ± 0.702 | 2.564 ± 0.633 | −0.201 (−0.212 to − 0.190) | 3.858 ± 0.717 | 3.812 ± 0.768 | −0.046 (−0.054 to − 0.038) | 3.583 ± 0.593 | 3.804 ± 0.591 | 0.221 (0.214 to 0.227) |
R19 (cm H2O.s/L) | 2.717 ± 0.538 | 2.766 ± 0.597 | 0.048 to (0.044 to 0.053) | 2.792 ± 0.592 | 2.739 ± 0.471 | −0.054 (−0.057 to − 0.050) | 3.715 ± 0.478 | 3.664 ± 0.531 | −0.051 (−0.055 to − 0.046) | 3.639 ± 0.645 | 3.711 ± 0.496 | 0.071 (0.067 to 0.076) |
R5–19 (cm H2O.s/L) | −0.061 ± 0.211 | 0.012 ± 0.225 | 0.073 (0.071 to 0.075) | −0.027 ± 0.309 | −0.175 ± 0.468 | −0.147 (−0.157 to − 0.138) | 0.143 ± 0.364 | 0.148 ± 0.368 | 0.005 (0.001 to 0.009) | −0.056 ± 0.208 | 0.093 ± 0.255 | 0.149 (0.144 to 0.154) |
X5 (cm H2O.s/L) | −0.841 ± 0.282 | −0.866 ± 0.290 | −0.025 (−0.027 to − 0.023) | −0.911 ± 0.456 | −0.862 ± 0.386 | 0.050 (0.048 to 0.052) | −1.329 ± 0.461 | −1.230 ± 0.428 | 0.029 (0.026 to 0.032) | −1.118 ± 0.286 | −1.029 ± 0.250 | 0.089 (0.086 to 0.091) |
Fres (Hertz) | 10.765 ± 1.844 | 11.157 ± 2.161 | 0.392 (0.373 to 0.410) | 11.597 ± 3.844 | 11.140 ± 3.319 | −0.457 (−0.468 to − 0.446) | 14.269 ± 4.026 | 13.756 ± 3.596 | −0.514 (−0.555 to − 0.472) | 13.375 ± 3.319 | 12.860 ± 2.422 | −0.515 (−0.547 to − 0.483) |
Ax (cm H2O/L/saHz) | 2.597 ± 1.618 | 2.812 ± 1.694 | 0.216 (0.203 to 0.228) | 3.538 ± 5.028 | 3.150 ± 4.134 | −0.389 (−0.403 to − 0.375) | 5.798 ± 3.513 | 5.510 ± 3.078 | −0.289 (−0.328 to − 0.249) | 4.557 ± 2.411 | 4.040 ± 2.018 | −0.517 (−0.534 to − 0.499) |
IC (L) | 2.698 ± 0.694 | 2.632 ± 0.731 | −0.046 (−0.050 to − 0.042) | 2.728 ± 0.628 | 2.697 ± 0.635 | −0.019 (−0.021 to − 0.016) | 2.616 ± 0.660 | 2.569 ± 0.695 | −0.047 (−0.053 to − 0.040) | 2.894 ± 0.708 | 2.701 ± 0.785 | 0.096 (0.086 to 0.107) |
TV (L) | 0.837 ± 0.346 | 0.904 ± 0.364 | 0.067 (0.066 to 0.069) | 0.890 ± 0.372 | 0.925 ± 0.422 | 0.035 (0.033 to 0.036) | 0.975 ± 0.297 | 0.942 ± 0.392 | −0.033 (−0.041 to − 0.025) | 0.983 ± 0.308 | 1.090 ± 0.422 | 0.106 (0.101 to 0.111) |
FeNO (ppb) | ND | ND | ND | ND | ND | ND | 25 ± 11 | 24 ± 11 | 0.40 (0.34 to 0.46) | 23 ± 12 | 21 ± 12 | 0.20 (0.13 to 0.27) |
CRP (mg/L) | ND | ND | ND | ND | ND | ND | 1.31 ± 1.38 | 1.00 ± 0.89b | −0.47 (−0.50 to − 0.44) | 1.89 ± 2.18 | 1.93 ± 2.22b | 0.039 (0.038 to 0.040) |