Table 1 . Differences in parameters of asthma severity in two groups of patients with and without GERD symptoms .
| Characteristic | With GERD Symptoms | Without GERD symptoms | P-value |
| Age (years) | 39.7 | 41.4 | 0.57 |
| Sex (numbers F/M) | 34/33 | 15/10 | 0.29 |
| BMI (Kg/M2) | 28.7 | 27.5 | 0.44 |
| Asthma Control: (No.) | |||
| Well controlled (ACT score≥20) | 2 | 7 | 0.72 |
| Not well controlled (ACT score15-19) | 9 | 23 | 0.94 |
| Uncontrolled(ACT score< 15) | 14 | 37 | 0.93 |
| Body Plethysmography (all in % predicted) | Mean ± SD | Mean ± SD | |
| FEV1/FVC | 66.74 ±16.69 | 69.19±12.05 | 0.43 |
| FEV1 | 69.69±22.86 | 76.39±24.67 | 0.24 |
| ITGV/TLC | 103.85±19.01 | 99.83 ±25.05 | 0.47 |
| RV/TLC | 120.64±47.92 | 116.51±39.74 | 0.67 |
| FEF50% | 44.96±29.64 | 50.40±31.03 | 0.43 |
| FEF25-75% | 43.06±46.63 | 48.98±34.45 | 0.47 |
| Raw Total | 236.95±124.02 | 201.30±122.51 | 0.26 |
| Raw Effective | 216.65±115.91 | 176.14±107.22 | 0.16 |
| Impulse Oscillometry: (KPa L-1S-1) | Mean ± SD | Mean ± SD | |
| Resistance at 5Hz(TAWR) | 256.64±161.21 | 191.68±98.64 | 0.02 |
| Resistance at 20Hz | 153.90±55.96 | 137.33±46.44 | 0.15 |
| PAWR | 102.73±122.39 | 56.76±71.43 | 0.02 |
GERD, Gastro-esophageal reflux; IOS, Impulse oscillometry; TAWR, Total airway resistance (R5 Hz); PAWR, Peripheral airways resistance (R5-R20); ACT, Asthma control test; FEV1, Forced expiratory volume in 1 second; FVC, Forced vital capacity; FEF 25% to 75%, Forced expiratory flow at of 25% to 75% FVC; FEF 50%, Forced expiratory flow at the beginning point of 50% of vital capacity; RV, Residual volume; TLC, Total lung capacity; ITGV, Intrathoracic gas volume (functional residual capacity); SGW, Specific airway conductance; Raw Total, Total airway resistance; Raw Effective, effective airway resistance; BMI, Body mass index.