To analyze the difference and clinical significance of reflux related parameters between patients with reflux asthma (RA) and typical gastroesophageal reflux disease (TGERD).

From June 2017 to June 2020, at PLA Rocket Force Characteristic Medical Center, the clinical data of 120 patients with gastroesophageal reflux disease (GERD) who underwent gastroscopy, high-resolution esophageal manometry (HREM) and 24 h pH-impedance monitoring contemporaneously were retrospectively analyzed. The GERD patients were divided into RA group and TGERD group according to the symptom correlated indexes, 60 cases in each group. The reflux related indexes of two groups were compared, which included reflux esophagitis (RE) score, esophageal hiatal hernia, Hill grade score of gastroesophageal flap valve, upper esophageal sphincter (UES) pressure, DeMeester score, and reflux episodes. Mann-Whitney U test and chi-square test were used for statistical analysis.

There were no significant differences in RE score and Hill grade score between TGERD group and RA group (0.0, 0.0 to 1.0 vs. 0.0, 0.0 to 1.8; 3.0, 2.0 to 3.0 vs. 3.0, 2.0 to 3.0) (both P>0.05). The detection rate of UES pressure less than 34 mmHg (1 mmHg=0.133 kPa) of RA group was higher than that of TGERD group (41.7%, 25/60 vs. 23.3%, 14/60), and the difference was statistically significant (χ²=4.596, P=0.032). The UES pressure of RA group was lower than that of TGERD group (51.7 mmHg, 23.6 mmHg to 70.1 mmHg vs. 62.0 mmHg, 37.4 mmHg to 77.4 mmHg), and the difference was statistically significant (Z=-2.105, P=0.035). There were no significant differences in other parameters of HREM between TGERD group and RA group (all P>0.05). The detection rates of DeMeester score more than 14.7, acid exposure time more than 4.5% and total reflux episodes more than 73 episodes of RA group were all higher than those of TGERD group (41.7%, 25/60 vs. 23.3%, 14/60; 40.0%, 24/60 vs. 21.7%, 13/60; 38.3%, 23/60 vs. 20.0%, 12/60, respectively), and the differences were all statistically significant (χ²=5.546, 4.728 and 4.881, all P<0.05). The total reflux episodes and weak acid gas reflux episodes of RA group were both higher than those of TGERD group (60 episodes, 43 episodes to 98 episodes vs. 52 episodes, 34 episodes to 69 episodes; 12 episodes, 6 episodes to 21 episodes vs. 9 episodes, 3 episodes to 14 episodes), and the differences were statistically significant (Z=-2.323 and -2.053, both P<0.05). There were no significant differences in other parameters of 24 h pH-impedance monitoring between TGERD group and RA group (allP>0.05).

Low UES pressure, abnormal esophageal acid exposure and increased reflux episodes, especially weak acid gas reflux episodes, may be more likely to induce RA.

Gastroesophageal reflux disease; Asthma; Gastroscopes; High-resolution manometry; pH-impedance monitoring