Correlation of acid reflux and esophageal motility in patients with gastroesophageal reflux disease

Meng-Long Zou, Xin Ning, Ya-Lu Chen, Kun Yang, Xiao-Yan Huang?

1.Guangxi University of Traditional Chinese Medicine, Nanning 530000,China;

2.The First Affiliated Hospital of Guangxi University of Traditional Chinese Medicine, Nanning 530023,China

Keywords:

ABSTRACT

1. Introduction

Gastroesophageal reflux disease (GERD) is caused by acid reflux and heartburn caused by the weakening of anti-reflux barrier function and the decrease of esophageal clearance ability[1-2]. Epidemiological data show that the incidence of male is higher than that of female [3], and can occur in any age group [4-8]. Risk factors include bad living habits, weight, age, heredity, etc. [9]. In recent years, with the change of lifestyle, the incidence of GERD is gradually increasing [10], the prevalence rate in China is about 12.5% [11], and the prevalence rate in Western Europe and North America has been as high as 25.9% and 27.8% [12]. The emergence of esophageal 24-hour pH detection technology has improved the accuracy of GERD diagnosis. The effective rate of anti-reflux therapy in patients with abnormal acid exposure time percentage is 73% to 76%. When the acid exposure time percentage is abnormal and the reflux-symptom correlation is positive, the specificity can reach 98% [13]. In this study, according to the percentage of acid exposure time and reflux-symptom correlation, patients were divided into acid reflux pathological group, acid reflux sensitive group and acid reflux physiology group, and the correlation between acid reflux and esophageal motility was analyzed. The report is as follows.

2. Materials and methods

2.1 Materials

From January 2018 to December 2019, 80 patients (34 males, 46 females, average age 45.33 years) with main symptoms of acid regurgitation, heartburn, and retrosternal pain were randomly collected from the Department of Gastroenterology, the First Affiliated Hospital of Guangxi University of traditional Chinese medicine. Inclusion criteria: patients did not take acid suppressor drugs or gastrointestinal motility drugs within 2 weeks; they signed the informed consent voluntarily. Exclusion criteria: Patients with malignant diseases; patients with reflux symptoms caused by other diseases; patients with other diseases affecting esophageal motility observation. All the patients in the group received 24-hour esophageal pH monitoring and high-resolution esophageal manometry, and the GerdQ score table of clinical symptoms and the quality of life score table should be filled in. According to the acid test results, the patients were divided into pathological group (AET positive), sensitive group (AET negative and reflux symptom positive) and physiological group (AET negative and reflux symptom negative) according to the acid exposure time (AET) and reflux symptom correlation. According to the Lyon consensus on gastroesophageal reflux disease, AET positive was defined as: AET > 4%; reflux symptom related positive was defined as: symptom index (SI) > 50% and / or symptom related probability (SAP) > 95% [14]. Results 32 patients in pathological group, 12 males and 20 females, aged 28-82 years, average 48.2 years, height 148-178cm, average 162.3cm, weight 41-86kg, average 59.8kg; 32 patients in sensitive group, 17 males and 15 females, age 26-67 years, average 44.3 years, height 152-180cm, average 166.5cm, weight 49-87kg, average 61.4kg; 16 patients in physiological group, 5 males and 11 females, age 26-61 years, average 43.5 years old , height 158-171cm, average 164.1cm, weight 46-68kg, average 57.9kg. The general data of the three groups were similar and comparable, as shown in Table 1.

Table 1 3 comparison of general data of patients in the group（x±s）

2.2 Methods and steps

2.2.1 24-hour PH detection of esophagus

A portable pH monitor was used to detect 24-hour esophageal pH,. The electrode was inserted into the nasal cavity and placed at the 5cm on the lower esophageal sphincter (loweresophagealsphincter,LES). The relevant parameters were recorded and the patients were told to abstain from irritating food.

2.2.2 High resolution esophageal manometry

The patients fasted for more than 8 hours before examination, and the manometric catheter was inserted into the esophagus from the nasal cavity. after 5 minutes of adaptation, the resting pressure of esophageal sphincter was recorded and wet pharynx was given for 10 times. The peristaltic amplitude and other related parameters of 3cm, 7cm and 11cm on the lower esophageal sphincter were measured.

2.3 Analytical indicators

The GerdQ score, quality of life scale, esophageal 24-hour PH and high resolution esophageal manometry were compared among the three groups. ①GerdQ score (see Table 2 for details of the score). ② quality of life score: the concise quality of life scale (SF-36) was used to score 8 dimensions, and the full score of each dimension was 100. the higher the score, the better the quality of life [15]. ③The 24-hour esophageal pH observation parameters included DeMeester score, orthostatic acid reflux time, recumbent acid reflux time, longest acid reflux time and acid reflux times, AET, SI and SAP. ④High resolution esophageal manometry parameters include lower esophageal sphincter pressure (LESP), lower esophageal sphincter length (LESD), intra-abdominal lower esophageal sphincter length (intra-abdominal LESD), and the abnormality rate of LES function calculated by combining the above parameters (LESP ≤ 6 mmHg, LESD ≤ 2cm and intra-abdominal LESD ≤1cm,One item can lead to abnormal LES function.) [16], distal contraction integral (DCI), amplitude at 3cm on LES, amplitude at 7cm on LES, amplitude at 11cm on LES and peristaltic wave conduction velocity of esophageal body. Swallowing is divided into four categories according to the strength of contraction (see Table 3) [17]. Effective contraction rate of swallowing = normal times of swallowing / total times of swallowing.

Table 2 GerdQ score table (score)

Table 3 Contraction strength type

2.4 Statistics and analysis

The data were analyzed by SPSS22.0 software. The measurement data among groups were analyzed by single factor analysis of variance, pairwise comparison by Q test, expressed by（x±s ）, and the counting data between groups were analyzed by χ2test.

3.Result

3.1 Comparison of GerdQ score and SF-36 score among the three groups

The GerdQ score was the highest in the pathological group, the lowest in the physiological group, and the lowest in the sensitive group, while the SF-36 score was the lowest in the pathological group, the highest in the physiological group, and the difference between the two groups was statistically significant (P < 0.05). The results are shown in Table 4.

Table 4 GerdQ score, SF-36 score comparison (x±s, points)

Table 5 Comparison of the results of 24-hour PH detection of esophagus (x±s)

3.2 Comparison of esophageal acid measurement among three groups of patients

The observation parameters of esophageal acid measurement in the pathological group were significantly higher than those in the sensitive group and the physiological group, and the difference was statistically significant (P<0.05). Although the esophageal acid observation parameters in the sensitive group were higher than those in the physiological group, the difference was not statistically significant (P > 0.05). The results are shown in Table 5.

3.3 Comparison of esophageal manometry among three groups of patients

3.3.1Comparison of functional parameters of lower esophageal sphincter

Compared with the sensitive group and the physiological group, the LESP of the pathological group was significantly lower than that of the sensitive group and the physiological group, but there was no significant difference in the abnormal rates of LESD, intraabdominal LESD and LES among the three groups (P > 0.05). The results are shown in Table 6.

Table 6 Comparison of lower esophageal sphincter parameters

3.3.2 Comparison of motor function parameters of esophageal body

The amplitudes of peristaltic waves at 3cm on DCI and LES in pathological group and sensitive group were significantly lower than those in physiological group, but there was no significant difference in peristaltic wave amplitude at 7cm and upper 11cm on LES and peristaltic velocity of esophageal body among the three groups. The effective swallowing contraction rate in the pathological group was significantly lower than that in the sensitive group and the physiological group, and the difference was statistically significant (P < 0.05). The results are shown in Table 7.

4. Discussion

Gastroesophageal reflux can occur in both physiological and pathological conditions, and physiological reflux has little effect on the body. however, in pathological reflux, reflux stimulates esophageal mucosa for a long time, and squamous epithelium is covered by columnar epithelium, resulting in barrett esophagus, which causes great trouble to the life of patients [18-19]. Patients' life satisfaction decreased and their mood fluctuated greatly, so patients with GERD were often accompanied by psychological and mental disorders [18]. Gastric acid is the main reflux that attacks the esophageal mucosa. After contact with the mucosa, on the one hand, it increases the sensitivity of the mucosa to acid, on the other hand, it also leads to LES motor dysfunction [20-21]. Therefore, GERD is not only a reflux disease, but also an esophageal motility disorder [22]. Esophageal motility disorders mainly include LES dysfunction (antireflux barrier dysfunction) and esophageal body motor dysfunction (esophageal clearance dysfunction) [23].

LESP ≤ 6mmHg, LESD ≤ 2cm and intra-abdominal LESD ≤ 1cm can lead to LES dysfunction [16]. Decreased LESP or LES dysfunction can not effectively act as a functional barrier, resulting in gastric contents reflux to the esophagus, which is an important factor in the mechanism of gastroesophageal reflux [24].

Esophageal body motor dysfunction is also known as ineffective esophageal motility (Ineffectiveesophagealmotility,IEM). Normal esophageal body movement can clear reflux, that is, acid clearing ability, when esophageal motility is insufficient, acid clearance ability decreases, which leads to the invasion of gastric acid on esophageal mucosa [18]. In Chicago standard v3.0, swallowing without peristalsis or weak peristalsis ≥ 50% is defined as IEM [17]. According to the percentage of AET, Si and sap, the patients were divided into pathological group, sensitive group and physiological group. The gerdq score, SF-36 score, 24-hour pH detection parameters and high-resolution esophageal manometry parameters of the three groups were analyzed. It was found that compared with the sensitive group and the physiological group, the gerdq score of the pathological group was higher, the SF-36 score was lower, and the demeester score, the time of standing acid reflux, the time of lying acid reflux, the time of longest acid reflux and the times of acid reflux were significantly higher. The differences were statistically significant Compared with the physiological group, the gerdq score of the sensitive group was higher, the SF-36 score was lower, and the difference was statistically significant (P Acid reflux was the most serious, life satisfaction was the worst, the physiological group was the best, and the sensitive group was between the other two groups. The research group believed that this was closely related to esophageal motility disorder. Comparison of Les functional parameters in three groups: LESP in pathological group was significantly lower than that in sensitive group and physiological group, with statistical significance (P < 0.05). There was no statistical significance in lesd, intraperitoneal lesd and Les functional abnormality rate in three groups (P > 0.05), which indicated that the decrease of LESP was an important factor leading to pathological acid reflux, while lesd and intraperitoneal lesd played an important role in pathological acid reflux The noise is small. Comparison of esophageal body movement: compared with the physiological group, the peristaltic amplitude of 3 cm on the DCI and LES in the pathological group and the sensitive group was significantly lower, the difference was statistically significant (P < 0.05); the effective swallowing contraction rate (57.5%) in the pathological group was significantly lower than that in the sensitive group (75.0%) and the physiological group (88.4%), the difference was statistically significant (P < 0.05); 7 cm on the LES and 11 cm on the LES in the three groups There was no significant difference between the amplitude and the peristaltic velocity of esophageal body (P > 0.05), which suggested that the pathological acid reflux was related to the amplitude of 3 cm on LES and the intensity of contraction of esophageal body, which might not be related to the amplitude of 7 cm on LES, 11 cm on les and the peristaltic velocity of esophageal body. In conclusion, the decrease of LESP is the key factor ofpathological acid reflux, and acid reflux in GERD patients is closely related to the peristaltic wave amplitude at 3cm on DCI and les.

Table 7 Comparison of motor function parameters of esophageal body(x±s)