Fasting and postprandial mechanisms of gastroesophageal reflux in children with gastroesophageal reflux disease

In order to define the mechanisms of gastroesophageal reflux (GER) in children, we performed simultaneous intraluminal, esophageal motility and pH studies in 24 children with symptomatic reflux and abnormal prolonged pH probe study, ten (group A) without endoscopic and histologic esophagitis, 14 (group B) with endoscopic and histologic esophagitis. Median (ranges) age (years) was 5.0 (6 months-10 years) and 3.0 (6 months-12 years), respectively. Recordings were done for 1 hr before and 1 hr after feeding apple juice (15 ml/kg; pH 4.0). All episodes of GER in group A patients and 77.1% in group B patients were accounted for by abrupt transient lower esophageal sphincter (LES) relaxation (TLESR); 22.9% of reflux events in group B patients occurred during gradual drifts of LES pressure (LESP) to undetectable levels. Esophageal refluxate exposure (mean percentage time with esophageal pH<4.0) the rate of TLESR (number of episodes/hr), and the percentage of TLESRs associated with reflux significantly increased in the fed period both in group A (18.5±5.4%, 6.2±2.65, 87.1%) and in group B (29.7±6.5 7.8±3.05, 84.9%) as compared to the fasting state (group A: 10.8±3.9, 3.9±3.17, 46.1%; group B: 16.1±2.6, 4.14±3.06, 55.17%) (p<0.01). The rate of LESP drifts (number of episodes/hr) was also significantly higher postprandially (4.85±1.24 vs 1.8±0.9,p<0.01); furthermore there was a postfeeding increase of the LESP drift percentage associated with reflux (79.41% vs 46.15%,p<0.01). Residual pressure of TLESRs associated with reflux was significantly lower than that of TLESRs without GER in both groups of patients, during fasting (group A:p<0.01; group B:p<0.05) and fed state (p<0.05), whereas duration of relaxation and LESP in the 1-min period before each TLESR did not discriminate TLESRs associated with reflux from those without reflux. In children with GER disease, TLESR is the most common mechanism of reflux, but gradual LESP drift is associated with more severe disease; the postprandial increase in the esophageal acid exposure is mainly due to increased rate of TLESRs and LESP drifts; degree of sphincter inhibition during TLESRs is a critical factor for the induction of reflux.Presented in part at the 91st Annual Meeting of the American Gastroenterological Association, San Antonio, Texas, May 12–18, 1990.     

Effect of prolonged gastric distention on lower esophageal sphincter function and gastroesophageal reflux

OBJECTIVES: Morbidly obese patients treated with an intragastric balloon report a transient increase in gastroesophageal reflux (GER) symptoms. In the present study, we evaluated the underlying mechanisms of GER and examined the effect of prolonged gastric distention on lower esophageal sphincter function. METHODS: Fasting and postprandial manometric studies were performed in obese subjects (n = 15) before, immediately after, and 10 and 20 wk after placement of a 500-ml water-filled balloon. RESULTS: Residual lower esophageal sphincter (LES) pressure after water swallows was not affected after balloon placement, excluding mechanical interaction with sleeve function. Postprandial LES pressure was significantly increased after 10 and 20 wk. GER was increased in the right recumbent position until 10 wk after balloon placement, mainly because of an increased percentage of transient lower esophageal sphincter relaxations (TLESRs) accompanied by GER. TLESRs were the main mechanisms underlying reflux both before and after balloon placement. The rate of TLESRs was increased significantly immediately after introduction of the balloon, returning to baseline values after 20 wk. After balloon placement, reflux episodes were evoked by gastric contractions that were not inhibited by meals. CONCLUSIONS: Chronic distention by an intragastric balloon increased reflux up to 10 wk after placement because of an increase in the percentage of TLESRs accompanied by a reflux episode. In addition, prolonged balloon distention increased the rate of TLESRs and created a postprandial state even 10 wk after balloon placement. After 20 wk these effects largely resolved, illustrating adaptation to this artificial situation.     

Gastric fullness, physical activity, and proximal extent of gastroesophageal reflux

OBJECTIVES: Proximal extent of gastroesophageal reflux (PER) is relevant for symptoms in GERD patients. It has been suggested that PER is determined by the volume of the refluxate that, in turn, might depend on the degree of gastric fullness. Abdominal straining, during ambulation, increases the likelihood of gastroesophageal reflux. We assessed the influence of gastric fullness and ambulation on proximal extent of reflux. METHODS: PER was assessed in 37 patients with GERD undergoing ambulatory pH impedance monitoring. In 14 controls and 19 GERD patients, esophageal pH impedance and gastric emptying were also studied simultaneously in stationary conditions. We compared PER during fasting, early postprandial (before half emptying), and late postprandial periods in ambulatory and stationary conditions. RESULTS: More reflux episodes reached the proximal esophagus in the postprandial period compared to fasting (60%+/-4 vs 29%+/-3, p<0.05). In stationary conditions, early postprandial reflux reached higher proximal extent than late postprandial reflux (15+/-3% vs 8+/-4%, p<0.05). The proportion of reflux events reaching the proximal esophagus was significantly higher in ambulatory than in stationary conditions (29+/-5% vs 15+/-3%, p<0.05). CONCLUSION: Compared to fasting, reflux episodes occurring after the meals are more likely to reach higher proximal extent, particularly so during the early postprandial period. The highest proportion of postprandial proximal reflux occurred in ambulatory condition. These findings suggest that reducing meal volumes and early postprandial physical activity might contribute to decrease proximal extent of reflux and postprandial GERD symptoms.     

Gastroesophageal reflux and gastric emptying,revisited

Total gastric emptying is delayed in 10% to 33% of adult patients with gastroesophageal reflux disease (GERD), but a strong correlation between duration of gastric emptying and severity of acid reflux or esophagitis has never been proved. Previous studies reported that patients with GERD might have exaggerated postprandial fundus relaxation with retention of food and triggering of transient lower esophageal sphincter relaxations (TLESRs). There is a positive correlation between postprandial fundus relaxation and number of TLESRs and also between proximal gastric emptying and esophageal acid exposure. However, new studies suggest that a high number of TLESRs and reflux events may occur even with accelerated gastric emptying, and prolonged gastric retention might be associated with less rather than more esophageal acid exposure. Using simultaneous gastric emptying and esophageal pH impedance we found that the rate of gastric emptying might determine the acidity and proximal extent of reflux: The slower the emptying, the higher the pH and proximal extent of the refluxate.     

Effect of different recumbent positions on postprandial gastroesophageal reflux in normal subjects

OBJECTIVE: Gastroesophageal reflux (GER) is increased in the right compared to the left recumbent position. Esophageal acid exposure is related to the acidity at the cardia, but the effect of body position on the acidity at the cardia has not yet been investigated. We aimed to investigate the mechanisms underlying increased esophageal acid exposure in the right recumbent position. METHODS: On 2 separate days a 4-h combined esophageal and lower esophageal sphincter (LES) manometry and pH recording of esophagus, gastric cardia, and corpus was performed in the right and left recumbent position after a high fat meal in 10 healthy subjects. RESULTS: In the right recumbent position a prolonged esophageal acid exposure (7.0% vs 2.0%, p < 0.03), a higher incidence of reflux episodes (3.8 vs 0.9/h, p < 0.03), more transient LES relaxations (TLESRs) (6.5 vs 3.2/h, p < 0.03), and higher percentage TLESRs associated with reflux (57.0% vs 22.4% p < 0.03) was recorded than in the left supine position. Acidity at gastric cardia and corpus was not affected by body position. CONCLUSIONS: Increased esophageal acid exposure in the right recumbent position relative to the left recumbent position is the result of a higher incidence of GER episodes caused by an increased incidence of TLESRs and higher percentage of TLESRs associated with GER. Body position does not affect the acidity at the gastric cardia and corpus.     

Effect of laparoscopic partial fundoplication on reflux mechanisms

OBJECTIVES: Transient lower esophageal sphincter relaxations (TLESRs) are the main mechanism causing gastroesophageal reflux. Since 1994 we have performed laparoscopic partial instead of complete fundoplication as standard surgical treatment for therapy resistant reflux disease to minimize postoperative dysphagia. To better understand the management of gastroesophageal reflux, we conducted a prospective study of the effects of laparoscopic partial fundoplication on TLESRs and other reflux mechanisms. METHODS: From 1994 to 1999, 65 patients underwent laparoscopic partial fundoplication (180-200 degrees) and 28 of these patients (16 female, 12 male, mean age 43 +/- 2 yr [range, 26-66 yr]) agreed to participate in this prospective study on reflux mechanisms. Before and 6 months after surgery, all patients were evaluated by simultaneous recording of pH and lower esophageal sphincter characteristics, using sleeve manometry. RESULTS: After partial fundoplication basal LES pressure increased significantly (p < 0.05), from 14.3 +/- 1.2 mm Hg to 17.8 +/- 1 mm Hg. Partial fundoplication significantly (p < 0.05) decreased the number of TLESRs, from 3.4 +/- 0.8 to 1.6 +/- 0.3 per hour in the fasting period, and from 4.7 +/- 0.5 to 1.9 +/- 0.3 per hour postprandially. The percentage of TLESRs associated with reflux also decreased significantly (p < 0.05), from 45 +/- 7% to 27 +/- 6% after operation. The number of reflux episodes decreased significantly (p < 0.05), from 4.1 +/- 0.7 to 1.3 +/- 0.3 per hour postoperatively. The majority of these episodes were associated with TLESRs: 57% and 46%, pre- and postoperatively, respectively. CONCLUSIONS: Laparoscopic partial fundoplication significantly increased fasting and postprandial LES pressure and significantly decreased TLESR frequency. This resulted in a significant reduction in esophageal acid exposure, with preservation of postprandial LES characteristics.     

Gastric distention: a mechanism for postprandial gastroesophageal reflux

The occurrence of gastroesophageal reflux after meals may be related to an increase in the rate of transient lower esophageal sphincter (LES) relaxations, the mechanisms of which are not understood. We investigated the effects of gastric distention on LES pressure in 16 normal subjects and 17 patients with gastroesophageal reflux disease. Intraluminal pressure was measured in the gastric fundus, LES, and esophageal body with a manometric catheter incorporating a sleeve device. Gastric distention was performed by injecting 0, 250, 500, or 750 ml of air in randomized order into a balloon and maintaining each stimulus for 15 min. Gastric distention did not significantly alter resting LES pressure in either group. During the basal period the rate of transient LES relaxation in the reflux patients (1.1 +/- 0.4 per 15 min) was greater than that in the normal subjects (0.6 +/- 0.1 per 15 min). Gastric distention resulted in a significant threefold to fourfold increase in the rate of transient LES relaxations in both groups. The reflux patients had a significantly greater proportion of complete relaxations (87%) than did the normal subjects (73%). We conclude that gastric distention, by significantly increasing the rate of transient LES relaxations in both normal subjects and patients with gastroesophageal reflux disease, may contribute to the postprandial increase in gastroesophageal reflux.     

Pathophysiology and pharmacological treatment of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is one of the most common diagnoses in a gastroenterologist's practice. Gastroesophageal reflux describes the retrograde movement of gastric contents through the lower esophageal sphincter (LES) to the esophagus. It is a common, normal phenomenon which may occur with or without accompanying symptoms. Symptoms associated with GERD include heartburn, acid regurgitation, noncardiac chest pain, dysphagia, globus pharyngitis, chronic cough, asthma, hoarseness, laryngitis, chronic sinusitis and dental erosions. The introduction of fiberoptic instruments and ambulatory devices for continuous monitoring of esophageal pH (24-hour pH monitoring) has led to great improvement in the ability to diagnose reflux disease and reflux-associated complications. The development of pathological reflux and GERD can be attributed to many factors. Pathophysiology of GERD includes incompetent LES because of a decreased LES pressure, transient lower esophageal sphincter relaxations (TLESRs) and deficient or delayed esophageal acid clearance. Uncomplicated GER may be treated by modification of life style and eating habits in an early stage of GERD. The various agents currently used for treatment of GERD include mucoprotective substances, antacids, H(2) blockers, prokinetics and proton pump inhibitors. Although these drugs are effective, they do not necessarily influence the underlying causes of the disease by improving the esophageal clearance, increasing the LESP or reducing the frequency of TLESRs. The following article gives an overview regarding current concepts of the pathophysiology and pharmacological treatment of GERD.     

Composition of the postprandial refluxate in patients with gastroesophageal reflux disease

OBJECTIVE: It is not known whether the characteristics of the postprandial refluxate in patients with gastroesophageal reflux disease (GERD) differ from those observed in normal subjects. The aim of this study was to characterize the postprandial refluxate in adult patients with GERD using combined intraluminal electrical impedance and pH measurements. METHODS: Postprandial gastroesophageal reflux was assessed in 16 patients with GERD and 15 controls. pH and intraluminal electrical impedance were used to identify acid and nonacid reflux of liquid, mixed (liquid + gas) or gas. RESULTS: Transient lower esophageal sphincter relaxations (TLESRs) and reflux of gastric contents were equally frequent in both groups. However, patients with GERD had more acid reflux [8 (4.7-10.5)/h vs 3.5 (2.6-6)/h, p < 0.05], and normal subjects had more nonacid reflux [5 (4.3-6.7)/h is 3 (1-3.5)/h, p < 0.05]. Gas reflux was less frequent in GERD than in controls (51% vs 68%; p < 0.05). Pure liquid reflux, however, was more frequent (40% vs 26%, p < 0.05) and twice as likely to be acid in GERD. During TLESRs, liquid acid reflux was more frequent in GERD than in controls. CONCLUSIONS: TLESRs and reflux of gastric contents are similarly frequent in patients with GERD and controls. However, patients with GERD have more acid reflux and less nonacid reflux. Differences in the air-liquid composition of the refluxate may contribute to the higher rate of acid reflux observed in these patients.     

Effect of sumatriptan, a 5HT1 agonist, on the frequency of transient lower esophageal sphincter relaxations and gastroesophageal reflux in healthy subjects

OBJECTIVE: Meals increase the rate of transient lower esophageal sphincter (LES) relaxations, in part by gastric distension. The 5HT1 agonist sumatriptan reduces fasting fundic tone, prolongs the meal-induced fundic relaxation, and delays gastric emptying. We therefore hypothesized that sumatriptan might have a significant effect on the rate of postprandial transient LES relaxations and gastroesophageal reflux. We aimed to study the effect of sumatriptan on postprandial transient LES relaxations and reflux in healthy subjects. METHODS: Esophageal manometry and pH monitoring were performed in 13 healthy volunteers for 30 min before and 90 min after a semiliquid meal (790 kcal). Sumatriptan 6 mg subcutaneous (s.c.) or s.c. placebo were administered on separate days 30 min after the meal. RESULTS: Sumatriptan significantly increased postprandial LES pressure from 11.0 +/- 1.2 mm Hg to 17.6 +/- 1.2 mm Hg (p < 0.05). However, reflux events were not diminished. In the contrary, reflux was more frequent after sumatriptan than after placebo (3 [1.5-4.5]/30 min vs 2 [0-3]/30 min, p < 0.05). Transient LES relaxations were more frequent after sumatriptan, particularly in the second 30-min period after drug administration (3 [2.5-5]/30 min vs 2 [1.5-2]/30 min, p < 0.05). CONCLUSIONS: Sumatriptan prevents the natural decay in rate of transient LES relaxations that occurs after a meal and favors the occurrence of gastroesophageal reflux despite increasing LES pressure. The sustained postprandial high rate of transient LES relaxations after sumatriptan may be a consequence of a prolonged fundus relaxation and retention of meal in the proximal stomach.     

Effect of bethanechol on gastroesophageal reflux

In this study we determined the acute effect of bethanechol (5 mg SC) on gastroesophageal reflux (GER) and lower esophageal sphincter pressure (LESP) in 27 patients with symptomatic esophagitis. The effect of bethanechol on esophageal acid clearance was also determined in 7 of the patients. Intraluminal pH monitoring prior to bethanechol administration demonstrated free or stress-induced reflux episodes in 18 of the 27 patients. Following bethanechol (1) LESP increased significantly, (2) GER diminished or ceased in many of the patients, and (3) acid clearance times decreased significantly. Some individuals, however, continued to reflux despite LESP elevation to 30 mm Hg or more. This latter finding suggests that LESP alone is not the sole factor governing LES competency. Other factors such as improved esophageal emptying may also contribute to the beneficial therapeutic effect of bethanechol in patients with heartburn.This work was supported in part by a grant (PR-58) from the Clinical Research Centers Program of the Division of Research Resources, NIH, and by USPHS Research Grant No. RO1 AM 15540-03.Abstracted in part in Clinical Research 22605, 1974 and presented in part at the American Federation for Clinical Research, Midwest Section, Chicago, Illinois, October 31, 1974.     

Excess gastroesophageal reflux in patients with hiatus hernia is caused by mechanisms other than transient LES relaxations

BACKGROUND & AIMS: Esophageal acid exposure is higher in gastroesophageal reflux disease (GERD) patients with hiatus hernia than in those without. We investigated the effect of a sliding hiatus hernia on the mechanisms underlying spontaneous gastroesophageal reflux over 24 hours. METHODS: Twelve GERD patients with and 10 GERD patients without hiatus hernia were studied for 24 hours. Combined esophageal pH and manometric recordings of the pharynx, lower esophageal sphincter (LES), and stomach were performed using a multiple-lumen assembly incorporating a Dent sleeve connected to a portable water-perfused manometric system and a pH glass electrode. RESULTS: Patients with hiatus hernia had greater esophageal acid exposure (7.6% vs. 3.3%; P < 0.01) and more reflux episodes (3.1 vs. 1.8/h; P < 0.001) than those without. LES pressure, the incidence of transient LES relaxations (TLESRs), and the proportion of TLESRs associated with acid reflux were comparable in both groups. Both groups had equal numbers of reflux episodes associated with TLESRs and swallow-associated prolonged LES relaxations. Patients with hiatus hernia had more reflux associated with low LES pressure, swallow-associated normal LES relaxations, and straining during periods with low LES pressure. CONCLUSIONS: The excess reflux in GERD patients with hiatus hernia compared with those without is caused by malfunction of the gastroesophageal barrier during low LES pressure, swallow-associated normal LES relaxations, deep inspiration, and straining.     

Effect of l-NMMA on Postprandial Transient Lower Esophageal Sphincter Relaxations in Healthy Volunteers

In a previous study we showed that nitric oxide (NO) synthesis inhibition by N ^G-monomethyl-l-arginine (l-NMMA) reduced the number of transient lower esophageal sphincter relaxations (TLESRs) triggered by gastric balloon distention. The role of NO in postprandial TLESRs and gastroesophageal reflux, however, is unknown. Therefore, we studied the effect of l-NMMA on meal-induced TLESRs and reflux episodes with simultaneous recording of esophageal peristalsis, intraesophageal and intragastric pH, and gastric emptying in healthy volunteers. Ingestion of a solid meal resulted in an increase in TLESRs [8.5 (6.3–11.0) 60 min] which was significantly inhibited by l-NMMA [6.0 (4.0–8.8) 60 min, P < 0.05]. In addition, the total number of reflux episodes was reduced. l-NMMA had no effect on intragastric meal distribution and gastric emptying, but attenuated the postprandial increase in intragastric pH. These results confirm the involvement of NO in the neurocircuitry underlying the triggering of TLESRs. The reduction in reflux by l-NMMA has to be confirmed in patients with gastroesophageal reflux disease. NO may be involved in the regulation of gastric acid secretion.     

Relationship between antral distension and postprandial symptoms in functional dyspepsia

INTRODUCTION Patients with functional dyspepsia (FD)[1] complain of several gastrointestinal (GI) and extra-gastrointestinal (extra-GI) symptoms[2-5] that are usually associated with food ingestion[6]. Several pathophysiological abnormalities have been im…     

Gastric emptying in infants with gastroesophageal reflux. Ultrasound evaluation before and after cisapride administration.

The present study aimed to evaluate gastric emptying in children with gastroesophageal reflux (GER) by means of real-time ultrasonography, on the basis of measurements of the cross-sectional area of the gastric antrum. Twelve children with GER were studied (seven males, five females; age range, 3-13 months) and compared with 12 normal control children (six males, six females; age range, 3-13 months). The diagnosis of GER was confirmed by 24-h esophageal pH-monitoring. The GER patients had a significantly greater antral area than the controls at 90, 105, and 120 min after eating a standard meal (cow's milk formula, 300 ml/m2 body surface area); in addition, final gastric emptying time was significantly greater in the patients than in the controls (145 +/- 36.9 versus 78.7 +/- 19.3 min; p less than 0.0025). After 8 weeks of treatment with cisapride (0.3 ml/kg, three times a day) 24-h esophageal pH-monitoring and ultrasonography studies were repeated in the patients. The total percentage reflux time was significantly lower (p less than 0.038), and ultrasonography showed a decreased antral area at all the various study times, with no significant difference between patients and controls; final gastric emptying time was also significantly lower than before treatment (p less than 0.009). Furthermore, in the GER patients there was a significant correlation between gastric emptying time and the sum of the various reflux times recorded in the 2 h after all meals over the 24 h.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of baclofen on gastric acid pocket in subjects with gastroesophageal reflux disease symptoms

Postprandial gastroesophageal reflux (PGER) in the distal esophagus (DE) is associated with a gastric juice ‘acid pocket’ (AP). Baclofen reduces AP extension into the DE in healthy volunteers, in part through increased lower esophageal sphincter (LES) pressure. We aimed to verify whether baclofen also affects postprandial AP location and extent in gastroesophageal reflux disease (GERD) patients. Thirteen treatment‐naive heartburn‐prevalent GERD patients underwent two AP studies, after pretreatment with baclofen 40 mg or placebo 30 minutes preprandially. We performed pH‐probe stepwise pull‐throughs (PT) (1 cm/min, LES ?10 to +5 cm) before and every 30 minutes from 30 minutes before up to 150 minutes after a test meal. After the meal, both after placebo and baclofen, gastric pH significantly dropped at 30, 60, 90 minutes postprandially (P: nadir pHs of 3.9 ± 0.6, 2.3 ± 0.6, 2.1 ± 0.4; B: nadir pHs of 2.5 ± 0.4, 2.8 ± 0.4, 2.5 ± 0.3; all P < 0.05). After placebo, LES pressure decreased at 60, 90 and 120 minutes postprandially (32.7 ± 6.1 vs. 24.5 ± 3.1, 27.3 ± 5.9, 27.3 ± 6.0 mmHg; analysis of variance [ANOVA], P = 0.037), but this was prevented by baclofen (25.4 ± 3.4 vs. 29.4 ± 2, 32.2 ± 1.4, 35.5 ± 1.7 mmHg, ANOVA, P = not significant (NS)). Baclofen did not significantly decrease the postprandial AP extent above the LES but prevented the postprandial increase in transient lower esophageal sphincter relaxations (TLESRs) (preprandial vs. postprandial, placebo: 1.1 ± 0.3 vs. 3.7 ± 0.7, P < 0.05; baclofen: 1.4 ± 0.4 vs. 2 ± 0.5, P = NS). In GERD patients, baclofen significantly increases postprandial LES pressure, prevents the increase TLESRs but, unlike in healthy volunteers, does not affect AP extension into the DE.     

The influence of rapid food intake on postprandial reflux: studies in healthy volunteers

BACKGROUND: The postprandial increase of gastroesophageal reflux (GER) results largely from an increase in the rate of transient lower esophageal sphincter relaxations (TLESRs). Gastric distension is believed to be the most important contributing factor. The aim of this study was to determine the impact of rapid food intake on GER in healthy volunteers using combined multichannel intraluminal impedance and pH (MII-pH) testing to record both acid and nonacid reflux. Our hypothesis was that rapid food intake overstresses the gastric pressure-volume response and contributes to increased postprandial GER. METHODS: Twenty healthy volunteers were included in the study. On two separate days the participants were asked to eat the same standard meal within 5 or 30 min in random order. Acid and nonacid reflux episodes were recorded over a 2-h postprandial period. RESULTS: Intake of a standard meal within 5 min was associated with more reflux episodes (median = 14) than an intake within 30 min (median = 10, p= 0.021). The increase was confined to the first postprandial hour and was caused predominantly by an increase of nonacid reflux. During the entire 2-h postprandial period, 469 reflux episodes were noted in the 40 studies. During the first postprandial hour 45% (135/303) of reflux events were nonacid as opposed to 22% (37/166) noted during the second hour (p < 0.0001). CONCLUSION: Since rapid food intake produces more GER in healthy volunteers, studies in GERD patients are warranted to evaluate if eating slowly may represent another "life-style modification" aimed at reducing GER.     

Upright versus supine reflux in gastroesophageal reflux disease

BACKGROUND: Postural measures are early recommendations in the management of heartburn, and are aimed at preventing acid reflux through an incompetent lower esophageal sphincter (LES). However, LES incompetence is found in only a minority of patients, and transient LES relaxations, primarily in the upright position, are currently recognized as the main pathophysiological abnormality in gastroesophageal reflux disease (GERD). We investigated the importance of supine acid reflux in patients with GERD. METHODS: Upon review of their clinical, manometric, pH monitoring and endoscopic characteristics, 85 patients with reflux symptoms were classified into three groups: Group A (n=22), consisting of symptomatic patients without esophagitis or pathological reflux; group B (n=38), symptomatic patients with reflux but no endoscopic esophagitis; and group C (n=25), symptomatic patients with both ulcerative or complicated esophagitis and pathological reflux. RESULTS: All groups were similar in age distribution. Groups B and C had a higher prevalence of hiatal hernia and reflux symptoms. Manometry revealed similar LES pressures in groups A and B, but lower LES pressure in group C (P < 0.005). In groups A and B, supine reflux, in terms of percentage of time with pH < 4, was less pronounced than upright reflux (P < 0.0001). In contrast, group C supine reflux was as pronounced as the upright reflux. CONCLUSIONS: The majority of patients reflux in the upright position. Only patients with complicated esophagitis have significant bipositional acid reflux. These findings suggest that unless the patient has severe reflux disease, postural measures may not be indicated.     

Evaluation of gastric emptying by electrogastrography and ultrasonography in gastroesophageal reflux disease

Background: It has been suggested that transient lower esophageal sphincter relaxation is involved in the occurrence of gastroesophageal reflux disease (GERD) and that decreased gastric emptying is an exacerbating factor of transient LES relaxation. In addition, the gastric emptying function is considered to be closely related to gastric motility. Methods: Gastric activity was evaluated by electrogastrography (EGG) in 22 patients with endoscopically positive reflux esophagitis (15 with mild esophagitis of Los Angeles grade A or B and seven with severe esophagitis of Los Angeles grade C or D) and 20 normal individuals. The gastric emptying function was also evaluated by abdominal ultrasonography. The sampling cycle of EGG was 1 s, and the measured frequency was 2.1–6.0 cycle/min (c.p.m.). The mean amplitude of EGG was compared by EGG spectral analysis among brady‐gastria cases with a contraction frequency of less than 2.4 c.p.m., normo‐gastria cases with a contraction frequency of 2.4–3.6 c.p.m., and tachy‐gastria cases with a contraction frequency exceeding 3.6 c.p.m. Results: In the patients with GERD, both the frequency of 3‐c.p.m. waves and peak frequency were reduced, and the gastric emptying function examined by ultrasonography had deteriorated, in comparison with normal individuals. Of those with GERD, the ultrasonographic gastric emptying function was significantly reduced in all patients with severe esophagitis compared with those with mild esophagitis, but the differences of the frequency of 3‐c.p.m. waves, the peak frequency, were not significant. Also, no significant difference was observed in the frequency of 3‐c.p.m. waves or the ultrasonographic gastric emptying function between the 16 patients with hiatal hernia and the six patients with no hiatal hernia. However, the mean amplitude in brady‐gastria and tachy‐gastria was significantly increased in the patients with hiatal hernia compared to those without hiatal hernia. Conclusions: Reduced gastric motility was suggested to be involved in the development of reflux esophagitis, and the presence of hiatal hernia was considered to have some effect on gastric motility.     

脂肪对胃食管酸反流的影响和体重指数与胃食管酸反流的关系

目的评估饮食脂肪对胃食管酸反流的影响和体重指数（BMI）与胃食管酸反流的关系。方法选择23例健康志愿者和22例胃食管反流病（GERD）患者,记录受试者基本情况,先行食管测压,先后两次服用低脂餐和高脂餐,每次监测餐后6h食管pH值。结果健康志愿者和GERD患者在两种热量相等的低脂餐和高脂餐后,pH〈4总反流时间百分率,反流时间〉5min的反流次数及总反流次数的比较,均无显著性差异（P〉0．05）;BMI≥25受试者的pH〈4总反流时间百分率和反流时间〉5min的反流次数高于BMI〈25受试者,两者有显著性差异（P〈0．01）。结论在同热量含量下,食物中脂肪含量对健康志愿者和GERD患者餐后6h酸反流无影响;而肥胖可能会增加胃食管酸反流。