Oesophageal pH-metry: should meals be standardized?

Total diet, individual meals, and their association with gastroesophageal reflux disease

Background: To identify the association of total diet and individual meals with gastroesophageal reflux disease (GERD).

Methods: This age- and sex-matched case-control study was carried out among 217 subjects (106 cases and 111 controls). Data were collected using a demographic questionnaire and a GERD checklist and a 3-day food record.

Results: Cases consumed more fat (median: 26.3 [3.2-71.5] g vs. 21.8 [4.3-58.1] g; P=0.04)and more energy percent form carbohydrates (median: 72.5 [0-100] vs. 69.0 [0-100]; P=0.02)at lunch, and less energy (median: 129.5 kcal [0-617.6] vs. 170.5 kcal [0-615.7]; P=0.01) and protein (2.4 [0-19.4] g vs. 3.1 [0-21.8] g; P=0.01) at evening snack, compared to controls.The volume of food was significantly different between the two group only at lunch (median:516 [161-1292] g vs. 468 [198-1060] g; P=0.02). The percentage of energy from total dietary protein showed a significant association with GERD after adjusting for confounders (odds ratio[OR]=0.89; 95% CI: 0.81-0.98). Regarding the individual meals, amount of fat consumed at lunch (OR=1.02; 95% CI: 1.00-1.05), and amount of protein intake at evening snack (OR=0.92;95% CI: 0.85-1.00) were significantly associated with GERD. Meanwhile, caloric density and meal frequency did not differ significantly between the two groups.

Conclusion: Amount of fat consumed at lunch is positively associated with GERD, whereas the percentage of energy from total protein and amount of protein intake at evening snack are more likely to be inversely associated with GERD.

Pediatric gastroesophageal reflux clinical practice guidelines: joint recommendations of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN)

OBJECTIVE

To develop a North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) and European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) international consensus on the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

METHODS

An international panel of 9 pediatric gastroenterologists and 2 epidemiologists were selected by both societies, which developed these guidelines based on the Delphi principle. Statements were based on systematic literature searches using the best-available evidence from PubMed, Cumulative Index to Nursing and Allied Health Literature, and bibliographies. The committee convened in face-to-face meetings 3 times. Consensus was achieved for all recommendations through nominal group technique, a structured, quantitative method. Articles were evaluated using the Oxford Centre for Evidence-based Medicine Levels of Evidence. Using the Oxford Grades of Recommendation, the quality of evidence of each of the recommendations made by the committee was determined and is summarized in appendices.

RESULTS

More than 600 articles were reviewed for this work. The document provides evidence-based guidelines for the diagnosis and management of gastroesophageal reflux and gastroesophageal reflux disease in the pediatric population.

CONCLUSIONS

This document is intended to be used in daily practice for the development of future clinical practice guidelines and as a basis for clinical trials.

Ingested acidic food and liquids may lead to misinterpretation of 24-hour ambulatory pH tests: focus on measurement of extra-esophageal reflux

Normal values of extra-esophageal reflux are difficult to determine owing to variation in the location of the proximal electrode, limited information on the ingestion of acidic food, different exclusion periods for meals, and poor reproducibility of measurement of extra-esophageal reflux. We studied whether ambulatory esophageal pH testing is disturbed by acidic food ingestion. Eighteen healthy subjects were enrolled in standard dual-channel esophageal pH tests (recorder 1). Ten subjects were equipped with another pH device (recorder 2), positioned to measure extra-esophageal reflux. The subjects were exposed to controlled ingestion of different acidic food or liquid for five 1-min periods. The present study showed that acidic food ingestion for 5 min has a significant effect on the outcome of standard dual-channel ambulatory pH testing. Reflux occurs equally on proximal channels during ingestion of acidic food, whether the proximal channel position is normal or 2 cm above the upper esophageal sphincter. We recommend avoiding acidic food intake during esophageal pH testing.

Intra-esophageal pH probe movement during eating and talking. A videoradiographic study

PURPOSE

To registrate the oscillations of the pH probe in the esophagus during phonation and swallowing in the erect and supine positions.

MATERIAL AND METHOD

Sixty-seven patients with suspicion of gastroesophageal reflux disease underwent manometry, 24-h pH monitoring, and videoradiography. In 43 patients the effect of dry, wet, and solid swallows in the erect and supine positions was determined, making a total of 258 swallows. In another 24 patients the effect of pH probe movement during phonation was studied.

RESULTS

During every swallow the probe moved in the proximal direction from 0.5 to 2.0 cm, returned to baseline, and in 48 swallows an additional descendent movement of up to 2.0 cm was seen, the last mentioned more pronounced during solid swallows. In the erect position, no significant difference was observed for the different swallowing types, whereas in the supine position, movements were significantly more pronounced during solid food swallows. During phonation the pH probe only ascended and returned to the baseline, with no descending part.

CONCLUSION

The pH probe movements are dependent on body position, bolus size, bolus composition, and talking. The ascending movements can only partially compensate for the esophageal shortening during swallow because of the time difference, and could perhaps explain the variation in results and reproducibility of 24-h pH monitoring.

Guidelines for evaluation and treatment of gastroesophageal reflux in infants and children: recommendations of the North American Society for Pediatric Gastroenterology and Nutrition

Gastroesophageal reflux (GER), defined as passage of gastric contents into the esophagus, and GER disease (GERD), defined as symptoms or complications of GER, are common pediatric problems encountered by both primary and specialty medical providers. Clinical manifestations of GERD in children include vomiting, poor weight gain, dysphagia, abdominal or substernal pain, esophagitis and respiratory disorders. The GER Guideline Committee of the North American Society for Pediatric Gastroenterology and Nutrition has formulated a clinical practice guideline for the management of pediatric GER. The GER Guideline Committee, consisting of a primary care pediatrician, two clinical epidemiologists (who also practice primary care pediatrics) and five pediatric gastroenterologists, based its recommendations on an integration of a comprehensive and systematic review of the medical literature combined with expert opinion. Consensus was achieved through Nominal Group Technique, a structured quantitative method. The Committee examined the value of diagnostic tests and treatment modalities commonly used for the management of GERD, and how those interventions can be applied to clinical situations in the infant and older child. The guideline provides recommendations for management by the primary care provider, including evaluation, initial treatment, follow-up management and indications for consultation by a specialist. The guideline also provides recommendations for management by the pediatric gastroenterologist. This document represents the official recommendations of the North American Society for Pediatric Gastroenterology and Nutrition on the evaluation and treatment of gastroesophageal reflux in infants and children. The American Academy of Pediatrics has also endorsed these recommendations. The recommendations are summarized in a synopsis within the article. This review and recommendations are a general guideline and are not intended as a substitute for clinical judgment or as a protocol for the management of all patients with this problem.

Effect of caloric density of a meal on lower oesophageal sphincter motility and gastro-oesophageal reflux in healthy subjects

BACKGROUND

Patients with gastro-oesophageal reflux disease are advised to avoid the ingestion of large meals. In healthy volunteers, a relationship between the amount of postprandial gastro-oesophageal reflux and the volume of a liquid meal has been demonstrated.

AIM

To evaluate whether the amount of postprandial gastro-oesophageal reflux is also related to the calorie content of a meal, a second parameter that will be reduced by avoidance of the ingestion of large meals.

METHODS

Twelve healthy volunteers (six female, 19-31 years) received two solid-liquid meals with either 842 kcal (solid 582 kcal, liquid 260 kcal) or 582 kcal (31% reduction) in a randomized order. The nutritional components (10% fat, 76% carbohydrates, 14% protein) and the volume of the meals were identical in both meals. The lower oesophageal sphincter pressure was measured continuously in the first postprandial hour with a Dent sleeve, and pH-metry was performed for 3 h postprandially with a glass electrode in the distal oesophagus. Blinded to the type of ingested meal, we calculated the mean lower oesophageal sphincter pressure, the frequency of transient lower oesophageal sphincter relaxations, the number of reflux episodes, and the fraction of time for which pH < 4.

RESULTS

A similar decrease in lower oesophageal sphincter pressure was observed after ingestion of the high calorie meal (median 10.9 mmHg, range 4.8-16.7 mmHg) and low calorie meal (median 9.9 mmHg, range 3.9-18.4 mmHg). No difference in the number of transient lower oesophageal sphincter relaxations (high calorie: median 9 per hour, range 5-13 per hour; low calorie: median 7 per hour, range 0-14 per hour) and of reflux episodes (high calorie: median 12 in 3 h, range 3-22 in 3 h; low calorie: median 12 in 3 h, range 3-30 in 3 h) was registered after intake of both types of meal. Additionally, no difference was identified regarding the fraction of time for which pH < 4 between the high calorie (mean 2.3%, 0.2-23.7%) and low calorie meal (3.3%, 0.5-17.8%).

CONCLUSION

Reducing the caloric density of a meal neither influences postprandial lower oesophageal sphincter pressure nor decreases gastro-oesophageal reflux in healthy volunteers. Thus, the amount of gastro-oesophageal reflux induced by ingestion of a meal seems to depend on the volume but not on the caloric density of a meal.

Overweight, but not high dietary fat intake, increases risk of gastroesophageal reflux disease hospitalization: the NHANES I Epidemiologic Followup Study. First National Health and Nutrition Examination Survey

PURPOSE

Gastroesophageal reflux disease is an important and increasingly common condition. Both overweight and high fat food consumption have been implicated as causes of reflux disease. We examined the relationship of overweight, high dietary fat intake, and other factors with reflux disease hospitalization.

METHODS

We studied participants in the first National Health and Nutrition Examination Survey, a population-based sample examined in 1971-75 and followed through 1992-93. Persons with a physician-diagnosed hiatal hernia at baseline or reflux disease hospitalization within the first five years of study were excluded. A second analysis included follow-up of 9851 participants free of reflux disease in 1982-84. Ninety-six percent of the baseline cohort were recontacted. Reflux disease cases were persons hospitalized with a diagnosis of esophagitis or uncomplicated hiatal hernia. Hazard rate ratios for reflux disease hospitalization according to body mass index (BMI) (kg/m2), total daily servings of high fat foods and other factors were calculated using Cox proportional hazards analysis.

RESULTS

A total of 12,349 persons were followed for a median of 18.5 years (range 5.0-22.1). Cumulative incidence of reflux disease hospitalization was 5.2% at 20 years. Multivariate survival analysis revealed higher reflux disease hospitalization rates with higher BMI (5 kg/m2) [hazard ratio (HR) = 1.22, 95% confidence interval (CI) = 1.13-1.32]. No relationship was found between higher fat intake and reflux disease hospitalization. Other factors associated with reflux disease hospitalization included age, low recreational activity, and history of doctor-diagnosed arthritis.

CONCLUSIONS

Overweight, but not high dietary fat intake, increases risk of gastroesophageal reflux disease hospitalization.

Gastroesophageal reflux in healthy subjects. Significance of endoscopic findings, histology, age, and sex

BACKGROUND

Our aim was to evaluate which specific factors are of importance for the gastroesophageal reflux seen in presumably healthy subjects.

METHODS

We investigated 57 healthy, asymptomatic volunteers with computer-aided medical history interrogation, endoscopy, biopsy specimens from the distal esophagus, manometry, and 24-h ambulatory pH-monitoring.

RESULTS

Eight subjects (14%) claimed intermittent reflux symptoms at the computer interview, but they did not have more acid reflux at pH-monitoring than asymptomatic volunteers. Thirteen subjects (23%) had abnormalities at endoscopy, 3 of whom had an erosion in the distal esophagus, and 12 had hiatus hernia. Subjects with hiatus hernia had increased acid reflux at 24-h pH-monitoring compared with those without hernia. If subjects with hernia were excluded, the degree of acid reflux was similar in all age groups. Men had more acid reflux than women, and these differences persisted if subjects with hernia were excluded. There was no correlation of histologic signs of esophagitis in the distal esophagus, lower esophageal sphincter pressure, smoking habit, or body mass index with reflux of acid to the esophagus.

CONCLUSION

Hiatus hernia is a common finding in healthy subjects, and it predisposes to gastroesophageal acid reflux. Histologic abnormalities are poorly related to acid reflux in healthy volunteers. We found increased acid reflux in healthy men compared with women, but larger studies are needed to confirm these findings. Symptom evaluation is not sufficient to exclude significant gastroesophageal reflux in healthy volunteers, and we suggest that the possibility of esophageal abnormalities should be excluded by endoscopy in comparative studies of gastroesophageal reflux disease.

Effect of smoking on the results of esophageal pH measurement in clinical routine

Because data on the effects of smoking on gastroesophageal reflux are controversial, we evaluated the effect of smoking on the results of esophageal 24-hour pH-metry in clinical routine. Participants were 280 consecutive patients with symptoms suggestive of reflux disease, 78 smokers, and 202 nonsmokers. Of the smokers, 45 actually smoked during the pH measurement and 33 abstained from smoking. The frequency of reflux episodes, the fraction of time pH was < 4, and the percentage of abnormal 24-hour pH-metry results were compared among actual smokers, abstaining smokers, and nonsmokers. In actual smokers, the effect of smoking on gastroesophageal reflux was further analyzed by comparing the reflux frequency and the fraction of time that pH was < 4 for a 10-minute period before, during, and after smoking. We found no difference in reflux frequency and fraction of time that pH was < 4 among actual smokers, abstaining smokers, and nonsmokers, regardless of a normal or an abnormal pH-metry result. The percentage of patients with a pH-metry result indicating disease was similar in the three groups, at 53%, 52%, and 50%, respectively. Gastroesophageal reflux was not increased during smoking a cigarette or in the postsmoking period compared with the presmoking period. Neither being a smoker nor actually smoking a cigarette had a negative influence on gastroesophageal reflux. Thus smoking or abstaining from smoking does not modify the results of pH-metry in clinical routine.

Exclusion of the meal period improves the clinical reliability of esophageal pH monitoring

Meal period exclusion from 24-h pH testing allows better separation between controls and patients with gastroesophageal reflux disease. We reviewed the results of 24-h pH studies of 350 patients with reflux symptoms. They were divided into two groups based on the 95th percentile of the total percentage of time when pH was < 4 for healthy persons in our laboratory. Thus group A consisted of 212 patients with symptoms and normal acid exposure and group B consisted of 138 patients with symptoms and abnormal acid exposure. The change in upright reflux excluding the meal period was calculated for each patient. Meal period exclusion resulted in opposite effects for the two groups of patients, with a change in median upright reflux of -0.6% for group A and +0.5% for group B (p < 0.0001). After meal exclusion, five patients were reclassified as having reflux, with four (80%) of these responding to antireflux therapy. Nine other patients were recategorized as not having reflux after meal exclusion. Only one of seven patients (14%) for whom data were available responded to treatment (two patients were lost to follow-up). We recommend meal period exclusion from pH analysis because it improves the clinical reliability of esophageal pH monitoring.

Exclusion of meal periods from ambulatory 24-hour pH monitoring may improve diagnosis of esophageal acid reflux

Distal esophageal pH less than 4 is frequently seen during meal ingestion in 24-hr ambulatory pH monitoring for the diagnosis of gastroesophageal reflux disease (GERD). The characteristics of this meal-related apparent reflux without diet restriction was evaluated. Data from normal volunteers (N = 21) and consecutive patients (N = 66) referred with heartburn and/or chest pain were studied with ambulatory pH monitoring. The median percent times pH < 4 in the distal esophagus were significantly greater in symptomatic patients than controls for total 24-hr, upright, and supine periods, and postprandial periods of 30, 60, 90, 120, and 150 min (P values of 0.007-0.03). However, the median percent time pH < 4 during the meal periods was the same for patients (4.4%) and for controls (6.6%) with P = 0.23. Excluding the meal periods from analysis resulted in greater separation between controls and patients with abnormal acid exposure when compared to the conventional method. Patients should maintain their usual routine without diet restriction during 24-hr ambulatory pH studies in the clinical setting. Furthermore, exclusion of meal periods can eliminate meal-time pH variabilities without affecting postprandial acid exposure and improve the diagnosis of GERD.