Management of non-ulcer dyspepsia

The Relationship Between Gastric Myoelectric Activity and SCN5A Mutation Suggesting Sodium Channelopathy in Patients With Brugada Syndrome and Functional Dyspepsia - A Pilot Study

BACKGROUND/AIMS

SCN5A encodes the cardiac-specific Na(V)1.5 sodium channel, and Brugada syndrome is a cardiac conduction disorder associated with sodium channel α-subunit (SCN5A) mutation. The SCN5A-encoded Na(V)1.5 channel is also found on gastrointestinal smooth muscle and interstitial cells of Cajal. We investigated the relationship between functional dyspepsia (FD) and SCN5A mutation to evaluate sodium channelopathy in FD.

METHODS

Patients with Brugada syndrome or FD were examined using upper endoscopy, electrogastrography (EGG), FD symptom questionnaire based on Rome III criteria and genetic testing for SCN5A mutation. Symptom scores of FD and EGG findings were analyzed according to SCN5A mutation.

RESULTS

A total of 17 patients (4 Brugada syndrome and 13 FD) participated in the study. An SCN5A mutation was noted in 75.0% of the patients with Brugada syndrome and in 1 (7.7%) of the patients with FD. Of 4 patients with SCN5A mutation, 2 (50%) had FD. Postprandial tachygastria and bradygastria were noted in 2 (50%) and 1 (25%) of the patients with SCN5A mutation, respectively. The EGG findings were not significantly different between positive and negative mutation in 17 patients.

CONCLUSIONS

Although we did not find statistically significant results, we suggest that it is meaningful to attempt to identify differences in symptoms and gastric myoelectric activity according to the presence of an SCN5A mutation by EGG analysis. The relationship between FD and sodium channelopathy should be elucidated in the future by a large-scale study.

Basal and stimulated hypothalamic-pituitary-adrenal axis activity in patients with functional gastrointestinal disorders and healthy controls

OBJECTIVE

The aim of this study was to investigate alterations of pituitary-adrenal activity under both stimulated and unstimulated conditions in patients with functional gastrointestinal disorders.

METHODS

Thirty subjects who fulfilled the Rome Diagnostic Criteria for either irritable bowel syndrome or nonulcer dyspepsia and 24 healthy controls took part in the study. Free salivary morning cortisol and diurnal cortisol profiles were obtained for all subjects. On a second day, a low-dose dexamethasone suppression test was applied. Additionally, in all subjects a corticotropin-releasing hormone (CRH) challenge test was performed.

RESULTS

The results show attenuated unstimulated cortisol levels in patients compared with controls. After CRH challenge, blunted adrenocorticotropic hormone and cortisol responses were observed. These findings suggest lower pituitary and adrenocortical activity in patients with functional gastrointestinal disorders.

CONCLUSION

The observed pituitary-adrenal reactivity in these patients is discussed as a possible consequence of lower adrenocortical activity, possibly resulting in a disinhibition of CRH in the brain.

Gastric myoelectrical activity and gastric emptying in patients with functional dyspepsia

OBJECTIVES

The aims of this study were to investigate gastric myoelectrical activity and gastric emptying (GE) and their relationship in patients with functional dyspepsia.

METHODS

The study was conducted in 15 healthy volunteers (six women, nine men, mean age: 42 yr) and 15 patients (13 women, two men, mean age: 43 yr) with functional dyspepsia. Gastric myoelectrical activity was recorded using cutaneous electrogastrography (EGG) for 30 min in the fasting state and for 120 min simultaneously with GE monitoring after an isotope-labeled solid meal. The anterior/posterior images of the stomach were taken using a technetium scanner immediately after eating, and then at 1, 2, and 4 h to determine the percentage of gastric retention. The dominant frequency of the EGG, the change of the postprandial EGG peak power (deltaP), and the percentage of normal 2-4 cycles/min (cpm) slow waves during each recording session were calculated and compared between the patients and healthy subjects.

RESULTS

The patients had a significantly lower mean percentage of 2-4 cpm slow waves, both in the fed state and in the fasting state, than did healthy subjects. Compared to the EGG in the fasting state, a significant increase of the EGG dominant frequency in the fed state was observed in healthy subjects but not in the patients. The mean postprandial EGG power increase in the patients was substantially less than in the healthy subjects during the first postprandial hour but similar during the second postprandial hour. The mean percentage of gastric retention in patients is substantially higher than in the healthy subjects, both at 2 h after eating and at 4 h after eating. Of 15 patients, nine (60%) had delayed GE (gastric retention at 2 h >50%) and 10 (66%) had abnormal EGGs (percentage of 2-4 cpm <70% and/or deltaP < 0). Eight of these 10 patients (80%) with abnormal EGGs had delayed GE.

CONCLUSIONS

A high proportion of adult patients (60%) with functional dyspepsia have abnormally slow GE and abnormalities in gastric myoelectrical activity.

Dyspepsia in general practice in Denmark. A 1-year analysis of consulters in general practice

OBJECTIVE

To estimate the incidence rate of patients with dyspepsia in general practice, related to age, gender and dwelling and to classify the patients into dyspepsia subgroups.

DESIGN

In a background population of 123,610 persons under the National Health Insurance System a systematic, prospective registration of dyspepsia patients consulting in general practice was done. Each patient was subject to a structured interview covering 18 dyspepsia symptoms and six alarm symptoms. A diagnostic chart was used to classify the patients into subgroups.

SETTING

General practice: 93 general practitioners in 63 centres in Denmark.

PATIENTS

Patients consulting the general practitioner with dyspepsia as their main complaint.

RESULTS

4215 dyspepsia patients were registered within 1 year. The annual incidence rate of dyspepsia was 3.4%. Alarm symptoms were present in 11.7% of the patients. The highest incidence rates were related to middle age, female gender and rural dwelling. Of these 34% had dysmotility-like, 30% had reflux-like, 17% ulcer-like and 3% uncharacteristic dyspepsia, while 16% were classified into two or more groups. Dysmotility-like dyspepsia was predominant in women and reflux-like dyspepsia was predominant in men.

CONCLUSIONS

Within 1 year 34 patients out of 1000 will seek medical advise in general practice with a new episode of dyspepsia. Based on the registration of symptoms 28 of 34 can be classified into a single subgroup of dyspepsia; 4 of 34 patients will present with one or more alarm symptom.

The epidemiology of functional gastrointestinal disorders in North America

This article has summarized the epidemiology of several disorders commonly seen in a gastroenterologist's practice. The emphasis has been on population-based data because many people with these disorders never seek health care, and psychological features have been shown to be strongly associated with health care-seeking behavior. Each of these disorders is common in the community; in fact, the majority of the population experiences intermittent gastrointestinal symptoms. In general, the national surveys sponsored by the U.S. Public Health Service have been shown to underestimate the prevalence of these conditions. In part, this is due to the fact that subjects are asked to report diagnoses rather than symptoms, and current coding schemes do not provide specific codes for each of the functional gastrointestinal disorders. Still, these studies have demonstrated the large number of physician visits and overall costs attributable to these disorders. A number of surveys of more limited populations have been done to assess the prevalence of these disorders. Rates have varied because of the definitions used and the degree to which organic diagnoses are excluded. These studies have been helpful in demonstrating the burden of illness in the community. Age and gender differences in the community have been much less marked than those identified in clinic-based studies, thus highlighting the importance of population-based research. Future studies need to focus on the incidence and natural history of these disorders. Studies of incidence cases can best evaluate the role of etiologic factors, whereas studies of prevalent cases are best for assessing the burden of disease in the community. Understanding the natural history of these disorders is important in determining the efficacy of future therapeutic interventions. The fact that these disorders represent 50% of visits to a gastroenterologist practice highlights the importance of these disorders and the potential contribution of gastrointestinal dysmotility in clinical practice.