Melatonin improves abdominal pain in irritable bowel syndrome patients who have sleep disturbances: a randomised, double blind, placebo controlled study

Pediatric functional gastrointestinal disorders

Functional gastrointestinal disorders continue to be a prevalent set of conditions faced by the healthcare team and have a significant emotional and economic impact. In this review, the authors highlight some of the common functional disorders seen in pediatric patients (functional dyspepsia, irritable bowel syndrome, functional abdominal pain) as well as one of the more intriguing (cyclic vomiting). The most recent Pediatric Rome Working Group has modified the definitions of functional gastrointestinal disorders. Current studies have used these categorizations to understand better the epidemiology, etiology, and treatment options for these disorders. As more data are available, children and their families will be offered a better understanding of the conditions and more effective treatments to overcome them. The importance of making an accurate diagnosis of a functional gastrointestinal disorder cannot be overemphasized.

Protective effect of melatonin on Ca2+ homeostasis and contractility in acute cholecystitis

Impaired Ca2+ homeostasis and smooth muscle contractility co-exist in acute cholecystitis (AC) leading to gallbladder dysfunction. There is no pharmacological treatment for this pathological condition. Our aim was to evaluate the effects of melatonin treatment on Ca2+ signaling pathways and contractility altered by cholecystitis. [Ca2+]i was determined by epifluorescence microscopy in fura-2 loaded isolated gallbladder smooth muscle cells, and isometric tension was recorded from gallbladder muscle strips. Malondialdehyde (MDA) and reduced glutathione (GSH) contents were determined by spectrophotometry and cycloxygenase-2 (COX-2) expression was quantified by western blot. Melatonin was tested in two experimental groups, one of which underwent common bile duct ligation for 2 days and another that was later de-ligated for 2 days. Inflammation-induced impairment of Ca2+ responses to cholecystokinin and caffeine were recovered by melatonin treatment (30 mg/kg). This treatment also ameliorated the detrimental effects of AC on Ca2+ influx through both L-type and capacitative Ca2+ channels, and it was effective in preserving the pharmacological phenotype of these channels. Despite its effects on Ca2+ homeostasis, melatonin did not improve contractility. After de-ligation, Ca2+ influx and contractility were still impaired, but both were recovered by melatonin. These effects of melatonin were associated to a reduction of MDA levels, an increase in GSH content and a decrease in COX-2 expression. These findings indicate that melatonin restores Ca2+ homeostasis during AC and resolves inflammation. In addition, this indoleamine helps in the subsequent recovery of functionality.

Seasonal variation in the presentation of abdominal pain

BACKGROUND

Anxiety and depression, conditions frequently associated with childhood chronic abdominal pain (AP), are characterized by seasonal exacerbations. A seasonal pattern characterized by a higher frequency of consultations for AP during winter has been suspected but has never, to our knowledge, been demonstrated. We hypothesize the presence of a seasonal variation in AP consultations with a winter predominance.

AIMS

To determine the seasonal distribution of AP consultations among centers across time and geographic latitude.

PATIENTS AND METHODS

This was a retrospective cohort study. The number of outpatient consultations from primary care clinics and every pediatric specialty clinic that resulted in a diagnosis of AP and the total number of outpatient consultations (2001-2004) from 6 tertiary care institutions (Chicago, Pittsburgh, Wilmington, Pensacola, Orlando, Jacksonville) was determined. Rates of consultations were compared across time and between cities. Four time periods of interest, with 2- and 3-month definitions, were arbitrarily selected. Seasonal rates across time were compared separately for each of the 2-month (January-February vs June-July) and 3-month periods (January-March vs June-August). Logistic regression models for each city were used to determine variations in the rate of outpatient AP cases by season or by year.

RESULTS

A total of 3,929,522 outpatient consultations and 73,591 AP consultations were analyzed. The rates of AP consultations were consistently higher in the winter months at all of the sites. The results differed between sites at northern and southern latitudes.

CONCLUSIONS

There seems to be a seasonal variation in consultation patterns for AP at the tertiary care level. A possible role of daylight hours, climate, latitude, and stress is proposed.

Exacerbated mechanical allodynia in rats with depression-like behavior

Although a clinical connection between pain and depression has long been recognized, how these two conditions interact remains unclear. Here we report that both mechanical allodynia and depression-like behavior were significantly exacerbated after peripheral nerve injury in Wistar-Kyoto (WKY) rats, a genetic variation of Wistar rats with demonstrable depression-like behavior. Administration of melatonin into the anterior cingular cortex contralateral to peripheral nerve injury prevented the exacerbation of mechanical allodynia with a concurrent improvement of depression-like behavior in WKY rats. Moreover, there was a lower plasma melatonin concentration and a lower melatonin receptor expression in the anterior cingular cortex in WKY rats than in Wistar rats. These results suggest that there exists a reciprocal relationship between mechanical allodynia and depression-like behavior and the melatoninergic system in the anterior cingular cortex might play an important role in the interaction between pain and depression.

Irritable bowel syndrome: current approach to symptoms, evaluation, and treatment

There are frequent advances in knowledge about the clinical presentation, pathophysiology, and treatment of irritable bowel syndrome. It is important for clinicians to be aware of available therapies and the supporting evidence for those therapies to increase patient satisfaction. This is best achieved with a collaborative and long-term clinician-patient relationship and mutual commitment to modify therapy and try new modalities until the greatest relief of symptoms and improvement in health-related quality of life is achieved. This article reviews symptoms, comorbidities, gender differences, and measure of severity in irritable bowel syndrome and current and evidence-based approaches to evaluation and treatment, and the new symptom-based Rome III diagnostic criteria are reviewed and explained.

Functional Dyspepsia: A New Rome III Paradigm

Functional dyspepsia (FD) is a condition commonly seen in gastroenterological practice. With the introduction of Rome III criteria in 2006, a new approach for categorizing patients has been recommended. The diagnostic criteria suggest that meal-related and pain-predominant symptom groupings that presumably have distinct pathophysiologic mechanisms and potentially different therapeutic targets exist. The new classification is in the early stages of testing; in the meantime, the umbrella term of FD should continue to be utilized in clinical practice. Treatment of FD remains a major challenge. Unfortunately, most of the agents used in practice have limited or no evidence of efficacy, and the results typically are short-lived once therapy is ceased. Appropriate therapy currently is based on a consideration of putative pathophysiologic mechanisms. Testing for and eradicating Helicobacter pylori is a first-line strategy irrespective of the symptom pattern. In patients who have epigastric pain, antisecretory agents are recommended. Antacids, bismuth, and sucralfate seem to be no better than placebo. For meal-related symptoms such as postprandial fullness or early satiety, prokinetics may confer some benefit. However, few choices are available, and the efficacy for those drugs on the market is limited at best. Antidepressants are of uncertain efficacy but are widely used. Psychological therapies seem promising and may confer benefits on both pain and meal-related symptoms. Efficacy of complementary medicines has been suggested in controlled trials, but more data are needed. Emerging treatments include gastric fundus relaxors and visceral analgesics, although their application in FD is still in the preliminary stages.

A meta-analysis of the placebo response in complementary and alternative medicine trials of irritable bowel syndrome

Among patients with irritable bowel syndrome (IBS) enrolled in clinical trials of conventional medical therapy, the placebo response rate is high. IBS patients also frequently use complementary and alternative medicine (CAM), which may act through an 'enhanced placebo effect'. The purpose of this study was to estimate the magnitude of the placebo response rate in CAM trials for IBS and to identify factors that influence this response. We performed a systematic review and meta-analysis of randomized, placebo-controlled clinical trials of CAM therapies for IBS identified from MEDLINE/EMBASE/PsychLIT databases from 1970 to 2006. Placebo and active treatment response rates for global symptom improvement were assessed. Nineteen studies met the inclusion criteria. The pooled estimate of the placebo response rate was 42.6% (95% confidence interval, 38.0-46.5%). Significant heterogeneity existed across trials (range 15.0-72.2%, P < 0.00001). Higher placebo response rates correlated with a longer duration of treatment (r = 0.455, P = 0.05) and a greater number of office visits (r = 0.633, P = 0.03). Among IBS patients in CAM trials, the placebo response rate is high. That this rate is similar in magnitude to that seen in conventional medicine trials suggests that the placebo response is independent of the type of therapy used and that it is not particularly 'enhanced' in CAM trials.

Overlap of gastro-oesophageal reflux disease and irritable bowel syndrome: prevalence and risk factors in the general population

BACKGROUND

Gastro-oesophageal reflux disease (GERD) and irritable bowel syndrome may occur more often than expected by chance, but little community data exists and risk factors are unknown.

AIM

To determine prevalence and risk factors for overlap of GERD and irritable bowel disease.

METHODS

Population-based, cross-sectional survey was conducted by mailing a valid symptom questionnaire to eligible residents of Olmsted County, MN, aged 30-95 years. Irritable bowel syndrome were defined by Rome III; GERD was defined by weekly or more frequent heartburn and/or acid regurgitation.

RESULTS

2298 questionnaires returned (women 52%, 55% response). Irritable bowel syndrome and GERD occurred together more commonly than expected by chance; the prevalence of irritable bowel syndrome-GERD overlap, GERD alone and irritable bowel syndrome alone were 3%, 15% and 5% in men, and 4%, 14% and 10% in women, respectively. Predictors of irritable bowel syndrome-GERD overlap vs. irritable bowel syndrome alone, and separately, GERD alone, were insomnia (OR 1.3, 95% CI: 1.06-1.70; OR 1.5, 95% CI: 1.13-1.90, respectively) and frequent abdominal pain (OR 3.9, 2.2-6.7; OR 1.8, 1.02-3.2, respectively). An additional predictor of irritable bowel syndrome-GERD overlap vs. GERD alone was higher somatization (OR 1.7, 1.1-2.4) and for irritable bowel syndrome-GERD overlap vs. irritable bowel syndrome alone was a higher body mass index (OR 1.0, 1.003-1.07).

CONCLUSIONS

Irritable bowel syndrome and GERD overlap is common in the population and does not occur by chance.

Novel therapeutic approaches in the treatment of irritable bowel syndrome

Az irritábilis bél szindróma (IBS) kezelése a változatos tünetek, a társuló neuropszichiátriai kórképek miatt nem könnyű feladat. Bár számos, különböző támadáspontú szert alkalmazunk a betegség kezelésére, a mai napig kevés olyan gyógyszer van, amelynek hatékonyságáról, biztonságosságáról és tolerabilitásáról egyértelmű bizonyítékok állnak rendelkezésre. Az IBS multikauzális jellegéből adódóan a visceralis hiperszenzitivitással, a motilitással, az agy-bél tengely szabályozási zavaraival kapcsolatos kutatások eredményei, a folyamatokban központi szerepet játszó neurotranszmitterek, ezek receptorainak megismerése teremtette meg az új kezelési lehetőségek alapját. Bár napjainkban néhány gyógyszert (alosetron, tegaserod) már törzskönyveztek egyes országokban IBS-ben, az új készítményekkel kapcsolatban még több, nagy betegszámú vizsgálatra van szükség.

Small intestinal motility

PURPOSE OF REVIEW

The aim of this article is to review recently published studies presenting novel and relevant information on small intestinal motility.

RECENT FINDINGS

The reviewed studies covered a variety of topics with several themes emerging. The presentation and causes of chronic intestinal dysmotility continue to expand. Evidence continues to accrue that at least a subset of patients with severe colonic inertia may have a more diffuse motility disorder highlighting the need for careful assessment prior to embarking on surgery for refractory constipation. While interest in bacterial overgrowth in irritable bowel syndrome continues, the utility and specificity of lactulose hydrogen breath testing is yet again being called into question. Methane appears to slow intestinal transit and constipation appears more common among methane-positive patients. The association is presently only correlative and further study is needed.

SUMMARY

Small intestinal motility remains an understudied area. Recent publications provide additional new information related to physiology and pathophysiology of small bowel motility. These findings should be of interest to clinician and investigator alike.

Therapeutic effect of melatonin in patients with functional dyspepsia

BACKGROUND AND GOAL

Melatonin may inhibit reactive oxygen species-related pathogenesis in the alimentary tract by neutralizing free radicals. In the present study we assessed the potential protective action of melatonin in ulcerlike dyspepsia.

STUDY

Sixty patients aged 19 to 39 years with the diagnosis of functional dyspepsia according to the Rome Criteria II and no Helicobacter pylori infection were involved in the study. Melatonin, at a dose of 5 mg (n=30), or placebo (n=30) were taken in the evening for a period of 12 weeks. At this time, patients were on an equivalent diet and were only to take an alkaline drug in case of the abdominal pain.

RESULTS

After 12 weeks, the dyspeptic symptoms completely subsided in 17 patients in the melatonin-treatment group (56.6%). In other 9 individuals (30.0%) a partial improvement in health was achieved, especially in the frequency and intensity of nocturnal pain. After placebo, the majority of patients (93.3%) did not experience any improvement in symptoms. Multivariate analysis indicated that melatonin (odds ratio 95.86, 95% confidence interval 3.72-2469.37, P<0.01) correlated independently with significantly improved patients health. H. pylori past infection decreased positive effect of melatonin in ulcerlike dyspepsia.

CONCLUSIONS

Melatonin can be considered as an auxiliary drug in the treatment of ulcerlike dyspepsia.

A preliminary study of melatonin in irritable bowel syndrome

BACKGROUND AND AIMS

Melatonin is involved in the regulation of gut motility and sensation. We aimed to determine if melatonin was effective in improving bowel symptoms, extracolonic symptoms, and quality of life (QOL) in irritable bowel syndrome (IBS) patients.

METHODS

Eighteen patients (aged 18 to 65 y; 6 females) were randomly assigned to receive either melatonin 3 mg (n=9) or matching placebo (n=9) at bed time for 8 weeks. The overall IBS scores, extracolonic IBS scores, QOL scores were assessed at 2, 4, 6, and 8 weeks during treatment and at 16, 24, and 48 weeks during follow up.

RESULTS

Compared with placebo, melatonin taken for 8 weeks significantly improved overall IBS score (45% vs. 16.66%, P<0.05). The posttreatment overall extracolonic IBS score was significantly lower (49.16% to 13.88%, P<0.05) when compared with placebo group. The overall improvement in QOL score was 43.63% in melatonin group and 14.64% in placebo group that is statistically significant.

CONCLUSIONS

The result of this study showed that melatonin has some beneficial role in IBS. Further studies using large number of patients may provide a definite answer.

Irritable bowel syndrome in the 21st century: perspectives from Asia or South-east Asia

Asian irritable bowel syndrome (IBS) studies not only confirm the truth of this functional disorder but also describe the current disease situation of this continent, with its variable socioeconomic backgrounds. Most Asian community IBS prevalence is within 5-10%, regardless of gender or ethnic character. As well as meeting the main Rome II criteria, Asian IBS subjects also have many minor symptoms. Thus this recommendation remains useful to diagnose Asian IBS. Also, female patients commonly express constipation-predominant (C-) symptoms. Extra-colonic symptoms are common in Asia, for example dyspepsia, insomnia and irritable urinary bladder. Asian IBS subjects do experience psychological disturbances including anxiety, depression, agoraphobia and neuroticism. Accordingly, their quality of life is poor and there is absenteeism leading to excessive physician visits. Abnormal gut motor and sensory functions have been indicated among the Asian IBS subjects. Now, there is evidence of altered colonic neuroimmune function leading to gut hypersensitivity and dysmotility. An Asia-Pacific trial also confirmed tegaserod efficacy on female C-IBS subjects. More than 90% of nurses have very limited IBS knowledge, and are unable even to explain it clearly. In conclusion, Western recommended criteria clearly diagnose Asian IBS and many factors are mutual leading to IBS. Current IBS treatments remain useful but additional reeducation for medical professionals appears to be needed.

Irritable bowel syndrome

Conceptually, the irritable bowel syndrome (IBS) has been considered a brain-gut functional disorder, but this paradigm is under serious challenge. There is increasing evidence that organic disease of the gastrointestinal tract can be identified in subsets of patients who fulfil the Rome criteria for IBS. Evidence for subtle inflammatory bowel disease, serotonin dysregulation, bacterial overgrowth and central dysregulation continue to accumulate. The underlying causes of IBS remain to be adequately identified, but postinfectious IBS is a clear-cut entity. Furthermore, a genetic contribution to IBS also seems likely. Diagnosis continues to be based on the symptom profile and the absence of alarm features. A heightened awareness of coeliac disease masquerading as IBS is becoming accepted. Management remains largely based on symptomatic rather than on disease-modifying therapy, but this is likely to change in the near future. Here, recent advances in the pathophysiology and management of IBS are considered.

Irritable bowel syndrome: recent and novel therapeutic approaches

Irritable bowel syndrome (IBS) is a highly prevalent functional gastrointestinal disorder affecting up to 3-15% of the general population in Western countries. It is characterised by unexplained abdominal pain, discomfort and bloating in association with altered bowel habits. The pathophysiology of IBS is considered to be multifactorial, involving disturbances of the brain-gut-axis: IBS has been associated with abnormal gastrointestinal motor functions, visceral hypersensitivity, psychosocial factors, autonomic dysfunction and mucosal inflammation. Traditional IBS therapy is mainly symptom oriented and often unsatisfactory. Hence, there is a need for new treatment strategies. Increasing knowledge of brain-gut physiology, mechanisms, and neurotransmitters and receptors involved in gastrointestinal motor and sensory function have led to the development of several new therapeutic approaches. This article provides a systematic overview of recently approved or novel medications that show promise for the treatment of IBS; classification is based on the physiological systems targeted by the medication. The article includes agents acting on the serotonin receptor or serotonin transporter system, novel selective anticholinergics, alpha-adrenergic agonists, opioid agents, cholecystokinin antagonists, neurokinin antagonists, somatostatin receptor agonists, neurotrophin-3, corticotropin releasing factor antagonists, chloride channel activators, guanylate cyclase-c agonists, melatonin and atypical benzodiazepines. Finally, the role of probiotics and antibacterials in the treatment of IBS is summarised.

Arzneimitteltherapie des Reizdarmsyndroms

The therapy of patients with irritable bowel syndrome (IBS) is often challenging, especially if a broad spectrum of symptoms is present and trigger factors, such as the influence of diet or stress, are lacking. Current pathogenetic concepts propose central or peripheral alterations that cause disturbed gastrointestinal function (motility, visceral sensitivity) and subsequent symptoms. These alterations are possibly related to psychological (stress, depression, anxiety) and biological (post-infectious residuals, micro-inflammation) influences. Since no universally effective medical treatment is available to treat the causes of the disease, standard medical therapy is symptom directed (especially for pain, constipation and diarrhoea). In addition to well established drugs (like spasmolytics, opioids and laxatives), newly developed compounds including those with other primarily indications (e.g. antidepressants) are available for highly differentiated individualized therapies. New medical approaches which are currently undergoing evaluation, promise further progress in the treatment of IBS.

Irritable bowel syndrome: update on colonic neuromuscular dysfunction and treatment

Recent discoveries regarding the relatively autonomous workings of the enteric nervous system have expanded our understanding of the pathophysiology of irritable bowel syndrome (IBS). However, the heterogeneity of the pathogenesis of IBS continues to create unique challenges for clinicians who care for these patients. Advances in our understanding of the structure and functions of the brain-gut axis and its interplay with other potentially important factors, such as genetic predisposition, inflammation, and psychological unrest, have led to new developments in the field of targeted pharmacotherapy for IBS sufferers. Therapies designed specifically to modulate gut motility, secretion, and/or sensation have been created and introduced into the marketplace in recent years, and additional designer formulations are in various stages of development. Concurrently, new discoveries of potentially beneficial effects of agents approved for other, often non-gastroenterologic, conditions continue to be reported. This article reviews the accumulating body of evidence supporting the importance of neuromuscular dysfunction as a central cause of IBS symptoms and provides a rationale for the discussion of current and future drug development.

Functional bowel disorders in rotating shift nurses may be related to sleep disturbances

OBJECTIVES

To compare the frequency and severity of bowel disturbances between rotating shift and regular day nurses and to determine whether functional bowel disorders (FBD) were related to sleep disturbances.

METHODS

Sixty regular day and 58 rotating shift nurses answered three standardized questionnaires: the Gastrointestinal Symptom Questionnaire; the Hospital Anxiety and Depression Scale; and the Irritable Bowel Syndrome Symptoms Evaluation Questionnaire, which included the Sleep Questionnaire, on the frequency and severity of gastrointestinal symptoms, sleep disturbances and psychological distress. Responses to these questions were numerically rated and the sums of individual symptom scores under the respective categories were computed and analysed using statistical tests, as appropriate.

RESULTS

Although 22 out of 58 rotating shift nurses (38%) had FBD, only 12 out of 60 regular day nurses (20%) had it (P=0.04). The mean FBD symptom score (P<0.002), sleep disturbance score (P<0.0001) and anxiety score (P<0.002) were all significantly higher among the rotating shift nurses. FBD symptom scores were positively correlated with the sleep disturbance (P=0.0001), anxiety (P=0.0001), depression (P=0.0001), well-being (P=0.0001), fatigue (P=0.0001), and somatic pain scores (P=0.0001). Sleep disturbance (P=0.04), decreased well-being (P=0.04), anxiety (P=0.02), and somatic pain (P=0.03) were independent predictors of FBD symptoms.

CONCLUSION

FBD were more common and severe among rotating shift nurses. The FBD symptom score was positively and independently correlated with the sleep disturbance score, suggesting that poor sleep might be associated with increased FBD symptoms in rotating shift nurses.

Small intestinal motility

PURPOSE OF REVIEW

To review recently published studies presenting novel and relevant information on small intestinal motility in humans and animals.

RECENT FINDINGS

Mechanisms of intestinal dysmotility in patients with pseudoobstruction and colonic inertia are becoming better clarified. The role of enteric flora in health and disease is an important and rapidly evolving area that will no doubt yield significant advances in the evaluation and treatment of many digestive disorders. The role of bacterial overgrowth in irritable bowel syndrome requires further study. The mechanisms underlying postoperative ileus are becoming both better understood and increasingly complex. Peripheral opioid antagonists may represent an important therapeutic advance in the treatment of ileus. Cannabinoids also appear to play a role in ileus and this echoes our rapidly evolving understanding of these compounds in the regulation of motility.

SUMMARY

Small intestinal motility remains an understudied area. Recent publications have shed additional light on myogenic, neural, and hormonal control mechanisms.