Functional gastrointestinal disorders and overlap syndrome in Korea

Re-investigation of functional gastrointestinal disorders utilizing a machine learning approach

BACKGROUND

Functional gastrointestinal disorders (FGIDs), as a group of syndromes with no identified structural or pathophysiological biomarkers, are currently classified by Rome criteria based on gastrointestinal symptoms (GI). However, the high overlap among FGIDs in patients makes treatment and identifying underlying mechanisms challenging. Furthermore, disregarding psychological factors in the current classification, despite their approved relationship with GI symptoms, underlines the necessity of more investigation into grouping FGID patients. We aimed to provide more homogenous and well-separated clusters based on both GI and psychological characteristics for patients with FGIDs using an unsupervised machine learning algorithm.

METHODS

Based on a cross-sectional study, 3765 (79%) patients with at least one FGID were included in the current study. In the first step, the clustering utilizing a machine learning algorithm was merely executed based on GI symptoms. In the second step, considering the previous step's results and focusing on the clusters with a diverse combination of GI symptoms, the clustering was re-conducted based on both GI symptoms and psychological factors.

RESULTS

The first phase clustering of all participants based on GI symptoms resulted in the formation of pure and non-pure clusters. Pure clusters exactly illustrated the properties of most pure Rome syndromes. Re-clustering the members of the non-pure clusters based on GI and psychological factors (i.e., the second clustering step) resulted in eight new clusters, indicating the dominance of multiple factors but well-discriminated from other clusters. The results of the second step especially highlight the impact of psychological factors in grouping FGIDs.

CONCLUSIONS

In the current study, the existence of Rome disorders, which were previously defined by expert opinion-based consensus, was approved, and, eight new clusters with multiple dominant symptoms based on GI and psychological factors were also introduced. The more homogeneous clusters of patients could lead to the design of more precise clinical experiments and further targeted patient care.

A Randomized, Double-Blinded, Placebo-controlled Study to Evaluate the Efficacy and Safety of DA-9701 (Motilitone) in Patients With Functional Dyspepsia and Constipation-type Irritable Bowel Syndrome Overlap: A Pilot Study

Background/Aims

To assess the effects and safety of DA-9701 in patients with constipation-type irritable bowel syndrome (IBS-C) which frequently accompany functional dyspepsia (FD).

Methods

FD and IBS-C were diagnosed based on the Rome III criteria. Randomized subjects were administered 30 mg of DA-9701 (Motilitone) or placebo 3 times a day for 4 weeks. The study endpoints were evaluated the percentage of responders in the overall symptom evaluation of IBS-C and FD.

Results

Thirty IBS-C patients and 30 placebos were prospectively enrolled. The proportion of responders with improvement in overall symptoms of IBS-C was 53.33% in the DA-9701 group and 40.00% in the placebo group (P = 0.301). Compared to the placebo group, the decrease of abdominal pain score in the DA-9701 group was significantly higher at week 3 in the DA-9701 group (0.96 ± 0.77 vs 0.55 ± 0.79, P = 0.042) but no significance at week 4. There was no significant difference in total IBS quality of life score at week 4 between the 2 groups (P = 0.897). Among patients with IBS-C accompanied by FD, the proportion of responders in the DA-9701 group was 50.00% (15/30), which was higher than 31.03% (9/29) of the placebo group (P = 0.138).

Conclusions

DA-9701 showed trend of treatment efficacy in patients with FD and IBS-C overlap including overall improvement, and safety, compared to placebo but without significance probably due to small numbers. It is suggested the need for a large-scale clinical trial to confirm this preliminary effect of DA-9701.

Sex and Gender Differences in Overlap Syndrome of Functional Gastrointestinal Disorder and Effect of Genetic Polymorphisms in South Korea: A Long-term Follow-up Study

BACKGROUND/AIMS

Overlap functional gastrointestinal disorder (FGID) is associated with more severe gastrointestinal symptoms and lower quality of life. The aim of this study is to evaluate clinical features of non-erosive reflux disease (NERD), functional dyspepsia, irritable bowel syndrome, their overlap in terms of sex and gender, and to assess the risk factors, including genetic polymorphisms.

METHODS

A total of 494 FGIDs and 239 controls were prospectively enrolled between 2004 and 2020. FGIDs were diagnosed based on the Rome III criteria and symptoms were evaluated using a questionnaire. Follow-up questionnaires were conducted to determine the change of symptoms during the 75.8-month mean observation period. Risk factors including genetic polymorphisms in neurotransmitter receptor (SLC6A4 5-HTTLPR, GNB3, ADRA2A, CCKAR, and TRPV1) and cytokine (TNFA and IL10) genes.

RESULTS

NERD was more prevalent in men, and functional dyspepsia in women. Overlap FGIDs (n = 239) were more prevalent than nonoverlap FGIDs (n = 255) in women (P = 0.019). Anxiety and depression scores were higher in the overlaps (P = 0.012 and P < 0.001, respectively). Symptoms were more frequent and severe in the overlap FGIDs than in the non-overlaps (P < 0.001). During followup, symptoms progressed more frequently in the overlap FGIDs, especially in patients with the L/S genotype of SLC6A4 5-HTTLPR and anxiety/depression.

CONCLUSIONS

Overlap FGID patients need attention given their association with anxiety/depression and more severe symptoms, especially in women. Genetic polymorphisms also may be associated with certain symptoms of overlap FGIDs.

Sex and Gender Differences in Overlap Syndrome of Functional Gastrointestinal Disorder and Effect of Genetic Polymorphisms in South Korea: A Long-term Follow-up Study

Background/Aims

Overlap functional gastrointestinal disorder (FGID) is associated with more severe gastrointestinal symptoms and lower quality of life. The aim of this study is to evaluate clinical features of non-erosive reflux disease (NERD), functional dyspepsia, irritable bowel syndrome, their overlap in terms of sex and gender, and to assess the risk factors, including genetic polymorphisms.

Methods

A total of 494 FGIDs and 239 controls were prospectively enrolled between 2004 and 2020. FGIDs were diagnosed based on the Rome III criteria and symptoms were evaluated using a questionnaire. Follow-up questionnaires were conducted to determine the change of symptoms during the 75.8-month mean observation period. Risk factors including genetic polymorphisms in neurotransmitter receptor (SLC6A4 5-HTTLPR, GNB3, ADRA2A, CCKAR, and TRPV1) and cytokine (TNFA and IL10) genes.

Results

NERD was more prevalent in men, and functional dyspepsia in women. Overlap FGIDs (n = 239) were more prevalent than non-overlap FGIDs (n = 255) in women (P = 0.019). Anxiety and depression scores were higher in the overlaps (P = 0.012 and P < 0.001, respectively). Symptoms were more frequent and severe in the overlap FGIDs than in the non-overlaps (P < 0.001). During follow-up, symptoms progressed more frequently in the overlap FGIDs, especially in patients with the L/S genotype of SLC6A4 5-HTTLPR and anxiety/depression.

Conclusions

Overlap FGID patients need attention given their association with anxiety/depression and more severe symptoms, especially in women. Genetic polymorphisms also may be associated with certain symptoms of overlap FGIDs.

Psychological Factors Influence the Overlap Syndrome in Functional Gastrointestinal Disorder and Quality of Life among Psychiatric Patients in South Korea

OBJECTIVE

The aim of this study was to investigate the predictor variables that could influence overlap syndrome in functional gastrointestinal disorders (FGID) among psychiatric patients.

METHODS

Data collected from 170 outpatients visiting the psychiatric clinic at a university hospital. FGIDs were screened according to the Rome III questionnaire-Korean version. Demographic factors were investigated, and psychosocial factors were evaluated using the Hospital Anxiety Depression Scale, Patient Health Questionnaire-15, Childhood Trauma Questionnaire-Korean and the Short form health survey. Chi-squared test, Student's t-test, one-way ANOVA, and Pearson's correlation test were used as statistical analysis methods.

RESULTS

There were no differences in the epidemiologic data between the two groups divided according to the FGID status. In those with FGID overlap syndrome, FD-NERD was most common (n=29), followed by IBS-NERD (n=20). Patients with overlap syndrome had the highest depressive, anxiety, and somatic symptoms. The overlap syndrome group had the lowest physical component summary and mental component summary. FGID symptom severity was significantly correlated with PCS and MCS in the overlap syndrome group.

CONCLUSION

Psychological factors are associated with the overlap syndrome of FGID. Acknowledging this common comorbidity may facilitate the recognition and treatment of patients with FGID.

Work-Life Conflict and Its Health Effects on Korean Gastroenterologists According to Age and Sex

BACKGROUND

This study aimed to evaluate the work-life pattern and prevalence of occupation-related symptoms, as well as the effect of work-life balance on health status according to age and sex among Korean gastroenterologists.

METHODS

A total of 222 gastroenterologists from 44 nationwide centers in South Korea participated in an anonymized self-responded electronic questionnaire survey about their daily activities and symptoms for 14 days. Musculoskeletal, gastrointestinal and mental symptoms were scored using a numerical scale. The Maslach Burnout Inventory was used to measure the burnout score.

RESULTS

Korean gastroenterologists (124 men and 98 women) spent 71.5 ± 19.0 h/week for work (54.0 ± 16.2 in-hospital and 17.5 ± 9.5 out-of-hospital), without any differences regarding sex. However, women spent more time performing housework and parenting (20.7 ± 19.0) compared to men (14.3 ± 13.3, P = 0.007). Musculoskeletal pain was found in 199 respondents (89.6%), and women had a higher total pain score compared to men in all age groups (P = 0.016). Gastrointestinal and mental symptoms were found in 119 (53.6%) and 153 (68.9%), respectively. Work-life ratio was significantly correlated with musculoskeletal (P < 0.001), gastrointestinal (P = 0.048) and mental symptoms (P = 0.003). Using the Maslach Burnout Inventory, 64.4% of the respondents demonstrated burnout. Moreover, emotional exhaustion, depersonalization and personal accomplishment scores were worst in women in their 30s or 40s.

CONCLUSION

Korean gastroenterologists suffered from musculoskeletal, gastrointestinal and mental symptoms and were highly prone to burnout due to long and laboring work. Work-life imbalance and burnout were most severe in young women doctors due to their domestic demands.

The Effect of Trimebutine on the Overlap Syndrome Model of Guinea Pigs

Background/Aims

Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are common gastrointestinal (GI) disorders and these patients frequently overlap. Trimebutine has been known to be effective in controlling FD co-existing diarrhea-dominant IBS, however its effect on overlap syndrome (OS) patients has not been reported. Therefore, we investigated the effect of trimebutine on the model of OS in guinea pigs.

Methods

Male guinea pigs were used to evaluate the effects of trimebutine in corticotropin-releasing factor (CRF) induced OS model. Different doses (3, 10, and 30 mg/kg) of trimebutine were administered orally and incubated for 1 hour. The next treatment of 10 μg/kg of CRF was intraperitoneally injected and stabilized for 30 minutes. Subsequently, intragastric 3 mL charcoal mix was administered, incubated for 10 minutes and the upper GI transit analyzed. Colonic transits were assessed after the same order and concentrations of trimebutine and CRF treatment by fecal pellet output assay.

Results

Different concentrations (1, 3, and 10 μg/kg) of rat/human CRF peptides was tested to establish the OS model in guinea pigs. CRF 10 μg/kg was the most effective dose in the experimental OS model of guinea pigs. Trimebutine (3, 10, and 30 mg/kg) treatment significantly reversed the upper and lower GI transit of CRF induced OS model. Trimebutine significantly increased upper GI transit while it reduced fecal pellet output in the CRF induced OS model.

Conclusions

Trimebutine has been demonstrated to be effective on both upper and lower GI motor function in peripheral CRF induced OS model. Therefore, trimebutine might be an effective drug for the treatment of OS between FD and IBS patients.

Identification and validation of functional gastrointestinal disorder subtypes using latent class analysis: a population-based study

OBJECTIVE

Attempts to categorize distinct functional gastrointestinal disorders based on reported symptoms continue but symptoms frequently overlap. The study objective was to use latent class analysis (LCA) which accommodates both continuous and discrete manifest variables to determine mutually exclusive subgroup assignments of a population-based sample using gastrointestinal symptom and patient data.

MATERIALS AND METHODS

A validated bowel disease questionnaire and somatic symptom questionnaire were mailed to an age and gender stratified randomly selected community sample. Responses to the symptom questions were dichotomized as frequent vs. infrequent based on Rome IV criteria. A LCA model was developed using a calibration subset and the results applied to the validation subset.

RESULTS

There were 3831 total respondents (48%) with 3425 having complete data. The LCA algorithm was run for each of 10 (random) splits of the dataset and 2-6 latent classes were specified. Using the values of Akaike's Information Criterion coefficient c to determine fit of the data, 4 latent classes yielded better values resulting in four subgroups: 'asymptomatic,' 'upper' abdominal symptoms, 'lower' abdominal symptoms, and 'mixed' (upper and lower abdomen).

CONCLUSIONS

Latent class analysis identified 4 groups based on symptoms. This approach resulted in differentiation by anatomical region rather than the Rome IV classification of symptoms.

Irritable bowel syndrome in Asia: Pathogenesis, natural history, epidemiology, and management

Historically, the epidemiology of gastrointestinal diseases in Asia was different from that in Western countries. Early studies suggested a low prevalence of irritable bowel syndrome (IBS) in Asia. As the diagnosis of IBS is symptom-based and as symptom perception, expression, and interpretation are influenced by sociocultural perspectives including language, the presentation of IBS is expected to vary in different communities. Furthermore, the pathogenesis is multifactorial with psychosocial (stress, illness, behavior, and diet) and biological (infection, gut microbiota, and immune activation) variables interacting, and so, the present study can anticipate that the development of IBS will vary in different environments. In recognition of this aspect of functional gastrointestinal disorders, the recently published Rome IV documents have provided greater focus on cross-cultural factors. In this review, the present study seeks to highlight Asian perspectives by identifying historical trends and recent publications from the region and comparing these with the observations from Western societies.

Nationwide Multicenter Study for Overlaps of Common Functional Gastrointestinal Disorders in Korean Patients With Constipation

Background/Aims

In spite of increased concerns about the overlaps among the various functional gastrointestinal disorders (FGIDs), studies for the overlap between constipation and other common FGIDs are rare. Therefore, we investigated the patterns of overlaps between constipation and other common FGIDs.

Methods

This study was designed as a prospective nationwide multi-center questionnaire study using Rome III questionnaires for functional dyspepsia (FD), irritable bowel syndrome (IBS), and functional constipation (FC), as well as various questionnaires about patients' information, degree of symptoms, and quality of life. For the evaluation of gastroesophageal reflux disease (GERD), GERD-Q was used.

Results

From 19 centers, 759 patients with constipation were enrolled. The proportions of FC and IBS subtypes of constipation (IBS-C) were 59.4% and 40.6%, respectively. Among them, 492 (64.8%) showed no overlap. One hundred and thirty-six patients (17.9%) presented overlapping GERD, and 80 patients (10.5%) presented overlapping FD. Fifty one (6.7%) of patients were overlapped by both GERD and FD. Coincidental herniated nucleus pulposus (HNP) (P = 0.026) or pulmonary diseases (P = 0.034), reduced fiber intake (P = 0.013), and laxative use (P < 0.001) independently affected the rate of overlaps. These overlapping conditions negatively affected the constipation-associated quality of life, general quality of life, and degree of constipation.

Conclusions

The overlap of GERD or FD was common in patients with constipation. Coincidental HNP or pulmonary diseases, reduced fiber intake, and laxatives use were found to be independent associated factors for overlapping common FGIDs in Korean patients with constipation.

The Effect of Peripheral CRF Peptide and Water Avoidance Stress on Colonic and Gastric Transit in Guinea Pigs

Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are common gastrointestinal (GI) diseases; however, there is frequent overlap between FD and IBS patients. Emerging evidence links the activation of corticotropin releasing factor (CRF) receptors with stress-related alterations of gastric and colonic motor function. Therefore, we investigated the effect of peripheral CRF peptide and water avoidance stress (WAS) on upper and lower GI transit in guinea pigs. Dosages 1, 3, and 10 μg/kg of CRF were injected intraperitoneally (IP) in fasted guinea pigs 30 minutes prior to the intragastric administration of charcoal mix to measure upper GI transit. Colonic transits in non-fasted guinea pigs were assessed by fecal pellet output assay after above IP CRF doses. Blockade of CRF receptors by Astressin, and its effect on GI transit was also analyzed. Guinea pigs were subjected to WAS to measure gastrocolonic transit in different sets of experiments. Dose 10 μg/kg of CRF significantly inhibited upper GI transit. In contrast, there was dose dependent acceleration of the colonic transit. Remarkably, pretreatment of astressin significantly reverses the effect of CRF peptide on GI transit. WAS significantly increase colonic transit, but failed to accelerate upper GI transit. Peripheral CRF peptide significantly suppressed upper GI transit and accelerated colon transit, while central CRF involved WAS stimulated only colonic transit. Therefore, peripheral CRF could be utilized to establish the animal model of overlap syndrome.

Stress and sleep quality in doctors working on-call shifts are associated with functional gastrointestinal disorders

AIM

To investigate the role of sleep quality and psychosocial problems as predictors of functional gastrointestinal disorders (FGIDs) in doctors that work 24 hour-on-call shifts.

METHODS

In this cross-sectional observation study, using the Rome III Questionnaire and Pittsburgh Sleep Quality Index (PSQI), we analyzed 170 doctors with 24 hour-on-call shifts.

RESULTS

Among the participants that had experienced a 24 hour-on-call shift within the last 6 mo, 48 (28.2%) had FGIDs. Overall prevalence of irritable bowel syndrome (IBS) and functional dyspepsia (FD) were 16.5% and 17.1%, respectively, with 5.3% exhibiting both. Sleep scores (PSQI) (8.79 ± 2.71 vs 7.30 ± 3.43, P = 0.008), the presence of serious psychosocial alarm (83.3% vs 56.6%, P = 0.004), and the proportion of doctors who experienced over two months of recent on-call work (81.2% vs 68.9%, P = 0.044) were significantly different between individuals with or without FGIDs. Multivariate analysis revealed that presenting serious psychosocial alarm was an independent risk factor for prevalence of FD (OR = 5.47, 95%CI: 1.06-28.15, P = 0.042) and poor sleep quality (PSQI ≥ 6) was a predictor of IBS (OR = 4.17, 95%CI: 1.92-19.02, P = 0.016).

CONCLUSION

Physicians should recognize the role of sleep impairment and psychological stress in the development of FGIDs and a comprehensive approach should be considered to manage patients with FGIDs.

Overlap of Dyspepsia in Patients with Gastroesophageal Reflux Disease: Impact of Clinical, Metabolic, and Psychosocial Characteristics

BACKGROUND

Gastroesophageal reflux disease (GERD) and dyspepsia are highly prevalent in the general population with significant symptom overlap, while the interaction between both remains poorly understood.

AIM

To examine whether GERD overlapping dyspepsia would have an impact on clinical and psychological features as compared with GERD alone.

METHODS

We performed a cross-sectional study in a GERD cohort (n = 868) that was previously recruited from a population-based GERD survey (n = 2752). We compared the clinical and psychological factors between patients with and without dyspeptic symptoms "epigastric pain or burning." All participants were evaluated with Reflux Disease Questionnaire score, Pittsburgh Sleep Quality Index score, Taiwanese Depression Questionnaire score, and State-Trait Anxiety Inventory score. Endoscopic findings were classified according to the Los Angeles classification.

RESULTS

Among the GERD population, 107 subjects had overlapping "epigastric pain or burning" (GERD-D), and 761 did not have these symptoms (GERD alone). GERD-D subjects had more severe GERD symptoms and were more often associated with irritable bowel syndrome (IBS) (OR 3.54, 95% CI 1.92-6.52) as compared subjects with GERD alone. In addition, GERD-D subjects had lower quality of sleep (OR 1.11, 95% CI 1.01-1.21), higher depression (OR 1.06, 95% CI 1.02-1.10), lower blood pressure (OR 0.45, 95% CI 0.22-0.95), and higher serum total cholesterol levels (OR 2.78, 95% CI 1.36-5.67) than GERD alone.

CONCLUSIONS

GERD-D subjects are characterized with worsening clinical symptoms as well as higher psychosocial, IBS, and metabolic comorbidities, but less erosive esophagitis. Our results indicate that clinical awareness of such overlapping condition would help optimize the management of GERD in clinical practice.

Psychological factors influence the overlap syndrome in functional gastrointestinal disorders (FGIDs) among middle-aged women in South Korea

This study investigated the psychological factors related to the overlap syndrome, i.e., multiple gastrointestinal conditions that are part of functional gastrointestinal disorders (FGIDs) in the same individual and potentially related to quality of life (QOL) among women aged 45-60 years (n = 627) in South Korea. The study was undertaken between July 2014 and March 2015. Depressive and anxiety symptoms were ascertained using the Center for Epidemiologic Studies Depression scale (CES-D) and the Beck Anxiety Inventory (BAI), respectively. Negative cognition and the cognitive triad were identified using the Automatic Thoughts Questionnaire-Negative (ATQ-N) and the Cognitive Triad Inventory (CTI), respectively. Resilience and QOL were assessed using the Connor-Davidson Resilience Scale (CD-RISC) and World Health Organization Quality of Life scale abbreviated version (WHOQOL-BREF). Women with the overlap syndrome had the highest CES-D (mean = 16.66 ± 11.79, p < .001), BAI (mean = 17.46 ± 12.67, p < .001), and ATQ-N scores (mean = 53.61 ± 20.88, p < .001), followed by women with gastrointestinal disorders but without the overlap syndrome and healthy controls. Healthy controls had the highest WHOQOL-BREF score (mean = 77.69 ± 12.53, p < .001). After stepwise selection, the final model explained 61.8 percent of the variance in QOL. Thus, depressive symptoms, anxiety, negative cognition, cognitive triad, and resilience were significantly related to QOL in women with the overlap syndrome.

Psychological factors influence the overlap syndrome in functional gastrointestinal disorders and their effect on quality of life among firefighters in South Korea

OBJECTIVE

The aim of this study was to investigate the predictor variables that could influence overlap syndrome in functional gastrointestinal disorders (FGID) among firefighters in Korea.

METHODS

Data collected from 1217 firefighters in Korea were reviewed. FGID were diagnosed according to the Rome III diagnostic criteria. Psychological factors were measured by self-reported questionnaires. The scores for depression, anxiety, quality of life (QOL) and occupational job stress were analyzed. The correlation between psychological factors and QOL was analyzed and a stepwise multiple regression analysis was performed.

RESULTS

FGID were observed in 461 (37.9%) participants. In those with FGID, functional heartburn (FH) was most common (32.2%), followed by functional dyspepsia (12.2%). Patients with overlap syndrome had the highest depression, anxiety and occupational stress score than those having non-overlap syndrome and healthy controls, respectively (depression: F = 142.29, η(2)  = 0.190; anxiety: F = 88.33, η(2)  = 0.127; occupational stress: F = 43.68, η(2)  = 0.067; all P < 0.001). Healthy controls had the highest QOL score (F = 73.39, P < 0.001, η(2)  = 0.108). Pychological factors were significantly correlated with QOL in the overlap syndrome of FGID. After the stepwise selection, the final model explained 45.6% of predictable variance and contained four significant variables: depression, self-esteem, occupational stress and anxiety.

CONCLUSIONS

Psychological factors are associated with the overlap syndrome of FGID. Acknowledging this common comorbidity may facilitate the recognition and treatment of patients with FGID.

Women and functional dyspepsia

Functional dyspepsia is relatively common yet poorly understood. The best accepted diagnostic criteria are the Rome III criteria. The epidemiology, healthcare seeking rates, impact and pathophysiology are reviewed with a focus on women. Treatment is limited with no clearly established regimen currently recommended. Duodenal eosinophilia may be found in a subset. Proton pump inhibitors and prokinetic agents represent the standard therapeutic regimen after Helicobacter pylori infection has been eliminated. Some novel agents such as the prokinetic acotiamide appear promising; however, the need for a safe and efficacious treatment remains largely unmet. This review also describes the currently available management options for functional dyspepsia.

Functional dyspepsia is associated with GNβ3 C825T and CCK-AR T/C polymorphism

BACKGROUND

A polymorphism (C825T) in G-protein β polypeptide-3 (GNβ3) gene alters intracellular signal transduction, which may cause motor or sensory abnormalities in the gastrointestinal tract. Cholecystokinin-A receptor (CCK-AR) gene T/C polymorphism is associated with a defective splicing of the primary transcript of CCK-AR mRNA, which may modulate satiety signal and delay gastric emptying. Therefore, we evaluated the role of these polymorphisms in patients with functional dyspepsia (FD) as compared with healthy controls (HC).

PATIENTS AND METHODS

A total of 237 consecutive patients with FD (Rome III) and 250 HC were genotyped for GNβ3 C825T and CCK-AR T/C polymorphisms (PCR-RFLP).

RESULTS

Patients with FD [173 (73%) men, age: 38 ± 12 years] were comparable with HC [195 (78%) men, age: 37 ± 12 years] with respect to age and sex. Out of 237 patients, 26 (11%) had epigastric pain syndrome (EPS), 55 (23.2%) had postprandial distress syndrome (PDS), and 156 (65.8%) had EPS-PDS overlap. Among 237 patients with FD, TT genotype (associated with increased intracellular signal transduction) of GNβ3 C825T polymorphism was more common among patients than among HC [26 (11%) vs. 12 (4.8%), P=0.014; odds ratio (OR): 2.47, 95% confidence interval (CI): 1.2-5.1]. CC (variant) genotype of CCK-AR T/C polymorphism was infrequent among patients than among HC [19 (8%) vs. 46 (18.4%), P=0.001; OR: 0.36, 95% CI: 0.19-0.66]. However, these polymorphisms were comparable among patients with different subtypes of FD (P=0.80 and 0.44).

CONCLUSION

TT genotype of GNβ3 C825T is more common among patients with FD than among HC, suggesting that increased signal transduction associated with this genotype may be important in its pathophysiology. However, CCK-AR polymorphism is protective against FD.

Development, Translation and Validation of Enhanced Asian Rome III Questionnaires for Diagnosis of Functional Bowel Diseases in Major Asian Languages: A Rome Foundation-Asian Neurogastroenterology and Motility Association Working Team Report

BACKGROUND/AIMS

The development-processes by regional socio-cultural adaptation of an Enhanced Asian Rome III questionnaire (EAR3Q), a cultural adaptation of the Rome III diagnostic questionnaire (R3DQ), and its translation-validation in Asian languages are presented. As English is not the first language for most Asians, translation-validation of EAR3Q is essential. Hence, we aimed to culturally adapt the R3DQ to develop EAR3Q and linguistically validate it to show that the EAR3Q is able to allocate diagnosis according to Rome III criteria.

METHODS

After EAR3Q was developed by Asian experts by consensus, it was translated into Chinese, Hindi-Telugu, Indonesian, Korean and Thai, following Rome Foundation guidelines; these were then validated on native subjects (healthy [n = 60], and patients with irritable bowel syndrome [n = 59], functional dyspepsia [n = 53] and functional constipation [n = 61]) diagnosed by clinicians using Rome III criteria, negative alarm features and investigations.

RESULTS

Experts noted words for constipation, bloating, fullness and heartburn, posed difficulty. The English back-translated questionnaires demonstrated concordance with the original EAR3Q. Sensitivity and specificity of the questionnaires were high enough to diagnose respective functional gastrointestinal disorders (gold standard: clinical diagnoses) in most except Korean and Indonesian languages. Questionnaires often uncovered overlapping functional gastrointestinal disorders. Test-retest agreement (kappa) values of the translated questionnaires were high (0.700-1.000) except in Korean (0.300-0.500) and Indonesian (0.100-0.400) languages at the initial and 2-week follow-up visit.

CONCLUSIONS

Though Chinese, Hindi and Telugu translations were performed well, Korean and Indonesian versions were not. Questionnaires often uncovered overlapping FGIDs, which were quite common.

Overlap in patients with dyspepsia/functional dyspepsia

Patients with dyspepsia/functional dyspepsia (FD) show frequent overlapping of other gastrointestinal (GI) diseases, such as irri-table bowel syndrome, and non-GI diseases, in addition to internal subgroup overlapping. These overlap patients have more frequent or more severe symptoms, poorer health-related quality of life and higher somatization scores, and they are more like-ly to experience anxiety, depression or insomnia compared to non-overlap patients. The higher prevalence of overlap in patients with dyspepsia/FD is not by chance, indicating common pathogeneses, including visceral hypersensitivity, altered GI motility, in-fection, and stressful early life events. There are few clinical trials targeting overlap in patients with dyspepsia/FD, and no ther-apeutic strategy has been established. Further studies in this research area are needed. In this review, we describe the epidemi-ology, pathogenesis and treatment of overlap in patients with dyspepsia/FD.(J Neurogastroenterol Motil 2014;20:447-457).

Association of SLC6A4 5-HTTLPR and TRPV1 945G>C with functional dyspepsia in Korea

BACKGROUND AND AIM

The association of various genetic polymorphisms with functional dyspepsia (FD) has been suggested, but the results were still controversial. The aim of the present study was to assess the association of GNB3 825C>T, SLC6A4 5-HTTLPR, ADRA2A-1291C>G, CCK-1R intron 779T>C, and TRPV1 945G>C polymorphisms with FD based on Rome III criteria in Korea.

METHODS

Study subjects were prospectively recruited from visitors to Seoul National University Bundang Hospital between 2009 and 2012. One hundred and twelve FD patients and 269 controls were enrolled.

RESULTS

In SLC6A4 5-HTTLPR polymorphism, the frequency of S/S genotype was significantly lower than that of L/L + L/S genotype in FD compared to controls (P < 0.05). After stratification according to Helicobacter pylori infection, the S/S genotype was significantly associated with H. pylori-positive epigastric pain syndrome (EPS) patients (adjusted odds ratio (OR) 0.46; 95% confidence interval (CI) 0.22-0.99; P = 0.048). In TRPV1 945G>C polymorphism, the frequency of C/C genotype was lower in FD compared to controls (P = 0.057). The C carrier and C/C genotype was significantly associated with postprandial distress syndrome (PDS) and EPS, respectively (adjusted OR 0.47 and 0.43; 95% CI 0.25-0.90 and 0.20-0.93; P = 0.021 and 0.033). After stratification, the significant associations remained in H. pylori-positive PDS and EPS patients (adjusted OR 0.37 and 0.28; 95% CI 0.16-0.88 and 0.09-0.85; P = 0.024 and 0.025).

CONCLUSIONS

The genetic polymorphism of SLC6A4 5-HTTLPR and TRPV1 945G>C could be one of the pathophysiological factors of FD, especially in the case of H. pylori-positive patients in Korea.

Psychosocial stress in nurses with shift work schedule is associated with functional gastrointestinal disorders

Background/Aims

The aim of this study was to investigate the role of psychosocial problems and their associations with rotating shift work in the development of functional gastrointestinal disorders.

Methods

In this cross-sectional observation study, survey was administered to nurses and nurse assistants in a referral hospital. In addition to demographic questions, subjects were asked to complete the Rome III Questionnaire, Pittsburgh Sleep Quality Index and Rome III Psychosocial Alarm Questionnaire.

Results

Responses from 301 subjects were assessed. The overall prevalence of irritable bowel syndrome (IBS) and functional dyspepsia (FD) were 15.0% and 19.6%, respectively. Psychosocial alarms were prevalent in the nursing personnel (74.8% with alarm presence and 23.3% with serious condition) and were more frequent among rotating shift workers (84.7% vs. 74.5% for alarm presence and 28.1% vs. 13.3% for serious condition). The prevalence of both IBS and FD significantly increased with psychosocial risk. An independent risk factor for IBS was serious psychosocial alarm (adjusted odds ratio [aOR], 10.75; 95% confidence interval (CI), 1.30–88.99; P = 0.028). Serious psychosocial alarm was an independent risk factor for FD (aOR, 7.84; 95% CI, 1.98–31.02; P = 0.003). Marriage (aOR 0.30; 95% CI, 0.09–0.93; P = 0.037) was associated with the decreased risk of FD.

Conclusions

The high prevalence of psychosocial stress among nurses who work rotating shifts is associated with the development of functional gastrointestinal disorders.

Relationship between IL-10 promoter gene polymorphisms and plasma level and susceptibility to overlap syndrome of diarrhea irritable bowel syndrome and functional dyspepsia

AIM: To investigate the relationship between interleukin-10 (IL-10) promoter gene polymorphisms and plasma levels and susceptibility to overlap syndrome of diarrhea irritable bowel syndrome (D-IBS) and functional dyspepsia (FD).

METHODS: Blood samples were collected from 164 patients and 200 healthy controls and genomic DNA was extracted. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine the genotypes in the -592A/C site, and amplification refractory mutation system polymerase chain reactions (ARMS-PCR) and DNA sequencing were performed to detect the polymorphism of the -1082G/A site. IL-10 plasma levels were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS: The -592A/C site in the IL-10 gene showed no significant differences in genotypes or allele frequency between the D-IBS-FD overlap syndrome group and control group, but the frequency of -592 CC genotype was significantly decreased in the D-IBS-FD overlap syndrome group. Compared with the CC genotype, the AA genotype and the AA+AC genotypes increased the risk of D-IBS-FD overlap syndrome 1.989 and 1.808 times, respectively. There were no significant differences in the distribution or the allele frequency of -1082 genotypes, the genotypes of the combination of -592 and -1082, and the distribution of the genotypes of different IL-10 levels between the D-IBS-FD overlap syndrome and healthy control groups. The average plasma IL-10 levels were significantly lower in patients with D-IBS-FD overlap syndrome than in healthy controls (14.60 pg/mL ± 7.14 pg/mL vs 22.86 pg/mL ± 10.62 pg/mL, P < 0.001). Among patients with D-IBS-FD overlap syndrome, the average plasma IL-10 levels in patients with -592 AA, -592 AC, -592 CC, and -592 AA+AC genotypes were 14.50 pg/mL ± 6.37 pg/mL, 14.85 pg/mL ± 7.75 pg/mL, 13.92 pg/mL ± 7.63 pg/mL, 14.68 pg/mL ± 7.10 pg/mL, respectively, which showed no significant differences. Plasma IL-10 levels showed no significant difference between the carriers of A allele and non-carriers.

CONCLUSION: The -592A site in IL-10 gene promoter and lower IL-10 plasma level may be associated with susceptibility to overlap syndrome of D-IBS and FD, but there is no association between them.

No association of G-protein beta polypeptide 3 polymorphism with irritable bowel syndrome: Evidence from a meta-analysis

AIM: To clarify the associations between G-protein beta polypeptide 3 (GNB3) C825T polymorphism and risk of the irritable bowel syndrome (IBS) by a meta-analysis.

METHODS: We searched relevant studies in PubMed, EMBASE, CNKI, Google Scholar, Ovid and Cochrane library prior to October 2013. The strengths of the associations between GNB3 C825T polymorphism and IBS risk were estimated by odds ratios (ORs) with 95% confidence interval (CIs).

RESULTS: We identified seven case-control studies with 1085 IBS cases and 1695 controls for the analysis. We found no significantly associations of GNB3 C825T polymorphism with IBS risk in the overall population (CC vs TT, OR = 1.12, 95%CI: 0.86-1.45; CC + CT vs TT, OR = 1.17, 95%CI: 0.92-1.49; TT + CT vs CC, OR = 0.93, 95%CI: 0.80-1.08; C vs T, OR = 1.08, 95%CI: 0.97-1.21). Subgroup analysis did not reveal significant associations either in Asian population or Caucasian population. The pooled results of four studies fail to show associations of GNB3 C825T polymorphism with subtypes of IBS (constipation-dominant type, diarrhea-dominant type and mixed type).

CONCLUSION: The present study suggests no associations of GNB3 C825T polymorphism with IBS risk.

Irritable bowel syndrome in middle-aged and elderly Palestinians: its prevalence and effect of location of residence

OBJECTIVES

The prevalence of irritable bowel syndrome (IBS) around the world is variable, ranging from as little as 1.1 to 45%. Limited studies have been carried out in Arab populations. The aim of this study was to determine the prevalence of IBS and its subtypes in the West Bank, Palestine, and to assess variation by locality of residence.

METHODS

We conducted a population-based, cross-sectional study. Participants were randomly selected from all districts of the West Bank, including cities, villages, and refugee camps, and they were at least 50 years of age. Participants completed the Rome III IBS questionnaire along with demographic data. The primary outcome was the effect of location of residence on the prevalence of IBS. A multivariable logistic regression model was used to assess the difference in IBS prevalence based on locality of residence.

RESULTS

A total of 1,601 people were approached for interview, of which 1,352 agreed to participate (response rate 84%). Most participants (53%; n=637) lived in urban centers. The overall prevalence of IBS was 30% (28-33%). IBS was more common in refugee camps (34%) and in villages (34%) compared with urban centers (27%) (P<0.05). Mixed IBS (IBS-M) was the most common of IBS subtypes (55%, n=244). In a multivariable logistic regression analysis, living in refugee camps (odds ratio (OR) 1.68 (95% confidence interval (CI) 1.14-2.40), P=0.005) and in villages (OR 1.33 (1.02-1.72), P=0.033) was associated with increased odds of having IBS when compared with residents of urban centers. IBS, IBS with constipation, and IBS-M were more common in women than in men (P<0.05).

CONCLUSIONS

The prevalence of IBS among middle-aged and elderly residents of Palestine is high. Residents in refugee camps and rural areas have a higher incidence of IBS than those in urban areas.

Current status of functional dyspepsia in Korea

Dyspepsia refers to group of commonly occurring upper gastrointestinal symptoms. The majority of patients with dyspepsia suffer from functional (nonulcer) dyspepsia. Although there is a lack of epidemiological data from population-based or patient cohort studies in Korea, the current understanding of this condition has been updated using data from various recent research studies, which have facilitated the development of clinical guidelines for functional dyspepsia. According to a survey using the Rome III criteria, more than 40% of respondents who visited primary clinics and tertiary hospitals were defined as having functional dyspepsia, most of who were within a subgroup of patients with postprandial distress syndrome. In addition, a population-based cross-sectional survey revealed considerable overlap between functional dyspepsia and other functional gastrointestinal disorders, including gastroesophageal reflux disease (especially nonerosive reflux disease) and irritable bowel syndrome. In contrast to the results of Western trials, there is insufficient evidence to recommend a Helicobacter pylori test-and-treat strategy as an initial management approach to functional dyspepsia in Korea, suggesting the need for early endoscopic evaluation. Additional studies are necessary to adjust the cutoff age for implementation of immediate endoscopic evaluation of patients without alarm symptoms. Considering the prevalence of H. pylori infection and the limited efficacy of symptomatic relief after its eradication, further well-qualified studies in Korea are warranted.

[Natural history and overlap of functional gastrointestinal disorders]

Functional gastrointestinal (GI) disorders are common in the general population. Based on the Rome III classification, these disorders are mutually exclusive disorders keeping the homogeneity of each functional GI disorder in research area. In contrast, many population and clinical studies have reported a considerably high rate of overlap between functional GI disorders. The overlap of functional GI disorders over other intestinal diseases might simply occur by chance due to a highly prevalent disorder. Moreover, functional GI disorders is considered a chronic stable disorder that may wax and wane for several years. However, a recent study about the natural history of functional GI disorders showed substantial transition among functional GI disorders over time. The natural history of functional GI disorders with overlapping other functional GI disorders are still in infancy and better understanding of these will be important in determining the efficacy of future therapeutic interventions.

A population-based study of associations between functional gastrointestinal disorders and psychosocial characteristics in Xi'an, China

BACKGROUND

Functional gastrointestinal disorders (FGIDs) are disorders with chronic and recurring gastrointestinal symptoms. This study investigated the prevalence of FGIDs, assessed the association between FGIDs and psychosocial factors, and identified potential risk factors for FGIDs in a population in Xi'an, China.

METHODS

Of 752 recruited residents in Xi'an, 720 were selected for an epidemiological survey using a cluster sampling method. All subjects were interviewed face-to-face to complete the Chinese version of ROME III FGIDs questionnaire, the Symptom Check-List-90, the Eysenck Personality Questionnaire, a Life Event Scale, and a questionnaire regarding personal childhood adversity. The prevalence of FGIDs and associations between FGIDs and psychosocial factors were determined using EpiData Software. Logistic regression analysis was performed to identify the potential risk factors for FGIDs.

KEY RESULTS

The prevalence of FGIDs in this sample population was 14.3% (103/720). There were 13 (1.8%) cases of overlap of different FGIDs. No significant difference in the prevalence of FGIDs was observed between men and women. Alcohol intake and smoking habits were significantly associated with the presence of FGIDs. The presence of FGIDs was significantly associated with psychological factors and influences such as personality type, life events, childhood adversity, and psychopathology. The potential risk factors for contracting FGIDs were certain life events, childhood adversity, somatization, and a hostile affect (P < 0.001).

CONCLUSIONS & INFERENCES

The prevalence of FGIDs and overlap syndrome in Xi'an, China was lower than that reported in other countries. There was a strong correlation between specific lifestyle habits and psychosocial characteristics and the presence of FGIDs.

A Rome III survey of functional dyspepsia among the ethnic Malays in a primary care setting

Backgrounds

The study aimed to survey for FD in a primary care setting in a population known to have an extremely low prevalence of Helicobacter pylori (H. pylori) infection, with the hypothesis that in such a population, dyspepsia should have been relatively less common.

Methods

The Rome III FD Diagnostic Questionnaire was translated into the Malay language and later tested for reliability. A prospective cross-sectional survey was then performed involving 160 Malay patients attending primary care clinic after informed consent. Patients positive for symptoms of FD were subjected to upper endoscopy and exclusion of H. pylori infection. Univariable and multivariable analyses were used to test for associated risk factors.

Results

The back-translated questionnaire was similar to the original English version and was reliable (Cronbach Alpha-coefficient 0.85). Of the 160 surveyed subjects, 19 of them (11.9%) had symptoms of FD. With exclusion of erosive diseases (3/160 or 1.9%) from endoscopy, 16 subjects or 10% had FD. None of the 19 subjects were positive for H. pylori infection. Epigastric pain syndrome was present in 11/16 (68.8%) and the rest, overlap with postprandial distress syndrome. With multivariable analysis, a married status (OR = 8.1; 95% CI 1.0-36.5) and positive psychosocial alarm symptoms (OR = 3.8; 95% CI 1.0-14.0) were associated with FD. Of those married subjects, females were more likely to have FD and psychosocial symptoms than men (6.3% vs. 1.9%), P = 0.04.

Conclusions

FD was more common than one had expected among Malays attending primary care clinic in an area with low prevalence of H. pylori.

Investigating functional dyspepsia in Asia

The diagnosis of functional dyspepsia (FD) is challenging since it depends largely on symptoms which are often heterogeneous and overlapping. This is particularly so in Asia with many different cultures and languages. Symptom-based diagnosis of FD based on Rome III criteria has not been fully validated and it may not be suitable in some Asian populations. Clinicians often assume that investigations in FD are not rewarding and physiological tests are often not available unless in the research setting. Investigation of alarm features and role of Helicobacter pylori in FD remain controversial but experts agreed that both should be tested. Physiological tests including gastric accommodation and chemical hypersensitivity tests are underutilized in Asia and available studies were few. While experts do not recommend routine clinical use of gastric accommodation tests but they agree that these tests can be advocated if clinically indicated. Empiric therapeutic trial is not currently a diagnostic option. The pathogenesis of FD is still poorly understood and there is a substantial placebo response. As a conclusion, a diagnosis of FD is challenging especially so in the context of Asia and despite the limitations of available physiological tests experts agreed that these tests can be advocated if and when clinically indicated.

Overlap syndrome of functional dyspepsia and irritable bowel syndrome - are both diseases mutually exclusive?

Among functional gastrointestinal (GI) disorders, functional dyspepsia (FD) and irritable bowel syndrome (IBS) are important to public health around the world and are frequently encountered in general practice. Upper GI symptoms such as heartburn, postprandial fullness, early satiety, epigastric pain or burning and lower GI symptoms such as constipation and diarrhea often coexist. Although the prevalence of FD-IBS overlap would be influenced by the selection of the study population, the overlap rate of FD-IBS could be in the range of 11%-27%. Specifically, FD-IBS overlap is associated with more severe symptoms than FD alone or IBS alone. Since clinical overlap, especially FD-IBS overlap, is very common, the 2 syndromes should not be treated in a mutually exclusive fashion.

Epidemiology of uninvestigated and functional dyspepsia in Asia: facts and fiction

Dyspepsia is a syndrome consisting of epigastric pain, burning, fullness, discomfort, early satiety, nausea, vomiting and belching. Functional dyspepsia (FD) is diagnosed if upper gastrointestinal endoscopy does not show structural abnormality explaining these symptoms. 8%-30% and 8%-23% of Asian people suffer from of uninvestigated dyspepsia and FD, respectively. Most patients with uninvestigated dyspepsia are found to have FD. Patients with FD are usually young and there is no predilection to any gender. Overlap of FD with other functional bowel diseases such as irritable bowel syndrome and gastroesophageal reflux disease is common in Asia. Cultural difference in reporting of symptoms of dyspepsia is well-known. Moreover, dietary factors, socio-cultural and psychological issues, gastrointestinal infection including that caused by Helicobacter pylori, frequency of organic diseases such as peptic ulcer and gastric cancer responsible for dyspeptic symptoms in the study population may also influence epidemiology of dyspepsia. There is considerable heterogeneity in the above issues among different Asian countries. More studies on epidemiology of FD are needed in Asia.