Visceral adiposity is associated with an increased risk of functional dyspepsia

Global prevalence of functional dyspepsia according to Rome criteria, 1990-2020: a systematic review and meta-analysis

Although functional dyspepsia (FD) is a common functional gastroduodenal disorder with a high socioeconomic burden, little is known about its global prevalence. Thus, we performed a comprehensive study to estimate long-term trends in the prevalence of FD. We searched PubMed/MEDLINE, Embase, and Google Scholar from 1990 to 2022 for population-based studies that reported the prevalence of FD in adults (≥ 18 years old) according to Rome I, II, III, or IV criteria. The prevalence of FD was extracted from included studies to obtain pooled prevalence with 95% confidence intervals (CI) and 95% prediction intervals. Subgroup analysis was performed according to certain characteristics, including geographic region. A total of 44 studies met the eligibility criteria, including 256,915 participants from 40 countries across six continents. The overall global pooled prevalence of FD was 8.4% (95% CI 7.4-.9.5). The prevalence was the highest in Rome I (11.9%; 95% CI 5.1-25.4) and lowest in Rome IV (6.8%; 95% CI 5.8-7.9). Developing countries showed a higher prevalence than developed countries (9.1% versus 8.0%), and prevalence was higher in women, irrespective of the definition used (9.0% versus 7.0%). The pooled prevalence gradually decreased from 1990 to 2020 (12.4% [8.2-18.3] in 1990-2002 versus 7.3% [6.1-8.7] in 2013-2020). The prevalence of FD differs by country, economic status, geographical region, and sex, and the global prevalence has been gradually declining. Despite the heterogeneity of sample population, our study estimates the current global burden of FD and provides information to heath care policy decisions.

Assesment of functional gastrointestinal diseases in obese children

Functional gastrointestinal disorders (FGID) are disorders of gut-brain interactions characterized by chronic recurrent gastrointestinal symptoms and are reported to be more common in obese individuals. The aim of the study was to evaluate FGID in obese children. A total of 405 children (6-18 years) were enrolled in this cross sectional study. The children were divided into two groups according to body mass index (BMI) as < 85th percentile and > 95th percentile. Diagnosis of FGID was based on ROME VI criteria. Demographic and clinical characteristics of the patients were evaluated. FGID and subgroups were determined. The mean age of the children was 12.73 ± 3.17 years; 52% (n = 211) of them was female and 47.9% (n = 194) was male. A total of 50.6% patients had BMI > 95th percentile, and 55.1% of those patients had FGID. The subgroups of FGID, functional abdominal pain disorders and functional defecation disorders were significantly more common in obese children than non-obese group (P < 0.01). Additionally, constipation-predominant irritable bowel syndrome (IBS), diarrhea-predominant IBS, functional diarrhea, and abdominal distention were significantly more common in obese children than non-obese children (P < 0.01).

CONCLUSION

 FGID in obese children was found to be increased significantly. Assessment of functional gastrointestinal symptoms in obese children will prevent unnecessary examinations.

WHAT IS KNOWN

• Functional gastrointestinal disorders are reported to be more common in obese individuals.

WHAT IS NEW

• Functional abdominal pain disorders and functional defecation disorders were significantly more common in obese children than non-obese group. • Constipation-predominant irritable bowel syndrome (IBS), diarrhea-predominant IBS, functional diarrhea, and abdominal distention were significantly more common in obese children than non-obese children.

Functional Gastrointestinal Disorders and Abdominal Visceral Fat in Children and Adolescents

Purpose

Few reports have investigated the correlation between functional gastrointestinal disorders (FGIDs) and the degree of obesity in children and adolescents. Thus, this study aimed to examine the relationship between FGIDs and the degree of obesity in children and adolescents.

Methods

Children and adolescents (<19 years old) who had undergone abdominopelvic computed tomography and had been diagnosed with FGIDs from 2015 to 2016 were included in this retrospective case-control study in a ratio of 1:2. Abdominal visceral fat was measured using an image analysis software.

Results

The mean age of all 54 FGID patients was 12.9±3.4 years, and the male: female ratio was 1:1.2. We observed no difference in body mass index (BMI) between the FGID and control groups (19.5±4.6 vs. 20.6±4.3 kg/m2, p=0.150). However, the FGID group had less abdominal visceral fat than that of the control group (26.2±20.0 vs. 34.4±26.9 cm2, p=0.048). Boys in the FGID group had lower BMI (18.5±3.5 vs. 20.9±4.3 kg/m2, p=0.019) and less abdominal visceral fat (22.8±15.9 vs. 35.9±31.8 cm2, p=0.020) than those of boys in the control group. However, we found no difference in BMI (20.5±5.3 vs. 20.4±4.2 kg/m2, p=0.960) and abdominal visceral fat (29.0±22.9 vs. 33.1±22.1 cm2, p=0.420) between girls in both groups.

Conclusion

Our study revealed a difference in the relationship between FGID and the degree of obesity according to sex, which suggests that sex hormones influence the pathogenesis of FGIDs. Multicenter studies with larger cohorts are required to clarify the correlation between FGID subtypes and the degree of obesity.

The prevalence and risk factors of functional dyspepsia among adults in low- and middle-income countries: An international cross-sectional study

Dyspepsia is one of the most common chronic digestive diseases, which is due to underlying organic causes that can be detected, or causes that cannot be detected called functional dyspepsia (FD). There is no epidemiological study to date that measures the prevalence and risk factors of the FD in low- and middle-income countries, so this international cross-sectional study was conducted in 15 low- and middle-income countries from data previously published its protocol NCT05340400. Participants were recruited in the period from 22/April/2022 to 14/June/2022. The diagnosis of the FD was according to clinical manifestations. We determined the physical activity, daily stress, and fatigue of the participants. A large number of collaborators were chosen from different regions and institutions within each country to achieve diversity within the sample and reduce the probability of bias. Our study concluded that the prevalence of FD is much higher in low- and middle-income countries 37.9% [6.2%-44.2%], compared to high-income countries 10% [8%-12%], with a higher rate among the Afro-Caribbean race 47.9%. Sudan obtained the highest prevalence 44.3%, then Egypt 41.4%, while the lowest prevalence was in Algeria 25.7%. Moreover, there are many risk factors, including modifiable ones, such as severe stress, chronic fatigue, smoking, abnormal BMI, insufficient or too many hours of sleep, and previous infection with Covid-19, and non-modifiable ones such as advanced age, chronic diseases, and female sex. Highlighting the prevalence and increasing risk factors of FD in low- and middle-income countries should draw the attention of those responsible for health care in these countries and reduce the risk factors.

Eosinophils, Hypoxia-Inducible Factors, and Barrier Dysfunction in Functional Dyspepsia

Functional dyspepsia (FD) is a highly prevalent disorder of gut-brain interaction (DGBI), previously known as a functional gastrointestinal disorder. Characterized by early satiety, postprandial fullness, and/or epigastric pain or burning, diagnosis depends on positive symptomatology and exclusion of obvious structural diseases. A subtle inflammatory phenotype has been identified in FD patients, involving an increase in duodenal mucosal eosinophils, and imbalances in the duodenal gut microbiota. A dysregulated epithelial barrier has also been well described in FD and is thought to be a contributing factor to the low-grade duodenal inflammation observed, however the mechanisms underpinning this are poorly understood. One possible explanation is that alterations in the microbiota and increased immune cells can result in the activation of cellular stress response pathways to perpetuate epithelial barrier dysregulation. One such cellular response pathway involves the stabilization of hypoxia-inducible factors (HIF). HIF, a transcriptional protein involved in the cellular recognition and adaptation to hypoxia, has been identified as a critical component of various pathologies, from cancer to inflammatory bowel disease (IBD). While the contribution of HIF to subtle inflammation, such as that seen in FD, is unknown, HIF has been shown to have roles in regulating the inflammatory response, particularly the recruitment of eosinophils, as well as maintaining epithelial barrier structure and function. As such, we aim to review our present understanding of the involvement of eosinophils, barrier dysfunction, and the changes to the gut microbiota including the potential pathways and mechanisms of HIF in FD. A combination of PubMed searches using the Mesh terms functional dyspepsia, functional gastrointestinal disorders, disorders of gut-brain interaction, duodenal eosinophilia, barrier dysfunction, gut microbiota, gut dysbiosis, low-grade duodenal inflammation, hypoxia-inducible factors (or HIF), and/or intestinal inflammation were undertaken in the writing of this narrative review to ensure relevant literature was included. Given the findings from various sources of literature, we propose a novel hypothesis involving a potential role for HIF in the pathophysiological mechanisms underlying FD.

Association Between Body Mass Index and Functional Dyspepsia in Young Japanese People

Background/Aims

Evidence regarding the association between body mass index (BMI) and functional dyspepsia (FD) in the Asian population is limited. Further, no study has evaluated this issue in young people in Asian and Western populations. Thus, we aim to investigate this issue among young Japanese people.

Methods

The study subjects comprised of 8923 Japanese university students. BMI was divided into 4 categories (quartiles) on the basis of the study subjects’ distribution (lowest, low, moderate, and high [reference]). The definition of lean, normal, overweight, and obese was BMI < 18.5 kg/m², 18.5 ≤ BMI < 25 kg/m² (reference), 25 kg/m² ≤ BMI < 30 kg/m², and 30 kg/m² ≤ BMI, respectively. The definition of FD was based on the Rome III criteria.

Results

The prevalence of FD was 1.9% in this cohort. The lowest BMI was independently associated with FD after adjustment (adjusted odds ratio [OR], 2.88; 95% confidence interval [CI], 1.46-3.67); P for trend = 0.001). The lowest BMI was independently associated with FD in women but not in men (OR, 2.94; 95% CI, 1.59-5.77; P for trend = 0.001). Leanness was independently associated with FD in total and in women but not in men (total adjusted OR, 2.01; 95% CI, 1.40-2.86) and women (OR, 2.19; 95% CI, 1.35-3.45). However, interaction analysis showed no significant difference for sex.

Conclusions

Among young Japanese people, BMI may be independently inversely associated with FD. Leanness may be an independent associated factor for FD in the young Japanese women.

[Duodenal Microbiome and Its Clinical Implications in Functional Dyspepsia]

Functional dyspepsia is one of the most common functional gastrointestinal disorders with chronic bothersome epigastric pain or postprandial fullness without a definite organic cause. Despite its high clinical burden, the treatment modalities for modulating impaired motor dysfunction and visceral hypersensitivity have been unsatisfactory. Recently, studies demonstrating low-grade inflammation and dysbiosis of the duodenal mucosa as potential triggers of the disease have attracted attention. Observations, such as an increase in the proportion of oral commensal bacteria in the duodenal mucosa, such as Streptococcus species, highlight the importance of bacterial ecology in developing symptoms of functional dyspepsia. In the near future, anti-inflammatory drugs and probiotics that modulate the host-microbiome interaction are expected to emerge to treat functional dyspepsia.

High prevalence of functional dyspepsia in nonalcoholic fatty liver disease: a cross-sectional study

BACKGROUND

Gastrointestinal (GI) symptoms are frequent complaints from individuals with nonalcoholic fatty liver disease (NAFLD). Dyspepsia is a universal clinical symptom and is among the most common GI complaints observed in the general population, but its prevalence in the population with NAFLD has not been previously investigated.

OBJECTIVE

To compare the prevalence of functional dyspepsia (FD) between patients with NAFLD and controls without liver disease.

DESIGN AND SETTING

Cross-sectional study at the Outpatient Liver Clinic, University Hospital, Belo Horizonte, Brazil.

METHODS

We included 96 NAFLD patients and 105 controls without liver disease. All participants were assessed for GI symptoms in accordance with the Rome III criteria. Evaluation methods included a questionnaire for FD (validated in Brazil), laboratory tests and upper GI endoscopy.

RESULTS

Mean age and sex were similar between the groups. The NAFLD group presented higher frequency of proton-pump inhibitor usage (31.3% vs 4.8%; P < 0.001) and prevalence of FD (25.0% versus 12.4%; P = 0.021). The symptom frequencies were as follows: postprandial distress, 22.9% versus 11.4% (P = 0.030); postprandial fullness, 18.8% versus 10.5% (P = 0.095); early satiation, 8.3% versus 5.7% (P = 0.466); and epigastric pain or burning, 18.8% versus 5.7% (P = 0.004), in NAFLD patients and controls, respectively. Multivariate analysis demonstrated that female sex (odds ratio, OR 6.97; 95% confidence interval, CI: 1.51-32.12; P = 0.013) and NAFLD diagnosis (OR 2.45; 95% CI: 1.14-5.27; P = 0.021) were independently associated with FD occurrence.

CONCLUSION

FD occurs more frequently in individuals with NAFLD than in controls without hepatic disease.

Systematic Survey of the Alteration of the Faecal Microbiota in Rats With Gastrointestinal Disorder and Modulation by Multicomponent Drugs

Gastrointestinal disorder (GID) is a global health disease which leads to heavy public medical burden. Disorders in the intestinal flora have been found in gastrointestinal disorder patients. However, the interaction between GID and the intestinal flora in faecal has not been studied comprehensively. In addition, multicomponent drugs represented by traditional Chinese medicine (TCM) are widely used for treating GID, but their modulation of the intestinal flora has not been investigated. Therefore, in this study, a high-throughput sequencing strategy was used to investigate alterations in the intestinal flora in a rat GID model, followed by an investigation of the modulation by a representative TCM, Xiaoerfupi (XEFP) granule. The results showed that in rats with GID, the relative abundances of Erysipelotrichaceae, Lachnospiraceae, Streptococcaceae increased and that of Ruminococcaceae decreased. At the macro level, the levels of LysoPC(16:0), LysoPC(20:2), LysoPC(15:0), LysoPC(20:2 (11Z, 14Z)), LysoPC(20:1), LysoPC(15:0), LysoPC(20:0) and LysoPE (0:0/20:0) in serum increased and levels of PC(36:4), PC(38:4), PC(o-36;4), PE (MonoMe(13,5)/MonoMe(11,5)) decreased. The imbalance of metabolites was restored by XEFP through ether lipid metabolism pathway. Increase in the phyla Firmicutes/Bacteroidetes (F/B) ratio of the GID rats was restored by XEFP as well. Moreover, XEFP can relief the symptoms of GID rats by increasing bacteria Ruminococcaceae and decreasing Streptococcaceae, Erysipelotrichaceae and Lachnospiraceae in faecal microbiota level. This study represents a comprehensive survey of the interaction between GID and the intestinal flora and a systematic evaluation of modulation by a multicomponent drug.

Obesity as a risk factor for diseases of the digestive system

Currently, the global prevalence of obesity among the worlds adult population is about 650 million people, which makes it possible to consider this chronic metabolic disease as a non-infectious pandemic of the 21st century. It has been proven that obesity is associated with several gastroenterological diseases, while the mechanisms of these associations are extremely heterogeneous and multifactorial. Hypertrophy and hyperplasia of adipocytes in obesity lead to a change in the profile of adipokine production (a decrease in adiponectin, an increase in leptin), an increase in the production of pro-inflammatory cytokines (interleukin-1, 6, 8, tumor necrosis factor ), C-reactive protein, free fatty acids, as well as active forms of oxygen (superoxide radicals, H2O2). All the above induces the development of chronic slowly progressive inflammation, oxidative stress, and insulin resistance. In addition, peptides secreted by adipocytes (adiponectin, leptin, nesfatin-1 and apelin) can modulate gastrointestinal motility, acting both centrally and peripherally. The qualitative and quantitative changes in the intestinal microbiota observed in obese patients (increased Firmicutes and decreased Bacteroidetes) lead to a decrease in the production of short-chain fatty acids and an increase in the intestinal permeability due to disruption of intercellular tight junctions, which leads to increased translocation of bacteria and endotoxins into the systemic circulation. Numerous studies have demonstrated the association of obesity with diseases of the esophagus (gastroesophageal reflux disease, Barretts esophagus, esophageal adenocarcinoma, esophageal motility disorders), stomach (functional dyspepsia, stomach cancer), gallbladder (cholelithiasis, gallbladder cancer), pancreas (acute pancreatitis, pancreatic cancer), liver (non-alcoholic fatty liver disease, hepatocellular carcinoma), intestine (diverticular disease, irritable bowel syndrome, colorectal cancer).

The association of body mass index with functional dyspepsia is independent of psychological morbidity: A cross-sectional study

BACKGROUND AND AIM

The association between body mass index (BMI) and functional gastrointestinal disorders (FGIDs) has been inconsistent. We aimed to explore the association of BMI with FGIDs in a primary care setting to provide more data in this area.

METHODS

A cross-sectional study of consecutive Asian adults attending a primary healthcare setting was conducted. This study was conducted in 2 phases: The association between BMI and common FGIDs (functional diarrhea/FD, irritable bowel syndrome/IBS, functional diarrhea and functional constipation/FC) was studied initially. The influence of anxiety and depression on BMI and FGIDs was additionally explored in phase 2.

RESULTS

A total of 1002 subjects (median age 32 years, 65.4% females, 90.7% Malay ethnicity, 73.2% higher than secondary level education) were recruited between August 2019 to January 2020. The majority of subjects were obese (39.2%), and had central obesity (51.7%), while 6.1% had metabolic syndrome. The prevalence of FD, IBS, functional diarrhea and FC were 7.5% (n = 75), 4.0% (n = 40), 1.2% (n = 12) and 10.5% (n = 105) respectively, based on the Rome III criteria. Among individual FGIDs, FD subjects had more underweight adults (BMI<18.5kg/m2) compared to controls (13.3% vs 3.5%, P = 0.002) and being underweight remained as an independent association with FD [OR = 3.648 (95%CI 1.494-8.905), P = 0.004] at multi-variate analysis. There were no independent associations between BMI and other FGIDs. When psychological morbidity was additionally explored, anxiety (OR 2.032; 95%CI = 1.034-3.991, p = 0.040), but not depression, and a BMI<18.5kg/m2 (OR 3.231; 95%CI = 1.066-9.796, p = 0.038) were found to be independently associated with FD.

CONCLUSIONS

FD, but not other FGIDs, is associated with being underweight. This association is independent of the presence of anxiety.

Role of Overweight and Obesity in Gastrointestinal Disease

The prevalence of obesity is increasing worldwide, leading to a severe impairment of overall health. Actually, obesity has been associated with several pathological conditions, causing an excess overall mortality. In particular, overweight and obesity are well known risk factors for a variety of gastrointestinal (GI) disorders i.e., functional GI disorders as well as, inflammatory bowel disease (IBD), pancreatitis, and GI cancer. The aim of the present review is to summarize the potential role of overweight and obesity in GI disease with particular focus on plausible biological mechanisms that could explain the association between obesity and GI disease based on the most recent evidence in the literature.

Association Between Obesity/Overweight and Functional Gastrointestinal Disorders in Children

OBJECTIVE

Although emerging data indicate that obese/overweight children are more likely to develop functional gastrointestinal disorders (FGIDs) than normal-weight peers, contrasting results have been reported. The present observational, case-control study aimed at estimating the prevalence of FGIDs in obese/overweight children compared to normal-weight peers.

METHODS

Consecutive obese and overweight children aged 4 to 18 years attending the obesity outpatient clinic were enrolled as study cases. Normal-weight children were enrolled as comparison group. All the enrolled patients received a thorough health examination from both a pediatric endocrinologist and gastroenterologist. Moreover, they were asked to fill out the Rome III questionnaire for the diagnosis of FGIDs. Data were analyzed to compare the prevalence of FGIDs between cases and controls.

RESULTS

Throughout the study period we enrolled 103 cases and 115 controls. No significant age and sex differences were found between the 2 groups. FGIDs were significantly more prevalent in obese/overweight compared to normal-weight children (47.57% vs 17.39%; P < 0.0001). Increased prevalence was observed for functional constipation (18.44% vs 7.82%; P = 0.025), functional dyspepsia (23.33% vs 6.95%; P = 0.001), and irritable bowel syndrome (10.67% vs 2.60%; P = 0.024), whereas no difference was observed for functional abdominal pain (1.94% vs 2.60%; P = 1.00).

CONCLUSIONS

Our data suggest that there is a link between excess body fat and FGIDs in children. This finding may offer a model of patients in which the effects of food and nutritional substances, the gut microbial environment, and psychosocial factors are fitting well with the emerging biopsychosocial conceptual model for FGIDs.

Definition, Pathogenesis, and Management of That Cursed Dyspepsia

Dyspepsia is an umbrella term used to encompass a number of symptoms thought to originate from the upper gastrointestinal tract. These symptoms are relatively nonspecific; not surprisingly, therefore, a myriad of conditions may present with any one or a combination of these symptoms. Therein lays the clinician's first challenge: detecting the minority who may have a potentially life-threatening disorder, such as gastric cancer, from a population whose symptoms are, for the most part, considered functional in origin. The second challenge lies in the definition and management of those individuals with functional dyspepsia (FD); the major focus of this review. The Rome process has addressed the issue of FD definition and a look back at the evolution of Rome criteria for this disorder illustrates the complexities that have so frustrated us. There has been no shortage of hypotheses to explain symptom pathogenesis in FD; initially focused on gastric sensorimotor dysfunction, these have now strayed well into the duodenum and have come to entertain such factors as immune responses and the microbiome. FD has proven to be an equally challenging area for therapeutics; while the staple approaches of acid suppression and eradication of Helicobacter pylori have some limited efficacy in select populations, strategies to ameliorate symptoms in the majority of sufferers based on presumed pathophysiology have largely foundered. Lacking a validated biomarker(s) FD continues to be an elusive target and is likely to remain so until we can better define the various phenotypes that it must surely contain.

Functional dyspepsia

Functional dyspepsia is one of the most prevalent functional gastrointestinal disorders. Functional dyspepsia comprises three subtypes with presumed different pathophysiology and aetiology: postprandial distress syndrome (PDS), epigastric pain syndrome (EPS) and a subtype with overlapping PDS and EPS features. Functional dyspepsia symptoms can be caused by disturbed gastric motility (for example, inadequate fundic accommodation or delayed gastric emptying), gastric sensation (for example, sensations associated with hypersensitivity to gas and bloating) or gastric and duodenal inflammation. A genetic predisposition is probable but less evident than in other functional gastrointestinal disorders, such as irritable bowel syndrome (IBS). Psychiatric comorbidity and psychopathological state and trait characteristics could also play a part, although they are not specific to functional dyspepsia and are less pronounced than in IBS. Possible differential diagnoses include Helicobacter pylori infection and peptic ulceration. Pharmacological therapy is mostly based on the subtype of functional dyspepsia, such as prokinetic and fundus-relaxing drugs for PDS and acid-suppressive drugs for EPS, whereas centrally active neuromodulators and herbal drugs play a minor part. Psychotherapy is effective only in a small subset of patients, whereas quality of life can be severely affected in nearly all patients. Future therapies might include novel compounds that attempt to treat the underlying gastric and duodenal inflammation.

A prospective study on symptom generation according to spicy food intake and TRPV1 genotypes in functional dyspepsia patients

BACKGROUND

Capsaicin is an ingredient of red peppers that binds to transient receptor potential vanilloid subtype 1 (TRPV1), and Koreans eat more capsaicin-rich food than do Japanese. This study aimed to compare symptom generation according to TRPV1 genotypes and the intake of spicy foods.

METHODS

Consecutive functional dyspepsia (FD) patients who were evaluated at Konkuk University Medical Centre (Korea) and Keio University Hospital (Japan) were included. Questionnaires on spicy food intake, patient assessment of gastrointestinal symptoms (PAGI-SYM), patient assessment of quality of life, and hospital anxiety and depression scale were provided. Blood was sampled for the detection of TRPV1 polymorphisms, and upper gastrointestinal endoscopy was performed with biopsies.

KEY RESULTS

Of 121 included subjects, 35 and 28 carried the TRPV1 CC and GG genotypes, respectively, with the prevalence rates not differing between Japan and Korea. The prevalence of FD subtypes did not differ with the spicy food intake, TRPV1 genotypes, or Helicobacter pylori infection. Neither TRPV1 polymorphisms nor H. pylori infections were related to scores on the PAGI-SYM questionnaires, but spicy food intake was positively correlated with the scores for stomach fullness (p = 0.001) and retching (p = 0.001). Using the linear regression analysis, stomach fullness was associated with spicy food intake (p = 0.007), whereas retching was related to younger age (p < 0.001) and female gender (p = 0.014).

CONCLUSIONS & INFERENCES

Upper gastrointestinal symptoms are more common in subjects with a higher consumption of spicy foods, younger age and female gender, regardless of TRPV1 genotypes and the H. pylori infection status. Capsaicin-rich foods may induce stomach fullness.