Influence of abuse history on gastric sensorimotor function in functional dyspepsia

Abstract  Patients with functional gastrointestinal disorders have elevated rates of sexual or physical abuse, which may be associated with altered rectal sensorimotor function in irritable bowel syndrome. The aim was to study the association between abuse history and gastric sensorimotor function in functional dyspepsia (FD). We studied gastric sensorimotor function with barostat (sensitivity, compliance and accommodation) and gastric emptying test in 233 consecutive FD patients from a tertiary care centre (162 women, mean age 41.6 ± 0.9). Patients filled out self-report questionnaires on history of sexual and physical abuse during childhood or adulthood. Eighty-four patients (out of 198, 42.4%) reported an overall history of abuse [sexual and physical in respectively 30.0% (60/200) and 20.3% (42/207)]. FD patients reporting general as well as severe childhood sexual abuse have significantly lower discomfort thresholds during gastric distension [respectively 10.5 ± 0.4 vs 7.5 ± 1.0 mmHg above minimal distending pressure (MDP), P  = 0.014 and 10.5 ± 0.4 vs 6.6 ± 1.2 mmHg above MDP, P  = 0.007]. The corresponding intra-balloon volume was also significantly lower (respectively 579 ± 21 vs 422 ± 59 mL, P  = 0.013 and 579 ± 19 vs 423 ± 79 mL, P  = 0.033). Gastric accommodation was significantly more pronounced in patients reporting rape during adulthood (91 ± 12 vs 130 ± 40 mL, P  = 0.016). Abuse history was not associated with differences in gastric emptying. A history of abuse is associated with alterations in gastric sensorimotor function in FD. Particularly sexual abuse, rather than physical abuse, may influence gastric sensitivity and motor function.     

Regional gastric emptying abnormalities in functional dyspepsia and gastro-oesophageal reflux disease

To characterize proximal and distal stomach emptying in functional dyspepsia (FD) and gastro-oesophageal reflux disease (GORD). Eighty-three patients underwent gastric emptying (GE) scintigraphy and symptom scoring for the evaluation of upper gastrointestinal symptoms and were divided into three groups: FD (n = 25), GORD (n = 20) and FD + GORD (n = 38). Total, proximal and distal gastric retention were determined scintigraphically and compared with normal controls. Delayed total GE was observed in each subgroup: FD (56%), GORD (45%) and FD + GORD (55%). Greater proximal gastric retention was observed after meal ingestion in GORD compared to FD. Greater distal gastric retention was observed in FD and FD + GORD but it was only mild in GORD. Nausea, vomiting, early satiety, distention and regurgitation were associated with proximal gastric retention whereas there was no symptom associated with distal gastric retention. Multiple regression demonstrated total gastric retention at 30 min and 1 h was positively correlated with regurgitation whereas early proximal gastric retention was positively correlated with regurgitation and negatively correlated with nausea. Selective abnormalities of proximal and distal stomach emptying were demonstrated in GORD and FD. GORD and FD symptoms were associated with proximal gastric retention suggesting that proximal stomach motor function may be important in the pathogenesis of symptoms associated with these disorders.     

Vagal activation by sham feeding improves gastric motility in functional dyspepsia

Abstract  Antral hypomotility and impaired gastric accommodation in patients with functional dyspepsia have been ascribed to vagal dysfunction. We investigated whether vagal stimulation by sham feeding would improve meal-induced gastric motor function in these patients. Fourteen healthy volunteers and 14 functional dyspepsia patients underwent a drink test twice, once with and once without simultaneous sham feeding. After ingesting 500 mL clear meat soup (20 kcal, 37 °C) in 4 min, sham feeding was performed for 10 min by chewing a sugar-containing chewing gum while spitting out saliva. Using two- and three-dimensional ultrasound, antral motility index (contraction amplitude × frequency) and intragastric volumes were estimated. Without sham feeding, functional dyspepsia patients had lower motility index than healthy volunteers (area under curve 8.0 ± 1.2 vs 4.4 ± 1.0 min⁻¹, P  =   0.04). In functional dyspepsia patients, but not in healthy volunteers, motility index increased and intragastric volume tended to increase by sham feeding ( P  = 0.04 and P  = 0.06 respectively). The change in motility index was negatively correlated to the change in pain score ( r  = −0.59, P  = 0.007). In functional dyspepsia patients, vagal stimulation by sham feeding improves antral motility in response to a soup meal. The result supports the view that impaired vagal stimulation is implicated in the pathogenesis of gastric motility disturbances in functional dyspepsia.     

Influence of tegaserod on proximal gastric tone and on the perception of gastric distention in functional dyspepsia

Background Abnormalities in gastric sensorimotor function (hypersensitivity to distention and impaired meal accommodation) have been implicated in the pathophysiology of functional dyspepsia (FD). To study the effect of the 5‐HT₄ agonist tegaserod on sensitivity to gastric distention and gastric accommodation in FD. Methods Thirty FD patients (7 males, mean age 42 ± 2 years) underwent a gastric barostat study on two separate occasions, 2 weeks apart, after 5 days of pretreatment with placebo or tegaserod 6 mg b.i.d. in a double‐blind randomized order. After introduction of the barostat bag, graded isobaric distentions (2 mmHg increments/2 min) were performed to determine gastric compliance and sensitivity to distention. Subsequently, the pressure level was set at intra‐abdominal pressure [minimal distending pressure (MDP)] + 2 mmHg for 90 min, with administration of a liquid meal (200 mL; 300 kcal) after 30 min. Key Results Tegaserod had no influence on MDP (7.9 ± 0.4 vs 7.4 ± 0.4 mmHg) or fasting gastric compliance (44 ± 10 vs 61 ± 6 mL mmHg^?1) and on fasting thresholds for first perception (3.6 ± 0.4 vs 4.2 ± 0.2 mmHg above MDP) or discomfort (9.9 ± 0.7 vs 10.5 ± 0.5 mmHg above MDP). Tegaserod did not alter intra‐balloon volumes before and after the meal [respectively 146 ± 14 vs 120 ± 11 and 297 ± 28 vs 283 ± 29 mL, not significant (NS)], or the amplitude of the meal‐induced gastric relaxation (151 ± 23 vs 162 ± 23 mL, NS). In the subgroup with normal gastric emptying (n = 22), tegaserod significantly enhanced meal‐induced accommodation (126 ± 23 vs 175 ± 29 mL, anova P < 0.001). Conclusions & Inferences Tegaserod does not alter gastric sensorimotor function in FD patients as a group. In the subgroup with normal gastric emptying, tegaserod 6 mg b.i.d enhanced gastric accommodation.     

Distension-induced gastric accommodation in functional dyspepsia: effect of autonomic manipulation

Functional dyspepsia (FD) is associated with impaired gastric accommodation and autonomic dysregulation. The aim of this study was to investigate the effects of autonomic manipulation on distension-induced gastric accommodation in subjects with and without FD, using a newly developed gastric barostat paradigm. Twelve healthy subjects (HS) and 18 subjects with FD had four barostat examinations each: no intervention, intravenous atropine (1 mg), vagal stimulation (mental relaxation with deep breathing) and acute stress stimulation (serial subtraction task). Intrabag pressure increased from 1 to 15 mmHg in 5 min (ramp phase), and was maintained at 15 mmHg for 5 min (tonic phase). Volume responses were analysed using predefined parameters. There were no significant group differences in accommodation variables between HS and subjects with FD. The FD group could be subdivided into two distinct subgroups: subgroup 1 (n = 7, 38%) with low maximum volume and accommodation rate, and subgroup 2 with normal accommodation (n = 11). In subgroup 1, but not in subgroup 2 atropine increased maximum volume and accommodation rate substantially. Neither mental stress nor mental relaxation changed any of the accommodation variables. In a subgroup of subjects with FD, impairment of distension-induced gastric accommodation can be improved by cholinergic blockade, but not by acute physiological autonomic manipulation.     

Dietary factors in functional dyspepsia

Functional dyspepsia (FD) is characterized by upper gastrointestinal symptoms, which are frequently exacerbated by meal ingestion. While subgroups of FD patients exhibit a range of disturbances in upper gastrointestinal motor function, including delayed gastric emptying and abnormal intragastric meal distribution, which may reflect impaired proximal gastric relaxation and/or antral dysmotility, the association between symptoms and abnormalities in motor function appears to be relatively weak. More recently, the concept of visceral hypersensitivity to mechanical and chemical/nutrient stimuli has been promoted as important in the aetiology of dyspeptic symptoms. Somewhat surprisingly, the role of 'dietary' factors, that is, those factors, related directly to food ingestion, including patterns of nutrient intake, potential intolerance to specific foods or macronutrients, as well as cognitive factors, have been largely ignored. Moreover, presently available treatments fail to take into account the fact that symptoms are frequently induced by eating. This review focuses on the relevance of 'dietary' factors to FD.     

Intersubject and intrasubject variability of gastric volumes in response to isocaloric liquid meals in functional dyspepsia and health.

Gastric emptying (GE) has a considerable variability, but data on reproducibility of gastric volume measurements are sparse. We aimed to study the reproducibility of postprandial gastric volume responses and GE using magnetic resonance imaging (MRI) in healthy controls (HC) and patients with functional dyspepsia (FD). Eight HC and eight FD patients underwent a MRI study on two occasions. MR images were acquired in seated position before and up to 120 min after liquid meal administration (200 mL, 300 kcal). Fasting (V0), initial postprandial stomach volumes (V1), volume changes (V1 - V0) and meal emptying half-times (T 1/2) were determined. Intersubject and intrasubject coefficients of variation (CV(inter), CV(intra)) and Pearson's correlation coefficients (r) were calculated. T 1/2 on both occasions were (mean +/- SD) 113 +/- 28 and 121 +/- 30 min in HC (ns) and 127 +/- 31 and 128 +/- 37 min in FD (ns), respectively. In HC, CV(inter), CV(intra), r were 31%, 23%, 0.49 for V0; 13%, 7%, 0.68 for V1; 10%, 4%, 0.71 for V1 - V0 and 25%, 7%, 0.90 for T 1/2. In FD these parameters were for V0: 42%, 41%, -0.06; for V1: 18%, 10%, 0.40; for V1 - V0: 20%, 14%, 0.74 and for T 1/2: 26%, 10%, 0.84. The stomach accommodates to a given meal volume, resulting in similar and reproducible postprandial volumes within- and between-subjects. MRI provides reproducible measurements of gastric volume responses in health and disease.     

Reproducibility and symptomatic predictors of a slow nutrient drinking test in health and in functional dyspepsia

Abstract  Impaired accommodation to a meal has been recognized as a pathophysiological mechanism in functional dyspepsia (FD). Based on observations in tertiary care patients, the drinking test has been proposed as a non-invasive tool to estimate accommodation. Our aim was to assess the reproducibility of the drinking test and its correlation with demographic, symptomatic and pathophysiological parameters in secondary care FD patients and healthy controls. Thirty-four healthy controls and 78 FD patients completed a drinking test (3 respectively 2 times), a gastric emptying study and an FD symptom questionnaire. Factors influencing maximal volume and gastric emptying were determined, and the reproducibility of the drinking test was investigated. The maximal satiety was reached at a lower volume in patients (489 ± 276 and 503 ± 248 mL for first and second test respectively vs 937 ± 428 and 1048 ± 421 mL, P  < 0.0001). The ingested amount depended on age, sex and baseline FD symptom score. Patients' sex, final satiety score, total score for stomach complaints at screening and total symptom score before test accounted for the total symptom score after the test. The slow nutrient drinking test confirms its possible role as an attractive non-invasive and reproducible tool for the diagnosis of impaired accommodation and for the assessment of treatment responsiveness.     

Assessment of gastric sensorimotor function in paediatric patients with unexplained dyspeptic symptoms and poor weight gain

Recent studies indicate that impaired meal accommodation or hypersensitivity to distention are highly prevalent in adult functional dyspepsia (FD). Our aim was to investigate whether similar abnormalities also occur in paediatric FD. Sixteen FD patients (15 girls, 10-16 years) were studied. The severity (0-3; 0, absent; 3, severe) of eight dyspeptic symptoms (epigastric pain, fullness, bloating, early satiety, nausea, vomiting, belching and epigastric burning) and the amount of weight loss were determined by questionnaire. All children underwent a gastric barostat study after an overnight fast to determine sensitivity to distention and meal-induced accommodation, which were compared with normal values in young adults (18-22 years). On a separate day, all patients underwent a gastric emptying breath test. A mean weight loss of 4.8 +/- 0.9 kg was present in 14 children. Compared with controls, patients had lower discomfort thresholds to gastric distention (8.8 +/- 1.0 mmHg vs 13.9 +/- 1.9 mmHg, P < 0.02) and gastric accommodation (87 +/- 25 mL vs 154 +/- 20 mL P < 0.04). Hypersensitivity to distention and impaired accommodation were present in respectively nine (56%) and 11 (69%) patients. No relationship was found between barostat and gastric emptying, which was delayed in only three patients. The majority of children with unexplained epigastric symptoms have abnormalities of gastric sensorimotor function.     

Symptom pattern and pathophysiological correlates of weight loss in tertiary-referred functional dyspepsia

Abstract  In patients with gastrointestinal symptoms, weight loss is an alarm symptom, indicative of organic disease. Recent studies reported weight loss in subsets of functional dyspepsia (FD) patients. The aim of this study was to analyse symptom patterns associated with weight loss in tertiary care FD. Six hundred and thirty-six FD patients (67% female, mean age 43 years) completed a dyspepsia questionnaire, and underwent gastric emptying and gastric barostat studies. After identifying independent symptom domains through orthogonal factor analysis, patients were clustered on the basis of symptom profile. Clusters were compared in terms of their association with weight loss and gastric emptying or sensorimotor function. Weight loss (4.2 kg on average) correlated most strongly with early satiety followed by nausea and vomiting ( ρ respectively 0.38, 0.28 and 0.23, all P  < 0.0001). Factor analysis revealed three factors: Factor 1 characterized by nausea, vomiting and early satiety; factor 2 by early satiety, postprandial fullness and bloating; and factor 3 by pain, epigastric burning and belching. Subsequent cluster analysis revealed six patient clusters. The most severe cluster, which loaded high on all three factors, and a cluster dominated factor 2 were associated with the highest average weight loss (6.8 and 8.0 kg, respectively). The former cluster was also characterized by visceral hypersensitivity and delayed gastric emptying. The lowest weight loss occurred in the two clusters that had depressed scores for both early satiety associated factors (2.4 and 2.5 kg, respectively). In tertiary care FD, weight loss is strongly associated with two early satiety associated symptom clusters.     

Visceral and somatic sensory function in functional dyspepsia

Background Visceral hypersensitivity is one of the proposed underlying mechanisms in functional dyspepsia (FD). It is not clear whether visceral hypersensitivity in FD is a manifestation of a central sensitization also encompassing somatic sensitization. Transient receptor potential vanilloid‐1 (TRPV₁) pathways are involved in gastric mechanosensory physiology and the TRPV₁ receptor agonist, capsaicin, has been used as a chemical stimulant. Methods In this double‐blind, randomized study we evaluated both visceral and somatic sensory function in 34 FD patients and 42 healthy controls using quantitative sensory testing. Visceral pain sensitivity was assessed using a validated gastric pain model with oral capsaicin capsule titration and somatic pain sensitivity was determined by foot heat and hand electric stimulation. Key Results The median capsaicin dose required to attain moderate pain was 0.5mg in FD and 1mg in controls (P = 0.03). At these doses, mean pain intensities on a 0–100 visual analog scale were greater for FD than controls [56.9 (95% confidence intervals, 52.2–61.5) vs 45.1 (41.6–48.6), resp.] (P = 0.005). Overall, mean somatic sensory and pain thresholds were similar in FD and control groups, but in a subgroup of FD pain hypersensitivity was seen on the hand and on the foot at different stimulation thresholds. Conclusions & Inferences A majority of patients with FD have visceral chemo‐hypersensitivity involving TRPV₁ pathways. A substantial subgroup also has somatic hypersensitivity as evidence of central sensitization.     

A dose-ranging, placebo-controlled, pilot trial of Acotiamide in patients with functional dyspepsia

Abstract  Impaired gastric accommodation, hypersensitivity to distension and delayed gastric emptying are major pathophysiological mechanisms in functional dyspepsia (FD). Acotiamide (Z-338) was well-tolerated in healthy volunteers. To determine the effect of three doses of Acotiamide on major pathophysiological mechanisms, symptoms, quality of life (QOL) and safety in functional dyspeptics. A phase IIa, randomized, double-blind, placebo-controlled study (14, 21 and 28 days, respectively, for run-in, study drug administration and follow-up). Gastric accommodation, sensitivity to distension and gastric emptying were assessed by barostat and ¹³C breath test, symptoms by daily diary cards and QOL by SF-36. A total of 71 patients were enrolled (62 evaluable). There was no effect on gastric emptying and sensitivity to distension. 300 mg was better than placebo for meal accommodation ( P  = 0.024). 100 mg was better than placebo at week 2 for upper abdominal bloating ( P  = 0.001) and overall symptom score ( P  = 0.022), and at week 3 for bloating ( P  = 0.008) and heartburn ( P  = 0.041). 100 mg was also better than placebo for QOL (physical function) ( P  = 0.003). Acotiamide was safe and well-tolerated in patients with FD. The involved mechanism could at least in part depend on an effect on meal-induced accommodation. 100 mg Acotiamide exhibited the potential to improve FD symptoms and QOL. Further studies are indicated.     

Intragastric distribution of a standardized meal in health and functional dyspepsia: correlation with specific symptoms

In functional dyspepsia, abnormal intragastric distribution of a test meal has been identified but has never been correlated to any symptom pattern. The aim of this study was to compare the intragastric distribution of a meal between functional dyspepsia patients and controls, and to correlate distribution with symptom patterns, using scintigraphic gastric emptying studies. In forty patients with functional dyspepsia and 29 healthy volunteers, scintigraphic planar images were obtained immediately after ingestion of a mixed radiolabelled test meal and every 20 min for 2 h. The images of the stomach were divided into proximal and distal compartments. The mean intragastric distribution was similar in patients and controls. Over the whole test, 18 (45%) and 20 (50%) patients had a distal redistribution of the solid and liquid phase of the meal, respectively, while proximal retention of these phases was found in 13 (33%) and 9 (23%) patients. Early satiety was associated with early distal redistribution of the liquid phase and fullness was associated with late proximal retention. This study shows similar intragastric distribution of a test meal in health and functional dyspepsia. Within the patient group, an association between abnormal intragastric distribution patterns and symptom profiles was found, which might be related to different pathophysiological mechanisms.