Poor Subjective Sleep Quality Predicts Symptoms in Irritable Bowel Syndrome Using the Experience Sampling Method.

INTRODUCTION: Sleep quality may affect symptom experience in irritable bowel syndrome (IBS). Our aim was to investigate the relationship between sleep quality and gastrointestinal (GI) symptoms using actigraphy and the experience sampling method. METHODS: Patients with IBS were recruited from a tertiary Neurogastroenterology clinic and the community. GI symptoms and mood were recorded on a smartphone application, 10 times per day, over 7 consecutive days. Subjective sleep quality was recorded every morning to reflect the night before. Objective measures of sleep quality were estimated from wrist-worn actigraphy. Cross-lagged structural equation models were built to assess the directionality of sleep-symptom relationships over time. RESULTS: Eighty patients with IBS completed the study (mean age: 37 years [range 20-68], 89% female, 78% community). Approximately 66% had a Pittsburgh Sleep Quality Index score ≥ 8, indicating a clinically significant sleep disturbance. Approximately 82% (95% CI: 72-90) screened positive for a sleep disorder, most commonly insomnia. In cross-lagged analysis, poor subjective sleep quality predicted next-day abdominal pain (0.036 < P < 0.040) and lower GI symptoms (0.030 < P < 0.032), but not vice versa. No significant relationship with GI symptoms was found for any objective sleep measure using actigraphy. DISCUSSION: Poor subjective sleep quality was associated with higher next-day lower GI symptom levels, but not vice versa. Objective sleep measures did not predict next-day abdominal symptoms, potentially supporting the conclusion that it is the perception of sleep quality that is most influential. This study may be used to guide future research into the effect of sleep interventions on GI symptoms.

Gut-brain axis dysfunction underlies FODMAP-induced symptom generation in irritable bowel syndrome.

BACKGROUND: FODMAPs produce similar small bowel water and colonic gas in patients with irritable bowel syndrome (IBS) and healthy controls (HCs), despite IBS patients reporting increased gastrointestinal (GI) symptoms. AIM: To unravel the mechanisms underlying FODMAP-induced symptom reporting, we investigated gut and brain responses to fructan administration in IBS patients and HC. METHODS: This randomised, double-blind, cross-over study consisted of three visits where fructans (40 g/500 mL saline), glucose (40 g/500 mL saline) or saline (500 mL) were infused intragastrically during 1 h MR brain scanning; abdominal MRI was performed before, 1 h, and 2 h post-infusion. Symptoms were rated using validated scales. RESULTS: In IBS (n = 13), fructans induced more cramps, pain, flatulence and nausea compared to glucose (P = 0.03, 0.001, 0.009 and <0.001 respectively), contrary to HC (n = 13) (all P > 0.14), with between-group differences for cramps and nausea (P = 0.004 and 0.023). Fructans increased small bowel motility and ascending colonic gas and volume equally in IBS and HC (between-group P > 0.25). The difference in colonic gas between fructans and saline covaried with differences in bloating and cramps in IBS (P = 0.008 and 0.035 respectively). Pain-related brain regions responded differentially to fructans in IBS compared to HC, including the cerebellum, supramarginal gyrus, anterior and midcingulate cortex, insula and thalamus (pFWE-corrected  < 0.05); these brain responses covaried with symptom responses in IBS. CONCLUSIONS: Fructans increase small bowel motility and colon gas and volume similarly in IBS patients and HC. Increased symptom responses to fructans in IBS covary with altered brain responses in pain-related regions, indicating that gut-brain axis dysregulation may drive FODMAP-induced symptom generation in IBS.

Cardiac-induced liver deformation as a measure of liver stiffness using dynamic imaging without magnetization tagging-preclinical proof-of-concept, clinical translation, reproducibility and feasibility in patients with cirrhosis.

PURPOSE: MR elastography and magnetization-tagging use liver stiffness (LS) measurements to diagnose fibrosis but require physical drivers, specialist sequences and post-processing. Here we evaluate non-rigid registration of dynamic two-dimensional cine MRI images to measure cardiac-induced liver deformation (LD) as a measure of LS by (i) assessing preclinical proof-of-concept, (ii) clinical reproducibility and inter-reader variability, (iii) the effects of hepatic hemodynamic changes and (iv) feasibility in patients with cirrhosis. METHODS: Sprague-Dawley rats (n = 21 bile duct ligated (BDL), n = 17 sham-operated controls) and fasted patients with liver cirrhosis (n = 11) and healthy volunteers (HVs, n = 10) underwent spoiled gradient-echo short-axis cardiac cine MRI studies at 9.4 T (rodents) and 3.0 T (humans). LD measurements were obtained from intrahepatic sub-cardiac regions-of-interest close to the diaphragmatic margin. One-week reproducibility and prandial stress induced hemodynamic changes were assessed in healthy volunteers. RESULTS: Normalized LD was higher in BDL (1.304 ± 0.062) compared with sham-operated rats (1.058 ± 0.045, P = 0.0031). HV seven-day reproducibility Bland-Altman (BA) limits-of-agreement (LoAs) were ± 0.028 a.u. and inter-reader variability BA LoAs were ± 0.030 a.u. Post-prandial LD increases were non-significant (+ 0.0083 ± 0.0076 a.u., P = 0.3028) and uncorrelated with PV flow changes (r = 0.42, p = 0.2219). LD measurements successfully obtained from all patients were not significantly higher in cirrhotics (0.102 ± 0.0099 a.u.) compared with HVs (0.080 ± 0.0063 a.u., P = 0.0847). CONCLUSION: Cardiac-induced LD is a conceptually reasonable approach from preclinical studies, measurements demonstrate good reproducibility and inter-reader variability, are less likely to be affected by hepatic hemodynamic changes and are feasible in patients with cirrhosis.

Quantitative assessment of terminal ileum motility on MR enterography in Crohn disease: a feasibility study in children.

OBJECTIVES: Investigate the relationship between quantified terminal ileal (TI) motility and histopathological activity grading, Crohn Disease MRI Index (CDMI) and faecal calprotectin. METHODS: Retrospective review of children with Crohn disease or unclassified inflammatory bowel disease, who underwent MR enterography. Dynamic imaging for 25 patients (median age 12, range 5 to 16) was analysed with a validated motility algorithm. The TI motility score was derived. The primary reference standard was TI Endoscopic biopsy Assessment of Inflammatory Activity (eAIS) within 40 days of the MR enterography. Secondary reference standards: (1) the Crohn Disease MRI Index (CDMI) and (2) faecal calprotectin levels. RESULTS: MR enterography median motility score was 0.17 a.u. (IQR 0.12 to 0.25; range 0.05 to 0.55), and median CDMI was 3 (IQR 0 to 5.5). Forty-three percent of patients had active disease (eAIS > 0) with a median eAIS score of 0 (IQR 0 to 2; range 0 to 5). The correlation between eAIS and motility was r = - 0.58 (p = 0.004, N = 23). Between CDMI and motility, r = - 0.42 (p = 0.037, N = 25). Motility score was lower in active disease (median 0.12 vs 0.21, p = 0.020) while CDMI was higher (median 5 vs 1, p = 0.04). In a subset of 12 patients with faecal calprotectin within 3 months of MR enterography, correlation with motility was r = - 0.27 (p = 0.4). CONCLUSIONS: Quantified terminal ileum motility decreases with increasing histopathological abnormality in children with Crohn disease, reproducing findings in adults. TI motility showed a negative correlation with an MRI activity score but not with faecal calprotectin levels. KEY POINTS: • It is feasible to perform MRI quantified bowel motility assessment in children using free-breathing techniques. • Bowel motility in children with Crohn disease decreases as the extent of intestinal inflammation increases. • Quantified intestinal motility may be a candidate biomarker for treatment efficacy in children with Crohn disease.

Transcutaneous vagus nerve stimulation prevents the development of, and reverses, established oesophageal pain hypersensitivity.

BACKGROUND: The vagus nerve exerts an anti-nociceptive effect on the viscera. AIM: To investigate whether transcutaneous vagal nerve stimulation (t-VNS) prevents the development of and/or reverses established visceral hypersensitivity in a validated model of acid-induced oesophageal pain. METHODS: Before and after a 30-minute infusion of 0.15M hydrochloric acid into the distal oesophagus, pain thresholds to electrical stimulation were determined in the proximal non-acid exposed oesophagus. Validated sympathetic (cardiac sympathetic index) and parasympathetic (cardiac vagal tone [CVT]) nervous system measures were recorded. In study 1, 15 healthy participants were randomised in a blinded crossover design to receive either t-VNS or sham for 30 minutes during acid infusion. In study 2, 18 different healthy participants were randomised in a blinded crossover design to receive either t-VNS or sham, for 30 minutes after acid infusion. RESULTS: Study 1: t-VNS increased CVT (31.6% ± 58.7 vs -9.6 ± 20.6, P = 0.02) in comparison to sham with no effect on cardiac sympathetic index. The development of acid-induced oesophageal hypersensitivity was prevented with t-VNS in comparison to sham (15.5 mA per unit time (95% CI 4.9 - 26.2), P = 0.004). Study 2: t-VNS increased CVT (26.3% ± 32.7 vs 3 ± 27.1, P = 0.03) in comparison to sham with no effect on cardiac sympathetic index. t-VNS reversed established acid-induced oesophageal hypersensitivity in comparison to sham (17.3mA/unit time (95% CI 9.8-24.7), P = 0.0001). CONCLUSIONS: t-VNS prevents the development of, and reverses established, acid-induced oesophageal hypersensitivity. These results have therapeutic implications for the management of visceral pain hypersensitivity.

Rumination syndrome: Assessment of vagal tone during and after meals and during diaphragmatic breathing.

BACKGROUND: Pathophysiology of rumination syndrome (RS) is not well understood. Treatment with diaphragmatic breathing improves rumination syndrome. The aim of the study was to characterize vagal tone in patients with rumination syndrome during and after meals and during diaphragmatic breathing. METHODS: We prospectively recruited 10 healthy volunteers (HV) and 10 patients with RS. Subjects underwent measurement of vagal tone using heart rate variability. Vagal tone was measured during baseline, test meal and intervention (diaphragmatic (DiaB), slow deep (SlowDB), and normal breathing). Vagal tone was assessed using mean values of root mean square of successive differences (RMSSD), and area under curves (AUC) were calculated for each period. We compared baseline RMSSD, the AUC and meal-induced discomfort scores between HV and RS. Furthermore, we assessed the effect of respiratory exercises on symptom scores, and number of rumination episodes. KEY RESULTS: There was no significant difference in baseline vagal tone between HV and RS. During the postprandial period, there was a trend to higher vagal tone in RS, but not significantly (P > .2 for all). RS had the higher total symptom scores than HV (P < .011). In RS, only DiaB decreased the number of rumination episodes during the intervention period (P = .028), while both DiaB and SlowDB increased vagal tone (P < .05 for both). The symptom scores with the 3 breathing exercises showed very similar trends. CONCLUSIONS AND INFERENCES: Patients with RS do not have decreased vagal tone related to meals. DiaB reduced number of rumination events by a mechanism not related to changes in vagal tone.

Radio-metal cross-linking of alginate hydrogels for non-invasive in vivo imaging.

Alginate hydrogels are cross-linked polymers with high water content, tuneable chemical and material properties, and a range of biomedical applications including drug delivery, tissue engineering, and cell therapy. However, their similarity to soft tissue often renders them undetectable within the body using conventional bio-medical imaging techniques. This leaves much unknown about their behaviour in vivo, posing a challenge to therapy development and validation. To address this, we report a novel, fast, and simple method of incorporating the nuclear imaging radio-metal 111In into the structure of alginate hydrogels by utilising its previously-undescribed capacity as an ionic cross-linking agent. This enabled non-invasive in vivo nuclear imaging of hydrogel delivery and retention across the whole body, over time, and across a range of model therapies including: nasal and oral drug delivery, stem cell transplantation, and cardiac tissue engineering. This information will facilitate the development of novel therapeutic hydrogel formulations, encompassing alginate, across disease categories.

Whole-body MRI for staging and interim response monitoring in paediatric and adolescent Hodgkin's lymphoma: a comparison with multi-modality reference standard including 18F-FDG-PET-CT.

OBJECTIVES: To prospectively investigate concordance between whole-body MRI (WB-MRI) and a composite reference standard for initial staging and interim response evaluation in paediatric and adolescent Hodgkin's lymphoma. METHODS: Fifty patients (32 male, age range 6-19 years) underwent WB-MRI and standard investigations, including 18F-FDG-PET-CT at diagnosis and following 2-3 chemotherapy cycles. Two radiologists in consensus interpreted WB-MRI using prespecified definitions of disease positivity. A third radiologist reviewed a subset of staging WB-MRIs (n = 38) separately to test for interobserver agreement. A multidisciplinary team derived a primary reference standard using all available imaging/clinical investigations. Subsequently, a second multidisciplinary panel rereviewed all imaging with long-term follow-up data to derive an enhanced reference standard. Interobserver agreement for WB-MRI reads was tested using kappa statistics. Concordance for correct classification of all disease sites, true positive rate (TPR), false positive rate (FPR) and kappa for staging/response agreement were calculated for WB-MRI. RESULTS: There was discordance for full stage in 74% (95% CI 61.9-83.9%) and 44% (32.0-56.6%) of patients against the primary and enhanced reference standards, respectively. Against the enhanced reference standard, the WB-MRI TPR, FPR and kappa were 91%, 1% and 0.93 (0.90-0.96) for nodal disease and 79%, < 1% and 0.86 (0.77-0.95) for extra-nodal disease. WB-MRI response classification was correct in 25/38 evaluable patients (66%), underestimating response in 26% (kappa 0.30, 95% CI 0.04-0.57). There was a good agreement for nodal (kappa 0.78, 95% CI 0.73-0.84) and extra-nodal staging (kappa 0.60, 95% CI 0.41-0.78) between WB-MRI reads CONCLUSIONS: WB-MRI has reasonable accuracy for nodal and extra-nodal staging but is discordant with standard imaging in a substantial minority of patients, and tends to underestimate disease response. KEY POINTS: • This prospective single-centre study showed discordance for full patient staging of 44% between WB-MRI and a multi-modality reference standard in paediatric and adolescent Hodgkin's lymphoma. • WB-MRI underestimates interim disease response in paediatric and adolescent Hodgkin's lymphoma. • WB-MRI shows promise in paediatric and adolescent Hodgkin's lymphoma but currently cannot replace conventional staging pathways including 18F-FDG-PET-CT.

Detection of extracolonic pathologic findings with CT colonography: a discrete choice experiment of perceived benefits versus harms.

PURPOSE: To determine the maximum rate of false-positive diagnoses that patients and health care professionals were willing to accept in exchange for detection of extracolonic malignancy by using computed tomographic (CT) colonography for colorectal cancer screening. MATERIALS AND METHODS: After obtaining ethical approval and informed consent, 52 patients and 50 health care professionals undertook two discrete choice experiments where they chose between unrestricted CT colonography that examined intra- and extracolonic organs or CT colonography restricted to the colon, across different scenarios. The first experiment detected one extracolonic malignancy per 600 cases with a false-positive rate varying across scenarios from 0% to 99.8%. One experiment examined radiologic follow-up generated by false-positive diagnoses while the other examined invasive follow-up. Intracolonic performance was identical for both tests. The median tipping point (maximum acceptable false-positive rate for extracolonic findings) was calculated overall and for both groups by bootstrap analysis. RESULTS: The median tipping point for radiologic follow-up occurred at a false-positive rate greater than 99.8% (interquartile ratio [IQR], 10 to >99.8%). Participants would tolerate at least a 99.8% rate of unnecessary radiologic tests to detect an additional extracolonic malignancy. The median tipping-point for invasive follow-up occurred at a false-positive rate of 10% (IQR, 2 to >99.8%). Tipping points were significantly higher for patients than for health care professionals for both experiments (>99.8 vs 40% for radiologic follow-up and >99.8 vs 5% for invasive follow-up, both P < .001). CONCLUSION: Patients and health care professionals are willing to tolerate high rates of false-positive diagnoses with CT colonography in exchange for diagnosis of extracolonic malignancy. The actual specificity of screening CT colonography for extracolonic findings in clinical practice is likely to be highly acceptable to both patients and health care professionals. Online supplemental material is available for this article.