Background &Aims: Evidence suggests that postprandial platelet-depleted plasma 5-hydroxytryptamine (5-HT) concentrations may be abnormal in irritable bowel syndrome (IBS). However, interpretation of the data has b...Background &Aims: Evidence suggests that postprandial platelet-depleted plasma 5-hydroxytryptamine (5-HT) concentrations may be abnormal in irritable bowel syndrome (IBS). However, interpretation of the data has been hampered by the variable methodology and rather small numbers used in previous studies. Therefore, the aim of this study was to measure concentrations of platelet-depleted plasma 5-HT and its metabolite 5-HIAA under fasting and fed conditions in a large group of patients with diarrhea-predominant (d-) and constipation-predominant (c-) IBS, compared with controls. The ratio of plasma 5-HIAA:5-HT and platelet stores was also assessed. Methods: Twenty-nine c-IBS patients (aged, 19-53 years), 55 d-IBS patients (aged, 19-52 years), and 35 healthy volunteers (aged, 18-46 years) had platelet-depleted plasma 5-HT/5-HIAA concentrations measured using reverse-phase, high-performance liquid chromatography with fluorimetric detection before and after a standard meal. Results: d-IBS patients had raised platelet-depleted plasma 5-HT concentrations under fasting and fed conditions (P < .05). However, the postprandial relative to fasting concentration was similar to controls. In contrast, c-IBS patients failed to show an increase in platelet-depleted plasma 5-HT concentration with meal ingestion compared with controls (P < .01). c-IBS was associated with decreased 5-HIAA (P < .01) but normal 5-HIAA:5-HT ratio and d-IBS with normal 5-HIAA concentrations but reduced 5-HIAA:5-HT ratio (P < .005). c-IBS but not d-IBS patients had increased platelet 5-HT. Conclusions: These results support the concept that d-IBS is characterized by reduced 5-HT reuptake, whereas impaired release may be a feature of c-IBS. These results also provide a rational basis for current pharmacologic approaches involving modulation of different 5-HT receptors in c-and d-IBS.展开更多
Background: Patients with irritable bowel syndrome (IBS) often feel they have some form of dietary intolerance and frequently try exclusion diets. Tests attempting to predict food sensitivity in IBS have been disappoi...Background: Patients with irritable bowel syndrome (IBS) often feel they have some form of dietary intolerance and frequently try exclusion diets. Tests attempting to predict food sensitivity in IBS have been disappointing but none has utilised IgG antibodies. Aims: To assess the therapeutic potential of dietary elimination based on the presence of IgG antibodies to food. Patients: A total of 150 outpatients with IBS were randomised to receive, for three months, either a diet excluding all foods to which they had raised IgG antibodies (enzyme linked immunosorbant assay test) or a sham diet excluding the same number of foods but not those to which they had antibodies. Methods: Primary outcome measures were change in IBS symptom severity and global rating scores. Noncolonic symptomatology, quality of life, and anxiety/depression were secondary outcomes. Intention to treat analysis was undertaken using a generalised linear model. Results: After 12 weeks, the true diet resulted in a 10%greater reduction in symptom score than the sham diet (mean difference 39 (95%confidence intervals (CI) 5-72); p = 0.024) with this value increasing to 26%in fully compliant patients (difference 98 (95%CI 52-144); p<0.001). Global rating also significantly improved in the true diet group as a whole (p = 0.048, NNT = 9) and even more in compliant patients (p = 0.006, NNT = 2.5). All other outcomes showed trends favouring the true diet. Relaxing the diet led to a 24%greater deterioration in symptoms in those on the true diet (difference 52 (95%CI 18-88); p = 0.003). Conclusion: Food elimination based on IgG antibodies may be effective in reducing IBS symptoms and is worthy of further biomedical research.展开更多
文摘Background &Aims: Evidence suggests that postprandial platelet-depleted plasma 5-hydroxytryptamine (5-HT) concentrations may be abnormal in irritable bowel syndrome (IBS). However, interpretation of the data has been hampered by the variable methodology and rather small numbers used in previous studies. Therefore, the aim of this study was to measure concentrations of platelet-depleted plasma 5-HT and its metabolite 5-HIAA under fasting and fed conditions in a large group of patients with diarrhea-predominant (d-) and constipation-predominant (c-) IBS, compared with controls. The ratio of plasma 5-HIAA:5-HT and platelet stores was also assessed. Methods: Twenty-nine c-IBS patients (aged, 19-53 years), 55 d-IBS patients (aged, 19-52 years), and 35 healthy volunteers (aged, 18-46 years) had platelet-depleted plasma 5-HT/5-HIAA concentrations measured using reverse-phase, high-performance liquid chromatography with fluorimetric detection before and after a standard meal. Results: d-IBS patients had raised platelet-depleted plasma 5-HT concentrations under fasting and fed conditions (P < .05). However, the postprandial relative to fasting concentration was similar to controls. In contrast, c-IBS patients failed to show an increase in platelet-depleted plasma 5-HT concentration with meal ingestion compared with controls (P < .01). c-IBS was associated with decreased 5-HIAA (P < .01) but normal 5-HIAA:5-HT ratio and d-IBS with normal 5-HIAA concentrations but reduced 5-HIAA:5-HT ratio (P < .005). c-IBS but not d-IBS patients had increased platelet 5-HT. Conclusions: These results support the concept that d-IBS is characterized by reduced 5-HT reuptake, whereas impaired release may be a feature of c-IBS. These results also provide a rational basis for current pharmacologic approaches involving modulation of different 5-HT receptors in c-and d-IBS.
文摘Background: Patients with irritable bowel syndrome (IBS) often feel they have some form of dietary intolerance and frequently try exclusion diets. Tests attempting to predict food sensitivity in IBS have been disappointing but none has utilised IgG antibodies. Aims: To assess the therapeutic potential of dietary elimination based on the presence of IgG antibodies to food. Patients: A total of 150 outpatients with IBS were randomised to receive, for three months, either a diet excluding all foods to which they had raised IgG antibodies (enzyme linked immunosorbant assay test) or a sham diet excluding the same number of foods but not those to which they had antibodies. Methods: Primary outcome measures were change in IBS symptom severity and global rating scores. Noncolonic symptomatology, quality of life, and anxiety/depression were secondary outcomes. Intention to treat analysis was undertaken using a generalised linear model. Results: After 12 weeks, the true diet resulted in a 10%greater reduction in symptom score than the sham diet (mean difference 39 (95%confidence intervals (CI) 5-72); p = 0.024) with this value increasing to 26%in fully compliant patients (difference 98 (95%CI 52-144); p<0.001). Global rating also significantly improved in the true diet group as a whole (p = 0.048, NNT = 9) and even more in compliant patients (p = 0.006, NNT = 2.5). All other outcomes showed trends favouring the true diet. Relaxing the diet led to a 24%greater deterioration in symptoms in those on the true diet (difference 52 (95%CI 18-88); p = 0.003). Conclusion: Food elimination based on IgG antibodies may be effective in reducing IBS symptoms and is worthy of further biomedical research.
