Evaluations of measurement techniques in functional dyspepsia : electrogastrography, satiety drinking test and 14C-urea breath test

Abstract

The overall aim of this thesis was to evaluate the clinical usefulness of certain measurement techniques that may be helpful in the understanding of functional dyspepsia (FD). Electrogastrography (EGG) parameters were evaluated and found unable to discriminate one specific motility disorder from other motility disorders of the gut. Moreover the relationship between the electrical activity of the stomach determined by EGG and contractile activity of the gastric antrum assessed by antro-duodenal manometry (ADM) were analyzed and no spatial correlation between EGG and ADM was observed. These results suggest that the clinical usefulness of EGG in the diagnosis of a motility disorder is generally poor and that EGG and ADM measure two different aspects of gastric physiology.

The validity of 14C urea breath test (UBT) was compared with histology and rapid urease test (RUT) for the diagnosis of H. pylori infection. Both sensitivity and specificity of 14C UBT for the diagnosis of H. pylori infection were high. This study also indicated a very good concordance between UBT, histology, and RUT for the diagnosis of H. pylori infection. These observations suggest that 14C UBT is a reliable test for diagnosis of H. pylori infection. Satiety drinking tests were done in healthy volunteers by using drinking water at 100 ml/minute or nutrient drinks at 20 and 100 ml/minute. It was found that the maximum tolerated volume (MTV) determined by slow nutrient drinking (SND) was not influenced by body mass index, age and gender compared to rapid water and rapid nutrient drinking. Moreover there was more symptom generation after drinking nutrient liquid at a slow rate. These results suggest that SND is more meaningful in the assessment of MTV. This study also determined the normal values of MTV for satiety drinking tests in a Pakistani population.

The relationship between MTV and dyspepsia symptoms in patients with FD before and after the treatment was assessed. We found a significant correlation between dyspepsia symptom severity scores and MTV. Some of the individual symptom severity scores also correlated with MTV before and after treatment. The findings of this study indicate that determination of MTV by SND can be a surrogate marker for symptoms severity in patients with FD.

This thesis concluded that the diagnostic usefulness of EGG is limited, that 14C UBT is a reliable test for the diagnosis of H. pylori infection, that SND is a better test for the assessment of MTV compared to rapid water and nutrient drinking, and that MTV determined by SND may be useful for the assessment of response to treatment in patients with FD.