Postprandial drowsiness in dyspepsia

Abstract

Functional dyspepsia (FD) is widely used in clinical practice to describe a symptom complex that always includes chronic or recurrent pain or discomfort in the upper abdomen in absence of structural or biochemical abnormality. Specific dyspepsia symptoms comprise epigastric pain, postprandial fullness, early satiation, and epigastric burning however, FD patients frequently reported other symptoms not referable to the gastrointestinal (GI) tract, including headache and drowsiness. Drowsiness is a common sensation often and variably reported also by healthy subjects. Bi-directional brain-gut interactions play an important role in the regulation of digestive process, including appetite and food intake, in health and disease. Feeding behavior is dependent upon the integration of metabolic, autonomic, endocrine, and environmental factors coordinated with an appropriate state of cortical arousal. The hypothalamus has been regarded to play a pivotal role in maintaining energy homeostasis. The arcuate nucleus modulates satiety in response to metabolic signals, neuropeptides released postprandially by the GI tract, and vagus nerve stimulation. The arcuate nucleus integrates these signals and transmits them to the ventromedial hypothalamus, that indirectly, through the inhibition of lateral hypothalamic area, stimulates the sleep centres. It has been hypothesized that an alteration of brain-gut interactions may underlie the symptom generation in functional gastrointestinal disorders and may be involved in the pathophysiology of various eating disorders. An over distension of the gastric antrum has been found in a subgroup of patients with FD complaining of postprandial drowsiness. In these dyspeptic patients postprandial drowsiness occurs later than the usual gastrointestinal dyspeptic symptoms and is associated with antral distension and delayed gastric emptying. The onset of drowsiness is usually preceded by an increment of antral distension and the duration of the symptom appears to be related to the persistence of antral distension. Several substances, released and/or inhibited as result of antral distension and∕or delayed gastric emptying might be involved in mediating postprandial drowsiness in FD patients.