Gastric electromechanical and neurohormonal function in anorexia nervosa

The gastrointestinal motor function in patients with anorexia nervosa is poorly understood, although it may be relevant to the pathophysiology of the disorder. We have undertaken a multidisciplinary study of 8 patients with anorexia nervosa and 8 age- and sex-matched controls. We have characterized their gastrointestinal and neurohormonal function by measuring (a) gastric electrical activity, (b) antral phasic pressure activity, (c) gastric emptying of solids and liquids, and (d) hormonal and autonomic function. Patients with anorexia nervosa at the time of the initiation of therapy presented with (a) increased episodes of gastric dysrhythmia (mean percentage of dysrhythmic time: 9.75 patients vs. 0.48 controls during fasting, p less than 0.02; 7.21 patients vs. 0.18 controls postcibally, p less than 0.001), (b) impaired antral contractility (mean motility index, 12.8 patients vs. 14.2 controls, p less than 0.002), (c) delayed emptying of solids, (d) decreased postcibal blood levels of norepinephrine and neurotensin (levels of beta-endorphin, insulin, glucagon, gastric inhibitory polypeptide, gastrin, cholecystokinin, and human pancreatic polypeptide were normal), and (e) impaired autonomic function (resting diastolic blood pressure and skin conductance were decreased and the response to the cold pressor test was dampened). Differences between patient and control groups were statistically significant. We conclude that patients with anorexia nervosa present multiple gastrointestinal abnormalities involving control mechanisms as well as target organs.