Respiratory function in patients with stable anorexia nervosa.

BACKGROUND: The impact of undernutrition on lung physiology and respiratory muscle performance is still incompletely investigated. The purpose of this study was to assess the functional consequences of malnutrition on the respiratory system in stable patients with anorexia nervosa (AN). METHODS: Pulmonary function tests, maximal inspiratory pressure (Pimax), maximal expiratory pressure (Pemax), and the parameters of control of breathing were obtained in 27 patients with AN (mean [+/- SD] age, 24 +/- 7 years; BMI, 16 +/- 1 kg/m(2); duration of disease, 6 +/- 6 years) and in a group of matched healthy subjects. RESULTS: Compared with control subjects, significant reductions in the diffusing capacity of the lung for carbon monoxide (Dlco) and lung diffusion capacity corrected for alveolar ventilation (p < 0.001), which progressively worsened with the duration of disease, were found in the AN group. Only the membrane diffusing capacity was reduced in patients with AN (p < 0.05), while pulmonary capillary blood volume was similar to that of control subjects. Lung density measurements based on CT scan analysis were normal in a subgroup of eight patients with AN with low Dlco. Both Pimax and Pemax were decreased in patients with AN (p < 0.001), but the mild-to-moderate impairment to generate force of the respiratory muscles did not progress with time. In these patients with AN, the parameters of control of breathing were in the normal range and were comparable to those of control subjects. CONCLUSIONS: The functional alterations found in patients with AN indicate the presence of the progressive enlargement of peripheral lung units without relevant alveolar septa destruction. In the first 3 years of disease, appreciable weakness of respiratory muscles develops in patients with stable AN without further impairment over time.

Visual evaluation of food amount in patients affected by Anorexia Nervosa.

OBJECTIVE: The study compares visual evaluation of an amount of food and an amount of nonedible objects in patients affected by Anorexia Nervosa and control subjects. METHOD: 59 anorexic subjects were asked to evaluate an amount of candies and plastic bricks shown to them. Their answers were compared to both the real number of objects and the parallel evaluations given by 56 control subjects. RESULTS: There were no significant differences in stimuli evaluation between patients affected by AN and control subjects. Both groups reported a significantly lower number of both candies and bricks in comparison to their real number. DISCUSSION: In an experimental condition not related with food intake there is the same under-evaluation of the amount of presented food and nonedible objects among patients affected by AN and Control Subjects. The clinical finding of overestimation of food intake among patients affected by AN seems not to be due to a perceptive bias.