atrial-natriuretic-factor and Anorexia-Nervosa

Topics: Anorexia Nervosa; Atrial Natriuretic Factor; Biomarkers; Body Mass Index; Female; Humans; Male

Plasma atrial natriuretic peptide (ANP) concentrations were determined in basal conditions and after infusion of 1000 ml of 0.9% NaCl in women with anorexia nervosa, in normotensive obese women and in healthy women of the control group. Additionally, in the obese women and in the controls, plasma ANP was measured after iv injection of clonidine. Anorectic patients were investigated in the period of weight loss (mean deficit of body weight was 40%). The mean body mass index (BMI) in the obese women was 36.44 +/- 0.36 kg/m2. Basal plasma ANP concentrations were significantly higher in both anorectic and obese women (p < 0.001 and p < 0.01, respectively). The response of ANP to acute water load was markedly blunted in anorexia nervosa and in obesity (delta % = 232% in control group, 14% in anorexia nervosa and 21% in obesity. A significant increase of ANP was found after iv injection of clonidine in the control group and in obesity (p < 0.001 and p < 0.01, respectively). However, the increase of response (expressed as a percentage change) in obese patients was lower than that in the control group (delta % = 64% and 199%, respectively). The response of ANP to alpha 2-adrenergic stimulation was higher than to hemodynamic stimulus. Our results suggest that the disturbed control of neuropeptides and neurotransmitters as well as changes in peripheral metabolism may explain the impaired responsibility of ANP to hemodynamic stimuli in anorectic and obese patients.

Topics: Adolescent; Adult; Anorexia Nervosa; Atrial Natriuretic Factor; Body Weight; Clonidine; Female; Humans; Injections, Intravenous; Middle Aged; Obesity; Sodium Chloride; Water

To examine the effects of chronic dehydration and starvation on plasma levels of human atrial natriuretic polypeptide (hANP) in human subjects, the basal level and saline-induced rise of plasma hANP in 7 patients with anorexia nervosa were compared with those in age-matched healthy subjects. The unstimulated level of plasma hANP was markedly high in the patients with anorexia nervosa (patients vs. control; 55.4 +/- 9.0 pg/ml vs. 11.4 +/- 6.1 pg/ml, P less than 0.01). However, no significant increase of plasma hANP in the anorectic patients was observed in response to saline-infusion, while a 3-fold increase over the basal level of plasma hANP was noted in the saline-infused normal young subjects. These results show that hANP may be secreted to an inadequate extent, hence the release would be resistant to volume-loading. The pathophysiological meaning of such a high plasma concentrations of hANP in anorexia nervosa is the subject of ongoing studies.

Topics: Adolescent; Adult; Anorexia Nervosa; Atrial Natriuretic Factor; Biomarkers; Chromatography, Gel; Female; Humans; Male; Radioimmunoassay