Endocrine Abstracts

Anorexia nervosa (AN) and obesity are prevalent in modern societies.

This study evaluate circulating levels of Neuropeptide Y (NPY) and of Peptide Tyrosine-Tyrosine (PYY) in 60 women: 20 affected by AN (Body Mass Index=BMI 15.74±2.09 kg/m², age 30.19±10.52 years), 10 restricter (BMI 14.89±1.64 kg/m²) and 10 binge-purge subtype (BMI 18.27±0.81 kg/m²); 20 affected by severe Obesity (BMI>40 kg/m², age 33.56±5.2 years) with type II diabetes with no therapy, and 20 healthy controls (BMI 22.06±0.93 kg/m², age 32.44±4.35 years).

NPY is higher in AN than obese and controls (70.17±20.84 vs 25.12±7.26 and 52.20±10.88 pmol/l; P<0.001) and lower in obese than controls (P<0.001). PYY is higher in AN than obese and controls (219.77±83.51 vs 116.42±41.42 and 94.97±12.74 pg/ml; P<0.001), with no differences between obese and controls.

In AN, NPY and PYY are quite higher (P=0.059; P=0.06) in restricter (75.77±20.86 pmol/l; 241.78±84.6 pg/ml) than in binge-purge subtype (53.39±8.72 pmol/l; 153.73±29.45 pg/ml). Increase of NPY despite simultaneous PYY increase in AN might be related to reduced sensitivity to PYY inhibitory effect on NPY production or increased production of NPY from simpathetic peripheral nervous system, a finding evident mainly in restricter AN. In obese PYY is close to controls suggesting a reduced intestinal production of this peptide because of the stimulus of continous overfeeding, whereas the reduced NPY production could be explained by increased levels of insulin and leptin. Reduced NPY levels suggest that in these obese the overfeeding is not dependent on increased hungry signal, but on inadequate satiety signal.