Plasma levels of Neuropeptide Y, Peptide YY and Adiponectine in patiens affected by anorexia nervosa and severe obesity

Background: Anorexia Nervosa (AN) and Obesity are prevalent in modern societies, their pathogenesis is not yet well understood. Materials and methods: This study evaluate circulating levels of Neuropeptide Y (NPY), Peptide Tyrosine-Tyrosine (PYY), and Adiponectine (Apn), in 60 women: 20 with AN (BMI 15Æ7 ± 2Æ1 kg/m2, age 30Æ2 ± 10Æ5 years), 12 restricter (BMI 14Æ9 ± 1Æ6 kg/m2) and 8 binge-purge subtype (BMI 18Æ3 ± 0Æ8 kg/m2); 20 with severe Obesity (BMI>40 kg/m2; age 33Æ6 ± 5Æ2 years) with type II diabetes with no therapy, and 20 healthy controls (BMI 22Æ06 ± 0Æ93 kg/m2, age 32Æ4 ± 4Æ4 years). Results: NPY was higher (P < 0Æ001) in AN (70Æ2 ±20Æ8 pmol/L) than obese and controls and lower (P < 0Æ001) in obese than controls (25Æ1 ± 7Æ3 and 52Æ2 ± 10Æ98 pmol/L, respectively). PYY was higher (P < 0Æ001), in AN (219Æ77 ± 83Æ51 pg/mL) than obese and controls (116Æ42 ± 41Æ42 e 94Æ97 ± 12Æ74 pg/mL; P = n.s.). Apn was higher (P < 0Æ001) in AN (36Æ84 ± 13Æ12 ng/ mL) than obese and controls (12Æ8 ± 4Æ7 and 15Æ1 ± 3Æ0 ng/mL; P = n.s.). NPY, PYY and Apn were higher (P = 0Æ06; P = 0Æ06; P = 0Æ004) in restricter (75Æ8 ± 20Æ9 pmol/L; 241Æ8 ± 84Æ6 pg/mL; 41Æ8 ±11Æ0 ng/mL) than in binge-purge AN subtype (53Æ4 ± 8Æ7 pmol/L; 153Æ7 ± 29Æ5 pg/mL; 22Æ1 ± 4Æ5 ng/mL). Conclusions: 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. Increased levels of Apn are related to fat mass reduction in AN. In obese women, PYY levels are similar to controls suggesting reduced intestinal production possibly secondary to overfeeding. Reduced NPY levels suggest that overfeeding is not dependent to increased hungry signal, but to inadequate satiety signal, and they could be explained by increased levels of insulin and leptin.