Increased plasma neuropeptide Y concentration in elderly subjects

Background. It is well known that aging is associated with several hormonal and metabolic alterations. Elderly patients are also characterized by increased activity of the sympathetic nervous system. As neuropeptide Y (NPY) is a mediator of the sympathetic nervous system. Objectives. The aim of the present study was to determine the plasma NPY concentration in elderly subjects. Material and Methods. Sixty apparently healthy elderly subjects 65-93 years old were included in this study. They were divided into two groups: those between 65 and 80 years old and those older than 80. The control group consisted of 57 apparently healthy younger subjects 20-64 years old. Plasma NPY concentration was measured by radioimmunoassay in blood samples drawn three times in one day, at 8 a.m., 4 p.m., and midnight. Results. Plasma NPY concentration was significantly higher in the subjects between 65 and 80 and those older than 80 years than in the subjects younger than 65. In the entire studied group, significant positive correlations were found between the plasma NPY concentrations measured at 8 a.m., 4 p.m., and midnight and age. Conclusions. Elderly subjects are characterized by significantly elevated plasma NPY concentration (Adv Clin Exp Med 2008, 17, 2, 161-166).