Plasma neuropeptide Y levels differ in distinct diabetic conditions

Neuropeptide Y (NPY) is an important hormone in appetite regulation. Although the contribution of NPY to metabolic disease has been previously demonstrated, there are only a few reports addressing NPY plasma levels under distinct diabetic conditions. In this study we evaluated NPY plasma levels in diabetes mellitus type 2 (DM2) patients with (n = 34) and without (n = 34) diabetic polyneuropathy (PNP) and compared these with age and gender matched healthy controls (n = 34). We also analyzed NPY plasma levels in gestational diabetes mellitus (GDM) patients with age and pregnancy-week matched controls with normal glucose tolerance (NGT). NPY concentration was determined using a commercially available radioimmunoassay kit. In addition, metabolic parameters of DM2 and GDM patients were recorded. One-way ANOVA tests with appropriate post hoc corrections showed elevated levels of NPY in DM2 patients with and without PNP when compared with those of healthy controls (122.32 ± 40.86 and 117.33 ± 29.92 vs. 84.65 ± 52.17 pmol/L; p < 0.001, p < 0.005, respectively). No significant difference was observed between diabetic patients with and without PNP. The NPY levels were similar in the GDM group and in pregnant women with NGT (74.87 ± 14.36 vs. 84.82 ± 51.13 pmol/L, respectively). Notably, the NPY concentration correlated positively with insulin levels in DM2 patients (R = 0.35, p < 0.01). Our data suggest a potential involvement of circulating NPY in DM2 pathology.