Endocrine Abstracts

Background and aims: Neuropeptide Y (NPY) cause decrease glomerular filtration rate, aldosterone concentration, and plasma renin activity by stimulating NPY receptors in the kidney. Previous studies have suggested that NPY polymorphism is related to development of advanced diabetic nephropathy (DN). The aim of this study was to evaluate the relationship between the serum neuropeptide Y levels and different stages of DN in patients with type 2 diabetes mellitus (T2DM).

Materials and Methods: Seventy-five T2DM patients were divided into two groups according to estimated glomerular filtration rate (eGFR by MDRD (Modification of Diet in Renal Disease)): 16 cases with moderate and severe renal dysfunction (Ccr<60 ml/min/1.73 m²) were included in group A and 59 cases with mild to normal renal function (Ccr>60 ml/min/1.73 m²) in group B. Serum fasting glucose, HbA1c levels, high-sensitvity C-reactive protein (hsCRP), lipid profile, urinary microalbumin excretion, serum NPY, and eGFR were determined and BMI was calculated. We measured serum NPY (ELISA, BioAspect^®) in fasting blood in the morning. The groups were matched by gender and duration of diabetes.

Results: NPY level was significantly higher in group A than group B (P<0.05). NPY levels (Geom.mean (95% CI), pg/ml) were 19.08 (5.7–58.02) and 15.14 (1.32–32.01) in group A and B respectively. Baseline characteristics of both groups will be presented. Urinary microalbuminuria levels (Geom.mean (95%CI), mg/day) were 21.6 (9.5–172.5) and 22.1 (8–150.4) in both groups respectively, and wasn’t significantly different (P=0.539). NPY was inversely associated with the eGFR by MDRD (Spearman rho=−0.27, P=0.015), and positively correlated with diabetes duration (rho=0.26, P=0.022) and HDL (rho=0.339, P=0.004). There was no correlation between NPY and urinary microalbumin excretion (P=0.653). Although triglyceride level was high in group B, there was no correlation between triglyceride and NPY.

Conclusion: NPY and eGFR were negatively correlated, so NPY may be important predictor of advanced DN independent of presence of microalbuminuria. Also increased NPY level in moderate to severe renal dysfunction group may be the underlying pathogenetic factor in T2DM.