Correlations of Neuropeptide Y and Adiponectin Serum Levels in Obese Type 2 Diabetics in Relation to Insulin Resistance

Abstract

Background The importance of obesity in the progression of Type 2 Diabetes Mellitus (T2DM) is represented by defective biochemical markers' production and release that may interact with each other, resulting in negative outcomes for the diabetic state. When neuropeptide Y is released and interacts with adipose tissue, it may affect the adiponectin release, which plays a role in glucose metabolism and insulin sensitivity.Objectives: To estimate the serum levels of neuropeptide-Y and its impact on adiponectin release in obese T2DM patients in relation to the insulin resistance state.Materials and Methods: Eighty-seven T2DM patients attending the clinic of the National Center of Diabetes Treatment and Research, Baghdad, Iraq, were categorized into two groups; Group 1: 45 obese T2DM patients with BMI of ≥ 30 kg/m2 and age 31-59 years, and Group 2: Normal body weight T2DM patients with BMI of 18.5-24.9 kg/m2, included 42 patients, with an age 33-60 years. Fasting blood specimens were utilized to measure serum neuropeptide-Y, adiponectin, and glycemic markers for each participant.Results: The fasting blood glucose (FBG), glycated hemoglobin (HbA1c), Homeostasis Model Assessment Insulin Resistance (HOMA-IR), and neuropeptide-Y values were significantly elevated (P-value = 0.001) in Group 1 in comparison with Group 2. Serum insulin and adiponectin levels were significantly higher (P-value = 0.001) in Group 2 compared to Group 1. Furthermore, serum neuropeptide-Y, FBG, HbA1c and HOMA-IR were negatively correlated with adiponectin serum levels, where (rho = -0.617, P-value = 0.001), (rho = -0.684, P-value = 0.001), (rho = -0.359, P-value = 0.001), and (rho = -0.271, P-value = 0.011) for neuropeptide Y, FBG, HbA1c and HOMA-IR, respectively, while the fasting serum insulin was positively correlated with adiponectin serum level (rho = 0.310, P-value = 0.003).Conclusion: Elevated serum neuropeptide-Y and declined adiponectin levels in obese as compared with normal-weight diabetic patients may reflect the negative impact of serum levels of neuropeptide-Y- on adiponectin release. Furthermore, adiponectin levels were negatively correlated with glycemic markers; which is an indication of its beneficial role in T2DM improvement.

Keywords

• adiponectin
• neuropeptide y
• obesity
• type 2 diabetes mellitus