Connection between the Plasma Level of Apelin and Diabetic Nephropathy in Type 2 Diabetic Patients. A Case Control Study

Abstract
Background: Apelin is an adipokine that may play a beneficial role in predicting early diabetic nephropathy. While a few studies have explored the role of apelin in diabetes, this research aims to establish the link between the apelinergic system and diabetic nephropathy.

Materials and Methods: The study included 60 patients with type 2 diabetes mellitus (T2DM), who were evenly divided into two groups: Group I (diabetic nephropathy) and Group II (non-diabetic nephropathy). Additionally, 30 healthy subjects were included in the control group (Group III). Measurements such as body mass index (BMI), waist circumference, fasting blood glucose (FBG), 2-hour postprandial glucose (2h-PPG), HbA1c, fasting lipids, urea, creatinine, estimated glomerular filtration rate (eGFR), urine analysis, albumin-to-creatinine ratio (A/C ratio), and apelin levels were assessed.

Results: A statistically significant difference in plasma apelin levels was observed between the groups (P < 0.001). Apelin levels were highest in Group I (diabetic nephropathy) compared to Group II (non-diabetic nephropathy) and Group III (healthy controls), with levels of 325.79 ± 59.42 pg/mL, 162.83 ± 29.88 pg/mL, and 77.43 ± 8.44 pg/mL, respectively. Among diabetic patients, plasma apelin levels were significantly positively correlated with disease duration (r = 0.612), systolic blood pressure (SBP) (r = 0.427), diastolic blood pressure (DBP) (r = 0.466), weight (r = 0.372), height (r = 0.372), FBG (r = 0.684), 2h-PPG (r = 0.744), HbA1c (r = 0.890), total cholesterol (r = 0.316), low-density lipoprotein cholesterol (LDL-C) (r = 0.397), urea (r = 0.575), and creatinine (r = 0.591). A significant negative correlation was found between plasma apelin and high-density lipoprotein cholesterol (HDL-C) (r = -0.303), and eGFR (r = -0.566).

Conclusion: Apelin levels were found to be elevated in diabetic patients with ML162 nephropathy, impaired glucose tolerance, and dyslipidemia, supporting the association between the apelinergic system and diabetic nephropathy.