Background: The kidneys are essential organs that keep blood pH stable and eliminate excess water, salts, and aid in the body's waste removal. Aim of the study: The study aims to investigate the importance of myostatin in the development of diabetic nephropathy patients. In addition, the level of urea, creatinine, sodium, potassium, and phosphorus. Materials and methods: A Case-Control study lasted from- November 2023 to January 2024, at Al-Amal Kidney Dialysis Center and Azadi Teaching Hospital in Kirkuk Governorate. The 135 blood samples, their ages (25-70), were divided into three groups. The first group G1 (n:50) patients with T2DM. The second group G2 (n:55) with diabetic nephropathy. The third group G3 for control. Serum samples were utilized to measure MSTN by ELISA, blood urea, serum creatinine, S.PO4, S. Na+, S. K+, and S. Ca++ by spectrophotometer. Results: Significant variations (P<0.05) in MSTN were seen between study groups (8.43±4.69, 10.99±7.05, 5.63±3.38) ng/ml. Additionally, significant differences exist between (G1 vs G2), (G1 vs G3), and (G2 vs G3) with p-value <0.05 Diabetic nephropathy G2 had the highest mean urea and creatinine levels (136.69±38.21, 5.99±1.87), followed by G1 (34.92±9.06, 0.89±0.26) and control group G3 (31.00±4.72), with significant differences (p ≤ 0.001) among three groups. Additionally, G1 with G2, G2 with G3, and G1 with G3 had significant differences (p-value>0.01). Conclusion: This study found higher myostatin, urea, and creatinine in diabetic nephropathy and diabetic patients. The data also showed hyponatremia, hypocalcemia, hyperkalemia, and hyperphosphatemia in diabetic nephropathy and diabetic patients.