C1QTNF5 and type 2 diabetes mellitus: - Patients with PDR had the lowest serum and aqueous humor myonectin levels, followed by those with NPDR.- Higher myonectin levels were associated with a reduced risk of T2D and DR.- Serum myonectin levels negatively correlated with disease duration, BMI, and HbA1c.⁃ Aqueous humor myonectin levels negatively correlated with disease duration, systolic, and diastolic blood pressure.