Reduced Lutein Levels in Elderly Type 2 Diabetics: Implications for Diabetic Kidney Disease Risk

Background: Type 2 diabetes mellitus (T2DM) is considered a widespread metabolic condition associated with morbidity, particularly when complicated by diabetic kidney disease (DKD). Lutein, a natural carotenoid with antioxidant anti-inflammatory properties. The purpose of this work was to evaluate serum lutein levels among elderly T2DM cases to investigate its relationship with diabetic kidney disease relevant metabolic parameters. Methods: We carried out this case-control study on 63 elderly participants categorized into three groups: healthy controls, T2DM patients without DKD, T2DM patients with DKD (21 subjects per group). Clinical data, anthropometric measurements, laboratory tests, involving fasting blood glucose, HbA1c, renal liver function tests, lipid profile, serum lutein were collected. performance. Results: Serum lutein levels differed significantly among groups (F = 128.237, p < 0.001). Post hoc analysis showed lower levels in both diabetic groups vs. controls (p1 < 0.001, p2 < 0.001), and in DKD vs. Non-DKD (p3 = 0.002). Levels were lowest in DKD group, followed by non-DKD, highest in controls. Serum lutein demonstrated high diagnostic accuracy for diabetes. A cutoff ≤0.515 μmol/L identified diabetes without DKD with 95.2% sensitivity, 90.5% specificity, 92.9% accuracy (AUC = 0.988, p < 0.001). For DKD, cutoff ≤0.36 μmol/L showed 95.2% sensitivity, 81% specificity, 85.7% accuracy (AUC = 0.961, p < 0.001). Conclusion: Serum lutein levels were significantly reduced in elderly patients with type 2 diabetes, especially those with diabetic kidney disease. Its strong association with glycemic renal markers suggests that lutein may serve as a useful indicator for early renal involvement in this population