Serum magnesium, iron and ferritin levels in patients with diabetic retinopathy attending Makkah Eye Complex, Khartoum, Sudan.

Diabetic retinopathy is the most common complications of diabetes mellitus that, in most occasions, lead to blindness. Multiple evidences linked the serum magnesium, iron and ferritin disturbance with diabetes and its complications. A case-control study was conducted at Makkah Eye Complex, Khartoum, Sudan, to compare the levels of serum magnesium, iron and ferritin in patients with diabetic retinopathy with diabetic patients without diabetic retinopathy (controls). Findings indicate that all patients had type 2 diabetes. The two groups (50 in each arm) were well matched in their basic characteristics. Median (25th-75th interquartile) of serum magnesium in patients with diabetic retinopathy were significantly lower than patients without diabetic retinopathy [1.48 (0.75-1.64) vs. 1.92 (1.4-2.3)mg/dl, P = 0.022]. The median of serum iron and ferritin were lower in cases than control group but did not reach a statistical significance [20.5 (17.2-48.0) vs. 27.0 (16.0-54.0) μg/dl, P = 0.568; 98.0 (45.0-134.75) vs. 101.0 (47.0-161.0) μg/l, P = 0.818]. The duration of diabetes [16.5 (9.3) vs. 11.2 (6.6) years; P = 0.014] and haemoglobin level [13.7 (0.9) vs. 12.5 (2.0) g/dl; P = 0.039] were significantly higher in cases group than control group. A significant inverse correlation was observed between serum magnesium and iron levels. Twenty (40 %) patients had severe non-proliferative diabetic retinopathy with mild macular edema, which is the most prevalent type among the cases group. Hypomagnesaemia among diabetic patients was associated with diabetic retinopathy, while serum iron and ferritin have no significant effect in this setting. Severe non-proliferative diabetic retinopathy with mild macular edema is the prevalent type in this study.