A comparative study of serum magnesium in type 2 diabetes mellitus with and without retinopathy and healthy controls and its correlation with glycemic status

Type 2 diabetes mellitus(DM) is a disease of impaired carbohydrate metabolism. The onset of uncontrolled hyperglycemia causes various microvascular complications such as retinopathy and nephropathy. The present study aimed to see the effect of serum magnesium on glycemic control in the presence of retinopathy and to show their role in pathogenesis.

The study was designed to estimate and compare serum magnesium levels in cases of type 2 diabetes mellitus with and without retinopathy and healthy controls. A correlation of serum magnesium was done with glycosylated hemoglobin in diabetics with retinopathy and without retinopathy.

It was a case control study. The study included 60 cases of clinically diagnosed type 2 DM with retinopathy, 60 cases of type 2 DM without retinopathy and 60 matched healthy controls. Venous blood sample was analyzed for fasting blood sugar(FBS), post prandial blood sugar (PPBS), serum magnesium and glycosylated hemoglobin(HbA1c) in both cases and controls. Statistical analysis was done using student ‘t’ test. Pearson's correlation was performed to establish the relationship between study variables.

There was significantly decreased levels of serum magnesium (p<0.001) in cases of retinopathy as compared to the controls. There was highly significant negative correlation between serum magnesium and glycosylated hemoglobin (HbA1c) in cases of DM with retinopathy.

The severity of diabetic retinopathy in the study group was influenced by factors such as good glycemic control and hypomagnesemia. These parameters could be used as a supportive diagnostic tool in type 2 DM.