Introduction: Diabetes is frequently associated with Mg deficit. The most but not all diabetic subjects have low magnesium (Mg). Hypomagnesaemia has been reported to occur in 25-38% of patients with Type 2 DM especially in those without good metabolic control. Deficiency of Mg may increase the incidence of diabetes mellitus (DM) and occurrence of diabetic complications. It is frequently overlooked and undertreated. A low Mg intake and an increased Mg urinary loss appear to be the most important mechanisms that may favor Mg depletion in patients with type 2 diabetes. Objectives: The present study was conducted with an objective to evaluate the serum magnesium level in type 2 Diabetes mellitus. The present study also attempts to evaluate an association between the serum magnesium levels with duration of diabetes, glycosylated hemoglobin and diabetic complications. Methods and Materials: This is a cross sectional study which was done between July 2016 to August 2017 in Khaja Banda Institute of Medical College and Hospital. A total of 100 Type 2 DM patients were included in the study. The serum blood sugar level, HbA1C (%), magnesium level was estimated and the serum magnesium levels were correlated with the duration of diabetes, glycosylated hemoglobin and diabetic complications. Results: Among the 100 patients, 58% were men and 42% were women. Mean age was 56.98±8.76 years and the mean duration of diabetes were 8.2±4.8 years. The mean glycosylated hemoglobin (HbA1c) was 7.44±1.43%. The mean serum magnesium was 1.78±0.48 mg/dl. Out of 100 patients, 66 patients had normal serum magnesium levels and 34 patients had hypomagnesaemia. There was no correlation between serum magnesium levels with increasing duration of diabetes. Out of the 34 patients who had  hypomagnesaemia, 29 patients had HbA1c > 7%. This correlated between hypomagnesaemia and poor glycemic control in our study. There were 16 patients who had retinopathy, 20 patients had nephropathy and 26 patients had neuropathy. Among the 34 patients, 24 had complications and 10 patients did not have any complications. However there was a weak negative correlation between serum Mg levels (r =-0.110, p =0.004) and diabetic complications. 

Conclusion: Serum magnesium level was low in most of the Type 2 DM patients with poor glycemic control. Mg depletion affects both glycemic regulation and the occurrence of complications. Also, poor glycemic regulation affects serum Mg levels.