Association of serum magnesium with type 2 diabetes mellitus and diabetic retinopathy

Introduction and Objective: The rising burden of type 2 diabetes mellitus (T2DM) globally has led to huge morbidity and socioeconomic impact in developing countries. In India, too, it has become a silent epidemic and it is estimated that there are over 60 million diabetics. Although in recent years, a lot of research papers have come up on the management of diabetes, latest treatment modalities may not be affordable to all. So, it becomes imperative to prioritize research on prevention and primary care. Magnesium is an intracellular cation and coenzyme for various reactions of the glycolytic pathway. Hypomagnesemia has been shown to precipitate hyperglycemia and has, therefore, been implicated in insulin resistance and its microvascular complications. Poor glycemic control has been associated with retinopathy. Hence, we evaluated association of serum magnesium with T2DM and diabetic retinopathy. Materials and Methods: In a cross-sectional study in North India, 250 consenting adult patients from outpatient department of family medicine of our hospital were recruited. Critically ill patients and those on magnesium supplements were excluded. Clinicolaboratory profile was evaluated. Patients were divided based on serum magnesium level <= 1.7 mg/dL (group 1) and > 1.7 mg/dL (group 2). Glycemic control and proportion of diabetic retinopathy were compared between these two groups by using univariate regression analysis. Results: Out of 250 patients, 110 patients (44%) were found to have hypomagnesemia. Glycemia by fasting blood sugar (P = 0.02), post-Prandial blood sugar (P = 0.04), and HbA1C(P = 0.01) was poorly controlled in hypomagnesemia group. In group 1, 62.7% had non proliferative diabetic retinopathy and 21.8% had proliferative diabetic retinopathy, whereas in group 2, 14.3% had nonproliferative diabetic retinopathy and 8.6% had proliferative diabetic retinopathy (P < 0.001). Conclusions: Magnesium deficiency is associated with increased risk of diabetic retinopathy and poor glycemic control. Dietary supplementation may be advised to prevent such complications and improve glycemic control.