Aim: To estimate the prevalence of hypomagnesaemia (Mg2+ < 1.7 mg/dl) in patients with type 2 DM and its correlation with insulin resistance and glycemic status.
Materials and Methods: 100 cases of type 2 diabetes mellitus fulfilling ADA criteria and 50 age and sex matched healthy controls presenting to a tertiary care hospital from October 2014 to September 2016 were included in our Case-Control study. Serum Mg++, fasting insulin, HbA1c along with other parameters were measured in all study subjects. Insulin resistance and sensitivity was calculated using the HOMA-IR model and QUICKI respectively.
Results: 34% of cases and 18% of controls had hypomagnesaemia. Prevalence of Hypomagnesaemia increased with the duration of diabetes. Patients with diabetic retinopathy had a significantly higher prevalence of hypomagnesaemia compared to those without retinopathy (29% VS 5%). 23% of patients with HbA1c >7% had hypomagnesaemia as compared to 9% of patients with an HbA1c of <7%. A statistically significant inverse correlation was found between serum magnesium and HbA1c levels (r = -0.4395, P < 0.0001). 21% of patients with Insulin resistance (HOMA-IR >2.6) had hypomagnesaemia whereas 12% of patients without Insulin resistance (HOMA-IR <2.6). The difference was significant. (P value = < 0.0001, RR = 0.1092, 95% CI = 0.6343-0.1879). A highly statistically significant inverse correlation was found between serum magnesium and HOMA-IR level (r = -0.6677, P < 0.0001). A statistically non-significant correlation was found between serum magnesium and HOMA-ß. Logistic regression analysis showed fasting insulin levels, HbA1c levels and duration of diabetes to be independent predictors of hypomagnesaemia.
Conclusion: Prevalence of hypomagnesaemia was significantly more in diabetics and it increased with the duration of disease. Hypomagnesaemia contributed towards development of insulin resistance and impaired glycemic status in patients with type 2 diabetes.