Patterns and Correlates of Serum Magnesium Levels in Subsets of Type 2 Diabetes Mellitus Patients in Nigeria

Background: Magnesium (Mg) is the 4th most common mineral and the 2nd most abundant intracellular cation in the body. It plays major roles in various physiological activities and has been implicated in many disease states. Aim: The aim of this study was to study the patterns and correlates of serum Mg in cohorts of type 2 diabetic patients in Nigeria. Subjects and Methods: One hundred and twenty-five patients comprising 63 with type 2 diabetes mellitus (T2DM) alone and 62 with diabetes and hypertension (HT) were compared with fifty controls matched for sex and age. Basic data, HbA1c, and fasting blood glucose (FBG) were obtained while serum Mg was measured by colorimeter. Relationship between serum Mg and glucose control was considered while serum Mg < 1.6 mg/dl was considered as hypomagnesemia. Results: The mean serum Mg of all patients was 2.06 ± 0.49 mg/dl, not statistically different from controls at 2.22 ± 0.48 mg/dl. About ¼ (23.2%) of the patients had hypomagnesemia which was significantly more than 12% of controls. Although the patients with diabetes and HT were older and more of females than those with DM alone, the mean serum Mg was comparable (2.03 ± 0.49 vs. 2.09 + 0.50 mg/dl). Twenty-seven percent (27%) of patients who had DM alone was more than 19.3% with HT and diabetes combined. Whereas the FBG was comparable in patients with hypomagnesemia and normal serum Mg, HbA1c was significantly higher in the hypomagnesemia group (8.39 ± 0.98 vs. 6.75 ± 1.22%, P = 0.021). Conclusion: Hypomagnesemia is common in T2DM outpatients occurring approximately one in four patients. It is associated with poor long-term control.