Association Between Serum Magnesium and Glycemic Control, Lipid Profile and Diabetic Retinopathy in Type 1 Diabetes

Introduction: Many studies have shown an association between decreased serum magnesium (Mg) levels and poor glycemic control and dyslipidemia in individuals with type 1 diabetes (T1D). Few studies evaluated the association between magnesium (Mg) levels and diabetic retinopathy (DR) in individuals with type 1 diabetes (T1D). Methods: Retrospective study of adults with T1D, with an ophthalmological evaluation and a serum Mg level determination. According to Mg levels, the individuals were stratified into two groups: normal Mg levels (1.81-2.60 mg/dL) and low Mg levels (≤1.80 mg/dL). Exclusion criteria were individuals on diuretics or proton-pump inhibitors, malabsorption or diarrhea, oral magnesium supplementation in the recent past, pregnancy, or sepsis. Results: 105 individuals, with median Mg levels of 1.96 (interquartile range 0.23) mg/dL. Hypomagnesemia (≤1.80 mg/dL) was detected in 20.0% individuals and 26.7% had DR. Individuals with hypomagnesemia had higher HbA1c (p = 0.014) and triglycerides (p = 0.024). Mg levels were negatively correlated with systolic blood pressure (r = -0.200, p = 0.041), HbA1c (r = -0.281, p = 0.004) and body mass index (BMI) (r = -0.197, p = 0.041). There was no significant difference between Mg levels or prevalence of hypomagnesemia in individuals with or without DR. Also, there was no significant difference between Mg levels and the severity of DR. Conclusion: Hypomagnesemia is a common problem in adults with T1D, and it was correlated with poor glycemic control, although we did not find a significant association between Mg levels and prevalence or severity of DR.