Serum Magnesium May Improve Diabetic Retinopathy Risk Assessment: Study
China: A study published in BMC Ophthalmology involving 450 participants found that measuring serum magnesium along with HbA1c may improve the assessment and diagnosis of diabetic retinopathy. The findings suggest that magnesium levels could provide additional information beyond glycemic control alone when evaluating retinopathy risk.
The study was conducted by Yicang Wang, Department of Ophthalmology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi Province, China, and colleagues. The researchers investigated the relationship between serum magnesium levels and diabetic retinopathy (DR), while also examining magnesium concentrations in a mouse model of the condition.
For the clinical analysis, researchers divided 450 participants equally into three groups: individuals without diabetes, patients with diabetes and patients with diabetic retinopathy. Demographic characteristics, cardiovascular and metabolic measures, electrolyte levels and systemic inflammatory markers were assessed. Statistical analyses were performed to identify factors associated with DR, while receiver operating characteristic (ROC) analysis evaluated the diagnostic value of HbA1c and serum magnesium.
The analysis showed that serum magnesium levels declined progressively from the non-diabetes group to diabetes and then diabetic retinopathy. In contrast, heart rate and HbA1c increased across the three groups.
Key findings:
- Patients with diabetic retinopathy had a longer duration of diabetes than those with diabetes without retinopathy.
- Higher HbA1c levels were associated with increased DR risk, while higher serum magnesium was associated with lower risk.
- Among patients with diabetes, longer disease duration, higher systolic blood pressure and elevated HbA1c were linked to greater DR risk.
- Serum magnesium showed an inverse association with DR occurrence.
- Combining HbA1c with serum magnesium improved diagnostic performance compared with either marker alone.
- For diabetes, the combined assessment achieved 78.7% sensitivity and 90.0% specificity at a cut-off value of 0.500.
- For diabetic retinopathy, combined HbA1c and magnesium testing showed 75.3% sensitivity and 66.0% specificity at a cut-off value of 0.441.
- In the animal experiments, mice with diabetic retinopathy had lower magnesium concentrations in both serum and retinal tissue than control mice.
The researchers noted that the findings should be interpreted in light of the study's limitations, including its cross-sectional design, lack of follow-up and absence of treatment-status data. The study was also not blinded, and the direction of the relationship between low magnesium and DR could not be established. Further research is needed to determine whether magnesium deficiency contributes to retinal damage or occurs as a consequence of diabetic retinopathy.
Overall, the findings indicate that lower serum magnesium is associated with diabetic retinopathy, while diabetes duration and poor glycemic control are linked to higher risk. Combining serum magnesium with HbA1c may offer better diagnostic information for DR than either measure alone, although prospective studies are needed to clarify the underlying mechanisms and clinical relevance.
Reference:
Wang, Y., Li, J., Lin, Y. et al. The association between magnesium and diabetic retinopathy: a cross-sectional study. BMC Ophthalmol 26, 545 (2026). https://doi.org/10.1186/s12886-026-05020-3
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