Association of Dietary and Plasma Magnesium with Glycaemic Markers in a Chinese Population

Certain metals play a role in the pathogenesis of diabetes. This study aimed to investigate the potential association of plasma magnesium (Mg) and dietary intake of Mg with glycaemic markers. A cross-sectional study was conducted on 2373 subjects in Guangxi, China. Dietary Mg was obtained through a food frequency questionnaire containing 109 common foods. Plasma Mg concentration was determined by inductively coupled plasma mass spectrometry. Multiple linear regression combined with multivariable restricted cubic spline (RCS) functions was applied to evaluate the association of plasma Mg and dietary Mg with haemoglobin A1c (HbA1c) and fasting plasma glucose (FPG). In linear regression, dietary Mg was significantly associated with FPG in the overall population (β =  - 0.087, P < 0.05) and in women (β =  - 0.098, P < 0.05). Plasma Mg was significantly associated with FPG in the overall population (β =  - 0.096, P < 0.05) and in men (β =  - 0.110, P < 0.05) and women (β =  - 0.088, P < 0.05). In the RCS model, no non-linear association was found between dietary and plasma Mg and HbA1c levels. Dietary and plasma Mg are significantly negatively associated with fasting glucose.