Association of magnesium in serum and urine with carotid intima-media thickness and serum lipids in middle-aged and elderly Chinese: a community-based cross-sectional study

Previous studies suggested that magnesium (Mg) might protect against atherosclerosis, but data were scarce in an Asian population. We examined the association of Mg levels in serum and urine with carotid intima-media thickness (cIMT) and serum lipids in Chinese adults.

This community-based cross-sectional study recruited 2,837 participants aged 40–75 years in Guangzhou, China. General information, lifestyle factors, serum and urinary concentrations of Mg and cardiometabolic factors were determined. The cIMTs of the common carotid artery (CCA) and the carotid bifurcation (BIF) were measured ultrasonographically.

The mean (SD) concentration of serum Mg was 0.85 (0.07) mmol/L and median (IQR) for urinary Mg excretion was 2.29 (1.56–3.51) mmol/L. After adjustment for potential covariates, both serum and the urinary concentrations of Mg were inversely associated with CCA-IMT, but not with BIF-IMT. The regression coefficients (standard errors) were −100 (29) µm (total), −86 (34) µm (women) and −117 (52) µm (men) CCA-IMT per 1 mmol/L of serum Mg, and −41 (8) µm (total), −41 (10) µm (women) and −44 (15) µm (men) CCA-IMT per 1 unit of urinary Mg/creatinine (log mmol/mmol) (all p < 0.05), respectively. Higher serum Mg levels were associated with higher total cholesterol, HDLc, LDLc and triglyceride, but lower non-HDLc/HDLc in total population (all p < 0.05). Similar relationships of urinary Mg with lipoproteins were also found in total population (all p < 0.05).

Higher levels of serum and urinary Mg are associated with lower CCA-IMTs, and the role of Mg in lipid metabolism needs further investigation.