Objective: To evaluate circulating serum ionized magnesium (i-Mg) concentrations in patients with type 2 diabetes mellitus, and to investigate its relationship with the components of the metabolic syndrome.
Design: cross-sectional study.
Setting: Outpatients' service for diabetic patients at the University Hospital of Messina, Italy.
Subjects: 290 patients with type 2 diabetes mellitus.
Measures of outcome: Serum i-Mg was measured by ion selective electrode. Age, gender, body mass index (BMI), waist circumference, blood pressure, fasting glucose, HbA1c, HDL cholesterol, triglycerides, and urinary albumin excretion rate (UAER) were considered in the analyses. Patients with hypomagnesemia, defined as serum i-Mg <0.46 mmol/l, were compared with those having normal serum i-Mg levels, and variables proven to be associated with low i-Mg levels in the univariate analysis were entered in a multivariable logistic regression model to obtain a deconfounded estimate of the association between metabolic parameters and hypomagnesemia.
Results: In univariate analysis, serum i-Mg levels were significantly reduced in patients with low HDL cholesterol, high triglycerides values, high waist circumference, high blood pressure, microalbuminuria and clinical proteinuria. Hypomagnesemia was highly prevalent in our study population (N = 143, 49.3%). After adjusting for potential confounders, plasma triglycerides (OR = 4.71; 95% CI = 2.56-8.67), waist circumference (OR = 2.21; 95% CI = 1.21-4.04), microalbuminuria (OR = 2.43; 95% CI = 1.16-5.08) and clinical proteinuria (OR = 2.04; 95% CI = 1.02-5.68) were independently associated with hypomagnesemia.
Conclusions: Hypomagnesemia is highly prevalent in diabetic outpatients. High plasma triglycerides, waist circumference and albuminuria are independent correlates of hypomagnesemia.