Association between magnesium concentration and HbA1c in children and adolescents with type 1 diabetes mellitus

Background: Magnesium levels may be decreased in patients with type 1 diabetes mellitus (T1DM), influencing disease control. Relevant studies concern mainly adults and there are few data from the pediatric population. The aim of the present study was to evaluate magnesium levels and examine their possible association with glycemic control in youths with T1DM. Methods: In all, 138 children and adolescents with T1DM aged between 1.9 and 20.3 years were recruited to the study. Using a cross-sectional design, we measured anthropometric parameters, HbA1c, serum magnesium, ionized and total calcium, phosphorus, potassium, sodium, and urinary albumin (UA). Estimated glomerular filtration rate (eGFR), based on serum creatinine concentrations, was also calculated. Results: Lower levels of magnesium were found in subjects with poor versus good glycemic control (0.79 +/- 0.09 vs 0.82 +/- 0.09 mmol/L, respectively; P = 0.002). Serum magnesium levels were negatively correlated with HbA1c (P < 0.001) and positively correlated with UA, calcium, phosphorus, and potassium levels (P < 0.05). After adjustment for confounding factors, only magnesium levels remained significantly associated with HbA1c (adjusted r(2) = 0.172; P = 0.004). The odds ratio for poor glycemic control, indicated by HbA1c >7.5%, between the highest and lowest magnesium concentration quartiles was 0.190 and amounted to a decrease of 1.7% in the HbA1c level. Conclusions: The present study shows that low serum magnesium levels in children and adolescents with T1DM are associated with an increased risk of poor glycemic control, potentially contributing to the early development of cardiovascular complications.