Objective: To determine the association between markers of hepatic injury and serum, urinary, and intra-erythrocyte magnesium concentrations and dietary magnesium intake in obese children.
Methods: In a casecontrol cross-sectional study, we studied 42 obese children and adolescents and 42 sex- and puberty-matched lean controls. Serum, urinary, and intra-erythrocyte magnesium levels, indexes of insulin sensitivity, and liver enzymes were measured. Dietary magnesium intake was assessed using a food frequency questionnaire.
Results: Obese children exhibited insulin resistance as determined by a higher fasting insulin and the HOMA-IR (P<0.001) and lower QUICKI indices (P=0.001); in addition these children had significantly higher intra-erythrocyte magnesium (IEM) concentration than non-obese ones (3.99±1.05 vs 3.35±1.26 mg/dl of packed cells, P=0.015). Serum, urinary, and dietary magnesium levels were comparable between groups. Among liver enzymes only gamma-glutamyl transferase (GGT) was significantly higher in obese than in non-obese subjects (22.7±9.4 vs 17.1±7.9 U/l, P=0.002). Positive association was found between GGT and IEM in both groups; however in multivariate analysis, in obese subjects, only GGT (β=0.375; P=0.026, model R=0.38) and, in non-obese subjects, only age (β=−0.466; P=0.006, model R=0.47) remained as significant predictors of IEM.
Conclusions: Increased IEM concentration was seen in insulin resistant obese children; furthermore, serum GGT was associated with IEM independently of body mass index and HOMA-IR.
25 - 29 Apr 2009
European Society of Endocrinology