The relationship between serum magnesium levels with childhood obesity and insulin resistance: a review of the literature

Background: Magnesium, the second most abundant intracellular cation, plays a major role in regulating insulin effect and insulin mediated glucose uptake. It has been shown that serum magnesium levels were negatively correlated with HOMA-IR (homeostasis model of insulin resistance) index. Aim: To investigate the relationship between serum magnesium levels with obesity and insulin resistance in childhood. Methods : Two hundred and three children and adolescents (117 obese children and 86 controls) were included. Obese cases were also subgrouped according to the presence or absence of insulin resistance (IR) as "IR (+) obese" and "IR (-) obese", respectively. Serum glucose, insulin and magnesium levels were measured after a 12-h fasting at 8-8.30 a.m. We assessed insulin sensitivity by using HOMA-IR index as a surrogate marker of insulin resistance. Results: Serum levels of magnesium were significantly lower in the IR (+) obese group than controls (p=0.014). At the same time, there was a positive correlation between serum magnesium levels and body mass index-standard deviation score (BMI-SDS) (r=-0.28, p=0.03) in the IR (-) obese group. Conclusions: Low serum magnesium levels may contribute to the development of insulin resistance in obese children.