Diabetes Is the Main Factor Accounting for Hypomagnesemia in Obese Subjects

OBJECTIVE: Type 2 diabetes (T2DM) and obesity are associated with magnesium deficiency. We aimed to determine whether the presence of type 2 diabetes and the degree of metabolic control are related to low serum magnesium levels in obese individuals. METHODS: A) Case-control study: 200 obese subjects [50 with T2DM (cases) and 150 without diabetes (controls)] prospectively recruited. B) Interventional study: the effect of bariatric surgery on serum magnesium levels was examined in a subset of 120 obese subjects (40 with type 2 diabetes and 80 without diabetes). RESULTS: Type 2 diabetic patients showed lower serum magnesium levels [0.75±0.07 vs. 0.81±0.06 mmol/L; mean difference -0.06 (95% CI -0.09 to -0.04); p<0.001] than non-diabetic patients. Forty-eight percent of diabetic subjects, but only 15% of non-diabetic subjects showed a serum magnesium concentration lower than 0.75 mmol/L. Significant negative correlations between magnesium and fasting plasma glucose, HbA1c, HOMA-IR, and BMI were detected. Multiple linear regression analysis showed that fasting plasma glucose and HbA1c independently predicted serum magnesium. After bariatric surgery serum magnesium increased only in those patients in whom diabetes was resolved, but remain unchanged in those who not, without difference in loss weight between groups. Changes in serum magnesium negatively correlated with changes in fasting plasma glucose and HbA1c. Absolute changes in HbA1c independently predicted magnesium changes in the multiple linear regression analysis. CONCLUSIONS: Our results provide evidence that the presence of diabetes and the degree of metabolic control are essential in accounting for the lower levels of magnesium that exist in obese subjects

Induction motor analysis employing optimal torque predictor and massive conductor approach

This research presents a method for the simulation of the magneto-mechanical system dynamics taking motion and eddy currents into account. The major contribution of this work leans on the coupling the field-motion problem considering windings as the current forced massive conductors, modelling of the rotor motion composed of two conductive materials and the torque calculation employing the special optimal predictor combined with the modified Maxwell stress tensor method. The 3D model of the device is analysed by the time stepping finite element method. Mechanical motion of the rotor is determined by solving the second order motion equation. Both magnetic and mechanical equations are coupled in the iterative solving process. Presented method is verified by solving the TEAM Workshop Problem 30