Combined chromium and magnesium decreases insulin resistance more effectively than either alone.

BACKGROUND AND OBJECTIVES: Peroral supplementation with trivalent-chromium (Cr) or magnesium (Mg) has been shown to improve insulin resistance (IR). The objective of this study was to determine whether combined peroral supplementation with Cr and Mg improves IR more effectively than Cr or Mg alone. METHODS AND STUDY DESIGN: Subjects (n=120, age range 45-59 years old) and diagnosed with IR were randomly divided into four groups and monitored for a period of 3 months: group 1 (the placebo control group), group 2 (160 µg/d Cr), group 3 (200 mg/d Mg), and group 4 (160 µg/d Cr plus 200 mg/d Mg). Fasting blood glucose (FBG), fasting insulin (FIns), erythrocyte Cr and Mg content, and glucose-transporter-4 (GLUT4) and glycogen-synthase-kinase-3ß (GSK3ß) mRNA levels in activated T-lymphocytes were measured, and insulin resistant index (IRI) was calculated. RESULTS: Significant decreases between the baseline and study conclusion values of FBG (0.37 mmol/L, p<0.01), FIns (2.91 µIU/mL, p<0.01) and IRI (0.60, p<0.01) were observed in group 4, but not groups 1-3. Similarly, compared with baseline, significant changes in GLUT4 (2.9-fold increase, p<0.05) and GSK3ß (2.2-fold decrease, p<0.05) mRNA levels in activated T-lymphocyte were observed at the study's conclusion in group 4, but not in groups 1-3. CONCLUSIONS: Our results indicate that combining peroral supplementation with Cr and Mg improves IR more effectively than Cr or Mg alone, and this may be attributable to increased induction and repression, respectively, of GLUT4 and GSK3ß expression.

miRNA-103: molecular link between insulin resistance and nonalcoholic fatty liver disease.

AIM: To investigate the associations between miRNA-103 (miR-103) and insulin resistance and nonalcoholic fatty liver disease (NAFLD). METHODS: Serum samples were collected from 50 NAFLD patients who were overweight or obese (NAFLD group) and from 30 healthy subjects who served as controls (normal control group). Quantitative polymerase chain reaction was used to detect expression of miR-103. Fasting plasma glucose, fasting insulin, and triglyceride (TG) levels were measured. Homeostasis model assessment was used to evaluate basal insulin resistance (HOMA-IR). Patient height and weight were measured to calculate body mass index (BMI). RESULTS: Compared with the normal control group, higher serum levels of miR-103 were expressed in the NAFLD group (8.18 ± 0.73 vs 4.23 ± 0.81, P = 0.000). When P = 0.01 (bilateral), miR-103 was positively correlated with HOMA-IR (r = 0.881), TG (r = 0.774) and BMI (r = 0.878), respectively. miR-103, TG and BMI were all independent factors for HOMA-IR (ß = 0.438/0.657/0.251, P = 0.000/0.007/0.001). miR-103, TG, BMI and HOMA-IR were all risk factors for NAFLD (odds ratio = 2.411/16.196/1.574/19.11, P = 0.009/0.022/0.01/0.014). CONCLUSION: miR-103 is involved in insulin resistance and NAFLD, and may be a molecular link between insulin resistance and NAFLD and a therapeutic target for these disorders.