title: Combined chromium and magnesium decreases insulin resistance more effectively than either alone.
abstract: OBJECTIVE
  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
  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-3β (GSK3β) 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 GSK3β (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 GSK3β expression.
authors.affiliation: Institute of Medical Nutrition, Medical College of Qingdao University, Qingdao, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Dou
authors.affiliation: Institute of Medical Nutrition, Medical College of Qingdao University, Qingdao, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Institute of Medical Nutrition, Medical College of Qingdao University, Qingdao, China. Email: qdukyc@163.com.
authors.forename: Ai Guo
authors.initials: AG
authors.lastname: Ma
authors.affiliation: Nutrition Department, Affiliated Hospital of Qingdao University, Qingdao, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Han
authors.affiliation: Institute of Medical Nutrition, Medical College of Qingdao University, Qingdao, China.
authors.forename: Mi Mi
authors.initials: MM
authors.lastname: Song
authors.affiliation: Endocrinology Department, Affiliated Hospital of Qingdao University, Qingdao, China.
authors.forename: Yan Gang
authors.initials: YG
authors.lastname: Wang
authors.affiliation: Endocrinology Department, Central Hospital of Qingdao, Qingdao, China.
authors.forename: Min Xiu
authors.initials: MX
authors.lastname: Yao
authors.affiliation: Endocrinology Department, Affiliated Hospital of Qingdao University, Qingdao, China.
authors.forename: Xiao Fang
authors.initials: XF
authors.lastname: Sun
authors.affiliation: Endocrinology Department, Central Hospital of Qingdao, Qingdao, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.affiliation: Endocrinology Department, Central Hospital of Qingdao, Qingdao, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Gao
authors.affiliation: Angel Yeast Co. LTD, Yichang, Hubei, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D001786:Blood Glucose / Q000032:analysis; D002857:Chromium / Q000008:administration & dosage* / Q000097:blood; D019587:Dietary Supplements; D004359:Drug Therapy, Combination; D004912:Erythrocytes / Q000737:chemistry; D005215:Fasting; D051275:Glucose Transporter Type 4 / Q000235:genetics; D000071679:Glycogen Synthase Kinase 3 beta / Q000235:genetics; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008274:Magnesium / Q000008:administration & dosage* / Q000097:blood; D008875:Middle Aged; D012333:RNA, Messenger / Q000097:blood; D013601:T-Lymphocytes / Q000737:chemistry
chemical_list: D001786:Blood Glucose; D051275:Glucose Transporter Type 4; D007328:Insulin; D012333:RNA, Messenger; C495692:SLC2A4 protein, human; D002857:Chromium; D000071679:Glycogen Synthase Kinase 3 beta; D008274:Magnesium