title: Effects of green tea extract on insulin resistance and glucagon-like peptide 1 in patients with type 2 diabetes and lipid abnormalities: a randomized, double-blinded, and placebo-controlled trial.
abstract: The aim of this study is to investigate the effect of green tea extract on patients with type 2 diabetes mellitus and lipid abnormalities on glycemic and lipid profiles, and hormone peptides by a double-blinded, randomized and placebo-controlled clinical trial. This trial enrolled 92 subjects with type 2 diabetes mellitus and lipid abnormalities randomized into 2 arms, each arm comprising 46 participants. Of the participants, 39 in therapeutic arm took 500 mg green tea extract, three times a day, while 38 in control arm took cellulose with the same dose and frequency to complete the 16-week study. Anthropometrics measurements, glycemic and lipid profiles, safety parameters, and obesity-related hormone peptides were analyzed at screening and after 16-week course. Within-group comparisons showed that green tea extract caused a significant decrease in triglyceride and homeostasis model assessment of insulin resistance index after 16 weeks. Green tea extract also increased significantly high density lipoprotein cholesterol. The HOMA-IR index decreased from 5.4±3.9 to 3.5±2.0 in therapeutic arm only. Adiponectin, apolipoprotein A1, and apolipoprotein B100 increased significantly in both arms, but only glucagon-like peptide 1 increased in the therapeutic arm. However, only decreasing trend in triglyceride was found in between-group comparison. Our study suggested that green tea extract significantly improved insulin resistance and increased glucagon-like peptide 1 only in within-group comparison. The potential effects of green tea extract on insulin resistance and glucagon-like peptide 1 warrant further investigation.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01360567.
authors.affiliation: Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Chinese Medicine, Branch of Linsen and Chinese Medicine, Taipei City Hospital, Taipei, Taiwan.
authors.forename: Chia-Yu
authors.initials: CY
authors.lastname: Liu
authors.affiliation: Department of Metabolism, Branch of Linsen and Chinese Medicine, Taipei City Hospital, Taipei, Taiwan.
authors.forename: Chien-Jung
authors.initials: CJ
authors.lastname: Huang
authors.affiliation: Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Lin-Huang
authors.initials: LH
authors.lastname: Huang
authors.affiliation: Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Chinese Medicine, Branch of Linsen and Chinese Medicine, Taipei City Hospital, Taipei, Taiwan.
authors.forename: I-Ju
authors.initials: IJ
authors.lastname: Chen
authors.affiliation: Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Chinese Medicine, Branch of Linsen and Chinese Medicine, Taipei City Hospital, Taipei, Taiwan.
authors.forename: Jung-Peng
authors.initials: JP
authors.lastname: Chiu
authors.affiliation: Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Chinese Medicine, Branch of Linsen and Chinese Medicine, Taipei City Hospital, Taipei, Taiwan.
authors.forename: Chung-Hua
authors.initials: CH
authors.lastname: Hsu
mesh_terms: D003710:Demography; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance; D008055:Lipids / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010919:Placebos; D010936:Plant Extracts / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D008055:Lipids; D010919:Placebos; D010936:Plant Extracts; D052216:Glucagon-Like Peptide 1