title: Insulin-sensitizing effects on muscle and adipose tissue after dietary fiber intake in men and women with metabolic syndrome.
abstract: BACKGROUND
  Dietary fibers have been associated with a reduced incidence of type 2 diabetes mellitus in epidemiological studies; however, the precise mechanisms are unknown.
  
  
  OBJECTIVE
  The objective of the study was to evaluate the efficacy and site of action of an insoluble dietary fiber derived from maize (HAM-RS2) in improving insulin resistance in subjects at increased risk of type 2 diabetes mellitus.
  
  
  METHODS
  This study was a randomized, controlled crossover, dietary intervention study.
  
  
  METHODS
  The study was conducted at the Centre for Diabetes, Endocrinology, and Research, Royal Surrey County Hospital, Guildford, United Kingdom.
  
  
  METHODS
  Fifteen men and women with insulin resistance participated in the study.
  
  
  METHODS
  The intervention included 40 g/d HAM-RS2 compared with a matched placebo for 8 wk.
  
  
  METHODS
  After each supplement, participants underwent a two-step hyperinsulinemic-euglycemic clamp study with the addition of glucose tracers; a meal tolerance test; arteriovenous sampling across forearm muscle tissue; and a sc adipose tissue biopsy for assessment of gene expression.
  
  
  RESULTS
  There was enhanced uptake of glucose into the forearm muscle measured by arteriovenous sampling (65 ± 15% increase after resistant starch; P < 0.001). Adipose tissue function was also affected, with enhanced fatty acid suppression after HAM-RS2 treatment and an increase in gene expression for hormone sensitive lipase (P = 0.005), perilipin (P = 0.011), lipoprotein lipase (P = 0.014), and adipose triglyceride lipase (P = 0.03) in biopsy samples. There was no effect on the insulin sensitivity of hepatic glucose production or plasma lipids after HAM-RS2.
  
  
  CONCLUSIONS
  HAM-RS2 improved peripheral but not hepatic insulin resistance and requires further study as an intervention in patients with or at risk for type 2 diabetes.
authors: Department of Diabetes and Metabolic Medicine, Postgraduate Medical School, University of Surrey, Guildford GU2 7WG, United Kingdom. m.robertson@surrey.ac.uk
authors: M Denise
authors: MD
authors: Robertson
authors: John W
authors: JW
authors: Wright
authors: Emmanuelle
authors: E
authors: Loizon
authors: Cyrille
authors: C
authors: Debard
authors: Hubert
authors: H
authors: Vidal
authors: Fariba
authors: F
authors: Shojaee-Moradie
authors: David
authors: D
authors: Russell-Jones
authors: A Margot
authors: AM
authors: Umpleby
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects* / Q000378:metabolism*; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D001706:Biopsy; D016207:Cytokines / Q000378:metabolism; D004032:Diet; D004043:Dietary Fiber / Q000494:pharmacology*; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D015309:Glucose Clamp Technique; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D050356:Lipid Metabolism / Q000187:drug effects; D008099:Liver / Q000378:metabolism; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D024821:Metabolic Syndrome / Q000178:diet therapy* / Q000378:metabolism* / Q000503:physiopathology; D008875:Middle Aged; D009132:Muscles / Q000187:drug effects* / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D016037:Single-Blind Method; D003313:Zea mays / Q000737:chemistry
chemical_list: D015415:Biomarkers; D016207:Cytokines; D004043:Dietary Fiber; D012333:RNA, Messenger; D005947:Glucose