title: Sustained effects of a protein and lipid preload on glucose tolerance in type 2 diabetes patients.
abstract: BACKGROUND
  Small amounts of nutrients given as a 'preload' can reduce post-meal hyperglycaemic peaks in type 2 diabetes (T2D) patients by activating a number of mechanisms involved in glucose homoeostasis. This study was undertaken to ascertain whether this positive effect extends to the late absorptive phase and to identify the main mechanisms involved.
  
  
  METHODS
  Eight well-controlled T2D patients, aged 40-70 years, were randomized to consume a 'preload' of either water or non-glucidic nutrients (50g of Parmesan cheese, one boiled egg) 30min before a 300-min oral glucose tolerance test.
  
  
  RESULTS
  After the nutrient preload, significant reductions were observed in peak glucose (-49%; P<0.02), total plasma glucose (iAUC: -28%; P<0.03), exogenous glucose (iAUC: -30%; P<0.03) and insulin clearance (-28%; P<0.04), with enhancement of insulin secretion (iAUC: +22%; P<0.003). These effects were associated with higher plasma levels of GLP-1 (iAUC: +463%; P<0.002), GIP (iAUC: +152%; P<0.0003) and glucagon (iAUC: +144%; P<0.0002).
  
  
  CONCLUSIONS
  In T2D patients, a protein and lipid preload improves glucose tolerance throughout the whole post-absorptive phase mainly by reducing the appearance of oral glucose, and improving both beta-cell function and insulin bioavailability.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy. Electronic address: domenico.trico@for.unipi.it.
authors.forename: D
authors.initials: D
authors.lastname: Tricò
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Filice
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Baldi
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Frascerra
authors.affiliation: National Research Council, Institute of Neuroscience, Padua, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Mari
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Natali
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000178:diet therapy*; D004041:Dietary Fats / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D005260:Female; D005947:Glucose / Q000493:pharmacokinetics; D018149:Glucose Intolerance / Q000097:blood / Q000517:prevention & control*; D005951:Glucose Tolerance Test; D006801:Humans; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period / Q000502:physiology; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D004041:Dietary Fats; D004044:Dietary Proteins; D005947:Glucose
keywords: Beta-cell function; Glucose absorption; Insulin secretion in vivo; Nutrient preload; Type 2 diabetes