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Effects of a Small Protein and Lipid Preload on Glucose Tolerance in Subjects With Impaired Glucose Homeostasis

Not Applicable
Completed
Conditions
Diabetes Mellitus, Type 2
Interventions
Dietary Supplement: Small mixed protein and lipid meal
Registration Number
NCT02342834
Lead Sponsor
Azienda Ospedaliero, Universitaria Pisana
Brief Summary

The purpose of this study is:

* to measure the size of the effect on glucose tolerance of a small mixed protein and lipid meal given as a pre-load in individuals with different glucose tolerance status

* to investigate the underlying mechanisms by accurately evaluating beta cell function, insulin sensitivity, insulin clearance and glucose kinetics (oral absorption, endogenous production, rate of utilization) together with gut hormones plasma concentration.

Detailed Description

As supported by experimental and clinical data, oral carbohydrate tolerance is influenced by the coingestion of nutrients through multiple mechanisms. The ingestion itself, the contact with the gastric mucosa, the arrival into the intestine and the subsequent digestion are known to produce neural reflexes, hormonal responses and plasma substrates gradients which, by modulating gastric emptying, insulin secretion and insulin clearance participate in the regulation of postprandial glycaemia. The size of this effect is influenced by a number of factors: the specific nutrient chemical characteristics (fat vs protein and composition) and their physical properties (solid vs liquid), the timing (pre-load vs coingestion) and finally the individual glucose tolerance status. To our knowledge, the effect on glucose excursions of a combination of protein and fat given before carbohydrate is still unknown and also unknown is the contribution of different mechanisms involved in the control of glucose homeostasis in subjects with different degrees of glucose tolerance.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
35
Inclusion Criteria
  • healthy, prediabetic or diet-controlled type 2 diabetic patients
  • Subjects ≥ 18 and ≤65 years of age
  • Lean, Overweight or Obese (BMI: 18 to 35 kg/m2)
  • Normal liver and kidney function
  • Normal thyroid function
  • Read and understood the informed consent form and signed it voluntarily
Exclusion Criteria
  • Liver, heart, kidney, lung, infectious, neurological, psychiatric, immunological or neoplastic diseases.
  • Type 1 or insulin treated diabetes.
  • Pregnancy or lactation
  • Illicit drug abuse or alcoholism
  • Subject treated with insulin or treatment
  • Subjects taking anoretic drugs
  • Subjects on steroid treatment
  • Subjects after bariatric surgery.

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Small mixed protein and lipid mealSmall mixed protein and lipid mealDuring the "preload" study, each subject ingest a small mixed meal 30 minutes before a standard 75 g Oral Glucose Tolerance Test. The meal is composed by 50 g of parmesan cheese, one small size boiled egg and 300 ml of water (250 kcal, 23 g protein, 17 g fat and 2 g of carbohydrate).
Primary Outcome Measures
NameTimeMethod
Plasma glucose response during the Oral Glucose Tolerance Test120 minutes
Secondary Outcome Measures
NameTimeMethod
Plasma Non Esterified Fatty Acids120 minutes
Beta cells function parameters (glucose sensitivity, rate sensitivity, potentiation factor ratio), calculated by modeling insulin secretion and glucose concentration.120 minutes
Insulin secretion, estimated from C-peptide deconvolution120 minutes
Incretin secretion (plasma GLP-1, plasma GIP)120 minutes
Endothelial function assessed as the reactive hyperemia index by an EndoPAT devicefasting, 60 min and 120 min during the control and preload OGTT
Insulin clearance, estimated by calculating the Insulin secretion/Plasma insulin ratio120 minutes
Plasma glucagon120 minutes
Insulin sensitivity, estimated from glucose and insulin levels during the Oral Glucose Tolerance Test with the use of Oral Glucose Insulin Sensitivity index120 minutes

The Oral Glucose Insulin Sensitivity index (OGIS; equation for a 2-h oral glucose test with a glucose dose of 75 g) is the mean glucose clearance change (basal vs OGTT 60-120 min), divided by the mean plasma insulin concentration gradient over the same time interval.

Glucose fluxes (intestinal glucose absorption, endogenous glucose production, rate of disappearance of plasma glucose), assessed by modeling glucose tracers enrichments using a standard double tracers technique120 minutes

Trial Locations

Locations (1)

Azienda Ospedaliero-Universitaria Pisana

🇮🇹

Pisa, PI, Italy

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