Metabolic Phenotyping in Humans (MetPhe)
Recruitment status was: Recruiting
Type 2 Diabetes Mellitus
|Study Design:||Observational Model: Cohort
Time Perspective: Cross-Sectional
|Official Title:||Metabolic Characterization of Type 2 Diabetic, Obese, Lean Sedentary and Endurance Trained Individuals in Vivo, ex Vivo and in Vitro|
- Euglycemic-hyperinsulinemic clamp for measurement of insulin sensitivity and metabolic flexibility [ Time Frame: 10 hours ] [ Designated as safety issue: Yes ]After taking fasting blood samples, a primed constant infusion of glucose is initiated. Plasma glucose levels are clamped at ~5 mmol/L by variable co-infusion of 20% glucose. Every 5 minutes, blood is sampled for immediate determination of plasma glucose concentration. Glucose infusion rate is adjusted to obtain plasma glucose levels of ~5 mmol/L (euglycemia). A bolus of insulin is then infused. Before and during steady state, substrate oxidation is measured using an indirect calorimeter, which determines metabolic flexibility.
- Evaluating mitochondrial function through measurement of phosphocreatine (PCr) recovery by phosphorus magnetic resonance spectroscopy (31P-MRS) within the skeletal muscle [ Time Frame: 1.5 hours ] [ Designated as safety issue: Yes ]The quantification of energy metabolites (Pi, PCr and ATP) in skeletal muscle will be performed in the v. lateralis at rest, during submaximal knee-extension exercise and during recovery. The rate at which PCr concentration is restored after exercise is an excellent in vivo measure of skeletal muscle mitochondrial oxidative capacity.
Biospecimen Retention: Samples With DNA
|Study Start Date:||March 2011|
|Estimated Study Completion Date:||March 2013|
|Estimated Primary Completion Date:||March 2013 (Final data collection date for primary outcome measure)|
The aim of the present research proposal is to metabolically phenotype endurance trained athletes, lean and obese sedentary and type 2 diabetic individuals with the following objectives:
- assess metabolic flexibility as measured by a euglycemic-hyperinsulinemic clamp
- measure in vivo mitochondrial function by MRS of phosphocreatine (PCr) recovery
- establish primary myoblast cell lines to correlate with the above in vivo measurements, as well as further explore dietary, pharmacological and genetic manipulations in vitro
- quantify intramyocellular lipid (IMCL) and acetylcarnitine in vivo by MRS
A total of 132 male participants (18-70 years) will participate in this study. The first group of 33 participants will be lean endurance-trained athletes, the second group will be lean sedentary control participants, the third group will be sedentary type 2 diabetic participants, and the last group of 33 participants will be obese, non-diabetic sedentary control participants. It is preferred to use male participants in order to minimize variation in the measurements by avoiding confounding factors such as hormones.
Main study parameters/endpoints: The main study parameters are differences in metabolic flexibility as measured by euglycemic-hyperinsulinemic clamp, PCr recovery, IMCL and acetylcarnitines as measured by MRS and establishment of primary myoblast cell lines for future use.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01298375
|Maastricht, Limburg, Netherlands, 6200MD|
|Study Director:||Patrick Schrauwen, PhD||Maastricht University|
|Principal Investigator:||Lauren M Sparks, PhD||Maastricht University|
|Principal Investigator:||Madeleen Bosma, M.S.||Maastricht University|