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Completed

NCT Number: NCT02011581

Diurnal Variability in the Regulation of Beta-cell Function and Insulin Sensitivity in Overweight People

The purpose of this research study is to learn more about how our body produces sugar, breaks down fat for fuel, and makes insulin (the major hormone that controls the production of blood sugar and fat breakdown) during a 24-hour day and how body fat and muscle are involved in these processes.

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Key information

Conditions

Overweight Body Weight Nutrition Disorders Nutritional and Metabolic Diseases Overnutrition Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–55 year

Sex eligibility

Female

Study type

Observational

Primary location

Washington University School of Medicine

St Louis, Missouri, 63110, United States

About this study

The purpose of this study is to determine whether there are diurnal differences in postprandial beta-cell function and hepatic insulin sensitivity and the factors that influence these metabolic functions, including insulin signaling, adipose tissue and systemic inflammation, nicotinamide phosphoribosyltransferase (NAMPT)-mediated nicotinamide adenine dinucleotide(NAD) biosynthesis, and sirtuin (silent mating type information regulation 2 homolog 1 (SIRT1)) in overweight human subjects.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Females
  • 18-55 years old
  • BMI between 25.0-29.9 kg/m2
  • Must be sedentary (regular exercise <1hour/week or <2 times/week

Exclusion criteria

  • Regular exercise (>1hour/week or >2 times/week)
  • Diabetes
  • Severe organ dysfunction
  • Smokers
  • Severe hypertriglyceridemia (>300 mg/dl)
  • Medications that may alter the results of the study
  • Pregnant
  • Breastfeeding

Treatment and study plan

Primary outcomes

  1. Determine postprandial beta-cell function (insulin secretion) after ingesting breakfast and dinner meals.

    Time frame: 24 hours

    Postprandial pancreatic beta-cell function will be evaluated by using a mixed meal labelled with stable isotope tracers, in conjunction with stable isotope tracer infusion. Metabolic outcomes from the breakfast meal will be compared with values obtained after dinner.

  2. Determine postprandial hepatic insulin sensitivity (suppression of endogenous glucose production) after ingesting breakfast and dinner meals.

    Time frame: 24 hours

    Postprandial pancreatic hepatic insulin sensitivity will be evaluated by using a mixed meal labelled with stable isotope tracers, in conjunction with stable isotope tracer infusion. Metabolic outcomes from the breakfast meal will be compared with values obtained after dinner.

Secondary outcomes

  1. Determine whether there is diurnal variability in muscle insulin signaling

    Time frame: 24 hours

    This muscle samples will be obtained two times (every 12 hours for 24 hours)to assess NAMPT and NAD+ concentrations, SIRT1 activity, and factors involved in insulin signaling.

  2. Determine whether there is diurnal variability in adipose tissue and systemic inflammation.

    Time frame: 24 hours

    Subcutaneous adipose tissue samples will be obtained four times (every 6 hours for 24 hours) to evaluate NAMPT and NAD+ concentrations, SIRT1 activity, and markers of inflammation.

  3. Determine whether there is diurnal variability in NAMPT-mediated NAD+ biosynthesis and SIRT1.

    Time frame: 24 hours

    Blood samples will be obtained at regular intervals for 24 hours to evaluate; 1)plasma free fatty acids (FFA), glucose and insulin concentrations, 2)NAMPT and NAD+ concentrations, 3)SIRT1 activity,and 4)systemic markers of inflammation (C-reactive protein and interleukin (IL) -6).

Sponsors and collaborators

Lead sponsor

Washington University School of Medicine

Other

Registry information

Acronym: 24Hr

Important dates

Study start
2011
Primary completion
2013
Study completion
2014
First posted
Dec 13, 2013
Registry last updated
Apr 30, 2015

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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