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Completed

NCT Number: NCT03587727

Hepatic Mitochondrial Function in Youth

Assess the impact of bariatric surgery on hepatic energy metabolism and glucose and insulin dynamics in obese youth

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Key information

Conditions

Hepatic Steatosis Adolescent Obesity Bariatric Surgery Candidate Body Weight Digestive System Diseases Fatty Liver Liver Diseases Nutrition Disorders Nutritional and Metabolic Diseases Obesity Overnutrition Overweight Pathological Conditions, Signs and Symptoms Pediatric Obesity Signs and Symptoms

Age range

13 year–20 year

Sex eligibility

All sexes

Study type

Observational

Primary location

University of Colorado Anshutz Medical Campus/Children's Hospital Colorado

Aurora, Colorado, 80045, United States

About this study

A metabolic study that will be performed prior to and 12 months following bariatric surgery. The study will include 31-phosphorus magnetic resonance spectroscopy to measure phosphate concentrations in the liver; a 4 hour mixed meal tolerance test, an intravenous arginine test, Abdominal Magnetic Resonance Imaging (MRI) for visceral and hepatic fat, Magnetic Resonance (MR) Elastography of the liver, indirect calorimetry, body composition assessment with Bodpod, serum metabolomics and hepatic tissue mitochondrial measures from the time of surgery only.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Obese youth ages 13-20 years, scheduled for bariatric surgery at Children's Hospital Colorado
  • BMI 35-55 m2/kg
  • Maximal body circumference <200 cm

Exclusion criteria

  • Use of medications known to affect insulin sensitivity: oral glucocorticoids within 10; days, atypical antipsychotics, immunosuppressant agents, HIV medications.
  • Infectious hepatitis
  • Alcohol abuse
  • Mitochondrial disease
  • Type 2 diabetes
  • Medications that affect hepatic outcomes (e.g. PPAR-γ or PPAR-α, metformin)
  • Currently pregnant or breastfeeding women. Development of pregnancy during the study period will necessitate withdrawal from the study.
  • Severe illness requiring hospitalization within 60 days
  • Diabetes, defined as Hemoglobin A1C > 6.4%
  • Anemia, defined as Hemoglobin < 10 mg/dL
  • Diagnosed major psychiatric or developmental disorder limiting informed consent
  • Implanted metal devices that are not compatible with MRI

Treatment and study plan

Primary outcomes

  1. Change in Percentage of Liver Fat Per MRI

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Percentage of liver fat at 1 year post-bariatric surgery minus percentage of liver fat prior to bariatric surgery. Liver fat measured with MRI and calculated via the Dixon method as the proton density hepatic fat. A negative value means a decrease in liver fat after bariatric surgery.

  2. Change in %Direct TG-Glycerol Appearance

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Change in %TG-Glycerol appearance from a labeled glycerol drink via direct pathway. TCA substrate cycling assessed via change in fractional direct glycerol carbon contributions to newly synthesized triglycerides using a U-13C glycerol tracer drink. A higher direct percentage is beneficial, indicating decreased oxidative stress resulting from excess glycerol metabolism through the TCA cycle.

Secondary outcomes

  1. Change in Insulin Sensitivity

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Mixed meal tolerance test (MMTT): measured with SI. This is a measure of post-prandial (MMTT) insulin sensitivity as calculated with the Oral Minimal Model (OMM) using SAAM II Software. This software uses participant weight, glucose and insulin concentrations at various time points during the MMTT to calculate the participant insulin sensitivity. A positive Si value means an increase in insulin sensitivity.

  2. Change in Peak Glucose

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Mixed meal tolerance test (MMTT): Peak glucose concentration (mg/dL) during 4 hour MMTT with 16 time points.

  3. Change in Minimum Glucose

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Mixed meal tolerance test (MMTT): Minimum glucose concentration (mg/dL) during 4 hour MMTT with 16 time points.

  4. Change in Peak Insulin

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Mixed meal tolerance test (MMTT): Peak insulin concentration (uIU/mL) during 4 hour MMTT with 13 time points.

  5. Change in Minimum Insulin

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Mixed meal tolerance test (MMTT): Minimum insulin concentration (uIU/mL) during 4 hour MMTT with 13 time points.

  6. Change in Peak C-peptide

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Mixed meal tolerance test (MMTT): Peak c-peptide concentration (ng/mL) during 4 hour MMTT with 10 time points.

  7. Change in Peak GLP-1

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Mixed meal tolerance test (MMTT): Peak GLP-1 concentration (pmol/L) during 4 hour MMTT with 9 time points.

  8. Change in Fasting Glucagon

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Mixed meal tolerance test (MMT): Fasting glucagon concentration (pg/mL) at the beginning of a 4 hour MMTT 1 year post bariatric surgery minus prior to surgery. A negative value means there was a decrease in fasting glucagon concentrations one year post-bariatric surgery.

  9. Change in Liver Stiffness Per MRI

    Time frame: Prior to bariatric surgery and 1 year post-bariatric surgery

    Change from baseline in degree of hepatic stiffness, measured with Magnetic Resonance elastography (MRE).

  10. Mitochondrial Function in the Liver Assessed by Oroboros

    Time frame: At the time of surgery

    L/E Coupling Control Ratio: Maximal respiratory capacity was examined in permeabilized hepatic tissue from adolescents using pyruvate (carbohydrate) and palmitoylcarnitine (lipid) as a substrate. Respiratory capacity was normalized to hepatic tissue wet weight. Coupling control ratio (L/E) was calculated as oxygen flux in leak (oligomyocin) divided by ET capacity (FCCP) with a maximum coupling of 1.0.

  11. Hepatic Steatosis Score Via Tissue Biopsy

    Time frame: At the time of surgery

    NAFLD (non-alcoholic fatty liver disease) Activity Score (NAS) determined via liver tissue biopsy and graded by a pathologist. The NAS can range from 0 to 8 and is calculated by the sum of scores of steatosis (0-3), lobular inflammation (0-3) and hepatocyte ballooning (0-2). A higher number represent a worse outcome.

Sponsors and collaborators

Lead sponsor

University of Colorado, Denver

Other

Registry information

Official study title

Hepatic Fat Content and Mitochondrial Flux in Obese Youth Before and After Bariatric Surgery

Acronym: MANGO

Important dates

Study start
2018
Primary completion
2023
Study completion
2023
First posted
Jul 16, 2018
Registry last updated
Oct 10, 2025

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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