Cellular Dynamics of Subcutaneous Fat Distribution in Obese Women (Apple/Pear)

The body shape of obese women varies between having the majority of fat either above the waist ("apple" shape) or below the waist ("pear" shape). The study will investigate what restricts: apple"-shaped women from being "pear"-shaped at the cellular level. Since "pear" shaped women tend to have better health, this study will open the door to future research in regulating body shape and thus improving health.

Study Overview

• Status: Completed
• Conditions: Obesity; Metabolic Syndrome
• Intervention / Treatment: Drug: Placebo; Drug: Pioglitazone

Detailed Description

Adipose tissue expandability and the distribution of stored fat in the body are stronger predictors of health risk. A better understanding of the factors that determine regional fat mass growth may lead to developing new strategies for prevention or treatment of metabolic complications of obesity. The objective of this proposal is to study the responsiveness of different fat depots to adipogenic stimulation in upper-body and lower-body obese women.

• Study Type: Interventional
• Enrollment (Actual): 63
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Louisiana
    • Baton Rouge, Louisiana, United States, 70808
      • Pennington Biomedical Research Center
    • Baton Rouge, Louisiana, United States, 70809
      • Pennington Biomedical Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• You are a pre-menopausal woman between 18-40 years of age
• Your Body Mass Index (BMI, weight-to-height2 ratio) is 27 - 38 kg/m2, inclusive
• The ratio of your waist-to-hip circumferences is either >0.84 ("apple"-type body shape) or <0.77 ("pear"-type body shape)
• You are willing to undergo a drug intervention for 16 weeks
• You are willing to drink heavy water [similar to the ordinary water that is highly enriched in the naturally occurring stable (non-radioactive) form of hydrogen, deuterium; also called deuterium-labeled water] for 8 weeks before the beginning and during the second half of the drug intervention; you will need 24-hours access to a refrigerator for storage of the water.
• You agree to use a double barrier method as a form of birth control to prevent pregnancy. Oral contraceptives (birth control pills) are not allowed in the study. Acceptable methods of birth control are condoms, spermicide, IUD (intrauterine device, must be hormone free - see list in clinic), diaphragm and abstinence. An example of a double barrier method would be condoms plus spermicide, etc.

Exclusion Criteria:

• You have gained or lost more than 4.5 lb (2 kg) in the last 3 months
• You have had significant changes in the diet or level of physical activity within the past month
• You have a blood sugar of greater than 100 or a diagnosis of diabetes.
• You have abnormal liver enzyme values from your blood work
• You have a history of heart, kidney, lung, liver, and thyroid disease
• You have an average blood pressure >140/90 at your screening visit
• Have you had a positive test for human immunodeficiency virus (HIV), hepatitis B or hepatitis C?
• You require chronic use of medications including diuretics, steroids, thyroid hormones, and adrenergic-stimulating agents (bronchodilators, nasal decongestants)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Administration of placebo to upper- and lower-body obese women	Drug: Placebo
Active Comparator: Drug; Administration of pioglitazone to upper- and lower-body obese women	Drug: Pioglitazone; 30mg per day for four months; Other Names: Actos

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
In Vivo Adipose Cell Formation (Adipogenesis)	Following the consumption of water labeled with the stable isotope deuterium (2H2O; heavy water), adipose tissue biopsies from the subcutaneous abdominal and femoral (thigh) depots will be collected. The 2H from the heavy water is enriched into the DNA of newly synthesized cells. Measures of DNA synthesis (obtained via gas chromatography and mass spectrometry analysis of 2H-enrichment) denote new adipose cell formation, or adipogenesis. The primary outcome is to assess the change (from baseline) in adipose cell formation rates (i.e. adipogenesis) in response to 16-weeks of pioglitazone versus the control group.	Change from baseline in adipogenesis at 16 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visceral Adipose Tissue (Percentage of Total Abdominal Adipose Tissue)	The volume of fat tissue around the internal organs in the abdomen (visceral adipose tissue; VAT) and underneath the skin (subcutaneous abdominal adipose tissue; scABD) will be determined by Magnetic Resonance Imaging (MRI) of the abdominal region. VAT:total abdominal AT (TAT) reflects the percentage of abdominal fat that is VAT and is calculated as VAT/(scABD AT + VAT).	Change from baseline in visceral fat at 16 weeks
Lipid Accretion in the Liver (Intra-hepatic Lipid; IHL)	Lipid accretion in the liver cells will be measured using 1H-MRS of the liver.	Change from Baseline in intra-hepato-cellular lipid at 16 weeks
Matsuda Index (Measure of Insulin Sensitivity)	Insulin sensitivity (glucose tolerance) will be assessed using an oral 75 g oral glucose tolerance test (OGTT) after an overnight fast. Blood samples will be collected at 0, 30, 60, 90, and 120 min after glucose administration to measure serum glucose and insulin. Insulin sensitivity was calculated using the Matsuda insulin sensitivity index [10,000/ √(glucose 0' x insulin 0') X (mean glucose OGTT x mean insulin OGTT)]. A higher value denotes increased insulin sensitivity.	Change from Baseline in Matsuda Index at 16 weeks

Collaborators and Investigators

• Sponsor: Pennington Biomedical Research Center
• Collaborators: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Publications and helpful links

General Publications

• White U, Fitch MD, Beyl RA, Hellerstein MK, Ravussin E. Adipose depot-specific effects of 16 weeks of pioglitazone on in vivo adipogenesis in women with obesity: a randomised controlled trial. Diabetologia. 2021 Jan;64(1):159-167. doi: 10.1007/s00125-020-05281-7. Epub 2020 Oct 1.
• White UA, Fitch MD, Beyl RA, Hellerstein MK, Ravussin E. Racial differences in in vivo adipose lipid kinetics in humans. J Lipid Res. 2018 Sep;59(9):1738-1744. doi: 10.1194/jlr.P082628. Epub 2018 Jun 17.
• White UA, Fitch MD, Beyl RA, Hellerstein MK, Ravussin E. Differences in In Vivo Cellular Kinetics in Abdominal and Femoral Subcutaneous Adipose Tissue in Women. Diabetes. 2016 Jun;65(6):1642-7. doi: 10.2337/db15-1617. Epub 2016 Mar 18.

Study record dates

Study Major Dates

• Study Start: February 1, 2011
• Primary Completion (Actual): December 1, 2016
• Study Completion (Actual): December 1, 2016

Study Registration Dates

• First Submitted: December 10, 2012
• First Submitted That Met QC Criteria: December 11, 2012
• First Posted (Estimate): December 13, 2012

Study Record Updates

• Last Update Posted (Actual): April 30, 2021
• Last Update Submitted That Met QC Criteria: April 29, 2021
• Last Verified: April 1, 2021

More Information

Terms related to this study

• Keywords: Obesity; Adipocyte; Adipogenesis; Ectopic fat; Fat distribution; Preadipocyte
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Insulin Resistance; Hyperinsulinism; Metabolic Syndrome; Hypoglycemic Agents; Physiological Effects of Drugs; Pioglitazone
• Other Study ID Numbers: PBRC 10039; 5R01DK090607 (U.S. NIH Grant/Contract)