Cellular Dynamics of Subcutaneous Fat Distribution in Obese Women (Apple/Pear)
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|ClinicalTrials.gov Identifier: NCT01748994|
Recruitment Status : Completed
First Posted : December 13, 2012
Last Update Posted : August 29, 2018
|Condition or disease||Intervention/treatment||Phase|
|Obesity Metabolic Syndrome||Drug: Pioglitazone Drug: Placebo||Not Applicable|
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||49 participants|
|Intervention Model:||Parallel Assignment|
|Primary Purpose:||Basic Science|
|Official Title:||Cellular Dynamics of Subcutaneous Fat Distribution in Obese Women|
|Study Start Date :||February 2011|
|Actual Primary Completion Date :||December 2016|
|Actual Study Completion Date :||December 2016|
Placebo Comparator: Placebo
Administration of placebo to upper- and lower-body obese women
Active Comparator: Drug
Administration of pioglitazone to upper- and lower-body obese women
30mg per day for four months
Other Name: Actos
- Enrichment of DNA of adipose cells with deuterium [ Time Frame: Change from Baseline in Enrichment of DNA of adipose cells with deuterium at 4 Months ]Deuterium from the deuterium-labeled water is incorporated into the newly-synthesized DNA of newly-formed fat cell precursor cells through cell replication. The latter carry over the label when they become fat cells through differentiation. Enzymatic digestion of the fat tissue isolates the individual cells constituting the fat tissue. Centrifugation of the cell suspension allows the separation of fat cells into a floating layer and a pellet comprised of stromo-vascular cells including the fat cell precursor cells and small fat cells. As the fat cell precursor cells and small adipocytes have the property to attach quickly to plastic surfaces of culture dishes, a brief culturing of the stromo-vascular cells sorts these cells from the remaining cells. Thus, measuring the deuterium-enrichment of DNA from plastic-adherent stromo-vascular cells indicates the rate of in vivo formation of new fat cells and preadipocytes, a process collectively termed adipogenesis.
- Differentiation of adipose-derived stromo-vascular cultures [ Time Frame: Change from Baseline inDifferentiation of adipose-derived stromo-vascular cultures at 4 Months ]Adipose derived stromo-vascular cell cultures will be differentiated using an adipogenic cocktail for 10 days and various markers of differentiation will be determined including: 1) percent of in vitro differentiated fat cells using staining of lipid-containing cells with Oil Red O or BODIPY; and 2) gene expression and protein expression or secretion of main adipogenesis-regulatory factors including transcription factors and their upstream regulators or targets.
- Proliferation of adipose-derived stromo-vascular cultures [ Time Frame: Change from Baseline in Proliferation of adipose-derived stromo-vascular cultures at 4 Months ]Proliferation rate of these cultures will be determined using the changes of the cell number as a function of time or incorporation of BrdU (thymidine analogue) into synthesis of newly formed DNA of dividing cells (BrdU immunocytochemistry). In addition, gene or protein expression of genes encoding proteins involved in the cell cycle will be measured uring RT-PCR or immunoblotting techniques.
- Apoptosis of adipose-derived stromo-vascular cultures [ Time Frame: Change from Baseline in Apoptosis of adipose-derived stromo-vascular cultures at 4 Months ]The rate of cell death will be determined in response to apoptotic stimuli: tumor necrosis factor alpha (TNFα) plus the protein synthesis blocker cycloheximide and the measurement of DNA fragmentation (Cell Death Detection ELISAPLUS, Roche)
- Size of adipocytes [ Time Frame: Change from Baseline in Size of adipocytes at 4 Months ]Fat cell size will be determined using osmium fixation of the lipids and measurement of their diameter with Coulter Counter followed by calculation of fat cell volume. The mean lipid content of fat cells will be calculated by multiplying the fat cell volume by the density of triolein (0.915).
- Number of fat cells [ Time Frame: Change from Baseline in Number of fat cells at 4 Months ]Fat cell number will be estimated by dividing the volume of adipose tissue depot of interest to the mean fat cell volume or the fat mass of the depot to the mean lipid content in fat cell.
- Number of fat cell precursor cells [ Time Frame: Change from Baseline in Number of fat cell precursor cells at 4 Months ]The number of fat cell precursor cells will be estimated by an indirect approach. First, total number of cells in adipose tissue will be determined by measuring the DNA content per gram of adipose tissue and dividing it to the mean DNA per cell, 6pg. Subtracting the fat cell number from the total number will provide an estimate of the stromo-vascular cells per gram of tissue. The percent of fat cell precursor cells will be determined by staining of stromo-vascular cells with specific markers using flow cytometry. Multiplying the percent precursor cells by the number of stromo-vascular cells will give the number of fat cell precursor cells.
- Body composition [ Time Frame: Change from Baseline in Body composition at 4 Months ]Fat and lean fat masses will be assessed by Dual-energy X-ray Absorptiometry (DXA) using a whole body scanner GE iDXA. The scans will be analyzed with the software enCORE 13.4.
- Volume of abdominal fat depots [ Time Frame: Change from Baseline in Volume of abdominal fat depots at 4 Months ]The volume of fat tissue around the internal organs in the abdomen (visceral) and underneath the skin (subcutaneous) will be determined by Magnetic Resonance Imaging (MRI) of the abdominal region.
- Lipid accretion in the skeletal muscle cells (intra-myo-cellular lipid) [ Time Frame: Change from Baseline in intra-myo-cellular lipid at 4 Months ]Lipid accretion in the skeletal muscle cells will be measured using Proton Magnetic Resonance Spectroscopy of the calf muscle. Measurements will be obtained by collecting water-suppressed PRESS boxes (10 x 10 x 10 mm voxels) from the largest volume of the calf muscle [echo time = 35msec and a resonance time = 1500 sec] avoiding the fascia, vascular structures and gross marbling. Spectra will be quantified using jMRUi software.
- Lipid accretion in the cells of the liver (intra-hepato-cellular lipid) [ Time Frame: Change from Baseline in intra-hepato-cellular lipid at 4 Months ]Lipid accretion in the liver cells will be measured using 1H-MRS of the liver. Measurements will be obtained by collecting a single PRESS box (30 x 30 x 30 mm) in an area of the liver that is free from heavy vascularization as determined from the scout images. Spectra will be quantified using jMRUi software.
- Proinflammatory state of adipose-derived stromo-vascular cultures [ Time Frame: Change from Baseline in Proinflammatory state of adipose-derived stromo-vascular cultures at 4 Months ]The gene expression of inflammatory cytokines will be measured in adipose-derived stromo-vascular cultures before and after differentiation when treated or not (controls) with inflammatory cytokines.
- Glucose tolerance [ Time Frame: Change from Baseline in Glucose tolerance at 4 Months ]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 from the glucose administration to measure serum glucose, insulin, and free fatty acid concentrations.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01748994
|United States, Louisiana|
|Pennington Biomedical Research Center|
|Baton Rouge, Louisiana, United States, 70808|
|Pennington Biomedical Research Center|
|Baton Rouge, Louisiana, United States, 70809|
|Principal Investigator:||Eric Ravussin, PhD||Pennington Biomedical Research Center|