Obesity
Conditions
Keywords
Obesity, Single Photon Emission Computed Tomography, Functional Neuroimaging
Brief summary
This study evaluates the hypothesis that a meal constituted of only glucose produces differences in the brain blood flow in people with obesity that are not observed in people without obesity. These changes, at least in part, could explain the mechanisms involved in maintenance or development of obesity.
Interventions
OTHER75 grams of glucose plus water solution
A solution composed by 75 grams of glucose and water at ambient temperature is administered to each volunteer, being of the with obesity group or the without obesity group, as follow: * 300 mL final volume of the solution. * Time of oral ingestion inferior than 2 minutes. * 30 minutes before the radiopharmaceutical injection. * 12 hours fasting minimum.
OTHERPure water
Pure water at ambient temperature is administered to each volunteer, being of the with obesity group or the without obesity group, as follow: * 300 mL final volume of the solution. * Time of oral ingestion inferior than 2 minutes. * 30 minutes before the radiopharmaceutical injection. * 12 hours fasting minimum.
Sponsors
Fundação de Amparo à Pesquisa do Estado de São Paulo
University of Sao Paulo
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* Live in Ribeirão Preto, São Paulo - Brazil. * Age between 18 and 40 years old. * Female gender. * Regular menses. * Weight inferior than 120 Kg and body mass index (BMI) between 30 and 40 kg/m2, for the group with obesity. * BMI between 18,5 and 24,9 kg/m2, for the group without obesity.
Exclusion criteria
* High blood pressure, diabetes, glucose intolerance or impaired fasting glycemia, metabolic syndrome, hypothyroidism and any kidney, liver, heart or neurologic disease. * Psychiatric disorders, alcoholism, smoking or illicit drug abuse. * Pregnancy or desire to be pregnant * Use of medications, excluding contraceptives. * Contraindication for magnetic resonance imaging. * Be in treatment for obesity.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Regional cerebral blood flow (rCBF) changes after a meal challenge, measured by Single Single-photon emission computed tomography (SPECT) and statistical parametric mapping. | 30 minutes after a meal challenge (time of radiopharmaceutical injection) | Using 99m technetium ecd radiopharmaceutical, this study aims to detect rCBF differences between SPECT images performed after a meal challenge composed by 75 grams of glucose and water and also after a challenge constituted by only water (control), both ingested orally. This approach is performed in a group of 10 people with obesity and also in 10 people without obesity. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Blood levels mean differences within both groups, with and without obesity and across these groups, of hormones and metabolites by multiplexed assay using luminex technology and spectrophotometry, respectively. | 30 minutes before, at the time and 30, 60 and 90 minutes after the radiopharmaceutical injection. | This study looks for mean differences of blood levels within and across groups with and without obesity. The metabolites and hormones/cytokines measured are, respectively: glucose (measured by spectrophotometry), insulin, leptin, amylin, interleukin 6 (IL-6), tumor necrosis factor alpha, active ghrelin, peptide yy (PYY) and pancreatic polypeptide (PP) (multiplexed assay using luminex). |
| Resting energy expenditure (REE) and body composition measurements by indirect calorimetry and electrical bioimpedance, respectively. | 6 hours before SPECT acquisition. | This study also aims to measure and compare the REE by indirect calorimetry with a Quark (Cosmed, Italy) calorimeter and the body composition by Byodinamics 450 (Biodynamics Corp., United States) within the two groups and across them. |
Countries
Brazil
Outcome results
None listed