This study will investigate the effect of body weight, diet, and high blood sugar levels, under controlled feeding conditions, on immune function in individuals with and without obesity. This study will be a non-randomized, four-arm parallel group, clinical trial under controlled feeding conditions (4-week nutritional intervention using a North American-type diet). A sample size of n=128 participants will be allocated into one of the following groups: * Individuals without obesity and normoglycemia (NG) (Lean-NG) * Individuals with obesity and normoglycemia (Obese-NG) * Individuals with obesity and glucose intolerance (GI) (Obese-GI) * Individuals with obesity and type 2 diabetes (T2D) (Obese-T2D) The following outcomes will be analyzed: * Immune cell function (ex-vivo cytokine production after stimulation with mitogen and T cell proliferation); * Immune cell phenotypes; * Systemic inflammation (C-reactive protein and plasma cytokines); * Glucose, insulin, glycated hemoglobin (HbA1c), and lipids; * Fatty acids and phospholipds composition in plasma and red blood cells membrane.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
114
All groups will receive an isocaloric diet for 4 weeks composed of 48% of energy as carbohydrate, 17% as protein, and 35% as lipid (12.5% of saturated fat, 13% of monounsaturated fat, and 6% of polyunsaturated fat), designed to reflect as closely as possible current macronutrient intake averages in North America/Canada.America/Canada (35% of energy as fat, 12.5% as saturated fat, 13% as monounsaturated fat, 6% as polyunsaturated fat, 48% as carbohydrate, 17% as protein)
University of Alberta
Edmonton, Alberta, Canada
Differences between groups in IL-2 Secretion by Peripheral Blood Mononuclear Cells (PBMC) After Ex-vivo Stimulation with Phytohemagglutinin (PHA) at Week 4
PBMCs will be stimulated with PHA for 48h and IL-2 will be quantified using enzyme-linked immunosorbent assay (ELISA).
Time frame: Week 4
Differences between groups in circulating C-reactive protein (CRP) at Week 4
CRP will be measured by Alberta Precision Labs using an immunoturbidimetric assay
Time frame: Week 4
Change from Baseline in IL-2 Secretion by PBMC After Ex-vivo Stimulation with mitogens at Week 4 and Differences Between Groups at Baseline and Week 4
PBMCs will be stimulated with Pokeweed Mitogen (PWM) and Phorbol Myristate Acetate and Ionomycin (PMAi), for 48h and IL-2 will be quantified using ELISA
Time frame: Baseline and Week 4
Change from Baseline in IL-1B Secretion by PBMC After Ex-vivo Stimulation with mitogens at Week 4 and Differences Between Groups at Baseline and Week 4
PBMCs will be stimulated with Lipopolysaccharides (LPS) and PWM for 48h and PBMCs will be stimulated with PHA, LPS, PWM, and PMAi for 48h and IFN-y will be quantified using ELISA
Time frame: Baseline and Week 4
Change from Baseline in IFN-y Secretion by PBMC After Ex-vivo Stimulation with mitogens at Week 4 and Differences Between Groups at Baseline and Week 4
PBMCs will be stimulated with PHA, LPS, PWM, and PMAi for 48h and IFN-y will be quantified using ELISA
Time frame: Baseline and Week 4
Change from Baseline in TNF-a Secretion by PBMC After Ex-vivo Stimulation with mitogens at Week 4 and Differences Between Groups at Baseline and Week 4.
PBMCs will be stimulated with PHA, LPS, PWM, and PMAi for 48h and TNF-a will be quantified using ELISA
Time frame: Baseline and Week 4
Change from Baseline in IL-10 Secretion by PBMC After Ex-vivo Stimulation with mitogens at Week 4 and Differences Between Groups at Baseline and Week 4
PBMCs will be stimulated with PHA, LPS, PWM, and PMAi for 48h and IL-10 will be quantified using ELISA
Time frame: Baseline and Week 4
Change from Baseline in IL-6 Secretion by PBMC After Ex-vivo Stimulation with mitogens at Week 4 and Differences Between Groups at Baseline and Week 4
PBMCs will be stimulated with PHA, LPS, PWM, PMAi for 48h and IL-6 will be quantified using ELISA
Time frame: Baseline and Week 4
Change from Baseline in T cell proliferation at Week 4 and Differences Between Groups at Baseline and Week 4
PBMCs will be stimulated with anti-CD3/anti-CD28 for 72h and proliferation will be quantified using alamarBlue dye method, which is a reliable and sensitive assay
Time frame: Baseline and Week 4
Change from Baseline in T Cells at Week 4 and Differences Between Groups at Baseline and Week 4
Immune cell phenotype of T cells will be determined using immunofluorescence staining for flow cytometry. The following monoclonal antibodies will be used: CD3, CD4, CD8, CD25, CD28, CD45RA, CD45RO, CTLA-4 (CD152), CD192, FoxP3, CD183, CD194, CCR10, CD196, and CD185. Data visualization will be performed in FlowJo software
Time frame: Baseline and Week 4
Change from Baseline in B Cells at Week 4 and Differences Between Groups at Baseline and Week 4
Immune cell phenotype of B cells will be determined using immunofluorescence staining for flow cytometry. The following monoclonal antibodies will be used: CD19, CD20, ICAM-1 (CD54), CD80, and CD192. Data visualization will be performed in FlowJo software.
Time frame: Baseline and Week 4
Change from Baseline in Dendritic Cells at Week 4 and Differences Between Groups at Baseline and Week 4
Immune cell phenotype of dendritic cells will be determined using immunofluorescence staining for flow cytometry. The following monoclonal antibodies will be used: CD11c, CD80, CD213, CD273, and HLA-DR. Data visualization will be performed in FlowJo software
Time frame: Baseline and Week 4
Change from Baseline in Natural Killer Cells at Week 4 and Differences Between Groups at Baseline and Week 4
Immune cell phenotype of T cells will be determined using immunofluorescence staining for flow cytometry. The following monoclonal antibodies will be used: CD3, CD16, and CD56. Data visualization will be performed in FlowJo software
Time frame: Baseline and Week 4
Change from Baseline in Monocytes at Week 4 and Differences Between Groups at Baseline and Week 4
Immune cell phenotype of Monocytes will be determined using immunofluorescence staining for flow cytometry. The following monoclonal antibodies will be used: CD11c, CD14, ICAM-1 (CD54), CD80, CD86, CD273, and HLA-DR. Data visualization will be performed in FlowJo software
Time frame: Baseline and Week 4
Change from Baseline in IL-6 Concentrations at Week 4 and Differences Between Groups at Baseline and Week 4.
IL-6 will be quantified using a multiplex assay (mesoscale).
Time frame: Baseline and Week 4
Change from Baseline in TNF-a Concentrations at Week 4 and Differences Between Groups at Baseline and Week 4.
TNF-a will be quantified using a multiplex assay (mesoscale).
Time frame: Baseline and Week 4
Change from Baseline in Complete Blood Cell Count and Differential at Week 4 and Differences Between Groups at Baseline and Week 4
Blood count and differential will be analyzed by Alberta Precision Labs in whole blood by fluorescent flow cytometry using a semi-conductor laser and hydrodynamic focusing in dedicated channels using an automated hematology analyzer
Time frame: Baseline and Week 4
Change from Baseline in Circulating Glucose Levels at Week 4 and Differences Between Groups at Baseline and Week 4
Glucose will be measured by Alberta Precision Labs with an UV testing using an enzymatic reference method with hexokinase
Time frame: Baseline and Week 4
Change from Baseline in Circulating Insulin Levels at Week 4 and Differences Between Groups at Baseline and Week 4
Insulin will be measured by Alberta Precision Labs using an electrochemiluminescence immunoassay
Time frame: Baseline and Week 4
Change from Baseline in Circulating Hemoglobin A1c Levels at Week 4 and Differences Between Groups at Baseline and Week 4
HbA1c will be measured by Alberta Precision Labs using a turbidimetric inhibition immunoassay for hemolyzed whole blood
Time frame: Baseline and Week 4
Change from Baseline in Circulating Triglycerides Levels at Week 4 and Differences Between Groups at Baseline and Week 4
Triglycerides will be measured by Alberta Precision Labs using an enzymatic colorimetric assay
Time frame: Baseline and Week 4
Change from Baseline in Circulating Total Cholesterol Levels at Week 4 and Differences Between Groups at Baseline and Week 4
Total Cholesterol will be measured by Alberta Precision Labs using an enzymatic colorimetric assay
Time frame: Baseline and Week 4
Change from Baseline in Circulating Low-Density Lipoprotein Cholesterol Levels at Week 4 and Differences Between Groups at Baseline and Week 4
LDL-C is calculated using the following equation: \[Total cholesterol - HDLc - (Triglycerides/2.2)\]
Time frame: Baseline and Week 4
Change from Baseline in Circulating High-Density Lipoprotein Cholesterol Levels at Week 4 and Differences Between Groups at Baseline and Week 4
High-Density Lipoprotein Cholesterol will be measured by Alberta Precision Labs using an enzymatic colorimetric assay
Time frame: Baseline and Week 4
Change from Baseline in Circulating Non-High Density Lipoprotein Cholesterol Levels at Week 4 and Differences Between Groups at Baseline and Week 4
Non-HDL c is derived from the calculation of total cholesterol minus HDL-c
Time frame: Baseline and Week 4
Differences Between Groups at Week 4 in Circulating Glucose Levels before and after an Oral Glucose Tolerance Test
Blood will be collected at the following time points after consuming the glucose solution: 0, 30, 60, 90, 120, 150, and 180 minutes. Plasma glucose concentrations will be measured using the hexokinase/glucose-6-phosphate dehydrogenase method using a clinical chemistry analyzer
Time frame: Week 4
Change from Baseline in Total Lipids Fatty Acids Composition in Plasma and Red Blood Cells at Week 4 and Differences Between Groups at Baseline and Week 4
Proportion of fatty acids will be determined using gas chromatography
Time frame: Baseline and Week 4
Change from Baseline in Phospholipids Fatty Acids Composition in Red Blood Cells at Week 4 and Differences Between Groups at Baseline and Week 4.
Proportion of fatty acids from phospholipids will be determined using gas chromatography
Time frame: Baseline and Week 4
Change from Baseline in Phospholipids Classes Quantifications in Red Blood Cells at Week 4 and Differences Between Groups at Baseline and Week 4.
Quantification of phospholipds will be determined by high performance liquid chromatography
Time frame: Baseline and Week 4
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.