Obesity Adult Onset
Conditions
Keywords
metabolic syndrome, Very low-calorie diet, Microbiota, oxidative stress, Inflammation
Brief summary
It has been suggested that individuals with the condition known as metabolically healthy obesity (MHO) may not have the same increased risk of developing metabolic abnormalities as their non-metabolically healthy counterparts. In addition, to date, the identification of metabolic biomarkers and microbiota underlying the MHO state is limited. In this study, our goal is to provide insight into the underlying metabolic pathways affected by obesity. To achieve this, we will compare the metabolic profile, inflammatory parameters and mitochondrial function, as well as metabolomic analysis and differential expression of microbiota in obese patients categorized as metabolically healthy vs. non healthy. In parallel, the effect of a hypocaloric diet on obese subjects' metabolism and microbiota will be assessed to approve their use in the treatment of said disorder. Specifically, we propose an observational, clinical-basic, comparative and interventional study in a population of 80 obese (BMI\>35 kg/m2) patients clustered in two groups according to the presence or absence of altered metabolism (altered fasting glycemia, hypertension, atherogenic dyslipidemia). Anthropometric and clinical variables and biological samples (serum, plasma, peripheral blood cells and feces) will be collected for the determination of biochemical parameters (glucose, lipid and hormonal profile by enzymatic techniques) and protein-based peripheral biomarkers of mitochondrial function \[total and mitochondrial reactive oxygen species (ROS) production, mitochondrial membrane potential, glutathione levels by static cytometry\], markers of mitochondrial dynamics \[Mitofusin 1 (MFN1), Mitofusin 2 (MFN2), Mitochondrial fision protein 1 (FIS1) and Dynamin-related protein 1 (DRP1) by RT-PCR and Western Blot\], markers of inflammation \[Interleukin 6 (IL6), Tumoral necrosis factor alpha (TNFα), IL1b, adiponectin, resistin, plasminogen activator inhibitor 1 (PAI-1), Monocyte chemoattractant protein-1 (MCP-1), caspase 1 and NLRP3 by Western Blot and technology XMAP), metabolomic assay (NMR spectroscopy and PLS-DA), as well as gut microbiota content and diversity (16S rRNA, MiSeq sequencing). Finally, we will evaluate the effect of a dietary weight loss intervention on these biomarkers.
Interventions
DIETARY_SUPPLEMENTvery low-calorie diet
Subjects undergo two cycles of a very-low-calorie diet (VLCD) for 6 weeks each, alternating with a hypocaloric diet (12 weeks). The dietetic intervention consists of a VLCD using a liquid formula (Optisource Plus, Nestlé S.A., Vevey, Switzerland), providing 52.8 g protein, 75.0 g carbohydrates, 13.5 g fat, 11.4 g fiber, and essential vitamins and minerals based on Recommended Dietary Allowances (RDA). This formula supplies 2738 kJ/day (654 kcal/day), replacing the participants' three daily meals. Following this and before the second VLCD cycle, a dietician performs an individualized nutritional assessment to calculate the resting energy expenditure, and personalized hypocaloric diets were prepared, reducing 500 kcal for each individual on their daily caloric expenditure, maintaining the recommended intake of each of the macronutrients (55% carbohydrates, 30% fats and 15% proteins) for 12-weeks.
Sponsors
Instituto de Salud Carlos III
Celia Bañuls
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
No
Inclusion criteria
* Patients with BMI≥30kg/m2, with at least 5 years of diagnosed obesity evolution. * Patients have had stable body weight (±2 kg) during the 3 months prior to the study.
Exclusion criteria
* All patients with acute or chronic inflammatory diseases, neoplasic disease, secondary causes of obesity (uncontrolled hypothyroidism, Cushing's syndrome), and established liver and kidney failure (according to transaminase levels ±2 SD of the mean and estimated glomerular filtration rate using the CKD-EPI formula \>60) will be excluded.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Analyze the changes in the diversity of the intestinal microbiota after dietetic intervention. | 5 years | To assess the alpha-diversity of the intestinal microbiota, defined as the average diversity of species in an ecosystem, the Shannon index will be used. The results are interpreted as follows: values less than 2 are considered low in diversity and values greater than 3 are high in species diversity. |
| Evaluate the differences in the diversity of the intestinal microbiota depending on whether patients present metabolically healthy obesity (MHO) or metabolically unhealthy obesity (MUHO). | 5 years | To asses the differences in alpha-diversity of the intestinal microbiota in both groups, it will be evaluated whether there are significant differences between the Shannon indices of the two groups. The classification of patients between MHO and MUHO will be carried out using the following criteria: MUHO will be considered when patients with obesity present ≥2 metabolic abnormalities, and MHO with ≤1 metabolic abnormalities; the following cardiovascular risk factors are considered metabolic abnormalities: elevated blood pressure (defined as either SBP ≥130 mm Hg, DBP ≥85 mm Hg, or treatment with antihypertensive medications), elevated triglycerides (as fasting triglyceride concentration ≥1.7 mmol/l), low HDL-C levels (defined as HDL-C \<1.04 mmol/l, in men, \<1.29 mmol/l/l in women, or treatment with lipid-lowering medications), dysglycemia (fasting plasma glucose 5.6 to 6.9 mmol/l, and/or and insulin resistance as HOMA-IR \>3.8). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Evaluate significant changes in C3 protein as an inflammatory parameter after the dietetic intervention. | 2 years | Participants will be considered to have achieved an improvement in C3 protein if they normalize its value (normality values defined between 81 and 157mg/dl). |
| Assess significant changes in plasmatic homocysteine as an inflammatory parameter after the dietetic intervention. | 2 years | Participants will be considered to have achieved an improvement in plasmatic homocysteine if they normalize its value (normality values defined between 5 and 15µmol/L). |
| Evaluate significant changes in interleukin 1-beta (IL-1B) levels as a pro-inflammatory molecule after the dietetic intervention. | 2 years | IL-1B levels will be measured using the Luminex® 200 analyzer system. A significant improvement will be considered when notable differences are observed in the mean values between groups measured through p-value (\<0.05) with a 95% confidence interval. |
| Evaluate significant changes in interleukin 6 (IL-6) levels as a pro-inflammatory molecule after the dietetic intervention. | 2 years | IL-6 levels will be measured using the Luminex® 200 analyzer system. A significant improvement will be considered when notable differences are observed in the mean values between groups measured through p-value (\<0.05) with a 95% confidence interval. |
| Evaluate significant changes in tumor necrosis factor alpha (TNF-alpha) levels as a pro-inflammatory molecule after the dietetic intervention. | 2 years | TNF-alpha levels will be measured using the Luminex® 200 analyzer system. A significant improvement will be considered when notable differences are observed in the mean values between groups measured through p-value (\<0.05) with a 95% confidence interval. |
| Assess significant changes in superoxide dismutase (SOD) levels after the dietetic intervention. | 2 years | Superoxide dismutase levels will be measured using the Luminex® 200 analyzer system. A significant improvement will be considered when notable differences are observed in the mean values between groups measured through p-value (\<0.05) with a 95% confidence interval. |
| Evaluate significant changes in body fat mass percentage after the dietetic intervention. | 2 years | Percentage of body fat mass will be measured by bioelectrical impedance. It is considered to be high when ≥25% in men and ≥30% in women. A significant improvement will be considered when notable differences are observed in the mean values between groups measured through p-value (\<0.05) with a 95% confidence interval. |
| Evaluate if there is a significant reduction after the dietetic intervention in total ROS levels. | 2 years | Total ROS levels will be assessed by a flow cytometry assay. A significant improvement will be considered when notable differences are observed in the mean values between groups measured through p-value (\<0.05) with a 95% confidence interval. |
| Assess if there is a significant reduction after the dietetic intervention in glutathione levels. | 2 years | Total glutathione levels will be assessed by a flow cytometry assay. A significant improvement will be considered when notable differences are observed in the mean values between groups measured through p-value (\<0.05) with a 95% confidence interval. |
| Analyze if there is a significant change after the dietetic intervention in total free radicals and superoxide levels. | 2 years | Total free radicals and superoxide content will be assessed by a flow cytometry assay. A significant improvement will be considered when notable differences are observed in the mean values between groups measured through p-value (\<0.05) with a 95% confidence interval. |
| Analyze if there is a significant reduction after the dietetic intervention in mitochondrial ROS production. | 2 years | Mitochondrial ROS production will be assessed by a flow cytometry assay. A significant improvement will be considered when notable differences are observed in the mean values between groups measured through p-value (\<0.05) with a 95% confidence interval. |
| Evaluate if there is a significant improvement after the dietetic intervention in mitochondrial membrane potential. | 2 years | Mitochondrial membrane potential will be assessed by a flow cytometry assay. A significant improvement will be considered when notable differences are observed in the mean values between groups measured through p-value (\<0.05) with a 95% confidence interval. |
| Analyze the proportion of subjects achieving at least 10% reduction in weight compared with baseline. | 5 years | Proportion of subjects achieving at least 10% reduction in weight after the dietetic intervention (6 months). |
| Analyze the significant differences between metabolomic profile before and after the dietetic intervention. | 2 years | NMR spectra will be used to obtain spectra from serum samples from the cohort. In order to evaluate if there will be significant differences after the dietetic intervention, a PLS-DA model for discrimination between basal and post intervention levels will be performed. Scores plots will be calculated with a 95% confidence interval. |
| Assess significant changes in high-sensitivity C-reactive protein (hs-CRP) as an inflammatory parameter after the dietetic intervention. | 2 years | Participants will be considered to have achieved an improvement in high-sensitivity C-reactive protein levels if they normalize its value (normality values defined between 0 and 1.69mg/dl). |
Countries
Spain
Outcome results
None listed