Exploring the metabolic flexibility among the metabolic obesity phenotypes using the metabolic chamber

• Grant number: 23/17829-0
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: September 02, 2024
• End date: March 01, 2025
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Ana Carolina Junqueira Vasques
• Grantee: Isabela Solar
• Supervisor: Eric Ravussin
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Pennington Biomedical Research Center, United States
• Associated to the scholarship: 21/02008-5 - Brown adipose tissue and associated metabolites in women with different cardiometabolic health phenotypes, BP.DR

Abstract

Background: Individuals with obesity show metabolic inflexibility, with a decrease in fasting fat oxidation and an attenuated increase in the RER in insulin-stimulated states. However, it is still unclear, whether metabolic inflexibility is a feature of obesity or whether it is unique to metabolically unhealthy obesity (MUO) compared with metabolically healthy obesity (MHO) phenotype, which represents a unique model for studying mechanisms related to increased body adiposity. Indeed, studies involving metabolic flexibility with the MHO phenotype are scarce. Objective: Compare metabolic flexibility in adults characterized as having MHO, MUO and metabolically healthy normal weight (MHNW) phenotypes using metabolic chamber measurements. In addition, we are going to investigate which indicators of metabolic flexibility are most associated with anthropometric, body composition, plasma lipid, and glucose homeostasis parameters among all the phenotypes. Methods: This is a cross-sectional study, which will use the database of 19 studies conducted at the Pennington Biomedical Research Center Institute. The sample will consist of 407 participants of both genders, aged between 18 and 68. Individuals with a BMI e 30 kg/m² will be considered having obesity. For metabolic health, it will be used the harmonized definition of metabolic syndrome. Anthropometric parameters will consist of BMI, waist, and hip circumferences. Body composition was evaluated by a dual-emission densitometer with an X-ray. Fasting plasmatic glycemic and lipid profiles were determined. The metabolic flexibility will be the difference between the awake and sleep respiratory exchange ratio inside the metabolic chamber. Multivariate linear regression and binary logistic regression will be applied. Perspectives: the identification of which indicators of metabolic (in)flexibility are most associated with different phenotypes of metabolic health and body composition will provide information on novel biomarkers of metabolic health, which could provide greater granularity to improve the characterization and develop more tailored approaches for individuals in specific subphenotypic groups in the obesity field.