Association Between Adipose Tissue Characteristics and Metabolic Flexibility in Humans: A Systematic Review

Abstract

Adipose tissue total amount, distribution, and phenotype influence metabolic health. This may be partially mediated by the metabolic effects that these adipose tissue characteristics exert on the nearby and distant tissues. Thus, adipose tissue may influence the capacity of cells, tissues, and the organism to adapt fuel oxidation to fuel availability, i.e., their metabolic flexibility (MetF). Our aim was to systematically review the evidence for an association between adipose tissue characteristics and MetF in response to metabolic challenges in human adults. We searched in PubMed (last search on September 4, 2021) for reports that measured adipose tissue characteristics (total amount, distribution, and phenotype) and MetF in response to metabolic challenges (as a change in respiratory quotient) in humans aged 18 to <65 years. Any study design was considered, and the risk of bias was assessed with a checklist for randomized and non-randomized studies. From 880 records identified, 22 remained for the analysis, 10 of them measured MetF in response to glucose plus insulin stimulation, nine in response to dietary challenges, and four in response to other challenges. Our main findings were that: (a) MetF to glucose plus insulin stimulation seems inversely associated with adipose tissue total amount, waist circumference, and visceral adipose tissue; and (b) MetF to dietary challenges does not seem associated with adipose tissue total amount or distribution. In conclusion, evidence suggests that adipose tissue may directly or indirectly influence MetF to glucose plus insulin stimulation, an effect probably explained by skeletal muscle insulin sensitivity.Systematic Review Registration: PROSPERO [CRD42020167810].

Substrate metabolism in male astronauts onboard the International Space Station: the ENERGY study

“…Changes in FM were positively associated with changes in postprandial lipid oxidation, while postprandial carbohydrate oxidation and postprandial ∆RQ were negatively correlated. A recent systematic review 47 that combined clinical studies on the relationship between adiposity and ∆RQ in response to metabolic challenges reported inverse correlations between ∆RQ to glucose plus insulin stimulation (i.e., measured during a hyperinsulinemic-euglycemic clamp) and total FM, visceral adipose tissue, and waist circumference. However, the authors found no association between adipose tissue characteristics and postprandial ∆RQ in response to dietary challenges.…”

Substrate metabolism and metabolic flexibility in male astronauts onboard the International Space Station: The ENERGY study

“…Changes in FM were positively associated with changes in postprandial lipid oxidation, while postprandial carbohydrate oxidation and metabolic flexibility were negatively correlated. A recent systematic review 58 that combined clinical studies on the relationship between adiposity and metabolic flexibility reported inverse correlations between metabolic flexibility to glucose plus insulin stimulation (i.e., measured during a hyperinsulinemic euglycemic clamp) and total FM, visceral adipose tissue, and waist circumference. However, the authors found no association between adipose tissue characteristics and metabolic flexibility in response to dietary challenges.…”

The Association of Macronutrient Consumption and BMI to Exhaled Carbon Dioxide in Lumen Users: Retrospective Real-World Study

“…In addition, it was found to be impaired in individuals with obesity and T2D compared to lean and healthy individuals [ 9 , 10 ]. Assessment of metabolic flexibility can be conducted through postprandial changes (following a meal or any other insulin stimulation) in the respiratory exchange ratio (RER) from the metabolic cart [ 11 , 12 ], which estimates the body’s preference for macronutrient oxidation. Accordingly, several studies showed different RER responses between participants with high metabolic flexibility compared with participants with low flexibility for fasting, a high-carbohydrate diet, and a high-fat diet [ 13 ].…”