Similarities in Metabolic Flexibility and Hunger Hormone Ghrelin Exist between FTO Gene Variants in Response to an Acute Dietary Challenge

Abstract

The rs9939609 polymorphism of the fat mass and obesity-associated (FTO) gene has been associated with obesity, and studies have also shown that environmental/lifestyle interaction such as dietary intake might mediate this effect. The current study investigates the postprandial hormonal regulators of hunger and indirect markers of substrate utilisation and metabolic flexibility following a dietary challenge to determine if suppression of circulating ghrelin levels and/or reduced metabolic flexibility exist between FTO genotypes. One hundred and forty seven healthy, sedentary males and females (29.0 ± 0.7 yrs; 70.2 ± 1.1 kg; 169.1 ± 0.8 cm; 24.5 ± 0.3 kg/m2) complete a single experimental session. Anthropometric measures, circulating levels of active ghrelin, insulin and glucose, and substrate oxidation via indirect calorimetry, are measured pre-prandial and/or post-prandial. The FTO rs9939609 variant is genotyped using a real-time polymerase chain reaction. Metabolic flexibility (∆RER) is similar between FTO genotypes of the rs9939609 (T > A) polymorphism (p > 0.05). No differences in pre-prandial and/or postprandial substrate oxidation, plasma glucose, serum insulin or ghrelin are observed between genotypes (p > 0.05). These observations are independent of body mass index and gender. Altered postprandial responses in hunger hormones and metabolic flexibility may not be a mechanism by which FTO is associated with higher BMI and obesity in healthy, normal-weighted individuals.

<i>FTO</i> genotypes (rs9939609 T&gt;A) are Associated with Increased Added Sugar Intake in Healthy Young Adults

“…In this study related to the rs9939609 T>A on FTO gene and appetite traits in normal weight participants, we found a higher intake of added sugars in carriers of the TA + AA genotypes versus the TT genotype. This finding coincides with other studies in which a higher intake of carbohydrates has been reported, but the classification of the type of carbohydrates was not described [17, 41]. Nevertheless, the study of Brunkwall et al [19] found a higher consumption of pastry and bakery products in carriers of the A allele, which would coincide with what was reported in our study since these foods are characterized by a high content of added sugars.…”

Tackling Atherosclerosis via Selected Nutrition

“…FTO (rs9939609), GHRL (rs34911341), LEPR (rs1137101), polymorphisms which affect the amount of food consumed and the feeling of satiety [ 49 , 50 , 51 , 52 , 53 , 54 , 55 ];…”

FTO and PLAG1 Genes Expression and FTO Methylation Predict Changes in Circulating Levels of Adipokines and Gastrointestinal Peptides in Children

“…Magno et al, studying the FTO rs9939609 polymorphism, showed that the subject with AA genotype indeed had decreased postprandial ghrelin concentration [46]. In contrast, Danaher et al did not confirm the relationship between the rs9939609 polymorphism of the FTO gene and the preprandial or postprandial ghrelin level [81]. These various reports may highlight the complexity of the interaction mechanisms between FTO and ghrelin, but more research is needed to fully understand them.…”