Dietary Fatty Acid Composition Is Associated with FTO Gene Expression in Human Visceral and Subcutaneous Adipose Tissues

Abstract

Abstract Objectives The fat mass and obesity-associated gene (FTO) is a functional candidate gene for type 2 diabetes mellitus (T2DM) and metabolic syndrome, based on evidence from genome-wide association studies (GWAS) that linked it to obesity and metabolic disorders. The FTO gene regulates energy expenditure and intake. We aimed to determine how fatty acid species measured in plasma and dietary intake associate with FTO gene expression in subcutaneous and visceral adipose tissues. Methods In this study, 97 participants aged ≥18 years were selected from patients admitted to the hospital for abdominal surgeries. These underlying disorders leading to surgeries were not expected to alter the habitual dietary intake of participants. Participants with diagnosed diabetes or cancer, under treatment of dyslipidemia or dysglycemia, and being on prescribed or any special diets were excluded. Habitual dietary intake of participants was collected using a valid and reliable food frequency questionnaire (FFQ), from which the intake of fatty acids was quantified. Plasma fatty acids were assessed by gas-liquid chromatography. The mRNA expression of the FTO gene in visceral and subcutaneous adipose tissues obtained by biopsy was measured by real-time quantitative PCR. Results After adjusting for age, HOMA-IR and body mass index, total fatty acid intake was significantly associated with FTO gene expression in visceral (STZβ = 0.208, P = 0.037) and subcutaneous (STZβ = 0.236, P = 0.020) adipose tissues. Dietary intake of MUFA and PUFA had positive significant associations with the expression of FTO in visceral (STZβ = 0.227, P = 0.023; STZβ = 0.346, P < 0.001, respectively) and subcutaneous (STZβ = 0.227, P = 0.026; STZβ = 0.274, P = 0.006, respectively) adipose tissues. There were no significant associations between plasma fatty acids and FTO mRNA expression in either subcutaneous or visceral adipose tissues. Conclusions The association of dietary total fatty acids, MUFA, and PUFA with FTO gene expression in both adipose tissues highlight the importance of dietary fatty acids composition along with total fat intake in relation to FTO gene expression. Funding Sources This study was funded by Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.