Differential Effect of Fat Intake on Blood Pressure in Healthy Japanese Women with and without the Variant of Fat Mass and Obesity-Associated Gene

[Abstract]: A high-fat diet is believed to be a risk factor for hypertension through inducing obesity. It has been reported that variants of the fat mass and obesity-associated (FTO) and beta-3 adrenergic receptor (B3AR) genes are associated with obesity and blood pressure. The purpose of this study was to investigate the effect of dietary fat on blood pressure with or without the variant of the FTO and B3AR genes. A total of 227 healthy Japanese women aged 18 to 64 years were recruited for measurement of nutrient intake and blood pressure. The single nucleotide polymorphism rs9939609 of the FTO gene and rs4994 of the B3AR gene were genotyped. Spearman's rank correlation coefficient was applied to investigate the relationship between fat intake and blood pressure. A hierarchical multiple regression analysis was performed to determine whether the genotype interacts with fat intake to affect blood pressure. No significant correlations were found between fat intake and either systolic or diastolic blood pressure. A significant negative correlation was found between fat intake and both blood pressures in the FTO-gene-variant group, but not in the normal-FTO-gene group. In hierarchical multiple regression analysis, the interaction of fat intake and the gene variant showed significance, and the change in coefficient of determination (R2) was significantly increased with increases of the interaction variable. These results indicate that the effect of fat intake on blood pressure may be modified by the variant of the FTO gene such that a high-fat diet intake may be associated with a decrease of systolic and diastolic blood pressure in healthy Japanese women with the FTO variant. Our results did not support the hypothesis that a high-fat diet increases blood pressure.