When multivariable logistic regression was performed to examine the influence of the FTO gene on diabetes risk after combining African-American and white participants and adjusting for age, gender, and race, significant interaction between all of the FTO genetic variants and race was detected (p-value for interaction  = 0.001, 0.001, 0.002, and <0.001 for rs9939609, rs17817449, rs805136, and rs1421085, respectively). This evidence concerns the gene FTO and diabetes mellitus.