To investigate the effects of the increase and decrease of the serum DHA level on the Δ serum HDL-C/apoA-1 ratio, we carried out univariate and multivariate regression analyses using the Δ serum HDL-C/apoA-1 ratio as a dependent variable and the Δ serum DHA level as an independent variable, with adjustments for gender, age, ASCVD risk factors, and the Δ LDL-migration index (LDL-Rm value), as indicators of LDL-particle size, in 476 patients who could be followed up at least 6 months after this cross-sectional study. This evidence concerns the gene APOA1 and atherosclerosis.