In our step-wise logistic regression multivariate analysis, after adjusting for the effect of all genes evaluated (including MTHFR and APOE) and factors known to influence the prevalence of XFS/XFG, including sex, diabetes, hypertension, cardiovascular disease, and vascular disease, both SNPs remained significantly associated with the risk of developing XFS and XFG. This evidence concerns the gene MTHFR and diabetes mellitus.