Multivariate logistic regression (Table 4) revealed that MTHFR 677C>T genotype was still significantly associated, albeit marginally, with increased risk of PAD [OR 3.54 (1.01, 12.4), P = 0.049], after adjustment for age, sex, duration of diabetes, hypertension, current smoking habits, and use of insulin or oral treatment for diabetes. Here, INS is linked to diabetes mellitus.