MTHFR and rheumatoid arthritis: Regarding traditional CV risk factors, both SLE and RA predispose patients to arterial hypertension [134,135] and insulin resistance [136,137], but only SLE, as opposed to RA, increases the risk of dyslipidemia [138] and hyperhomocysteinemia [139], in particular in subjects with an MTHFR gene polymorphism [140].