Homocysteine levels in patients with primary and secondary Raynaud's phenomenon. Its association with microangiopathy severity.

The association between hyperhomocysteinemia (HHcy) and Raynaud's phenomenon (RP) remains a matter of debate. In 18 primary RP, 23 secondary RP and 41 controls, we investigated homocysteine (Hcy) levels along with biochemical and inflammatory parameters. The Hcy levels in both primary and secondary RP were elevated when compared with controls (p < 0.05 and p < 0.01, respectively). As age was higher in secondary RP as compared with controls (p < 0.01), both primary and secondary RP were age-matched with a corresponding control group, and with Hcy maintaining its statistical significance (p < 0.05). No differences in creatinine, B12 vitamin or folic acid were observed between groups (p > 0.05), or in the prevalence of cardiovascular risk factors (p > 0.05). When patients were classified according to presence or absence of digital ulcers, as a sign of microangiopathy severity, the former showed higher Hcy levels than the latter (p = 0.035). Our results indicate that both primary and secondary RP patients show a mild increase in Hcy levels, which is not related to age, vitamin deficiencies or impaired renal function, but is related to microangiopathy severity. Therefore the association of HHcy and RP suggest that Hcy may contribute to endothelial dysregulation, which characterizes this disease. Specific studies should be designed to elucidate the pathogenesis of HHcy in these patients.