The changes and significance of plasma level of homocysteine in Parkinson disease patients with cognitive function

Abstract

Objective To investigate the changes and significance of plasma level of homocysteine(Hcy)in Parkinson disease(PD)patients with cognitive dysfunction. Methods Ninety-two PD patients were enrolled. Among them, 51 patients had mild cognitive impairment(CI), and the other 41 had not CI. Forty healthy subjects were enrolled as control group. The information including gender, age, illness duration, years of education and Hoehn and Yahr(H-Y)stage were recorded. Cognitive function of all the patients with PD and the controls were measured by using Montreal Cognitive Assessment(MoCA)scale. Plasma levels of Hcy, folic acid and vitamin B12 were measured by high performance liquid chromatography or radioimmunoassay. Results The plasma level of Hcy in PD group was significantly higher than that in control group:(16.72 ± 5.52)μmol/L vs.(13.65 ± 5.16)μmol/L, there was statistical difference(P 0.05). There was no statistical difference in the plasma of vitamin B12 between the 2 groups(P>0.05). There was a negative relationship between plasma levels of Hcy and folic acid(r =-0.576, P 0.05). The correlation analysis results showed that MoCA score was positive correlation with years of education(β = 0.541, P = 0.000), MoCA score was negative correlation with illness duration, H-Y stag and plasma level of Hcy(β =-0.417,-0.367 and-0.515; P = 0.026, 0.037 and 0.000), but MoCA score was not correlation with age, plasma levels of folic acid and vitamin B12(P > 0.05). Conclusions The changes of plasma level of Hcy may be involved in the pathogenesis of patients with PD. The elevated plasma level of Hcy is significantly correlated with CI, it is an important risk factors of CI in patients with PD. Key words: Parkinson disease; Cognition disorders; Hyperhomocysteinemia; Folic acid; Vitamin B12