Hyperhomocysteinemia in L-dopa treated Parkinson's disease patients: effect of cobalamin and folate administration

Homocysteine (Hey) is a risk factor for vascular diseases, cognitive impairment and dementia. L-dopa treatment may represent an acquired cause of hyperhomocysteinemia (HHcy), as evidenced by studies in rats as well as in Parkinson's disease (PD) patients. Folate and cobalamin status also seems to influence the effects Of L-dopa on plasma Hey levels; therefore B-vitamins supplementation has been proposed to reduce the HHey in L-dopa treated PD patients. Plasma Hey, folate, and cobalamin levels were evaluated in 20 PD patients treated with L-dopa in the baseline condition and following a 5-week period of treatment with cobalamin and folate; results were compared with 35 controls. Analysis of data revealed that Hey levels were higher in L-dopa treated PD patients when compared with age- and sex-matched controls and that supplementation of the diet with cobalamin and folate is effective in reducing Hey concentrations; these findings may have important implications in the treatment of PD patients who are potentially at risk for vascular diseases and cognitive impairment or dementia.