Sympathetic modulation by levodopa reduces vascular risk factors in Parkinson disease

Background: Sympathetic nervous system hyperactivity promotes vascular disorders by its catabolic effects and by increasing arterial blood pressure. Levodopa-derived dopamine modulates sympathetic overactivity and is known to reduce blood pressure, but its effects on glucose and lipid metabolism have not been studied in large series of patients. Methods: We retrospectively examined 483 consecutive parkinsonian patients, admitted to a single institute between 1970 and 1987, before statins were available. We compared risk factors for vascular disease in the 305 who were on levodopa with the 178 who had never received the drug. Results: On admission levodopa-treated patients had significantly lower plasma levels of triglycerides, total cholesterol and lipids, and lower frequency of diabetes and hypertension than untreated patients. Mean body mass index, resting blood pressure, fasting plasma glucose, and smoking did not differ between the groups. A year after enrolment 160 patients were re-hospitalized; of these 63 had started levodopa during first hospitalization. In these new levodopa users total cholesterol, triglycerides and lipids had reduced to levels comparable with those of longer-term levodopa users. Conclusion: Levodopa use in parkinsonian patients is associated with reduced vascular risk factors. In causal terms this finding might be attributed to the inhibitory action of levodopa-derived dopamine on the sympathetic nervous system. (C) 2008 Elsevier Ltd. All rights reserved.