Reduced risk factors for vascular disorders in Parkinson disease patients: A case-control study

Background and Purpose - Sympathetic hyperactivity is a contributing cause of vascular disorders because it increases blood pressure, blood sugar, and blood lipids. Pervasive compromise of the central and peripheral autonomic nervous systems is common in idiopathic Parkinson disease (IPD) resulting in reduced sympathetic and parasympathetic function. We hypothesized that IPD was associated with reduced prevalence of cardiovascular disease risk factors as a result of reduced sympathetic activity. Methods - We performed a retrospective case-control study on 178 newly diagnosed consecutive IPD patients, and 533 age- (±3 years) and sex-matched controls with other neurological diseases seen over the same period at the same hospital. For each case and control the following were noted on admission: smoking, diabetes, hypertension, body mass index, serum glucose, plasma cholesterol, triglycerides and total lipid levels, and blood pressure. Results - Diabetes, history of smoking, high blood pressure, high blood glucose, high blood cholesterol, and triglycerides were significantly less frequent in IPD than controls. Conclusions - IDP is a natural model of impaired hypothalamic-pituitary-adrenal axis activity and generalized sympathetic denervation. We interpret the association of untreated IPD with reduced vascular diseases risk factors as attributable to reduced autonomic activity, suggesting that autonomic hyperactivity may be involved in the pathogenesis of vascular disorders.