Cardiac autonomic function, assessed using heart rate variability (HRV) and cardiac iodine-
123-meta-iodobenzylguanidine (MIBG), is altered in Parkinson’s disease (PD) patients. In
addition, vascular endothelial function, as measured by flow-mediated dilation (FMD), might
play a role in the pathogenesis and progression of neurodegenerative disease. However, little
is known about whether cardiac autonomic function might be used in the early diagnosis of
Parkinson’s disease (PD), and the extent to which such alterations contribute to the
neurodegenerative process is unclear. Further, the involvement of vascular endothelial function
in PD remains to be clarified. The clinical significance of cardiac autonomic function in the
diagnosis and prognosis of PD and the involvement of vascular endothelial function were
investigated in this study. HRV was significantly lower in early PD. Higher HRV was
associated with better cognitive function. A reduction in cardiac MIBG uptake was associated
with subsequent increased risk of dementia. In addition, FMD was significantly lower in PD
patients, and was negatively associated with levodopa treatment. Surgical deep brain
stimulation reduced levodopa administration and improved motor disability and FMD. In
conclusion, cardiac autonomic dysfunction occurs early in PD and is associated with
subsequent risk of developing PD-associated dementia. Vascular endothelial function is also
altered in PD and appears to be affected by chronic levodopa treatment.
